Why so much lighting for this event? Certainly, the record breaking amounts of atmospheric moisture streaming into the area the previous two days are prime candidates. Large amounts of moisture act like "fuel" for thunderstorms, since as the air rises in the cumulonimbus clouds, the moisture condenses, releasing latent heat, which makes the air more buoyant.
Another measure of the intensity of the thunderstorms yesterday were their heights. Typical thunderstorms around here usually rise to 15,000-20,000 feet at most. Wimpy stuff. But yesterday, several of the storms climbed to over 40,000 ft, as shown by the echo-top radar product shown below.
One of my graduate students went to the University of Oklahoma and even he was impressed. Torrential rain fell out of some of the more intense cells. In Auburn, 1.3 inches of rain fell in less than two hours. That is a deluge.
Well, the thunderstorms are over now, and light rain is moving in associated with a (typical) Pacific front. Oh well...
Finally, for the skiers in the crowd, the NW Avalanche Center is having their annual fundraiser, this time for improving mountain weather stations. More information here. And if you want to join local weather lovers at the Puget Sound American Meteorological Society meeting, check below.
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On Saturday May 6th, Larry Schick, lead meteorologist for the US Army Corps of Engineers in Seattle, will talk about Flood Risk Management and Atmospheric Rivers in Western Washington at 3pm at the Seattle Public Library Montlake branch, 2401 24th Ave. E., Seattle, WA 98112, http://www.spl.org/locations/m
North Tacoma had an incredible amount of rain, around 5:30 pm, in just a half-hour or so. Within a few short minutes our lawn was under water and we had water pouring in under the doors. We face due west, over the Narrows. It was extraordinary. Does anybody know how much rain fell during that deluge?
ReplyDeleteBernadette
We missed out in north Whatcom County. Was so looking forward to a genuine thunder & lightning storm, but it fizzled out before reaching us. Wind picked up slightly around 5pm, a few ominous booms now & then and that was that.
ReplyDeleteCliff, just wondering how the lightning strike map is recorded? Presumably it's done via satellite, but could you say a little more about how that works? What is actually being detected or measured?
ReplyDeleteThanks.
Alistair Spence,
Wedgwood, Seattle.
Bernadette; A civilian observer (CW1002) near N. Vassault St. and N. 50th St. recorded rain starting at approximately 4:45 pm. At 5:24 the gauge was up to .42 inch, but by 5:39 it was .90 inch! Texas type numbers for awhile for you folks in Tacoma.
ReplyDeleteCurious how there are strikes out over the Pacific, but hardly any over the Sound. You can almost trace the shoreline.
ReplyDeleteImaging artifact. The blue layer is on top, obscuring the red. Look closely at the coastline, Columbia river, even the Canadian border and it becomes clear...
DeleteOn the lighting map there are + and - , what do those denote?
ReplyDeleteI slept outside under my porch so I could watch. It was like old times back in Connecticut. As cliff says, there hasn't been anything like this in years.
ReplyDeleteFor a point if comparison it would be interesting to see a "normal" Seattle lightning strike map.
ReplyDeleteAnyone notice the very unusual convergence zone at 5:50pm Friday... it starts in Discovery Bay and crosses Admiralty Inlet to end up near Bellingham. Never seen a strong CZ this far north. Outside of Puget Sound in the Strait.
ReplyDeleteYes!
DeleteIt poured! Well over an inch in my rain gauge near the Admiralty inlet. Largest single rain event we have had since March I would guess.
Admiralty inlet gets in caught in the "normal" east/west CZ at times, but this one was weird, so North/south in orientation.
Yes, please do a post on the lightning map. Compare to a "usual" thunderstorm in the Puget Sound.
ReplyDeleteAs for the big event, Glacier WA witnessed two full hours of lightning between clouds with loud, near continuous rolling thunder that echoed through the mountains (about 6:20 pm through 8:20 pm). The event was so (pardon the pun) striking that I made some short audio recordings, but they're dominated by the sharp patter of rain. I may do some audio editing to isolate the thunder which was awesome (I'm originally from Pennsylvania).
ReplyDelete