November 13, 2009

Convective snow over the higher lowlands


There is snow falling in convective showers tonight. The air aloft is cool and heavy showers can drive the snow level down to the surface due to evaporation and melting.

The latest radar shows a strong band over the northern Sound...this is not your classical PS convergence zone, but rather a secondary convergence zone in the lee of Vancouver Island...something we don't talk about much. There is convergence and resulting upward motion between northerly flow moves southward down the Strait of Georgia and westerly inflow through the Strait. Check the wind plot below to see this.

7 comments:

  1. Beautiful plot... no snow here at 210' in East Bellevue... I'm OK with that!

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  2. We still have some rimy, frozen hail on the ground in north Kirkland from last night. A few flashes of lightning around 6:30pm last night, too.

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  3. A slight dusting of icy 'snow' here on Crown Hill.

    There were fantastic cumulonimbus glowing in the weak twilight as I drove home last night. Very impressive and beautiful.

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  4. it was absolutly white with frost here in chehalis this morning.

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  5. Here 3 miles south of Chehalis on a ridge we got an unexpected first frost that put ice on our ramp and deck. Only other frost this year was Oct 13, which did not kill any of our veggies or flower. Singed the Dahlias.

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  6. For those interested in the latest on El Nino since its implications on western weather are well known, I wrote about it recently.

    http://cloudyandcool.com/2009/11/07/el-nino-strengthening-winter-forecasts/

    Paul

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  7. wow, tonights GFS model is trending towards a stronger surface low. It has 50+ knot surface winds along the oregon coast. Very orographic event. Cliff, this will be a great storm to be analyzed afterwards, especially to see how the 4km domains performed with all the micro events.

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