Some mixed news on CA weather front over next couple of weeks. First, by Monday, another "inside slider" system will bring another burst of cooler & winder conditions statewide. Once again, some Sierra snow showers are possible, but most places stay dry. #CAwx#CAwater
Midweek, however, an even colder airmass and associated low pressure center will slide down the coast slightly farther to the west. This system, although still quite dry, stands a better chance of bringing convective activity (scattered showers/isolated thunder) statewide. #CAWx
The biggest impact from this mid-week system, outside of some additional modest Sierra snow accumulations and a few pockets of accumulating small hail showers at lower elevations (like last week in SoCal), will be a dramatic shift toward much colder temperatures. #CAwx
In fact, I would expect significant agricultural impacts in Central Valley where several consecutive nights of sub-freezing temperatures are possible. This may be especially disruptive following weeks of record warmth, which allowed some tree crops to bud unusually early. #CAwx
Despite this fairly active/unsettled pattern, I still don't foresee widespread hydrologically meaningful precipitation over the next 10+ days. But heading into early March, the pattern gets a bit murkier... #CAwx
It is possible that a cool & modestly unsettled pattern will bring slightly more widespread rain and mountain snow by early March. There are currently still *no signs* of big storms, but this would still represent a departure from unrelentingly dry Jan/Feb 2022. Stay tuned! #CAwx
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Amer. Meteorological Soc. (@ametsoc) just issued a (fully justified) dire statement regarding rapidly accelerating & potentially disastrous efforts to decimate weather & climate enterprise in U.S. If implemented, this would cost many lives & cause major/ long-term economic harm.
@ametsoc "In effect, the scientific backbone and workforce needed to keep weather forecasts, alerts, and warnings accurate and effective will be drastically undercut, with unknown — yet almost certainly disastrous — consequences for public safety and economic health."
@ametsoc "If you believe in the importance of NOAA research for maintaining and improving NWS forecasts and services to the nation then *THE TIME TO ACT IS NOW*. Reach out to your elected representatives and share your concerns."
The mass firing of both new hires and recently promoted senior staff within #NOAA, including mission-critical and life-saving roles at the National Weather Service (#NWS), is profoundly alarming.
1/11
It appears that staff fired today include meteorologists, data scientists responsible for maintaining weather predictive models, and technicians responsible for maintaining the nation’s weather instrumentation network (among many others).
2/11
The U.S. NWS is a truly world-class meteorological predictive service, perhaps singularly so. Its cost of operation is only ~$3-4/yr per taxpayer—equivalent to a single cup of coffee—and yields a truly remarkable return on investment (at least 10 to 1, and perhaps 100 to 1).
3/11
A period of very warm mid-winter conditions appear likely for much of California and portions of the interior West in late Feb. A strong ridge will form during this period, with large-scale subsidence & warm air advection allowing for a genuine winter "heat wave" next week. #CAwx
Temps in 80s will be widespread in SoCal, & even 90s are possible. T-shirt and shorts weather will also extend into NorCal and beyond (well into 70s), as well as desert SW (where late spring-like temps in 90s are likely). Late Feb records may be broken in some places. #CAwx #AZwx
Looking ahead to the end of winter and spring, the California/U.S. West precipitation dipole (i.e., unusually wet in the north and unusually dry in the south) appears likely to continue. The dryness may expand to include more of CA/West Coast later in spring, too. #CAwx #CAwater
Out today in @GlobalChangeBio is our (brief!) rapid-response piece on the broader context surrounding the January 2025 Southern California wildfires & relevance of wet-to-dry hydroclimate whiplash to fire both locally and globally on a warming Earth. [1/8] onlinelibrary.wiley.com/doi/full/10.11…
@GlobalChangeBio Coastal Southern California experienced an exceptional wet-to-dry "hydroclimate whiplash event" between May/June 2024 (following a second anomalously wet winter) and Dec/Jan 2024/5 (characterized by the driest start to season on record in many parts of the region). [2/8]
@GlobalChangeBio This whiplash event caused a pronounced vegetation accumulation-then-desiccation cycle, adding more fuel for (potential) fires to come then drying it out to record levels for time of year--setting stage for destructive fires when strong winds arrived.[3/8] onlinelibrary.wiley.com/doi/full/10.11…
After becoming increasingly enmeshed in the wildfire world, you start to notice things about the way we've systematically altered our relationship with the natural environment in a way that has increased the risk of destructive fires. And then you stop being able to unsee them.
I've always lived in the American West, in different parts of California and on the Colorado Front Range. I've traveled throughout the West extensively; even as a child, fire was always there in the distance--a companion on family roadtrips, a backdrop to summer afternoons.
One of my earliest memories (fuzzy though it is; I was very young) was ash falling from the sky while out at a San Francisco park. The date? October 20, 1991--the day the devastating Oakland Hills fire tore through around 3,000 structures and killed 25 in the Berkeley Hills.
Our paper on "Hydroclimate volatility on a Warming Earth" is out in Nature Reviews Earth & Environment. We assess existing scientific literature & conduct new analysis--concluding that "#HydroclimateWhiplash" is increasing due to #ClimateChange. [Thread] nature.com/articles/s4301…
"Hydroclimate volatility" refers to rapid transitions between unusually wet & dry conditions relative to local baseline. For quantitative analysis, we define a new "hydroclimate whiplash" metric using Standardized Precipitation & Evaporation Index (SPEI). nature.com/articles/s4301…
One key aspect of the framework for understanding such volatility is that it encompasses both "supply" & "demand" side of water balance--that is, not only precipitation (or lack thereof), but also evaporation (or evaporative demand). Precipitation doesn't tell the whole story!