Wetand News

 There are a number of humans that don't believe that summer will ever end.   But the birds know that fall is here. Last night, the weather radar showed an explosion of radar returns over land around sunset.  Many birds prefer to fly after sunset---safer that way. Here is a composite of several radar sites at 7:30 PM last night (Tuesday) before the sun set.  Not much to see. And here is the image at 10 PM.   Wow...lots of birds.  You notice they don't like to fly offshore!   Modern Doppler radars provide wind velocity (actually the velocity of targets like precipitation) towards or away from the radar.  But last night there was no precipitation but plenty of birds.  And radar really picks up birds...they appear like giant raindrops. Here is the velocity towards or away from the Langley Hill radar near Hoquiam.  Green indicates approaching birds and yellow/orange birds moving away.  These birds are moving south! There is a very good website that shows bird migration based on rad

 Satellite-based sensing has become an important tool for determining wildfire intensity in real time. And the latest satellite data suggests a profound lessening of the Bolt Creek fire on US 2 near Index. Many weather satellites have sensitive radiometers that can sense the heat emitted by wildfires.  The Bolt Creek fire really was apparent in satellite imagery over the weekend, but today there is no obvious heat signature (see below).  No orange/red dot. The infrared satellite image tonight shows no black dot  (black indicates warm temperatures in such imagery). The visible satellite picture had an unimpeded view of the Bolt Fire area before sunset.  There is still some smoke (which means some low-level burning remains), but nothing like a few days ago. Conditions have become MUCH more favorable for suppressing the fire.  Some rain fell on the fire yesterday.   Importantly, the strong easterly (from the east) winds that stoked the fire initially are gone, replaced by weak winds from

 Air quality is rapidly improving west of the Cascade crest as the easterly (from the east) airflow has been replaced with southerly (from the south) winds aloft.    And the change of wind direction and increased humidity should allow rapid control of the Bolt Creek fire near Route 2.   This morning clouds and wildfire smoke is found aloft over our region...and you can thank California for much of that! First, the air quality situation. The latest AIRNOW map shows good air quality on the southwest Washington coast (green) and moderate levels (yellow and orange) around Puget Sound.  Poor air quality is found near the Canadian border, but that should blow north during the next few hours.  Air quality is only slightly high over the eastern slopes of the Washington Cascades....unfortunately, that may worse during the next day. You can get a better idea of the trends of air quality (actually concentration of small particles--PM2.5) from a plot courtesy of the Puget Sound Clean Air Agency. 

  The feared occurrence happened .  A major new fire is growing rapidly on the western slopes of the central Washington Cascades.  Now known as the Bolt Creek fire, this human-initiated fire is being stoked by strong easterly winds and low relative humidity.   And the huge smoke plume is headed towards Everett and the north Sound. Take a look at the latest visible satellite imagery (for around 12:30 PM).  You can see the smoke plume from the Bolt Creek fire...heading northwest directly over Everett.  To the south, the large Cedar Creek Fire in the central Oregon Cascadses has spread smoke northwest towards the Long Beach Peninsula.    That smoke will move northward over central Puget Sound by dinnertime. The Bolt Creek fire formed overnight when very strong easterly winds developed.  No lightning, so this is human-initiated.  The fire is so vigorous that it has a pyrocumulus right over it (a thunderstorm-like deep convective cloud forced by the fire) and is even apparent in the Camano

 My podcast today has a lot of territory to cover:  smoke spreading over western Washington, warm temperatures, and strong easterly winds creating substantial wildfire danger over Northwest Oregon. The visible satellite picture this morning shows the smoky story for western Washington, as smoke from fires on the eastern slopes of the north Cascades is pushed westward by increasing easterly (from the east) winds aloft. The smoke layer tops out around 6-7 thousand feet, as evident from Crystal Mountain 360 cam this morning. Air quality started fine this morning over western Washington, but is rapidly declining as the solar heating of the surface causes vertical mixing that eventually reaches the smoke layer and brings it down to the surface (see Purple Air air quality map around 2 PM below, red and purple colors show the worst conditions, green is clean air.). The other issue is the potential for wildfires over NW Oregon as strong easterly winds are occurring over the region.  Here are t

Western Washington has avoided serious smoke throughout most of the summer, but that is going to change tomorrow, as hazy skies, red suns, and degraded air quality move west of the Cascade crest. The current visible satellite image shows a substantial plume of smoke moving southeastward from a collection of fires over the north Washington Cascades (I put on an arrow indicating the plume) Right now, eastern Washington is getting smoked up, but later today the weather pattern will change, with easterly (from the east) flow moving into Washington State.  As a result, the smoke plume will rotate and head southwestward towards Puget Sound. Let me now show you the smoke prediction from the NOAA HRRR smoke model. I will first present the vertically integrated smoke prediction, essentially summing up the smoke in a vertical column of air.  Smoke at the surface will be less.  But this is a good measure of how smoky the sky will appear. At 5 PM today, most of the smoke will be east of the Cascad

There is a serious wildfire threat for western Oregon and southwest Washington on Friday and Saturday. Not the equal of September 2020, but serious enough that we need to be careful. This blog will describe the situation. Historically, major wildfires west of the Cascades crest occur in August and September for two reasons.   First, the surface "fuels" are dry after our typically arid summers.   Second, this is the season of strong easterly (from the east) winds as cool air --and associated high pressure--begin to move into the continental interior. Air accelerates from the interior high pressure towards lower pressure along the coast.  Strong easterly winds dry as they descend the western slopes of our regional mountains.  Strong winds can initiate fire and stoke it. The USDA Forest Service created the Hot-Dry-Windy (HDW) index, which correlates strongly with fire growth.   This index is essentially wind speed times a measure of dryness (called Vapor Pressure Deficit, VPD).