Pattern Change Leading to Drier end of November

Pattern Change Leading to Drier end of November

Star Valley/Western Wyoming for the first three weeks of  November has been colder and wetter than  normal.  Over 3 feet of snow has fallen at Star Valley Ranch with a similar amount near Smoot  at the upper end of the valley.  The Numerical forecast  models are in agreement that the storm track which has been through this part of the country will be shifting back to the north the rest of the month. With the exception of a fast moving low pressure system that will move through late Thanksgiving day and Friday, it now appears that high pressure will be in control for the remainder of November.

Wednesday and Thanksgiving day will finally see temperatures rise to near or above normal. Afternoon highs will be warming to  40  or higher with more sunshine than in the past few days.  Friday will see a temporary return to cloudy with precipitation, likely in the form of snow.  At this time it appears that several inches are likely in the nearby mountains, but valley totals should be no more than a couple inches.

500 mb Forecast Friday afternoon Nov. 25 2011

High pressure quickly takes control over the weekend with the likelihood of mostly sunny and dry days.  With the clearing skies overnight temperatures will drop to single digits in the coldest valley locations.  Valley temperatures will be slow to warm given the low sun angle this time of year, with warmer temperatures in the higher elevations such as nearby ski areas.

500 mb Forecast Saturday Evening Nov. 26, 2011

With the jet stream and storm track well to the north early next week, fair conditions should dominate.  This time of year the substantial snow cover, under high pressure, will result in favorable conditions for overnight fog formation.  This could temper the amount of warming in the valleys, particularly if the fog fails to burn off in the afternoon.