Cloudy and some light showers moving into western Washington this afternoon as monsoon moisture heads north.
The latest radar images show some light rain (see below). No lightning has been detected at this time.
The latest visible satellite image identifies a medium-to-high cloud from the south rolling in west of Washington. Low-rise clouds on the west side of the Oregon coast.
The NOAA HRRR model, which does hourly forecasts, shows some light rain moving towards western Washington this evening (the forecast of the simulated radar image for 9 p.m. tonight is shown).
Last night was a warm temperature in some locations, represented by last night’s minimum temperature below. Warm locations are found east of the Sound, where temperatures only drop to about 70 degrees Fahrenheit, and on the eastern slopes of the Cascades.
Why is it so warm in some locations? We started with a warm sunny day yesterday, and then clouds came in from the south around sunset. The clouds (and the associated abundant moisture in the atmosphere) act as a blanket, slowing down the normal cooling process at night.
Recently, the Northwest has been the warmest part of the country relative to normal (or climate). The map below shows abnormal temperatures (differences from normal) at around 5000 ft across countries. Dark orange and red indicate much warmer than normal
Our region has the most unusually warm temperatures due to peaks of high pressure and all the moisture from the south.
Tonight, the warm elevated trough will weaken and move to the northeast as an approaching low pressure trough.
The latest NOAA National Blend of Models forecast suggests temperatures in Seattle will drop to around 80F over the next few days (see below). Crucially, low temperatures will drop to around 60F at night. Good for opening windows and resting comfortably.
East Washington will cool off a bit early next week, with the Three-City Cities going from a low of 100 in the mid to well above 90.
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Atmospheric Science 101
Like last year, I’m teaching atmospheric science 101: a general introduction to weather and climate, this fall. You can learn more about the class on class website. I talk about everything from atmosphere basics to weather prediction, thunderstorms, storms, and local weather to global warming and climate.
I will be teaching the class in person at UW, but will also deliver it via zoom. So people can get it remotely.
If you are over 60 years old, you can join the class via Access Program for a very small fee (about $15). Last year, I had over 100 people do so.
If you are a UW student interested in learning about the weather or a student who is not interested in the subject, I welcome you to join me this fall. My first class was on September 28.
