Heat Wave Update

Today will be the warmest day of the heat wave event in the western interior, with cooling already occurring over some coastal areas.

Yesterday's highs (shown below) ranged from over 100F east of the Cascade crest, to near 100F in the Willamette Valley, to the mid to upper 80s around Puget Sound, and to the 60s over the southern Oregon Coast.   Warmer than normal over most of the region, but few records fell.


Today, the temperatures are warmer aloft...and, in fact, the temperature around 5000 ft at the radiosonde site at Quillayute (UIL), on the northern WA coast, was near record levels for the date--not all time records, daily records (see below).  (the dot shows today's temperature and the red line is the record for the date).


Today is warmer in some locations and cooler in others.  Below is the difference in temperature at noon compared to yesterday at the same time.   Warmer over Puget Sound, similar in the Willamette Valley, but cooler along the southern Washington and Oregon Coasts.


Why cooler along the coast?   Because clouds and cool air are moving up the coast, as seen in the recent satellite image.  This is forced by falling pressure in the interior.


The latest forecasts for Seattle indicate today as the warmest day, but the cooling will only be minor during the next few days.


The situation in eastern Washington can only be described as torrid.  Check out the situation at Pasco in the Tri-Cities.  Scary.  Highs running to 112F on Friday.


I have studied Northwest heat waves for decades, and this is a different animal from normal.   

Why different?   Because the warmth is associated with a broad high-pressure ridge of high pressure aloft that is only slowly weakening and moving eastward.  As a result, cool marine air will very slowly move into the interior of western Oregon and Washington over the next several days.

There really won't be a rapid, energetic marine push of cool Pacific air into the west.  And this lazy influx of cool air will allow eastern WA to stay warm into early next week.

The long-term forecast suggests sustained cooling next week.

Comments

Post a Comment

Popular posts from this blog

The Time of Year You Can See the Air Move

Image
  Most of the time, you can not see the air move.   You can feel it, but the complex, turbulent motions are invisible to you, except when it interacts with leaves and branches on trees and plants. But for a few weeks of the year, the sky is full of small, cotton-like tuffs that like a natural MRI machine reveals the complex three-dimensional motions of the atmosphere.   Cottonwood season.  And we right in the middle of it.   Being cottonwood aware is of particular value this year.  It reveals the active dispersion and movement of air that makes the outdoors essentially COVID safe, and thus should be of some comfort for those nervous about transmission outside. Cottonwood seeds are embedded in small cotton-like fibers.   A million seeds weigh about 3 pounds.  Yes, each seed and tuff weights about .000003 pounds.   And that fact, plus the cottonwood tuff, means that these seeds fall VERY, VERY, VERY slowly.   So slowly that they are excellent markers for the three-dimensional flow of the
Read more

Why so little lightning in the Pacific Northwest? And a very nice weekend ahead.

Image
During the past 24-hours, there have been a few lightning strokes over the region (see below) but nothing to write home about (see below). It turns out that the Pacific Northwest and the remainder of the West Coast have some of the lowest frequencies of thunderstorms in the entire country (see below). But why?    My podcast provides the answer. And I also give the weekend forecast....and I think most will like what I have to say. To listen to my podcast, use the link below or access it through your favorite podcast service. Some major podcast servers:     Like the podcast? Support on Patreon 
Read more

Strong Atmosphere River Heads into British Columbia and Southeast Alaska

Image
While the Northwest has been drier than normal, it has been drenching wet a few hundred miles to the north. An unusually strong atmospheric river ....a long current of moisture stretching southward to the subtropics...has been in place for days, bringing large amounts of water vapor to Alaska.   And the atmospheric river will be in place for several more days, slowly moving southward. To illustrate, the scale and beauty of the atmospheric river, here is a water vapor satellite image for 11 AM today. The lighter areas have more water vapor.  You can see the current of moisture extending from near Hawaii into central BC.  This current is the result of low pressure over the Gulf of Alaska and high pressure offshore of California.   A forecast of total water vapor content in the atmosphere for 11 PM tonight shows a healthy atmospheric river (white and blue colors indicate the higher amounts of moisture). As this atmospheric river slams into the mountainous West Coast, the air is forced to
Read more