Wetand News

Update: The situation does not look as favorable now.  The clouds have made it up to central Puget Sound (see below) and the DSCOVR satellite is not picking up the expected influx of particles.    Not as skillful as weather prediction!  _____________________ Folks in the northern half of Washington State may well see an impressive auroral display tonight. A major Coronal Mass Ejection (CME) on the solar surface has resulted in a flux of particles moving into the earth's magnetic field. A measure of the disturbance of the earth's magnetic field is Kp:  auroral activity moving southward into our area generally requires Kp of 5 or more.   The estimated value right now is 6. And the predicted peak value is 7 between 8 and 11 PM tonight (see below) The weather tonight should be relatively clear in northern WA state and southern BC (see visible image below), but some cloud debris from thunderstorms/showers now in northern Oregon may mess up viewing the southern part of WA state. Here

 There is a good name for it:   a SuperMonsoon. In my previous blogs, I talked about the nature of the Southwest (or North American) Monsoon, and how water vapor from the Gulf of Mexico swings around a high-pressure area into the Desert Southwest from June to August. As a result, the southwest U.S. is usually MUCH wetter than the Pacific Northwest during mid-summer. The Southwest Monsoon has been particularly active this summer with lots of thunderstorms and an unusual westward and northward penetration of moisture. Take a look at the percent of normal rainfall during the past month.    Wow.  Some areas (Nevada and southwest California) have been hit by over 800% of normal rainfall.  Folks needed an umbrella in Las Vegas! The past week has been particularly wet, with large amounts of monsoon moisture pushing into eastern Oregon! (see below).  Much of that precipitation was associated with lightning, causing several fires. This summer's monsoon has been associated with unusual amou

This has been a particularly smoke-free summer so far over the entire West Coast, and to appreciate our clean-air bounty, let's compare satellite imagery between this afternoon and a year ago. Yesterday's MODIS visible satellite image shows smoke-free skies over nearly the entire western U.S., with two exceptions:  a very small fire west of Lake Chelan and a modest smoke area in northern CA.   That is about it! Compare that to the smoky miasma of exactly one year ago.  Yuck!  Smoke everywhere!  The air quality data provided by the EPA in their AIR NOW network shows the story on the ground.  This year, nearly all sensors indicate good (green) air quality.  You can breathe freely in virtually the entire West. But last year on the same date lots of yellow and reds (poor air quality), particularly over eastern Washington and northern California. Finally, looking forward in time, here is the  NOAA HRRR model smoke forecast for today at 5 PM.  This shows the total smoke in a vertical

This has been a very benign wildfire season so far this year, with far fewer than normal wildfires over the western U.S., with considerably less than normal area burnt (see figures below). Number of wildfires by year:  WA DNR area The area burned by year:  WA DNR Area The area burned by year, California. But we can not become complacent!    Historically, the most threatening wildfire season in the Northwest is the end of August and early September as the atmosphere starts to cool. But why?  What is so threatening about the cool late summer/early autumn periods?  All is revealed in the podcast. And I also provide the forecast for the next week.  Very pleasant in the west, but a bit toasty in the east.  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 movement of moist, unstable Southwest Monsoon air into the Northwest did not disappoint: as shown by the 24h lightning map ending 1 AM this morning, many hundreds of lightning strokes were observed over the region. There were several bands of thunderstorms and lightning.  One was along the coast and another moved up eastern Oregon and really hit hard around Walla Walla and far SE Washington.   A narrow band of boomers crossed Tacoma into Vashon Island. The monsoon moisture plume...directed from the desert southwest..was evident in the water vapor satellite image from yesterday morning (5 AM Wednesday) The dew points...a good measure of atmospheric water vapor content--were very high over eastern Washington, getting up into the mid-60s in portions of eastern WA, eastern Oregon, and Idaho (see below for noon on Wednesday).  That's unusually high for the normally dry region.  Today the moisture plume has slowly shifted eastward (see satellite image from tonight). As a result, the

 Welcome to monsoon season in the Northwest! Showers spread northward from Oregon this morning into Washington State (see radar at 6:30 AM this morning below).  Generally only a few sprinkles, but it was nice change in any case. The moisture is associated with a plume of water vapor coming out of the southwest---a northwestern extension of the Southwest Monsoon (also called the North American Monsoon). The water vapor satellite image this morning shows the moisture plume as does the infrared satellite image. The Southwest Monsoon occurs every summer from roughly late June through late August.    It occurs as high pressure tends to build over roughly the New Mexico area, resulting in moisture being swept up from the Gulf of Mexico, across Arizona and western New Mexico, and then up across Nevada into eastern Oregon (see schematic below, showing upper-level heights at 500 hPa (you can think of this like pressure at 18,000 ft).  The white area shows the direction of the flow at that level

 Climatologically, we are now moving past the climatologically warmest time of the year, as the weakening sun and shorter days finally start taking their meteorological toll.  And during the next few days, we will experience substantially warmer than normal high temperatures, but comfortable temperatures at night.   But on Wednesday, both cooling and showers will move in, with the side benefit of helping to get control of a few local wildfires. The visible satellite image this morning shows clear skies, but some smoke from the Vantage grass fire, and the northern extent of a lightning-caused fire in the central Oregon Cascades (the Cedar Creek Fire).  There is also a small fire in south-central BC. The warmth today and tomorrow will be associated with the northwest extension of an upper-level ridge over the Northwest (see upper-level map for 5 AM Monday, below).  But pay attention to the deep low west of northern California. It has our name on it. By Wednesday at 5 PM, the low will app