Notices by Daniel Swain (weatherwest@mastodon.social)

Fielding questions re: this article w/bizarre factual errors. First, there's no "Montecito County" in CA. Second, 2 fires are actually in *Monterey,* & 3rd in *Mendocino*. Third, 60k ac have *not* burned in either fictional Montecito nor real Mendocino.🤨 https://www.latimes.com/california/story/2026-09-12/three-montecito-county-fires-burn-60-000-acres

I'll host a short-notice, "pop-up" livestream TODAY, Aug 27 at 4pm PT to discuss:
1) What is known about the human impacts and geophysical causes of the Himalayan glacier collapse disaster, and
2) Severe humid heatwave/dry t-storms/fire risk in California https://youtube.com/live/m61bKp9NG0U?feature=share

The sheer scale of destruction amid Himalayan glacier collapse disaster is horrifying, as is presumptive human toll. This was no mere flash flood or mudslide--it was more akin to a geologic-scale debris avalanche or "inland tsunami." The footage emerging is almost unbelievable.

New Weather West Post: Major SoCal late August heatwave this week, with modest, but growing, possibility of tropical storm remnants affecting CA in September. Plus: Why parts of SoCal could *potentially* see more extreme heat than is currently in forecast.
https://weatherwest.com/archives/43983

On Tuesday, Aug 18th at noon PT, I'll have a "lunch hour" livestream covering a wide range of topics, including Hurricane Lala's severe flash flood-related impacts on Hawaii's Big Island, rebuilding heat/wildfire risk across interior West, and El Niño. https://youtube.com/live/-4Y6Ds1taII?feature=share

Unfortunately, and as anticipated, yesterday's widespread lightning-following-heat event amid severe drought has sparked a large number of additional wildfires, expanding existing outbreak across OR, WA, & BC. Numerous heat signatures & large smoke plumes are evident. #ORwx #WAwx

A major thunderstorm outbreak is unfolding across the interior Pacific NW. While not "dry thunderstorms" (w/briefly heavy showers), numerous wildfire ignitions are still likely due to strikes outside of rain cores, severe pre-existing drought, & heatwave to follow. #ORwx #WAwx

SE-to-NW monsoonal flow is in full effect across California this PM. There's also a notable remnant MCV (mesoscale convective vortex) currently over LA & moving NW-ward. This feature will potentially be the "trigger" for some dry thunderstorms to NorCal overnight into Mon. #CAwx

Well, the extreme heatwave across the Northern Rockies/Northern Plains/Upper Midwest is living up to expectations with some locations (as of only 2pm local time) reaching or breaking all-time (any month) temperature records today in Wyoming and eastern Montana. #MTwx #WYwx

Along the western flank of the gigantic interior west-central U.S. ridge, monsoonal moisture will surge northwestward across California and the Great Basin. This could bring some initially dry thunderstorms, including over parts of CA (slight chance coastal areas), Sun-Mon. #CAwx

On CO Western Slope, a pair of fires are rapidly spreading in a remote region SW of Grand Junction. With current extreme fire weather conditions, it's possible these fires could eventually spot over Colorado River and I-70, posing a (non-immediate) threat to more populated areas.

One problem is that numerous dry lightning strikes occurred over the past 72 hours; new ignitions, known as "holdovers," are popping up all over the place faster than they can be managed. Amid strong winds and historic drought, that's a dangerous combination.

This situation is already quite serious, and likely to escalate further in the coming hours and days. Most of these fire are far larger than is widely being reported as of Saturday evening; many small rural communities are under some kind of evacuation or will be shortly.

Unfortunately, the outlook is pretty concerning. Strong winds will continue overnight into Sun, only slowly dying down by Mon/Tue. In fact, fairly windy & still dry weather will persist essentially for predictable future (7+ days). SW monsoon is, unfortunately, not yet in sight.

Why is the vegetation here so dry, including record low fuel moisture in heavier fuel types? Well, this region record-low snowpack in 2026 (and a record-warm winter) and is experiencing a severe-to-extreme multi-year drought. (See just-issued NIFC Fuels and Fire Behavior.)

Today and in coming days, highly anomalous strong southwesterly winds (gusting to ~50 mph, at surface) and low humidity are co-occurring in a region with near-record or record vegetation dryness. Gravity waves (indicative of strong winds aloft) are visible in smoke plumes.

A serious and still-escalating wildfire outbreak is now underway across interior West, and has today expanded beyond NV & UT into western CO & AZ/NM. Extreme fire behavior and rapid spread is widespread; adverse conditions expected for 7+ days. #UTwx #COwx #AZwx #NMwx [Thread]

Elevated wildfire risk will continue each day for foreseeable future across some portion of interior West. Through Sat, a broad region of dry thunderstorm potential will arise within drought/snow drought zones following recent heatwave, with relatively high risk of new ignitions.

Okay, folks: The big El Niño update is now out on Weather West! This sure looks like it's going to be a dramatic year from a global climate perspective, and there are major implications for extreme events (across California, the U.S. West, & well beyond). https://weatherwest.com/archives/43880

The third chapter of this documentary series on #climate extremes is now out! This episode focuses specifically on the impacts of climate change and extreme weather-related disruptions to agriculture, as well as potential solutions to these challenges.

https://www.youtube.com/watch?v=AhpQFBEDvzY