Wetand News

 The air feels different today. Warm, humid, and with a determined breeze that should be moving a grove of palm trees. Your skin feels moistened and supple, and temperatures will rise to near 60F in the west and as high as 70F over the Columbia Basin. Seattle, November 14, 2021? The Northwest has been transported into the subtropics for a day, the result of an odd meteorological wormhole in meteorological space/time. This blog will explain. Some of you may demand proof of the tropical origins of our current air....here it is!   The top figure below shows the trajectories of air over the past five days ending above Tacoma at 500 meters (red), 1000 m (blue), and 2000 m (green).  All three air trajecotires come from south of 30 N west of Baja California.   The subtropics.   The bottom  panel shows the heights of the air over the past five days. The transition occurred last night. Below are observations of wind, temperature, and moisture (dew point temperature) at the University of Washing

 My new podcast is out, and I go into detail about the origins of Northwest flooding and describe the VERY active weather that is expected over the new few days. The current radar shows the atmospheric river precipitation over us (below)...and it clearly displays the radar gap along the central and southern Oregon coat. ANOTHER atmospheric river hits Saturday night/Sunday morning (see 24-h total ending 4 PM Sunday in the graphic below),  which will be most problematic over western Washington  and southern BC. And THEN a powerful front comes through on Monday that will bring even MORE rain (as much as 7 inches in the mountains and several inches over Puget Sound).  Expect street flooding. The front will be accompanied by strong winds and followed by MUCH colder air, with the snow levels plummeting  to roughly 2000 ft in the mountains. More details in the podcast! You can listen to the podcast below or through your favorite podcast server. Some major podcast servers:     Like the podcast

After a relatively dry summer, the Northwest is experiencing one of the wettest autumns in a long time. September and October brought above-normal precipitation around the region.  November is going to smash typical monthly precipitation amounts at most stations. Over the next few days, a powerful atmospheric river of moisture surging out of the subtropics will inundate our region, with the western slopes of some of our terrain barriers experiencing as much as 10 inches of rain.   Falling on saturated soils, westside rivers will surge to flood stage...some to major flood stage. Water vapor satellite imagery (which measures the amount of infrared radiation emitted by atmospheric water vapor), shows an impressive plume of water vapor extending from north of Hawaii into our region.  Perhaps a part of the "aloha spirit" that is not as welcome as others. Model simulations of total atmospheric moisture in a vertical column (in this case for 10 PM tonight) show the potent moisture p

 An exciting weather day.  The National Weather Service put out a tornado warning for Kitsap County through Bainbridge Island, including telling folks to TAKE COVER NOW! And for some reason, the warnings caused smartphones to beep all over central Puget Sound. There was no tornado observed as far as I can tell.   The warning was based on the radar showing intense precipitation (including hail) and the Doppler radar capability hinting at some rotation.  The image below shows the intense radar return and the bottom panel shows the Doppler velocities, which suggested....but was not definitive-- in indicaing rotation (the dark green and whitish color adjacent to each other near the lightning symbol). Right now, a band of heavy rain and some thunder are moving through (see current radar below, reddish colors are the most intense). The National Weather Service has a special weather statement out right now regarding the thunderstorms. And then there was the wind. A very strong front came thro

As predicted, the cold, unstable air streaming into our region has dropped substantial snow in the mountains. Even at low levels ( 3000 ft),  Snoqualmie Pass received enough to cover the roadway. The higher ( 5000 ft) Paradise Visitor Center is now snowbound and inaccessible. While the real-time snow ruler at Stevens Pass (around 4000 ft) has roughly 10 inches. The latest satellite picture shows an impressive array of cold, convective showers offshore, with the instability driven by cold air moving over relatively warm water.   Enough to warm the hearts of area skiers!   Our temperatures have been running much below normal the past few days, with today only getting to around 45 F today.  These are mid-winter temps. The latest regional high-resolution model run is in, predicting as much as 1 foot by Wednesday morning in the North Cascades and even more over the BC mountains (see accumulated snow graphic below).  A very good base to build upon for this season. Whistler is planning on ope

 First, an announcement.   I will be doing a book signing and dinner event at Ivar's Salmon House in Seattle on Wednesday, November 17th (6 PM).  You can come just to purchase a book and get it personalized or you can stay for a special dinner, where I will be giving a weather talk.   More information on the event is found here .  You need to make reservations for the dinner (only 80 spaces available). And information about the new edition of my book is here . I n any case, it will be nice to meet some of you in person after the long COVID period. La Nina Has Strengthened La Nina, the cooling of the central and eastern tropical Pacific, has strengthened, and this has big implications for our winter, particularly after January 1.   Think snow.   I will discuss this in my podcast.   The Start of the Cascade Snow Season And talking about snow, with cooling temperatures and lots of precipitation, the latest model runs suggest LOTS of the white stuff during the next week (see UW WRF mod

Yesterday I received a dramatic photograph from Steve Tongue, the Operations Manager of Holden Village, that shows a narrow cloud that extended along the central axis of Lake Chelan (see below). Mr. Tongue has a fun, descriptive name for this feature:  a "Boa Cloud", due to its snake-like appearance. This picture was taken yesterday (Wednesday) around 11 AM and Mr. Tongue suggests that such snake clouds occur fairly regularly. When I saw this cloud, positioned along the center of a body of water, I noted its similarity with a similar feature in western Washington--the line of clouds the sometimes form down the center of Puget Sound and Lake Washington during cool periods when the air temperature is below the water temperature. Here is an example for February 18, 2020.   You can see the snake (indicated by the white arrows). In western Washington, these narrow cloud features in the middle of long water bodies are virtually always associated with cold air over land and relative