Sunday, March 11, 2012

Moist, Mild Week Ahead, With a Return to Winter Next Weekend

A gradual shift in the large scale jet stream pattern will be taking place this coming week.  Several disturbances will be tracking onto the west coast accompanied by a moist and mild air mass for the next several days.  The first one now moving into the Pacific Northwest will only have a minor affect on Star Valley.

500 mb Analysis Sunday Evening 03/11/12

Some light rain and snow will spread across the area Sunday night, with no snow accumulation expected in the valley as temperatures remain near or above freezing.

While precipitation the next several days will be possible in a moist westerly flow off the Pacific, the strong jet stream will not impact the area until the end of the week.  This series of 300 mb forecast charts display the progression of the jet and its amplification by this coming weekend.

Forecast 300 mb chart noon Tuesday 3/13/12

Forecast 300 mb chart noon Thursday 3/15/12



Forecast 300 mb chart noon Saturday 3/17/12

By the end of the week the air will cool sufficiently as the trough develops into the western states to bring snow back to the floor of Star Valley.  Heavy amounts of snow are likely by the end of the week in the mountains.  It is still too soon to determine if the valley will also receive heavy snow, but the pattern needs to be watched as there will be considerable potential with the jet driving inland to the south of our area.  The models  forecasts  significant amounts of precipitation over the western states from Tuesday to Saturday.

Accumulated Precipitation Tuesday-Saturday March 13-17 2012

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