Friday, November 7, 2008

The Worst Will Soon Be Over in Seattle


We are now in a very warm, wet pattern, with rain falling at all elevations. At Sand Point in Seattle we have a device called the profiler that continuously measures wind and temp above (see figure). Time increases from right to left, the heights are in meters (1500 m is roughly 5000 ft), temps are in red and roughly 15C in the lower atmosphere right now . The winds switched from southeasterly to southwesterly and are now moderately strong.
During the last 24 hr, the lowlands have received 1-2.5 inches, with Sea-Tac getting a little over 2 inches. Shelton and coast roughly double that and exposed windward mountain slopes between 5 and 8 inches. Look at the radar (see below)--the rain now is mainly north of Olympia and there is a wonderful rain shadow. The satellite shows moisture streaming in from off the Pacific, but the tail of this pineapple express appears to have weakened (see photo). The National Weather Service has flood watches out for a number of rivers of the Olympic Peninsula and north-central Cascades.

You can think of this pattern like a hose, one that shifts north and south in time. Computer models indicate that the hose will shift a bit north today and the rainfall should back off this afternoon...so I suspect the worst will be over here by midday. Then we will enjoy intermittent showers with some breaks. A cold front comes through late tomorrow...rain will pick up with it, but after its passage we will definitely be in the shower regime. Temps will cool and the higher mountains will be back to snow. Sunday and most of Monday will be a break...but we will be in an active pattern next week after that. This IS November.

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