Wetand News

The media was abuzz last week with stories about a greatly increased threat of a massive flooding event along the West Coast, termed an ARk Storm.  The immediate stimulus of this apocalyptic vision was a r ecent paper by Xingying Huang and Daniel Swain in the journal Science Advances . This article suggests that global warming has already substantially increased the probability of West Coast catastrophic flooding events and that the potential for such flooding will be profoundly enhanced by the end of the century. In this blog, I will describe some serious problems with this study, which greatly overstates the threat.  And I will show you the actual trends of heavy, prolonged precipitation. What is an ARk Storm? This term denotes a record-breaking, extended, unimaginably heavy precipitation event along the West Coast (mainly California) that produces catastrophic flooding.  It represents a dual play on words. First, the story of Noah's ark in the bible, with global flooding after

 Even with cool temperatures this weekend, the specter of more warmth is on the horizon. But is this the end of the threat of real warmth in our region?    Let's start with the forecast.    Another ridge of high pressure will build over the West Coast on Monday and Tuesday, as illustrated by the upper level (500 hPa pressure, about 18,000 ft) map for Tuesday at 5 PM.  The red indicates higher than normal pressure, the blues and purples below normal (troughing. The latest National Weather Service National Blend of Models temperature forecast for Seattle indicated highs in the upper 80s on Tuesday and Wednesday before an extended cool-off to more seasonal temperatures around 80F.  Importantly, lows will reliably decline into the 50s, ensuring a good night's sleep. As apparent to all of you, the nights are getting longer, the days shorter, and the strength of the sun's rays is ebbing.   Eventually, we simply won't be able to get into the 80s and 90s anymore.    But when? 

  My podcast today starts with a very pleasant weekend forecast, with temperatures in the west in the 70s; 80s over the Columbia Basin.   But one more warm period is ahead, with highs climbing into the mid-80s by mid-week. The latest forecast for Seattle shows probably the last upper-80s temperature period for the rest of the year. The second half of the podcast is about microclimates--with large temperature variations in short distances.  I provide some dramatic examples from last week and tell you a bit on how they occur. 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 

 The latest NOAA map of coastal water temperatures along the southern Washington coast shows temperatures above 61F (16C)...see below.  Cooler water is found along the Oregon and California coasts.  Much warmer water is found offshore.  At Ocean Shores or Long Beach, you could almost go into the water without a wetsuit. How do these temperatures compare to normal?  Below are the anomalies (differences) from climatology (or normal conditions) of the sea surface temperatures. Warmer than normal by 2-3C along the coast and the warmth extends offshore. Cooler than normal along the California coast. Before I explain why, I wanted to mention that late August is the time of typically warmest temperatures along our coast.  To illustrate, here is a plot of climatological sea surface temperatures at Ocean Shores, WA from the excellent website, Weatherspark.  The typical highest ocean temperature is on August 28th at 58F, compared to the lower 60s today. So why are water temperatures warmer tha

 There was quite a lightning fest east of the Cascade crest today, with an impressive vortex of thunderstorms producing massive amounts of lightning. The lightning flashes for the ten minutes ending 5:20 PM  tonight were amazing (see below, with clouds shown as well), with lightning circling around the vortex centered near Omak, WA.  Just wow.... The visible satellite image a few hours earlier shows the vortex and the numerous associated thunderstorms (each producing a blob of clouds). These thunderstorms produced more than lighting, as illustrated by precipitation totals for today (Tuesday)...see below.  Some locations got over a half inch....a lot with a tenth of an inch or more. The origin of this impressive vortex of clouds and lightning is an upper-level low.   Below is the map of 500-hPa heights (like pressures at 18,000 ft) around 5 PM (the winds are shown as well).  The low is centered near the WA/Canadian border, northwest of Spokane. This low is not going anywh

If the nation is going to deal effectively with anthropogenic global warming, citizens must be provided with accurate information about the climate and how it is changing. Unfortunately, the Seattle Times does not believe in communicating the facts but frequently provides deceptive, false, or exaggerated information.    Last week, a story-- These areas of WA are likely to get hotter--but people keep moving there- - is a good example of the kind of problematic "journalism "coming out of the Seattle Times.  I will show you the deceptions in my blog below.  Perhaps it takes a magician to show you the details of the deceptive "dark arts" of another.  How information can be presented in a misleading way. The claim of this Seattle Times story is that there is an influx of new residents into areas (Tri-Cities) that will see a lot more severe heat waves during future decades. How foolish of them!  is the implied message. The material in the article is not from some peer-re

After a week of warmth and humidity, temporary relief is here...at least west of the Cascade crest. My podcast starts with a very pleasant forecast for the next four days over the western lowlands, but with a note about increased heat mid-week (see forecast temperatures for Seattle below). East of the Cascades, temperatures will hover around 100F (see forecast for Tri-Cities below) In my second segment, I talk about humidity in the Northwest.  Why was it so sticky last week?  What controls our humidity? All is revealed in the podcast. 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 

  There are clouds and a few light showers moving into western Washington this afternoon as monsoonal moisture heads northward. The latest radar image shows some of the light rain (see below).  No lightning is being detected at this time. The latest visible satellite image defines the plume of middle to high clouds from the south entraining into western Washington.  Low stratus clouds are west of the Oregon coast. The NOAA HRRR model, making forecasts every hour, shows some of the light rain moving up into western Washington tonight (the forecast of the simulated radar image for 9 PM tonight is shown). Last night was a warm one at some locations, as shown by the minimum temperatures last night below.  The warm locations were found on the east side of the Sound, where temps only dropped to around 70F, and on the eastern slopes of the Cascades. Why so warm in some locations?  We started with a sunny, warm day yesterday, and then the clouds streamed in from the south around sunset.  Cloud