Wetand News

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

If it were only a bit warmer, we might gators around here.  After incessant rain, grass is like mush, water is ponding and accumulating everywhere, landslides have started, the rivers are flooding, and the aroma of wetness is everywhere. A typical scene in North Seattle Western Washington is more like a swamp than a high-tech center, and much, more precipitation is coming.   A little over a month ago, some folks were talking about a progressive drought for our region.  The drought talk has ended. Some amazing statistics were noted by my colleagues at the National Weather Service this morning (see below)---nearly every day this month has rained and a number of observing sites will break their all-time record for number of days with rain in January.  Quillayute, Hoquiam, and Olympia will all beat the record, Seattle may tie it. And the rain totals have been extraordinary as well.  Quillayute, on the NW coast, has received 22.63 inches so far this month, 9.31 inches above

During the next few weeks, leadership in NOAA (the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) will make a key decision regarding the future organization of U.S. numerical weather prediction.  A decision that will determine whether U.S.  weather forecasting will remain third rate or advance to world leadership.    It is that important. Specifically, they will define the nature of new center for the development of U.S. numerical weather prediction systems in a formal solicitation of proposals  (using something called a RFP--Request for Proposals). This blog will describe what I believe to be the essential flaws in the way NOAA has developed its weather prediction models.  How the U.S. came to be third-rate in this area, why this is a particularly critical time with unique opportunities, and how the wrong approach will lead to continued mediocrity.  I will explain that only profound reorganization of how NOAA develops, tests, a

Sometimes the precipitation contrasts in our area can be mind blowing, and today was such a day. During the past 24-48 h, we have observed extremely heavy rain on the southwest side of the Olympics, with a super-rain shadow to the northeast. Below is total precipitation over the past 48 hours (ending 7 PM Thursday). Remarkable . On the southwest side of the Olympics, totals are as high as 9.45 inches , while just downstream of the barrier on the lee side (the Port Townsend area) one site only received .01 inch. Let me put it another way.  There was nearly one thousand times more precipitation on one side of the Olympics than over the other.   With huge differences in rain over very small differences. You will notice that precipitation was relatively low from Seattle northward to the San Juans and then picks up substantially on the western side of the Cascades. This pattern was evident in regional weather radar imagery, with the view at 7 PM Wednesday night providing a

One coast has a weather radar, which facilitated warning of a potential tornado. The other coast had no radar coverage, allowing a tornado to strike without warning. Yesterday (Tuesday), very unstable air mass with strong convection (thunderstorms) made landfall on the Northwest coastline.  The visible satellite image from the NASA MODIS satellite around noon showed lines of strong convection approaching the Oregon/Washington coast (see below) Why so active?  Cold air was moving over water water, which created a large temperature change with height that in turn produces substantial instability--the tendency of the atmosphere to convect. Roughly an hour before this satellite image, a funnel cloud was observed off of Manzanita, Oregon (on the northern coast) and around 11:15 AM it made landfall as a tornado, causing minor damage.   No tornado warning was provided.  This was a weak tornado:  an EF-0 with winds gusting to 65-75 mph. One reason there was little warning, is

Folks around Bellingham have been noting some wild temperature swings, with temperatures warming by 15-25F over an hour or two, before dropping back to the previous level. These features, known as "temperature spikes" in the weather business, are frequently noted in certain areas of the  Northwest. Let me illustrate what happened by showing you the temperatures at Bellingham during the past few days (see below).   On 14th and 15th temperatures were in the teens, as uber cold air from the interior of British Columbia, pushed through the Fraser River Valley and then over Bellingham and northwest Washington.  Temperatures slowly warmed on the 16th.  But suddenly over one hour, temperatures surged 20F to 45F.   Instant defrost.    But then temperatures dropped just as suddenly two hours later, back to the low 20s.    Startling. On the 17th temperatures dropped back down to 15F and everything froze solid again. But that would not last long. First, temperature rose rapidly to

This has been a hard week for meteorologists, with multiple threats of cold and snow.  Some aspects of the forecasts worked out, some did not.    For example, Seattle Public Schools cancelled classes, but the predicted snow did not show up.   I have gotten a number of emails asking:  why were the snow forecasts so good last February, but not so good this time around? > January 6 and > January 7 if you need proof. The mountains did get massive snow, it did get colder, and the lowlands would get some snow. >my blog discussing the situation.    To illustrate, here is the ensemble of many model snow forecasts for that period for a location in Seattle (North Seattle near Magnusson Park).  HUGE variation in forecasts from very little to six inches.  Uncertainty was large.  We need to communicate this better. And the fact that the high-resolution  models started backing off for Seattle snow after 6 PM was another sign of non-event over the city.  What Seattle Schools

A month ago, there were considerable concerns about the Northwest snowpack.  True, mid-December is too early to get worried, since there is a long history of poor December snowpack leading to bountiful snowpack by April 1.  But snowpack was sparse in December and folks were nervous.  Below is the snowpack summary from the SNOTEL network on December 14, 2010. Not good.  The Olympics and western slopes of the Cascades were at roughly 33% of normal, as was the eastern slopes of the central WA Cascades.  Only a small portion of the region (mainly SE Oregon) was at normal or above (green and blue colors). Fast forward to this morning (January 16th).  Wow.  No more red colors (less than 50% of normal) and most of the region is green.  Huge improvement. The meteorological bounty extended beyond snow.  There has been lots of rain that has helped to fill local reservoirs.   For example, consider Seattle's reservoir system (see below).  Its reservoirs have surged--not only WAY

The latest model output supports the threat of serious snow tonight for our region. The UW's highest resolution forecast model shows substantial regional variations, with the heaviest lowland snow from Seattle northward, with far less over Tacoma.    But there is uncertainty on the exact location of the snow band...so keep that in mind.  Seattle will face 2-5 inches if this forecast is correct.  Road temperatures are now near freezing...so this is going to stick in places where SDOT and WSDOT have not pretreated or where plows are not active. The very latest NOAA/NWS HRRR forecast (made hourly!) has a similar pattern but only about 1-2 inches over Seattle (see below).  This even does not have the strength to give us mega snow event (8 inches plus, but it will be more than few days ago for many. The official National Weather Service totals is for 2-3 inches over Seattle, which is quite reasonable.