Introduction: Transmogrification in California

We need a new word to describe this. Forgive those who sense that we have entered some sort of space-time warp, when two locations and microclimates separated by just a few miles could experience such radically different atmospheres, as if they were worlds apart. But it also seems unthinkable that such remarkable changes could occur within any specific region within just one year, challenging us again to check our calendars. Old descriptors for our once more dependable seasons and weather patterns have been evolving toward unfamiliar, unlikely, exceptional, and unprecedented. Comparing the final months of the calendar years 2024 and 2025 unveils a topsy-turvy environment that repeatedly produced chaotic scenes more common to a science fiction movie. Exceptional pattern anomalies amplified again through and beyond the first month of 2026.

Several years of stories on this website have documented widely researched seasonal disorders that have made news headlines each month … and they only seem to be getting weirder and more impactful. We are, at this time in this state, perfectly situated to explore and learn from these upheavals as our unparalleled diversity of microclimates, ecosystems, and landscapes continue calling out to us.

Calendar Contrariness

One year ago, our stories led you through the unprecedented weather patterns that set the stage for catastrophic historic and deadly wildfires which eventually consumed entire Southern California communities. We examined the momentous drought that left only around 1/10^th of an inch of rain in the SoCal coastal plains from spring into mid-January (the middle of our rainy season). This year stood out in stark contrast as many of those same locations had already equaled or exceeded half their average annual precipitation totals by mid-November, long before what are usually the wettest months of the rainy season. But as we advanced into November, 2025, nature performed another dramatic switch. Persistent weather patterns locked into place into mid-December and they were all powerfully connected: SoCal’s seemingly endless sun and above-average temperatures in the 80s versus consecutive days of record cold, dank, and dreary valley fog; merciless warm atmospheric rivers (ARs) from the tropics that produced record catastrophic flooding in Washington contrasted with arctic blasts that plunged the upper Midwest and East Coast into the deep freeze. Yet another radical shift near the end of December (and into 2026) brought powerful storms and flooding atmospheric rivers across California during the holiday season. Another reversal to persistent, resilient high-pressure systems and winter storm blockades dried out the entire West Coast through January while historic Arctic deep freezes paralyzed the continent east of the Rockies all the way to the Eastern Seaboard. The spectacular diversity of conditions and their theatrical impacts on us and our landscapes have ranged from astounding to unnerving. There’s so much going on in this story that should keep curious observers on the edge of their seats.  

Episode One: Odd Cutoff Lows Spin Their Moisture Magic

Some of the blame for these multiple twists of fate (sometimes coined weather whiplash) started with a series of odd early-season cold and unstable upper-level low-pressure troughs that dug down from the north and broke off from general circulation patterns. November’s cutoff low repeat performers skimmed down the West Coast, mostly whirled and sprinkled through Northern California, taking the bulk of their moisture and energy with them. Then, the pesky, reenergized storms anchored and spun their turbulence over waters just off the Southern California Bight, entrained Pacific moisture, and tossed it inland. Give the National Weather Service credit for warning us about these cutoff lows that remain a weather forecaster’s woe.

As hours ticked into days, trains of steady showers circulated from Mexico up through and past Santa Barbara County. When the unstable moisture was lifted up the Transverse Ranges, heavier orographic precipitation watered the slopes and snuffed out the fire season. Soils became saturated, seasonal streams resumed flowing early, fresh green spouts appeared everywhere, and premature weeds erupted in our gardens. Since the showers were mostly beneficial and steady rather than sporadic downburst gulley washers, we were first spared the worst of flooding and debris flows that could have coughed out of our burn scars. Observers were wondering how it was possible that the hills were so alive just one calendar year after debilitating drought and Santa Ana winds had primed these same landscapes for their dehydrated fiery destruction. One of the wettest starts to our rainy season this year had transposed last year’s driest into our rear-view mirrors.

Ocean Current Mysteries

Augmenting the improbability of these captivating whodunnits, all this early-season atmospheric chaos was raining down during the start of a weak La Niña year, when cooling water currents in the tropical East Pacific might be expected to result in more stable air and a relatively dry SoCal rainy season. Here’s more proof that the El Niño/La Niña Oscillations we research as ENSO cycles (such as in previous stories on this website) and their effects have NOT been as dependable or predictable during this century compared to late last century. We are reminded that we are observing and researching targets that are constantly moving and evolving.

A possible less-understood culprit for the October-December 2025 SoCal wetness could have been the now infamous North Pacific “blob” that peaked in September and circulated through the end of the year. This giant marine heat wave (which has reappeared in some form during recent years) expanded to 5,000 miles across the Northern Pacific Ocean until sea surface temperatures maxed out at a record 68°F (20°C). In addition to ongoing climate change, research suggests that recent decreases in air pollution (particularly sulfur dioxide) from cleaner shipping and Chinese sources have helped to clear Pacific air masses of reflective aerosols, allowing more direct solar radiation to heat ocean surfaces. Regardless, such a mysterious warm blob throws another complicating variable into our understanding of ocean-atmosphere interactions that could be responsible for these historic anomalies.

Episode Two: High Pressure Heat Versus Cold Fog

As if to keep us on our toes and our eyes on the skes, nature abruptly and dramatically flipped the switch again after mid-November. Massive high-pressure systems took control, building and oscillating off the Southern California coast and over the Southwest States into Mexico. The strength and extent of these tall, heavy domes of stacked air challenged seasonal records and eventually dominated the entire state. As air descended out of the monstrous fair-weather storm blockers, clear and dry became the latest curious forecast fads across most of the state, lasting an entire month through mid-December, a period which normally marks the annual start to our seasonal rains. The November air columns started out cool, but days of dry offshore flow and compressional heating pushed temperatures into the 80s along the SoCal coast and into the upper 80s in the inland valleys right into mid-December. Weather stations in the Coast Ranges (such as in the Santa Cruz Mountains) and Sierra Nevada foothills recorded high temperatures well into the 70s in the clear, dry, sinking air. Adding an additional layer of complexity, another conspicuous exception developed and stubbornly held out as the antithesis to the warm and dry: historic valley fog episodes.

Epic Fog Traps

The same powerful high pressure that squeezed Southwest air columns toward the surface for a month also capped a shallow layer of cold air that settled and pooled in Northern and Central California inland valleys like dense water in a vast bathtub. I’ve written on this website and in my latest California Sky Watcher book about how our Great Central Valley is the perfect winter laboratory to make valley fog (AKA as tule fog or radiation fog), which forms in place as cold, dense, heavy air often settles down to the lowest flatlands and becomes trapped for 400 miles from Redding to Bakersfield. In this latest classic episode, the valley floor had been moistened by those earlier October/November rain events; then, the air just sat down there below the inversion with little or no circulation as leftover heat radiated out, gradually cooling the air toward its dewpoint. Once the late-night air chilled to near 100% relative humidity, the moist haze turned to cold fog. Now, we have a saturated pool of air trapped in the confines of our natural oval-shaped beaker, with the Coast Ranges on one side and the Sierra Nevada Mountains on the other.

With such short daylight hours and low sun angles, weak sunlight struggled to boost temperatures above dewpoints, allowing the winter fog to further thicken during long nights until it didn’t even “burn off” during the daytime. This tule fog enshrouded the valley from late November well into mid-December, 2025. It became the star of conversations, news headlines, and memes as the cold and gray bled west through the Carquinez Strait to invade the Bay Area. As valley temperatures stalled in the 40s, Bay Area residents shivered through consecutive hazy and foggy days that could barely warm into the 50s. The dull creepy mist also condensed in other inland valleys through Central and Northern California, from wine country, to the Trinity, Klamath, and Eel River Basins. Such a remarkable and historic prolonged exaggeration of the annual valley fog doldrums was capable of depressing the most upbeat Pollyanna to beg for mercy in the form of some clear-sky relief.

To be or not to be Fog

Though we call it “fog”, this particular weeks-long episode often formed as low stratus cloud ceilings a few hundred feet above the ground. Visibilities near the ground (and below the thicker hovering blanket) were often measured at around a mile or so, decreasing at night and slightly improving again each afternoon. Just above the inversion, at around 2,000 feet above sea level, temperatures warmed well into the 70s each day thanks to dry, sinking air and unlimited visibilities. Some mountain and foothill communities could only look down through their pristine ether toward the distant layers of thick silver cotton below. In contrast, that same descending air often scoured out any inversions trying to form in SoCal. When the high pressure strengthened overhead, the Southland enjoyed a string of iconic warm and crystal-clear December days. When the resilient high weakened or drifted a bit, a shallow marine layer was enabled to spread night and morning fog into coastal valleys. During those days, most California coastal and valley communities were mired below stagnant inversions that forced air quality management districts to issue alerts and enforce no burn days: no chestnuts roasting on open fires to belch smoke that quickly gets trapped below shallow choking anvils.

Pollution and Fog Partnerships

Recent research shows that the frequency of cold valley fog events in California was increasing each decade into the 1980s, most likely because of increasing air pollution. Droplets of water are more likely to condense around certain particulate matter, known as cloud condensation nuclei. As emissions from fuels combustion and farm operations increased, fog episodes became thicker and more frequent. After the 1980s, as air pollution controls took effect and emissions decreased, so has the frequency of dense fog. Indeed, there is an exact correlation between NOx pollution (nitrogen oxides) content in valley air and fog density and frequency, measured both from the ground and satellite imagery. This could explain why the more recent thickest “fog” actually formed a few hundred feet above sea level, leaving the higher fringes of the valley shrouded while residents at lower elevations were looking up toward the grayest low blanket. Gradual climate change could also be playing a role when today’s warming surface temperatures remain just a degree or two above valley dew points.

Essential Fog

These might seem like foggy details, but they are important for a number of reasons, far beyond casting our brooding moods; here are two. First, transportation is often crippled by dense valley fog. There is a long history of deadly California accidents caused by low visibilities, followed by scenes of multiple mangled vehicles once the mysterious murk finally begins to clear. Surviving commuters have been caught in hours of gridlock on shrouded highways and narrow serpentine detour routes. Air traffic is often diverted and delayed when even the most experienced pilots with highly sophisticated cockpit instruments are challenged while attempting to take off or land through such dense curtains of potential aviation disasters. Second, the foggy winter chill deposits some moisture and may shield valley fruit and nut trees from direct sunlight during dormant periods of rest, which eventually increases annual production of these multi-billion-dollar agricultural products. (Before native plant communities were plowed, grazed, and developed into history, winter fog played an essential role in nurturing vast valley prairies that some coined California’s Kansas.)

Tule fog’s malaise is finally broken up when restraining high pressure eases or moves away and when turbulent instability sweeps in from the Pacific, allowing wind currents to scour down to valley floors. Regardless, this latest misty atmospheric quagmire kept millions of acres and millions of Californians from the Central Valley to the Bay Area enveloped throughout a remarkable string of consecutive clammy days and nights with temperatures stuck in the 40s F.

Episode Three: Catastrophic Floods and Frigid East Coast Connections

We can also recognize how our resilient high-pressure blocker was part of a larger pattern that dominated weather across the continent. As air descended out of our massive high, its winds were turned to the right by the Coriolis force, creating those familiar clockwise pinwheel circulations common to all high-pressure systems that often span thousands of miles in the Northern Hemisphere. These gyrating winds curved toward big, cold low-pressure systems spinning counterclockwise in the Gulf of Alaska. Strong pressure gradients and powerful air streams grew along narrow battlefronts between the highs and lows to drive abundant moisture and embedded disturbances flowing across the Pacific within atmospheric firehoses; a parade of rainmakers were directed north, up and over California’s tall stacks of fair weather and into the stormy Pacific Northwest.

The resulting archetypal atmospheric rivers (ARs) had sources so distant and farther south of Hawaii that Mango Express replaced the more familiar Pineapple Express monikers. The prolonged invasions of unusually warm moist air strengthened to attack the Pacific Northwest. Snow levels were so high, almost all the precipitation fell as torrential mountain rain that had to runoff somewhere. Rivers surged over their banks in December until record stream gauge heights sent catastrophic flooding across landscapes and into neighborhoods from north of Portland into Canada.

Amplified Waves Make West Coast-East Coast Connections

How is this connected to the December artic blasts that dropped clippers of snow, ice, and wind storms across the upper Midwest until temperatures plunged below zero F and wind chills could freeze flesh within a few minutes? Once that same stream of air arched up and over our West Coast high pressure ridge, it came diving down its opposite (east) side and into the middle of the continent. This downstream trough opened the door for arctic air to race directly out of Canada and all the way to the East Coast, proving how all of these pattern shifts and winds are connected. And these high-amplitude waves in the upper-level winds are just what computer models have warned us about. As the Arctic has warmed faster than most other locations on our planet, temperature gradients and pressure gradients between warmer air to the south and cool air to the north are decreasing. The jet stream that forms between these contrasting air masses tends to slow down and form large meanders (Rossby waves) of upper-level troughs and ridges that get stuck in place and that’s exactly what happened through mid-December. Two more powerful connections in one paragraph!      

Episode Four: Atmospheric Rivers Bring More Winds of Change 

Later in December, yet another major weather pattern whiplash changed everything again. The stubborn Southwest high-pressure system finally began weakening and drifting away, allowing that historic atmospheric river to gradually, mile by mile, sag south as pressures dropped. As it shifted south, the AR whipped back and forth, targeting most of California through the holiday season. To keep your attention and prove how these winter AR storms mean business in Northern California’s high country, consider this NWS forecast on December 23, 2025 for Mount Shasta:

“Snow. The snow could be heavy at times. Low around 13. Wind chill values as low as -13. Windy, with a south wind 85 to 95 mph increasing to 100 to 110 mph after midnight. Winds could gust as high as 115 mph. Chance of precipitation is 100%. New snow accumulation of 41 to 47 inches possible.” 

Unfortunately, snow levels remained very high especially early during most of these AR onslaughts, adding snowpacks only to the highest elevations, often above resort levels. A low-pressure trough forming off the coast finally bent the AR into a more southwest-northeast oriented arc to circulate copious amounts of rain and high-elevation snow into the state. As air pressure continued to drop offshore, fears of a “bomb cyclone” event grew, while pulses of damaging winds, thunderstorms, and other severe weather swung across California’s Central and North coast during the holidays.

And as the bullseye finally migrated into Southern California, this AR was following recent patterns, behaving much like computer models have also warned: as global temperatures increase, warmer water can evaporate into warmer air that has the capacity to hold more water vapor. These trends are loading ARs with moisture and energy since the air can hold about 7% more water vapor for every 1°C increase in temperature (about 4% more water vapor for each 1°F). Recent single AR events have produced more than a foot of rain as they get lifted over higher terrain. In this holiday episode, such orographic effects dumped more than a foot of water into rain gauges from north of Santa Barbara along the Transverse Ranges into the San Gabriel Mountains. Where ARs had stalled over them, some weather stations had already received their average annual rainfall totals even before the two normally wettest months (January and February) of the season. As expected, flooding and debris flows belched out of the mountains, particularly below recent burn scars. The resort communities of Wrightwood and Lytle Creek in the San Gabriel Mountains earned most of the media attention for mudflow destruction (see links to videos following these essays). With a few exceptions, many of these fitful storms lost much of their punch while trying to slip south toward San Diego County, bringing mostly lighter and beneficial precipitation there.  

Reiterating the power of atmospheric connections (again), upper-level winds dipping around the low-pressure trough that directed firehoses to blast California through the Christmas season were forced to turn back north over a massive high-pressure ridge dominating the central US. Air descending out of this monster dome of high pressure set countless records for both the hottest high and highest low temperatures ever recorded during the holiday season, from Arizona, Utah, and New Mexico, across the Rocky Mountains, through the Plains and Midwest and into the southern US. Temperatures peaked at 20-35°F above the average in many of these regions (high temperatures in and around Oklahoma City made it past 80°F) while some Californians were getting washed out.  

It would be difficult to overstate the difference between the start of last year’s rainy season and this 2025-2026 season, especially in Southern California. (The official water season begins on October 1 each year.) The parade of holiday storms continued across California through the first few days of January, raining on the Rose Parade for the first time in 20 years and cancelling celebrations into the New Year’s Weekend. Contrast this year’s drought-breaking and eventual deadly inundations with virtually no rain by this time last year and the deadly fires that followed. On January 1 alone, more than one inch of rain fell from Oxnard to Long Beach, setting new records for the date. By early January, 2026, numerous locations from north of Orange County to the Central Coast Ranges had already equaled or exceeded their average annual rainfall totals, just as the two traditionally wettest months of the year were to begin. Some stations (such as in Santa Barbara County) experienced their wettest start just after last year’s record driest start to any rainy season. On the first days of January this year, freshwater runoff coincided with another astronomical King Tides event, causing historic shoreline flooding (such as around the Bay Area), when the tides combined with low pressure, onshore winds, and storm surges. You can see why we can only guess what surprises to expect in the long run, so stay tuned.  

Epilogue: Following the Science that Connects the Dots to our Future

This story’s roller-coaster ride analysis of interconnected phenomena guides us into 2026, as we hope to settle back into more seasonable expectations; but nature likely has other plans. If you want to imagine 2026 and beyond, click back to some of 2025’s extreme weather events, such as those analyzed in our other recent website stories (rogue storms, Texas flash floods, SoCal wildfires, etc.). What do they all have in common? Though we were warned a few days ahead by remarkably accurate forecasts from the National Weather Service, the deadly catastrophes went on to destroy too many lives and too much property, often because local officials failed to properly prepare and respond.

We have learned that anything goes as we anticipate beyond those seven- and ten-day forecasts, and the mysteries grow as we look further into the next year. So, we wonder why, at this critical time when we must better comprehend the science behind what is rocking our world, the US Government is cutting the heart out of the very scientific organizations that help us make sense of these changes and anticipate what might be next. As I write this, the latest victim to be thrown on the chopping block is the National Center for Atmospheric Research (NCAR) in Colorado. Should we lose this and other vital agencies that objectively and efficiently guide us through the science of change and warn us what to anticipate, we all become victims. What took us decades to build and nurture may be lost forever. Such short-sided penny-wise and pound-foolish irreversible policies are certain signs of a less developed society in decline, a culture that celebrates ignorance only to suffer the long-term consequences.    

We could be forgiven for behaving like the frogs in the pot parable, except these are not gradual changes; they’re slapping our faces and kicking our butts every season. Changes that have always ruled our world have been growing in intensity and duration and these coalescing change agents are calling out for our immediate attention. Like uninvited intruders in our homes, such massive experiments are repeatedly and more frequently transforming our environments and our lives to remind us that we ignore them—and nature—at our peril.

For you dedicated weather enthusiasts and researchers who are hungry for even more discussion and details, continue on past this brief list of links, where you will find a chronological sequence of dynamic images from the last months and days of 2025. We then carry you through the next weather whiplash that delivered another record-breaking West Coast dry spell which coincided with the historic (and connected) cold waves of deadly ice and snow storms that froze the Midwest and East Coast through January 2026.       

California Current Marine Heatwave Tracker

Atmospheric Rivers Science

Mud and Debris Flow Videos from Wrightwood and Nearby High Desert:

https://www.facebook.com/watch/?v=4259235981063913

https://www.facebook.com/watch/?v=1576524737019441

Lytle Creek Mudflows

King Tides During the Storms Videos

Daniel Swaine’s Weather West year-end summary, including late December storms

Defunding National Center for Atmospheric Research

A History of Winter Dry Spells from Golden Gate Weather Services (and thanks to Bill Patzert)

By late January, 2026, the early warm storms followed by mid-season drought sounded alarms across the West as snowpacks dwindled.

The latest maps.

Trapped under another round of resilient high-pressure systems, dangerous tule fog episodes returned to California inland valleys through January.

The series of warm, sunny days that followed early-season heavy rains produced a premature season surprise desert bloom (in January!) at places such as Anza Borrego. This story explores the mysteries behind Joshua Tree early bloomers at higher desert elevations.

A wealth of additional images (from the ground and from space) and maps follows, carrying you through some of the more memorable and dynamic weather events and colorful scenes from late 2025. Captions are limited, but they are also in chronological order. This journey (we could consider it an appendix or addendum) incudes some details that should interest meteorologists and climatologists AND instruct newer students and casual observers. We will make it all the way to the start of 2026 and a break in the stormy weather, ending our photo ops with sunsets, moon rises, flowers, and feathered friends. Finally, our January 2026 epilogue II (a necessary addition) displays images and weather maps showing how the West Coast suddenly dried out as the Midwest and East Coast were experiencing their epic prolonged cold snap. Such connected West Coast/East Coast opposites extremes would play out into February.  

Revisiting Episode One (October-November, 2025): Odd Cutoff Lows Spin Their Moisture Magic

Revisiting Episodes Two and Three (December 9-10): High Pressure, Dry Heat Versus Cold Fog AND Catastrophic Floods Versus Frigid East Coast Connections

Revisiting Episode Four (December 20, 2025-early January, 2026): Atmospheric Rivers Bring More Winds of Change

Follow Us to the End-of-Story Bonus Colors: Rainbows, Trash, Cloud Murals, Sunset, Wetlands, Flowers, Birds, and the Return of El Sol.     

The rain paused and clouds parted just enough by the afternoon of January 1, 2026 to encourage a long walk (the next six photos) at Bolsa Chica Wetlands in Orange County …   

January into February, 2026 (Epilogue II): Yet Another Historic Weather Whiplash

January 2026 brought yet another meteorological shift that will go down in the record books. As if to mimic another movie sequel, a giant high-pressure system formed over California; but this time, it eventually elongated all the way up past the Canadian border. The big storm blocker kept California dry for weeks during the middle of the rainy season and left some Pacific Northwest locations (such as Seattle) with their longest period without precipitation during any January in history. And in what has become a familiar twist of weather pattern whiplash fate, upper-level winds that curved north of the West Coast and into Canada then made drastic U-turns to plunge toward the middle of the continent. These same winds raced south from the Arctic, driving temperatures below zero Fahrenheit into the Midwest, spreading historic freezing ice and snow storms across the continent to the East Coast, prompting deep freeze news stories that lasted through much of January. It was yet another example of how West Coast-East Coast antithetic extremes become connected by high-amplitude upper-level waves that seem to get stuck in place. The following images illustrate some of January’s weather dramas.    

The following photos were taken in mid-January, 2026, as the record-breaking arctic cold snap was freezing the Midwest and East Coast. By contrast, this was Southern California during the same time, a few weeks following those premature heavy rains, and during the unusually long winter warm spell when afternoon temperatures peaked well into the 80s.   

THE END … for now.

The post What a Difference a Year Makes first appeared on Rediscovering the Golden State.

Recently, news stories have circulated showing that a series of days in July of 2023 represented the warmest global temperatures on record. According to the National Oceanic and Atmospheric Administration (NOAA), July 3, 4 and 5th, all exceeded previous marks for global average temperature since climatologists began charting these means in 1979.

As of this writing, the global average air temperature of the planet (as measured 2 meters from the ground) was 17.18° C (62.88°F) on July 5th. If that holds, it will beat the previous record set just 2 days before of 17.01°C or 62.62°F.

(November, 2023 updates to this story: After the summer of 2023 ended as the hottest summer on record and 2023 races ahead to become the hottest calendar year on record, November 2022 – November 2023 has already broken the all-time 12-month global heat record. You will find a summary here and more details here. Also, here is a recent article that summarizes our predicament and connects the many facets of global change. Finally, another informative treat appears in this message to you from Professor Jing Liu: “I discovered a new GIS resource hub for climate change visualization and analysis. Check it out – it is pretty cool!” Thank you Jing! Now, we can continue with Rob O’Keefe’s earlier story.)…  

This may confuse those expecting to see a much higher reading, say in the neighborhood of 57.42°C (135°F). But remember, the record above is an average of all temperatures everywhere . This record combines temp readings in tropical regions where it is hot all year round. It adds the temps in the midlatitudes, where it is alternately warm or cold depending on the season. And it factors in the teeth-shatteringly cold reaches of the poles which stay cold, or relatively cold, 12 months of the year.

So far, few direct rebuttals from the fossil fuel industry and other climate change deniers have surfaced. But some in the news and amplified by social media have started to shout to El Niño as the culprit. That is misleading at best, malfeasance at worst.

El Niño is a real and recurring phenomenon with the power to drastically alter weather globally in the short-term every few years. But as it is but a part of the overall ocean-atmosphere system, it cannot be singled out as a separate entity. Anthropogenic alteration of the atmosphere affects every aspect of the atmosphere. In this case, human-caused emissions of greenhouse gases are now helping to drive and intensify ENSO (El Niño/Southern Oscillation) events, as well as everything else related to our weather and climate.

This is another reason why it is important to have a broad and deep understanding of the many processes that effect the Earth’s weather and climate before using individual weather events, no matter how dramatic, to make a point on climate.

Case in point …

From time to time in my physical geography or weather and climate classes, I’ll get a student who passionately expresses doubt about climate change. I vividly remember such one student who challenged the notion of a warming world by pointing out that the official record high was recorded over 100 years ago in Death Valley. In this student’s “gotcha” moment, they essentially argued the following: how can the world be getting hotter if the record has not been broken in over a century? On the face of it, it seems a valid question.

But questions like this, with no context or supporting evidence, represent the seeds from which climate denialism germinates.

But getting back to the question at hand, it is all a matter of statistics.

Outliers grab our attention. Record temperatures, on either end of the thermometer, make headlines. But these unusually high or low measurements only indicate conditions at both a specific location and a discrete time. Taken by themselves, such measurements are almost meaningless. That is even true of the recent record. Earth’s climate cannot be defined by single values.

NASA, for instance, has determined that the temperature on Mars has reached 21°C or 70°F, on occasion, since direct observations began in the 1970s. Based on that measure alone, the uneducated might be tempted to assume the red planet has a balmy climate not far off than say Santa Monica. In reality, the mean temperature of Mars is a bone-numbing -80°C (-112°F). Even in the coldest of winters high in the snowbound Sierra Nevada, the Golden State never sees temps that low.

This is why climatologists focus on the mean temperature when making statements about either a specific location’s climate or the global climate in general. Mean temperatures represent the average temperature over a specific period. It is a simple calculation. Sum up all the individual temperature readings and then divide by the number of observations. The standard convention is to have at least 30 years of uninterrupted weather observations/measurements in order to assess climate.

Record temperatures, by contrast, are isolated events that occur sporadically. There may be no rhyme or reason to them. Mean temperatures, on the other hand, reflect long-term trends and patterns. Climate change is characterized not by isolated heat waves but rather by shifts in average temperature over extended periods, often spanning decades or centuries. Analyzing mean temperatures, therefore, allows for a more comprehensive understanding of climate change patterns and their impacts than focusing on a single hot day or string of them.

You may be saying to yourself by now, aren’t the record global atmosphere temps set in July also just outliers? Not exactly. They do not deviate drastically from the mean. They will also be averaged into the data like all other observations, making the overall mean temperature of the Earth rise incrementally, relentlessly, with no thought or care about the worries of humanity.

With that thought, look again at the graph included in the link (and the other graphics in our other links) above and you will see the reality of climate change revealed in a frighteningly short period of time.

But there is also a certain irony I noticed as I wrote this piece comparing weather events with climate, contrasting outliers and means. While Death Valley may continue to hold the record high temperature on Earth for years or even decades to come, the planet’s mean temperature (as measured by day, month or year) is now likely to be broken over and over again. This tragedy is going unnoticed, or outright ignored, by a large swath of the public.

Increasingly, where you live and who represents you is coming to define how you view the problem of anthropogenic climate change.

California has led the way in charting a course that will help humanity avoid the the worst-case scenarios. Here are but 5 ways the Golden State has been and remains a vanguard in combatting global climate change.

1. Ambitious Emissions Reduction Targets: California has set aggressive emissions reduction targets, aiming to reduce greenhouse gas emissions to 40% below 1990 levels by 2030 and achieve carbon neutrality by 2045. These targets have provided a strong policy framework for climate action and have become models for other progressive states and nations.
2. Renewable Energy Transition: California has been a pioneer in promoting renewable energy sources. The state has significantly increased its renewable energy capacity, with a focus on solar and wind power. The California Renewables Portfolio Standard requires utilities to procure 60% of their energy from renewable sources by 2030, and the state aims for 100% clean electricity by 2045.
3. Cap-and-Trade System: California established the first economy-wide cap-and-trade program in the United States. Under this system, a limit is set on greenhouse gas emissions, and companies must obtain permits (allowances) to cover their emissions. The program has successfully reduced emissions while generating revenue for clean energy investments.
4. Energy Efficiency Initiatives: California has implemented rigorous energy efficiency standards for buildings and appliances. These standards include requirements for energy-efficient lighting, insulation, and appliances, leading to reduced energy consumption and greenhouse gas emissions.
5. Electric Vehicle Promotion: California has been a leader in promoting electric vehicles (EVs) to reduce transportation emissions. The state offers incentives for EV purchases, has established a comprehensive charging infrastructure, and aims to transition to 100% zero-emission vehicle sales by 2035.

** Now it should be noted that data used to calculate global mean temperatures does not represent actual ground measurements for every square inch on the globe. Numerical climate/weather modeling is used to accurately estimate values in areas where no direct measurements exists. Such interpolation techniques do not offer precision but they can be very accurate and often closely reflect actual conditions on the ground.

The post Now There Is No Denying Our World Is Getting Hotter first appeared on Rediscovering the Golden State.

The climate of the planet has been warmer or cooler at various times in the Earth’s 4.6 billion year history. Yet we only have detailed climate records for a scattering of populated places stretching back to 1880 or so.  Accurate and reliable climate data is a much more recent development – beginning generally after the end of the Second World War.   Even if using 1880 as a starting point, recorded temperatures above 120°F (48.89°C) are fairly rare outside of Death Valley and a handful of other locations. And for each degree above that benchmark, Fahrenheit or Celsius, those readings get rarer still.   By the time you get to the 130° mark, you’ll find less than a handful of plausible observations. 

At first, one might surmise that the equatorial regions of the globe would be home to the hottest temperatures.  That is where solar insolation is the highest year-round. It is certainly true that there is a surplus of heating that goes on in the tropics. However, the heat found in the low latitudes is doing more than just warming the surface. Vast quantities of water are being evaporated and lifted into the atmosphere by that energy. This liquid water must absorb tremendous amounts of energy to evaporate into water vapor and the water vapor then escapes with this stored energy that we call latent heat, leaving behind a cooler surface. This surface cooling helps prevent the humid tropical regions from experiencing temperatures much above 100°F (37.7° C).

So the contenders for the title of the “Hottest Spot on Earth” are, somewhat paradoxically, found a bit farther pole-ward. They are to be found in the belt of subtropical deserts, within a few latitudinal degrees of 30° N or S, where the air is reliably far less humid.  During the summer months, dry and clear air, warming as it descends from Hadley cell circulation that began in the tropics, produces seemingly endless sunny days with some of the highest insolation values on the planet.  This bakes the relatively barren surfaces which then, first through conduction and longwave radiation, and later convection, transfer that heat energy into the atmosphere.  That “barrenness” is an important detail because vegetated ground does not absorb nor radiate heat as efficiently as sandy or rocky surfaces. This combination of factors means the deserts of North Africa, the Middle East, Australia and the southwestern United States, are where virtually all of the claims for the world’s highest temperature have been made. 

Death Valley has all those aforementioned things going for it and an ace or two up it’s sleeve.  The valley is located a couple hundred miles inland, far from maritime influences and shielded by successive mountain ranges that “wring out” almost all of the available atmospheric moisture. The biological result of this rainshadow effect means precious little can grow on the surface in Death Valley’s hyper-arid climate.  Under cloudless skies, that naked surface can be heated to as much as 200°F (93.3° C).  Conduction, then convection warms then lifts the dry and heated air aloft where it expands and finally cools at the dry adiabatic lapse rate. The high mountains on either side of the valley help prevent escape and mixing with other air masses. The air must descend down mountain slopes to get back down to the valley floor, forcing it to heat further by compression.

So when and where was the hottest temperature on Earth recorded?

According to the World Meteorological Organization, the current record holder for highest temperature is, not surprisingly, Death Valley.  On July 10, 1913 an air temperature of 134.1 °F (56.7 °C) in the shade was recorded at Furnace Creek Ranch. Impressive as that may be, there are valid questions and plausible doubts which now surround both the environmental circumstances and the recording instrumentation on the day that reading was observed.  Ironically enough, Death Valley’s claim to the top spot had been only recently re-instated in 2012.  After investigation, an even higher reading of 57.8 °C (136.0 °F) on September 13, 1922 in ‘Aziziya, Libya was concluded to be in error.  

In order for a recorded temperature to be accepted as a record-breaker, it must first be validated by the Climate Extremes Committee of the WMO.  This body also sets certain standards for the recording of various weather events. Reliably and accurately measuring temperature is not quite like taking your child’s temperature when they are sick.  These days, the familiar glass thermometer with red or silver “mercury” is rarely used by meteorologists to record the temperature. Instead, sophisticated thermistors (think: thermometer + transistor) do most of the recording. 

Whether thermometer or thermistor, both need to be shielded from the sun, as direct solar insolation will give an elevated reading.  This is easily relatable. Note how different the sensible temperature feels in the sun versus under an umbrella next time you are at the beach.  Shielding is most often accomplished with a small, light colored box (high albedo) with small slats to allow air circulation.  Instrumentation for recording temperature must also be a few feet off the ground, lest the temperature of the ground influence the reading.  Ideally, the measurement should take place at least 5-6 feet above the ground and over a natural surface.

But what about the hottest temperature ever on the surface of the planet? Where and when did that occur? To answer those questions, we must look at the variables involved.

Temperature, like rainfall or elevation, represents a continuous data set.  It is termed “continuous” because it has an infinite number of possible values. Such data can be thought of like a gradient of unique values spread out over a space.  The values in adjacent spaces (cells in raster data) may differ by the slightest of amounts – amounts too small for our instrumentation to precisely record.

But while temperature and its values are continuous,  our instrumentation for collecting such data is not.  They exist as a series of fixed points. We only know the temperature at a given spot.  We don’t have thermometers covering every square inch of Death Valley, nor anywhere else for that matter.  It is therefore entirely possible that a few dozen feet or meters away a temperature of 131 could have been recorded on 08/16/20  if there was an instrument there to record it.  

Meteorologists use tools like GIS (Geographic Information Systems) to interpolate data values from known values for places (points) where no instrumentation or values exist.  Considering things like elevation, continentality, past climate data, current conditions etc.,  weather data can be “stretched” on to a surface of a map or graphic and covered with estimated values.  You may have seen such representations on the National Weather Service website (www.nws.gov).  Go ahead and try it.  Click on the map and you will receive projected forecasts (including temperatures) for just about any place in the United States. Depending on where you click there might not be a weather station for miles. But you will see the distance and direction of the nearest station detailed in the “Point Forecast” at the bottom of the map thumbnail.

At times in the past, conditions have been such that even higher temperatures than have been recently measured were definitely possible.  It is postulated that the early part of the Eocene Epoch (~ 54 to 48 million years ago) saw global average temperatures as much as 9 to 14°C higher than today.  This incredibly warm period in Earth’s not so distant past was brought on primarily by, you guessed it, much higher levels of atmospheric greenhouse gasses. Scientists estimate that CO2 concentrations back then were in the neighborhood of 1,000 to 2,000 parts per million. As of July, 2020, the atmospheric concentration of CO2 is 414.38 ppm and rising as you read this. Among the scientific community there is little doubt that we face a warmer future and we won’t have to wait 48 million years for it to arrive.

A personal recollection. 

Back in 2004 when I took the photograph above, I wanted to get a sense of what it was like to endure intense heat.  So after snapping the picture in air-conditioned comfort, I rolled the windows down and let the furnace-like air rush in.   The instantaneous change of 40 or more degrees in air temperature can take your breath away.  It hit me like a right-cross to the jaw. No lie, heat like that is painful to breathe.

I had tried to prepare myself for this ad-hoc experiment by purchasing an ice-cold half gallon of water a little while before in Stovepipe Wells.   My plan was to drive across the valley with the windows rolled down and take sips off the jug to keep hydrated as I went.  I soon found out that a car window rolled down in 120+ heat offers no relief, quite the opposite is true. It feels as comfortable as you might feel if you had a bank of hair dryers set on high and aimed at your face.

The miles rolled slowly by and I sipped away at my jug.  It didn’t feel like I was sweating all that much.  The combination of the hot, dry air and the wind from my open windows was wicking away my perspiration nearly as fast as it beaded up on my warm skin.

After a little more than an hour I started my slow rise out of the valley near it’s south end. I took the last sips from my jug.  Nature did not call.  The water I poured in was leaving my body nearly as fast though my pores.  I was curiously bemused by it all.

Dry heat or not, it was a very uncomfortable exercise.

References:

Death Valley National Park (U.S. National Park Service)

The National Weather Service

NOAA/climate

The post But it’s a dry heat … first appeared on Rediscovering the Golden State.

Surface travel from California will require navigating down the coast to get around the North American Continent even if you use the Panama Canal. From there, you will have to sail more than 5,000 miles across the Atlantic Ocean and at least 50 degrees of latitude. Even the direct flight over southern Greenland is about 5,000 miles (~8,000 km).  Norway’s southernmost locations are at least 16 degrees north of northern California and that may be the most notable difference that has influenced the natural and human landscapes and cultures of these two places.

But they are also similar in surprising ways. They are both elongated north-south, draped across a range of climate zones (warmer south and colder north, milder west coast and harsher east) and landscapes that have helped diversify their natural and human histories. Norway wins this latitude competition, stretching more than 14 degrees north-south, compared to California’s 9.5 degrees. Norway also covers more longitude (more than 25 degrees versus 10 degrees for California), though the distance difference isn’t as great as it may first seem since the length of a degree of longitude is a lot less in Norway, as it is so much closer to the pole, where lines of longitude converge. Though Norway is only a little smaller than California in total area, its population is just more than 5 million, compared to California’s approximately 40 million. This leaves Norway with more open space even when compared to the Golden State’s sprawling natural landscapes.    

California’s coastline is famously jagged, but Norway’s coastline is so rugged and frequently interrupted with fjords and dotted with islands, it totals tens of thousands of miles, much longer than the Golden State’s  cherished coast. We know that California’s coast is cooled by powerful ocean currents as waters generally drift from north to south (the California Current) and those mild climates gradually disappear as we move inland. But Norway’s coast is also milder than might be expected for its latitude, thanks to the south to north drift of the North Atlantic Current (or Gulf Stream) to become what researchers know as the Norwegian Atlantic Current. These relatively warm waters release tremendous amounts of heat into an otherwise colder latitude. And similar to California, prevailing west winds push Norway’s milder coastal air masses inland until climates gradually become more harsh to the east. Of course, the big difference is that because Norway is so far north, heavy snow and ice may dominate landscapes into spring, especially as you attempt to travel north or to just slightly higher elevations.

And so we begin to understand why glacial landscapes (the focus of this essay) in the two places are so different and yet similar. Enormous glaciers dominated Ice Age Norway, leaving spectacular glacial topography throughout the country, especially to the north, and impressive active glaciers are still evident at northern and higher elevation locations. But in California, only a necessary combination of extensive lofty mountain ranges could catch enough moisture and freeze it long enough to support glaciers during the Ice Age, leaving more isolated examples of alpine glacial geomorphology. And though active glaciers are still commonly seen shaping mountain landscapes in Norway and only a few smaller ones remain isolated in California’s high country, glaciers are retreating in both places.             

It was Louis Agassiz in the mid-1800s who cleverly theorized that large glaciers shaped many mountain ranges on Earth. Clarence King of the U.S. Geological Survey in 1870 was first to document glaciers in California (on Mt. Shasta). And in October 1871, John Muir discovered and measured glaciers in Yosemite’s high country and then wrote about them; his discoveries were followed by 60 years of ridicule, until scientists confirmed that impressive glaciers had not only once carved Sierra Nevada landscapes, but that several small glaciers remained active there. Though the Golden State’s glaciers and the landscapes they left behind could never compete with Norway, there are similarities.

In both regions, the spectacular glacial landscapes that remain are admired for their unique natural beauty. The relatively small glaciers are important sources for summer runoff into lower elevations and plant communities. They and their runoff produce unique microclimates that have formed around the ice and the frigid meltwater that flows from them. More recently, as the glaciers and ice fields retreat, they are all helping us measure the accelerating rate of climate change that is impacting all landscapes, plants, and animals in these two regions that are thousands of miles apart. Todays’ pinnacles and sun cups remaining in the ice fields and small glaciers that are scattered northward from Mineral King’s peaks into northern California’s highest elevations are tiny samples that remain to temp us to imagine a landscape where great alpine (mountain-valley) glaciers more common to today’s Norway once carved parts of the Golden State.

Look for spectacular erosional features such as isolated sharp-edged pyramidal peaks called horns, saw-toothed arêtes, bowl-shaped amphitheaters called cirques sheltering their crystal tarns of meltwater, and tributary hanging valleys and waterfalls that plunge into deeper, U-shaped valleys once carved by more massive glaciers. You might even notice grooves and striations on the exposed granites that were carved by coarser imbedded material dragged with the glaciers and polish left by finer material as it scoured its way downhill. Glacial till carved from above was deposited downstream in the form of jumbled contours of lateral, medial, and terminal moraines that may still block and pool today’s runoff from the high country. You can explore these landscapes that may seem more Norwegian in California’s high country, from the Sierra Nevada up to Shasta and even farther west in the Klamath’s Trinity Alps. But you will never find fiords in California, as our glaciers were never large enough to carve down near sea level or to the coast.

We hope you enjoy the following images in this daring attempt to compare and contrast Norway and California glacial landscapes. 

The post Norway vs. California first appeared on Rediscovering the Golden State.

On Saturday, November 10, 2018, people in many parts of northern and southern California woke up to another eerie orange and red smoky sky that had become all too common, the choking residue from the latest most destructive and deadly wildfires in our state’s history. Most of the larger ashes remaining from so many California dreams had already fallen out of what were once such well-defined towering pyrocumulus (flammagenitus) clouds.

Smoke from the deadly Camp Fire in Sierra Nevada foothill country eventually spread across the Sacramento Valley and later into the Bay Area. Smoke from the Hill and Woolsey Fires in southern California first blew out over the ocean and then gradually mixed into the atmosphere. When the offshore winds eased and turned gently onshore the next day, the clouds had diffused into veils of stifling smoky haze that would decorate sunrises and sunsets red as they drifted onshore, discouraging physical excursion for the next few days, and punishing millions with respiratory ailments. It was as if we were again witnessing the hangovers from what many viewed as nature’s latest tantrums, as she leaves behind the bodies of those who couldn’t escape the flames on foot or in their cars. But nature’s latest way of reminding us who is really in charge was also a reminder that we must better understand the science behind these events and we must also be more careful and thoughtful about where and how we choose to live.  

Some of us natives are old enough to remember how these occasional infernos played out every fall, and more recently during other times of year, more evidence that fire seasons have expanded in area, severity, and time. We examine the science and human factors that help explain and contribute to these catastrophes in our publication. Here, we will focus on the factors that combined to produce these latest disasters that make 2018 the latest in this string of worst wildfire years in the state’s history. It turns out that these firestorms that scorched through iconic neighborhoods in southern California and literally destroyed Paradise in northern California have become more common for several reasons.

Let’s begin by understanding what is NOT primarily to blame for most of these recent infernos. A few clueless demagogues have suggested the state has allowed some mysteriously magical source of accessible firefighting water to flow into the ocean. Our project’s analysis of California water resources and geography proves why they have failed their lessons in hydrology and water policy before they even started. Other opportunist politicians and the echo chambers following them have suggested that California is to blame for allowing tree densities to increase in our forests. They have even threatened to cut off our funding to punish us for these “mistakes”. But a rational analysis of the facts doesn’t support such shamelessly uniformed anti-California hysteria.  

First, the vast majority of the state’s most deadly and destructive wildfires in the last several years have started and burned in chaparral, coastal sage, and woodlands, NOT in forests with dense trees. You could cut down every tree in every California forest and most of these deadly fires would still have raged. You’d have to bulldoze and pave all the other plant communities that cover the majority of the state if you want to end these fires.  

Second, the majority of California forests that do exist are on federal lands, meaning that the very outside politicians blaming California are in charge of the very forest management they blame for the disasters. And those already underfunded forest management programs have been suffering from past budget cuts championed by those same feds. History haunts us here. More than a century of snuffing out all fires that started in our National Forests and parklands finally ended in the 1970s when forest managers realized that occasional beneficial fires cleared dangerous fuel that would otherwise accumulate to cause more intense, devastating, and out-of-control catastrophes. We were stuck with the fuel from poorly informed policies of the past. Control burns have become a vital part of forest and woodlands management in California ever since the 1970s, lessons we could have learned from Native Americans who practiced this for centuries before we managed these lands.  

More recently, after more than 100 million trees died from drought and bark beetle infestations in the Sierra Nevada, it is estimated that about half of all California forests are in serious trouble. In response, California has doubled the acreage open to vegetation thinning, and the U.S. Congress has finally stopped cutting programs that could save billions in losses and instead has restarted funding for sound forest management in the state. Many local communities have thinned their forests and required defensible spaces around structures. Appalling and repeated losses of life and property remind us that short-term investments in sustainable forest management will result in saving lives and a lot of money in the long term.             

Now that we see how we are tackling just one of the perceived problems, what is really to blame for these historic conflagrations? First and most obvious is climate change. Those bark beetle infestations are directly linked to some of the longest and most severe droughts and heat waves in recorded history. Additionally, forest managers have demonstrated that several inches of rain may be required to replace evapotranspiration losses from just one degree of warming above the historic average in places like Sierra Nevada foothill country. And average California temperatures have increased roughly the same as global temperatures over the last century, more than 1.5 degrees F.

The 2017 and 2018 fire years also illustrate the importance of those first rains of fall (as the jet stream and storm tracks commonly migrate south) to douse what would otherwise be critical fire conditions each year in northern California so that fire responders can focus on the often still dry southern California and its Santa Ana winds. In the 2017 season, the storms arrived late in northern California, following one of the hottest and driest summers on record, and it happened again during the even drier autumn of 2018. This left an abundance of exceptionally dry fuels waiting like open buffets for the autumn winds that whipped flames into a feasting frenzy. Exhausted fire crews were fighting in northern California as southern California’s fires, as anticipated, erupted amid the annual Santa Anas.            

Though researchers emphasize how dehydrated introduced non-native invasive species (such as cheatgrass) serve as added conduits to spread fires, these growing threats earn little attention in the media. Throw increasing populations into these fire-prone plant communities and it is easier to understand this recipe for disaster that has repeatedly broiled into death and destruction from north to south. More recently, we have seen how PG&E and SCE are facing crippling liabilities as their aging power infrastructures fail and throw sparks into the fuels parched by these relentless, unprecedented weather patterns. Arson, target shooting, landscaping work, careless smokers and campfire enthusiasts, and sparks and heat from vehicles round out some of the other sources for fire starts. You can see why lightning no longer leads the list of culprits.

Solving California's Firestorms

Here, western potions of the Santa Monica Mountains were recovering from another fire just a few years before the 2018 Woolsey Fire would burn some of the same landscapes.

Fuel for the Fires

Fuel for the Fires

Smoke on High

Drought and Bark Beetles

Ready to Burn

Destroying Paradise

Pyrocumulus (flammagenitus) Cloud

The post Solving the Historic California Firestorms Puzzle first appeared on Rediscovering the Golden State.