Notices by Daniel Swain (weatherwest@mastodon.social), page 2

What does #ElNiño really mean for California winter precipitation? In short: it depends on how strong El Niño becomes. Weak events exert only a negligible influence, but strong ones can profoundly increase the likelihood of wet winters and heavy downpours. https://youtu.be/JxQGuoDfovo

I wanted to offer some historical context re: the current #ElNiño forecast, including (real but still TBD) prospects of a potentially historically significant "Super El Niño" event. https://youtu.be/aOMZ-IV05RI

What is #ElNiño, in a nutshell, from an atmospheric and oceanic perspective? The 60-second version: https://youtu.be/CWF4MZwCUtw

Looking farther out into May, it does appear that a quieter, drier, and warmer pattern may be on the way for CA as modest ridging replaces persistent troughing. Additionally, the extreme marine heatwave persists in Pacific, which will boost coastal temps further.

In early May, a "Rex blocking" configuration will develop, allowing the PacNW to warm to well above average levels and California to cool back toward (but not below) seasonal averages. Additional mainly mountain showers are possible during this period. #CAwx

A period of warmer weather will return the rest of this week across most of California before yet another spring low pressure system brings unsettled conditions again this weekend. This will be a much more "typical" and lower-impact April showers scenario than recent storms.

Today was already quite active in NorCal, w/several severe thunderstorms & at least one photogenic supercell. Fri & Sat will be even more unusual, w/widespread t-storms & likely at least a few severe ones. I may have a pop-up livestream, time TBD, on Fri or Sat for a radar tour!

I can't believe we have reached this point, but this bears crystal clear emphasis: Our global climate system ensures that even "limited" use of lower-yield "tactical" nuclear weapons against civilian or industrial targets would have major regional-to-global scale consequences.

Incredibly, even *more* locations across U.S. are today experiencing their warmest March temperatures on record--many by a wide margin, with some even breaking April records. This includes most or all of: AZ, UT, CO, NM, WY, NE, KS, MO, IA, plus portions of many other states. 🫠

Earlier today, I was asked to comment on the current state of disaster preparedness in the United States.

That was already a fraught question, even prior present chaos, but then I saw today's headlines. 🫠

"Top Disaster Response Official Claims He Teleported to a Waffle House"

Well, if yesterday's map was ridiculous, I'm running out of superlatives to characterize today's. Countless locations from Pacific Coast to Great Plains are currently experiencing all-time record March warmth, w/ some locations approaching/exceeding April (or even May) records.

I'll be live on KQED Forum from 9-10am PT on Mon, Mar 16 (yes, for the full hour!) to discuss what is likely to become a historic March heatwave across Western U.S. We'll be taking listener questions live; you can listen online as well as over the air. https://www.kqed.org/radio/schedule?date=2026-03-16

All signs continue to point to an exceptional, long-duration, and record-breaking to (in some cases) record-shattering March heatwave initially centered across U.S. Southwest but expanding to much broader region next week. This is effectively a full-on summer heatwave in March.

The official NOAA stats out this week confirm that winter 2025-26 was the warmest on record across a huge portion of the western and central U.S., which has contributed to extremely low mountain snowpack & worsened the CO River crisis. Meanwhile, record March heat is in forecast.

I just submitted my letter to NSF responding to its proposal to dismantle the National Center for Atmospheric Research (NCAR). I argue that doing so would be an astonishing and avoidable misstep, and that federal support for the institution should in fact be *increased.* [1/4]

Whew.

All signs are increasingly pointing to a significant, if not strong to very strong, El Niño event. I'll have more to say in coming weeks & months, but for now I'll just say that this is increasingly likely to become a major regional-to-global climate driver in 2026-2027.

#BlueBellFire in #Boulder, CO (near Chautauqua Park) currently burning amid extremely dry and near record-warm conditions (69F and 7% RH). Lack of strong winds right now thankfully a major mitigating factor. So far, mostly sfc fire plus occasional torching in confers. #COwx

After a relatively brief colder & snowier interlude, we've re-entered a period that will be characterized by sustained anomalous warmth in U.S. West. Today, daily record high temperatures are again occurring across portions of Southern Rockies and interior SW. #CAwx #COwx

A major avalanche in the "high risk" Avalanche Warning zone (per Sierra Avalanche Center) has occurred in the vicinity of Castle Peak, near Truckee. It unfortunately sounds like over a dozen people (skiers) were in the path, and some are still missing. https://www.nbcnews.com/news/us-news/skiers-missing-stranded-avalanche-california-rcna259472

Today's forecast indicated that "large to very large" avalanches were "very likely." https://www.sierraavalanchecenter.org/forecasts/avalanche/central-sierra-nevada#/central-sierra-nevada/