Will Cowan
@floodmeridians.bsky.social
There are many maps of one place and many histories of one time.
-J. Frederikse
Uchinaanchu Angeleño 與儀
-J. Frederikse
Uchinaanchu Angeleño 與儀
Reposted by Will Cowan
🎧🎤 Episode 2 of Western Edition Season 5 is live!
Watersheds West: Adaptation and Repair
www.buzzsprout.com/1837352/epis...
We talk with Dr. Karletta Chief about engaging with Indigenous communities in addressing environmental disasters and a future shaped by climate change.
Watersheds West: Adaptation and Repair
www.buzzsprout.com/1837352/epis...
We talk with Dr. Karletta Chief about engaging with Indigenous communities in addressing environmental disasters and a future shaped by climate change.
January 27, 2026 at 8:19 PM
🎧🎤 Episode 2 of Western Edition Season 5 is live!
Watersheds West: Adaptation and Repair
www.buzzsprout.com/1837352/epis...
We talk with Dr. Karletta Chief about engaging with Indigenous communities in addressing environmental disasters and a future shaped by climate change.
Watersheds West: Adaptation and Repair
www.buzzsprout.com/1837352/epis...
We talk with Dr. Karletta Chief about engaging with Indigenous communities in addressing environmental disasters and a future shaped by climate change.
Reposted by Will Cowan
CW3E AR Update: Multiple #AtmosphericRivers are forecast to bring heavy precipitation to portions of the Pacific Northwest this week.
See our latest Quick Look for more information: cw3e.ucsd.edu/wp-content/u....
See our latest Quick Look for more information: cw3e.ucsd.edu/wp-content/u....
![Page 3 of Quick Look. (Top) GEFS ensemble probability of AR conditions [IVT≥250 kg/(ms)] along the West Coast of North America for the 16-day period valid 4 AM PST Mon 26 Jan through 4 AM PST Wed 11 Feb. (Bottom) GEFS 7-day control and ensemble AR Scale and IVT forecasts for 47°N, 124°W (coastal southern Washington).](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:m6wmrhwljxz43udvb5drleue/bafkreico7df53z2pfzqjyk5w4sy6zoh6yyvuawyefoxaxajub4h64tgoru@jpeg)
January 26, 2026 at 10:28 PM
CW3E AR Update: Multiple #AtmosphericRivers are forecast to bring heavy precipitation to portions of the Pacific Northwest this week.
See our latest Quick Look for more information: cw3e.ucsd.edu/wp-content/u....
See our latest Quick Look for more information: cw3e.ucsd.edu/wp-content/u....
Reposted by Will Cowan
A 2026 factsheet on California's rivers and streams (led by the guy--Jeff Mount--who wrote the classic book of the same title) from @ppicwater. Useful and updated numbers, figures for our times.
www.ppic.org/publication/...
www.ppic.org/publication/...
California’s Rivers and Streams
California’s rivers and streams are vital to the state’s residents, economy, and environment—but they also face challenges from a changing climate and decades of alterations. How can the state improve...
www.ppic.org
January 27, 2026 at 5:22 PM
A 2026 factsheet on California's rivers and streams (led by the guy--Jeff Mount--who wrote the classic book of the same title) from @ppicwater. Useful and updated numbers, figures for our times.
www.ppic.org/publication/...
www.ppic.org/publication/...
Reposted by Will Cowan
January 26, 1918:
A small tornado impacted Los Angeles County in southern California. The estimated F2 tracked for 2 miles and had a path length of 70 yards. Five homes and two churches were impacted. One residence was destroyed. No injuries or fatalities occurred.
A small tornado impacted Los Angeles County in southern California. The estimated F2 tracked for 2 miles and had a path length of 70 yards. Five homes and two churches were impacted. One residence was destroyed. No injuries or fatalities occurred.
January 26, 2026 at 7:03 PM
January 26, 1918:
A small tornado impacted Los Angeles County in southern California. The estimated F2 tracked for 2 miles and had a path length of 70 yards. Five homes and two churches were impacted. One residence was destroyed. No injuries or fatalities occurred.
A small tornado impacted Los Angeles County in southern California. The estimated F2 tracked for 2 miles and had a path length of 70 yards. Five homes and two churches were impacted. One residence was destroyed. No injuries or fatalities occurred.
Reposted by Will Cowan
Record warmth across much of the West this winter has left the Sierra Nevada and the Rocky Mountains with very little snow.
“That is the classic global warming mountain snowpack signature.” @weatherwest.bsky.social
Graphics by @sean-greene.bsky.social www.latimes.com/environment/... @latimes.com
“That is the classic global warming mountain snowpack signature.” @weatherwest.bsky.social
Graphics by @sean-greene.bsky.social www.latimes.com/environment/... @latimes.com
January 26, 2026 at 10:11 PM
Record warmth across much of the West this winter has left the Sierra Nevada and the Rocky Mountains with very little snow.
“That is the classic global warming mountain snowpack signature.” @weatherwest.bsky.social
Graphics by @sean-greene.bsky.social www.latimes.com/environment/... @latimes.com
“That is the classic global warming mountain snowpack signature.” @weatherwest.bsky.social
Graphics by @sean-greene.bsky.social www.latimes.com/environment/... @latimes.com
Reposted by Will Cowan
Join me on February 4, from 7 to 9pm PT for a First Wednesdays event on "Weather and Water Extremes on a Warming Planet: The California Experience," hosted by the Aquarium of the Pacific 🐋 in Long Beach, CA! The event will also be recorded & live-streamed.
First Wednesdays: Lecture, Cocktail Hour, and Music
Join us for an engaging talk with Dr. Danial Swain on California’s climate and extreme weather events.
www.aquariumofpacific.org
January 20, 2026 at 9:31 PM
Join me on February 4, from 7 to 9pm PT for a First Wednesdays event on "Weather and Water Extremes on a Warming Planet: The California Experience," hosted by the Aquarium of the Pacific 🐋 in Long Beach, CA! The event will also be recorded & live-streamed.
Reposted by Will Cowan
Well, it's now official (per NOAA): Dec (and Nov-Dec) 2025 were the warmest such periods on record for Western U.S. (and also for most individual Western states). It has been an extraordinarily sustained period of winter warmth, and this eerily balmy winter continues into Jan.
January 14, 2026 at 3:57 AM
Well, it's now official (per NOAA): Dec (and Nov-Dec) 2025 were the warmest such periods on record for Western U.S. (and also for most individual Western states). It has been an extraordinarily sustained period of winter warmth, and this eerily balmy winter continues into Jan.
Reposted by Will Cowan
Remarkably, at least one observing site in every single Western U.S. state is currently reporting *record low* snowpack for this mid-winter date. In some states, esp. UT and CO, *most* sites are either record low or second lowest on record. More during Wednesday's livestream.
January 19, 2026 at 11:01 PM
Remarkably, at least one observing site in every single Western U.S. state is currently reporting *record low* snowpack for this mid-winter date. In some states, esp. UT and CO, *most* sites are either record low or second lowest on record. More during Wednesday's livestream.
Reposted by Will Cowan
A natural approach to managing floodplains — the low-lying areas around a river — can reduce flood risk to our communities and provide critical habitat for waterfowl, fish, land animals, and freshwater species.
🎥 Watch how: https://www.youtube.com/watch?v=XiX_1vimFcs
🎥 Watch how: https://www.youtube.com/watch?v=XiX_1vimFcs
American Rivers Restoring Floodplains
Small, regular floods are part of the natural ebb and flow of a healthy river. But development and increasingly frequent and powerful storms are making floods bigger and more damaging. A natural approach to managing floodplains -- the low-lying areas ar...
www.youtube.com
January 14, 2026 at 8:39 PM
A natural approach to managing floodplains — the low-lying areas around a river — can reduce flood risk to our communities and provide critical habitat for waterfowl, fish, land animals, and freshwater species.
🎥 Watch how: https://www.youtube.com/watch?v=XiX_1vimFcs
🎥 Watch how: https://www.youtube.com/watch?v=XiX_1vimFcs
Reposted by Will Cowan
This Thursday’s Workshop will include news from NOAA on products & research re: compound flooding, from ASCE on their Compound Flooding Manual of Practice, & discussion of how insurance & reinsurance industry assess compound flood risks in nonstationary climate.
docs.google.com/forms/d/e/1F...
docs.google.com/forms/d/e/1F...
Compound Flooding Workshop Registration Form
The National Oceanic and Atmospheric Administration (NOAA) through the National Centers for Environmental Information (NCEI) is excited to invite you to participate in a Compound Flooding Workshop for...
docs.google.com
January 20, 2026 at 4:19 PM
This Thursday’s Workshop will include news from NOAA on products & research re: compound flooding, from ASCE on their Compound Flooding Manual of Practice, & discussion of how insurance & reinsurance industry assess compound flood risks in nonstationary climate.
docs.google.com/forms/d/e/1F...
docs.google.com/forms/d/e/1F...
Reposted by Will Cowan
🎧🎤 The first episode of Western Edition Season 5 is live!
This episode orients us to a region defined by its aridity and considers how humans have interacted with water over the past two centuries, from Indigenous cosmologies to American conquest.
www.buzzsprout.com/1837352/epis...
This episode orients us to a region defined by its aridity and considers how humans have interacted with water over the past two centuries, from Indigenous cosmologies to American conquest.
www.buzzsprout.com/1837352/epis...
January 20, 2026 at 5:05 PM
🎧🎤 The first episode of Western Edition Season 5 is live!
This episode orients us to a region defined by its aridity and considers how humans have interacted with water over the past two centuries, from Indigenous cosmologies to American conquest.
www.buzzsprout.com/1837352/epis...
This episode orients us to a region defined by its aridity and considers how humans have interacted with water over the past two centuries, from Indigenous cosmologies to American conquest.
www.buzzsprout.com/1837352/epis...
Reposted by Will Cowan
CW3E has prepared a detailed event summary discussing the multiple #AtmosphericRivers that produced heavy precipitation, significant snowfall, and widespread impacts over the US West Coast between 18–27 Dec 2025. Read our extensive analysis here: cw3e.ucsd.edu/cw3e-event-s...
January 13, 2026 at 9:27 PM
CW3E has prepared a detailed event summary discussing the multiple #AtmosphericRivers that produced heavy precipitation, significant snowfall, and widespread impacts over the US West Coast between 18–27 Dec 2025. Read our extensive analysis here: cw3e.ucsd.edu/cw3e-event-s...
Reposted by Will Cowan
CW3E Publication Notice: "Compound Atmospheric Drivers of the Catastrophic 2025 Los Angeles Urban Firestorm" in @nature.com's npj Natural Hazards.
For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....
For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....
December 30, 2025 at 1:38 AM
CW3E Publication Notice: "Compound Atmospheric Drivers of the Catastrophic 2025 Los Angeles Urban Firestorm" in @nature.com's npj Natural Hazards.
For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....
For a summary of this paper, visit: cw3e.ucsd.edu/cw3e-publica....
Reposted by Will Cowan
We posted a quick summary of the #AtmosphericRivers that influenced precipitation across the US West Coast and led to heavy precipitation in CA this past week. Check out more here: cw3e.ucsd.edu/wp-content/u...
January 6, 2026 at 10:19 PM
We posted a quick summary of the #AtmosphericRivers that influenced precipitation across the US West Coast and led to heavy precipitation in CA this past week. Check out more here: cw3e.ucsd.edu/wp-content/u...
Reposted by Will Cowan
"Managing fire risk is about more than construction practices, regulations and rules. It is also about people and neighborliness – the ethos and practice of caring for those in your community, including making choices and taking steps on your own property to help keep the people around you safe."
January 8, 2026 at 5:50 PM
"Managing fire risk is about more than construction practices, regulations and rules. It is also about people and neighborliness – the ethos and practice of caring for those in your community, including making choices and taking steps on your own property to help keep the people around you safe."
Reposted by Will Cowan
ICW co-directors Bill Deverell and Elizabeth Logan reflect on the importance of collective care in the face of wildfire threats @us.theconversation.com.
theconversation.com/la-fires-sho...
theconversation.com/la-fires-sho...
LA fires showed how much neighborliness matters for wildfire safety
Managing fire risk is about more than regulations and rules. It’s also about caring for neighbors and taking steps on your own property and in your community to help keep neighbors safe.
theconversation.com
January 8, 2026 at 5:50 PM
ICW co-directors Bill Deverell and Elizabeth Logan reflect on the importance of collective care in the face of wildfire threats @us.theconversation.com.
theconversation.com/la-fires-sho...
theconversation.com/la-fires-sho...
Reposted by Will Cowan
Time is now short...January 15 is the deadline for applying for the Summer 2026 Center for Western Weather & Water Extremes Undergraduate Internship Program! @CW3EScripps does a great job of making it an inclusive AND financially accessible chance to work w/the best.
cw3e.ucsd.edu/cw3e-interns...
cw3e.ucsd.edu/cw3e-interns...
January 6, 2026 at 10:37 PM
Time is now short...January 15 is the deadline for applying for the Summer 2026 Center for Western Weather & Water Extremes Undergraduate Internship Program! @CW3EScripps does a great job of making it an inclusive AND financially accessible chance to work w/the best.
cw3e.ucsd.edu/cw3e-interns...
cw3e.ucsd.edu/cw3e-interns...
Reposted by Will Cowan
"In Los Angeles, the #LARiver overflowed & the Pueblo was underwater. LA’s ranches were devastated, while the many vineyards along the river were destroyed, buried in gritty sand & gravel washed down from the #SanGabrielMountains," via @floodmeridians.bsky.social. dornsife.usc.edu/news/stories...
When the Floods Came
We think of Southern California as arid and drought-ridden, but from 1861 to ’62, much of it was underwater after a series of deadly winter storms caused widespread devastation and flooding. USC Dorns...
dornsife.usc.edu
December 24, 2025 at 8:15 PM
"In Los Angeles, the #LARiver overflowed & the Pueblo was underwater. LA’s ranches were devastated, while the many vineyards along the river were destroyed, buried in gritty sand & gravel washed down from the #SanGabrielMountains," via @floodmeridians.bsky.social. dornsife.usc.edu/news/stories...
Reposted by Will Cowan
Yet another rainy (at basin-scales) AR storm headed our way. Its been a real winter for them so far.
Check out whats forecast, in this regard, for your locale at
cw3e.ucsd.edu/DSMaps/DS_fr...
Check out whats forecast, in this regard, for your locale at
cw3e.ucsd.edu/DSMaps/DS_fr...
December 15, 2025 at 7:48 PM
Yet another rainy (at basin-scales) AR storm headed our way. Its been a real winter for them so far.
Check out whats forecast, in this regard, for your locale at
cw3e.ucsd.edu/DSMaps/DS_fr...
Check out whats forecast, in this regard, for your locale at
cw3e.ucsd.edu/DSMaps/DS_fr...
Reposted by Will Cowan
Yeah, THAT is a strong and classic “Pineapple Express” atmospheric river configuration!
www.sfchronicle.com/weather-fore...
www.sfchronicle.com/weather-fore...
Storm forecast shows Pineapple Express may head straight for Bay Area
The Bay Area could be in the path of an atmospheric river this weekend, with forecast models trending toward a wetter, multiday storm.
www.sfchronicle.com
December 17, 2025 at 3:34 PM
Yeah, THAT is a strong and classic “Pineapple Express” atmospheric river configuration!
www.sfchronicle.com/weather-fore...
www.sfchronicle.com/weather-fore...
Reposted by Will Cowan
An #AtmosphericRiver is forecast to move over the Pacific Northwest on Thu., bringing additional rainfall to WA, OR, and Northern CA as it shifts down the coast thru Fri. A second AR will follow behind on Sat. with additional impacts forecast over Northern CA thru Mon. Read more: go.ucsd.edu/451WXPa
December 17, 2025 at 11:20 PM
An #AtmosphericRiver is forecast to move over the Pacific Northwest on Thu., bringing additional rainfall to WA, OR, and Northern CA as it shifts down the coast thru Fri. A second AR will follow behind on Sat. with additional impacts forecast over Northern CA thru Mon. Read more: go.ucsd.edu/451WXPa
Reposted by Will Cowan
CW3E AR Update: AR activity is forecast to continue over the PNW thru early Wed., with a 2nd AR forecast to move onshore late on Wed. over the PNW and N. CA, through Fri. Models are also highlighting the potential for AR activity over CA next week. Read more here: cw3e.ucsd.edu/cw3e-ar-upda...
December 15, 2025 at 10:42 PM
CW3E AR Update: AR activity is forecast to continue over the PNW thru early Wed., with a 2nd AR forecast to move onshore late on Wed. over the PNW and N. CA, through Fri. Models are also highlighting the potential for AR activity over CA next week. Read more here: cw3e.ucsd.edu/cw3e-ar-upda...
Reposted by Will Cowan
The atmospheric river (AR) presently impacting the Pacific Northwest will continue to produce very heavy precipitation in western Washington today into early tomorrow, leading to potentially historic riverine flooding.
Read more here: cw3e.ucsd.edu/wp-content/u...
Read more here: cw3e.ucsd.edu/wp-content/u...
December 10, 2025 at 6:24 PM
The atmospheric river (AR) presently impacting the Pacific Northwest will continue to produce very heavy precipitation in western Washington today into early tomorrow, leading to potentially historic riverine flooding.
Read more here: cw3e.ucsd.edu/wp-content/u...
Read more here: cw3e.ucsd.edu/wp-content/u...
Reposted by Will Cowan
🌧️ How do we study #AtmosphericRivers? 🛫 By flying planes into them, obviously! @cw3escripps.bsky.social's Alex Tardy caught up with Fox Weather to share why flights are critical for understanding ARs ahead of a powerful atmospheric river headed for the Northwest. U.S. ⬇️
Powerful atmospheric river headed for the Northwest U.S. | Latest Weather Clips | FOX Weather
Project Policy Analyst and Meteorologist with the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography, Alex Tar
www.foxweather.com
December 11, 2025 at 12:23 AM
🌧️ How do we study #AtmosphericRivers? 🛫 By flying planes into them, obviously! @cw3escripps.bsky.social's Alex Tardy caught up with Fox Weather to share why flights are critical for understanding ARs ahead of a powerful atmospheric river headed for the Northwest. U.S. ⬇️
Reposted by Will Cowan
CW3E Publication Notice: "Insights from a 25-year Database of Post-Fire Debris Flows in California" published in the International Journal of Wildland Fire with collaborators @cageosurvey.bsky.social Read more about this research here: cw3e.ucsd.edu/cw3e-publica...
December 11, 2025 at 3:54 AM
CW3E Publication Notice: "Insights from a 25-year Database of Post-Fire Debris Flows in California" published in the International Journal of Wildland Fire with collaborators @cageosurvey.bsky.social Read more about this research here: cw3e.ucsd.edu/cw3e-publica...