November 15, 2009

Major Windstorm Possible on Tuesday


Well, the next few days is going to bring a range of extreme weather here...and now the U.S. models are locking on a major windstorm on Tuesday. But there are hold outs...the UKMET office model...which just as skillful on average.. and the European Center Model...which is better that the top US model (a terrible embarrassment for us that should not be!)

Anyway, below is the 48-h sea level pressure and wind speed forecasts--a major event if this becomes true. I suspect we will know tonight whether the US or American models are right. Right now we will have to live with some uncertainty.


And don't forget the rain. We will see huge amounts in the Olympics and northern Cascades, some Olympic slopes getting more than 10 inches. Olympic rivers will flood and there is a strong possibility of flood downstream of the N. Cascades (e.g., Nooksack). And even the lowlands could get deluged with several inches.

November 14, 2009

Potentially Serious Olympic Flooding


As noted earlier, a pineapple express event is now setting up, with clouds overhead right now a sign of the incoming warm front that will bring rain starting tonight.

The latest series of forecast model output shows extraordinary heavy rains on the SW side of the Olympics. Take a look at the attached 24-forecast rainfall predictions from the UW WRF (4-km). Just amazing. The first period (ending 4 AM on Monday ) shows 2-5 inches, while the second period (ending 4 AM on Tuesday) indicates area of 10-20 inches! This amount of precip will flood not only the flood-prone Skokomish watershed, but others as well. The North Cascades also gets heavy rain, and the rivers draining from it are vulnerable as well. Green River should be ok for this one....but more is coming.

Warm temperatures will flood our region starting tomorrow. Take a look at the 850 mb (around 5000ft) temperatures on Monday morning at 1 AM--a plume of very warm air with strong SW flow will be pushing straight in. All the nice new snow we got? Its toast---in meteorological speak...it is going to be "consolidated."

And did I mention the winds? Hold on to your hat...particularly on Monday. Winds will reach 50kt+ on the coast and over NW Washington over water...and 20-30 kts with higher gusts elsewhere.

. A serious and threatening event.

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