Big Coastal Storm Late Wednesday

11pm Tuesday…

January, February, and this first week of March have been very quiet weatherwise.  But one very strong storm is developing to our southwest.  It’s going to be a classic “southwester” as the deepening surface low races almost straight north along the 130 west longitude line.  Typically for a widespread windstorm in our area we need a deep low to move along this track EAST of that line, so this one will be pretty far out.  But it’ll bottom out down around 970 millibars as it moves towards Haida Gwaii or the northern tip of Vancouver Island.  That’s a strong storm and one capable of giving widespread 65-75 mph gusts at the coast.  I wouldn’t be  surprised to see an isolated spot or two (not Mt. Hebo or Meares Hill) around 80-90 mph.MarkWarnings_Wind_Coast_Valleys

After a strong easterly Gorge wind in the morning (gorge and east metro), a southerly pressure gradient will set up in the Willamette Valley in the late afternoon and evening.  That’s when wind will pick up in the Valley.  I sure don’t expect a damaging wind in the valley, but breezy and rainy for the evening

MarkWarnings_Wind_Coast_Valleys2

One would think that we could get a decent windstorm with the extremely strong wind overhead tomorrow night.  The WRF-GFS cross section shows 90 mph wind over Portland around 10pm-1am tomorrow night; one of the only times I’ve seen an 80 kt. wind barb overhead.

wrf_sounding

But the isobar orientation is not lined up correctly down here at the surface since the low is way offshore.  Thus the wind won’t get too strong.  It would be a totally different story tomorrow night if we had a strong south to north pressure gradient in the western valleys.

Chief Meteorologist Mark Nelsen

10 Responses to Big Coastal Storm Late Wednesday

  1. Looks like this storm is coming along faster than forecasted: Rain began falling here at about 2:25pm- the forecast for Vancouver BC said it would begin in the late afternoon. Fairly breezy winds now too.

  2. Hal in Aims says:

    gusting to 90 at Mt. Hebo………

  3. W7ENK says:

    I guess the NWS is expecting this storm to push a little closer to the coastline now??

    WIND ADVISORY
    NATIONAL WEATHER SERVICE PORTLAND OR
    249 AM PST WED MAR 9 2016

    WINDS: SOUTH WINDS 20 TO 30 MPH WITH GUSTS UP TO 50 MPH.

  4. Paul D says:

    Power outages!!!

  5. runrain says:

    I’ll bite! Love a good wishcast. How about a few gusts to 60 around 10pm with an occasional blue power flash to light up the night. I’m in!

  6. I guess there’s technically still time for some last-minute “Wind Wishcasting” in terms of moving the low closer to the coast. Anyone want to try???

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