Wetand News

There has been a lot of discussion about heavy rain and flooding around the Northwest, but one region really stands out, with river levels and flooding unmatched in many decades, if ever:  the region on and near the northwest side of the Blue Mountains of northeast Oregon. Walla Walla River from Hwy 12 Provided By Kevin Pogue of Whitman College Walla Walla River Provided by Kevin Pogue To orient you, a topographic map of the region is shown below.  The Blue Mountain's slopes on the northeast side are oriented southwest to northeast--that is going to be very important in understanding what happened a few days ago.  Heavy rains on these northeast slopes flowed into rivers heading to the northwest, bringing most to flood stage and some to record flood levels not observed in a century.  I-84 and other roads were closed in places. I-84 West of Baker Oregon The rainfall totals for this precipitation event were extraordinary: some places received nearly 10 inche

If you picked up the Seattle Times on Wednesday, you would have seen at the very top of the front page a reference to an article "Why your weather apps isn't very good" ______________________________________________________________________ __________________________________________________________________________ Heading to the article, you learn you can't necessarily trust your smartphone weather app, that one should go "straight to the source" and use the National Weather Service forecast, and that weather apps  “ don’t factor in that we are sandwiched in between mountains and the very warm Lake Washington and the warm Pacific.” ________________________________________________________________________ __________________________________________________________________________ Unfortunately, most of the information in the Seattle Times article was simply not true.     The truth is that many of the leading weather apps available on yo

The murky, wet conditions during the past few days are some of the worst I have seen in years for February in our region.  Unbelievably dark and wet.  For example, below is the view from the SpaceNeedle PanoCam around 9:30 AM today (left) compared to four days ago.   It was like the city was not there. And, of course, there is the heavy rainfall along the western slopes of the Cascades that is producing flooding and landslides. The origin of all this water is a moderate atmospheric river that is coming from an unusual direction. An atmospheric river is a narrow current of warm, moist air from the tropics and subtropics that extends northward into the midlatitudes.    A NOAA satellite two days ago, shows the tongue of moisture passing northwest of Hawaii and then bending eastward toward the Northwest. A model simulation of the water vapor added up in the vertical (known as column-integrated water vapor) for 4 PM Wednesday shows the tongue of moisture reaching

I have to admit, I am still a kid at heart when it comes to snow. Well, snow is now reaching the ground around Puget Sound. The National Weather Service has an app that allows folks to report their weather conditions (MPING) and latest download shows a number of folks reporting snow: And snowflakes are being reported at a number of airport locations around the area. A Pacific weather system reached our region this morning and at first the snow was aloft and then subsequently extended to the surface, with sublimation/evaporation of the snow causing sufficient cooling to allow snow to reach the surface in places.  Near the warm water and close to sea level, only light rain is being observed. The surfacing of the snow was really dramatic from the Seattle Space Needle PanoCam....let me show you.  The first image is at 7:55 AM, the last one is 10:30 AM In the first images, did you notice that the cloud bases are fuzzy and indistinct? When you see that, you know th

Tuesday is going to be a day of great contrasts in the Northwest, and particularly west of the Cascade crest. It will start off cold--in the lower 30s-- with overcast skies. As the clouds thicken, light snow could fall during late morning or early afternoon over some of the western lowlands.  Nothing to worry about. The temperatures will rapidly warm and the snow will turn to rain during the afternoon And then the rain will get steadily harder, while the winds increase and turn blustery. Cold, snow, rain, wind, followed by warmth.   All the basic food groups of Northwest winter weather.  What a wonderful place to live! Tonight, a plume of clouds and moisture is approaching our region (see below). In this blog I will show you a new graphic from the UW high-resolution modeling system.  One that shows precipitation, but separates wet stuff into rain (gray scale) and snow (colors).  Very educational. At 10AM tomorrow, rain is just reaching Puget Sound, where marginally

After a period of wet conditions with far above-normal temperatures, much cooler air is flooding into the region behind a Pacific cold front. The latest visible image from the GOES-17 satellite clearly shows the story, with the long cloud band of the front  just starting to exit western Washington, while cold, unstable air (indicated by energetic convective activity--indicated by the popcorn looking clouds) is found offshore. The current weather radar imagery below, illustrates the weakening remnant of the frontal precipitation, now over Oregon.  Behind the front, a Puget Sound Convergence zone has formed north of Seattle.  You can see some of the cold, instability showers moving in over the coast. This cold, unstable air mass, with lots of convective showers, should drop the temperatures by 10-20 degrees during the next day....already temperatures around western Washington are in the 40sF, after climbing into the mid 50s yesterday.   The snow level will decline to roughly

There will be plenty of action during the next week---more than I can possibly describe in this blog. We start with a modest atmospheric river--a plume of enhanced low-level moisture--aimed at our area on Friday and early Saturday (see below), bringing substantial rain to the Olympics and north Cascades. Atmospheric moisture early Friday evening, reds and white indicate high values--the  atmospheric river This atmospheric river will result in substantial rain over the next 48h, as shown by the figure below (accumulated precipitation through 4 PM Saturday).  Over 5 inches over the upper windward slopes of the Olympics and north Cascades.   Much less rain in the lowlands, with a dramatic rainshadow centered south of Port Townsend.  This is not a record-breaking rain event, but typical of the stronger ones we have several times a winter. This rain is falling on saturated ground and flowing into rivers that are already high.  The past 72 hr have been quite wet over the sout