SOME WARMING THIS WEEKEND…..THEN STRONG GUSTY NE WINDS TO RAKE THE CREST…..RETROGRESSION OF THE EASTERN PACIFIC HIGH STILL IN THE CARDS FOR LATER NEXT WEEK
Friday November 12, 2010
Posted at 8:58 am by Howard
Fabulous opener yesterday for Mammoth Mt, on a 1 to 3 foot base. a combination of natural and man made snow is an excellent mix! A very snow warming trend of a degree or two each day is expected as we go through the weekend…….expect highs in Mammoth 45 to 50. lows in the low to mid 20s.
The Eastern Pacific high will remain parked out near 140 west the next 6 to 7 days bringing for the most part, beautiful weather to the Eastern Sierra. The only areas of discomfort will be the very upper elevations where winds will kick up later in the weekend due to short wave energy dropping south through the Great Basin. The Dweebs did notice quite a bit of 700mb moisture coming through early Sunday morning into the late afternoon from the north. Precipitation graphics did not indicate any QPF. With the eastern pacific high strengthening into the weekend, warmer temps should occur aloft while shots of cooling will reach the Eastern Sierra valleys, possibly strengthening inversions.
With the upper high anchored through Wednesday little change is expected between the weekends weather and mid week. High temps will probably push just above the 50 degree mark by Wednesday.
Beyond mid week, the GFS is the most aggressive in bringing in a storm to the west coast by Friday/Saturday, although it does not have enough support of its ensemble members for the big changes touted from the several operational runs of recent days. The ECMWF (Euro) shows a much slower trend to the idea of dropping the upper jet south through the pacific northwest, then into California by the end of the week. However, it still keeps the upper jet core north of the Mammoth area. The Dweebs will say that potentially there are all kinds of possibilities with this pattern change including at some point a subtropical/ tropical tap for the west coast…..and in that there has been little history of this winter so far, the Dweebs will wait until early next week before speculating on the longer term.
GUSTY WINDS OVER THE CREST TODAY…CHILLY WEATHER WILL MODERATE OVER THE WEEKEND….FAIR WEATHER IS LIKELY TO CONTINUE THROUGH NEXT WEDNESDAY…THEN RETROGRESSION OF THE LONG WAVE PATTERN THE 2ND HALF OF NEXT WEEK
Thursday November 11, 2010
Posted at 9:38 am by Howard
It was a chilly morning here in the Eastern Sierra with lows in the mid teens. A building surface high over the Great Basin will keep a NNE flow going over the crest for a few days. Temps will moderate towards Climo by weekend. Mammoth will remain storm free through next Wednesday. High temps will range in the upper 30s today with lows in the teens…then rise into the 40s over the weekend.
It appears that by Friday night…another short wave will drop through the Rockies, rebuilding pressures at the surface and reinforcing the cold air over the great basin. With the mean position of the eastern pacific high at 140west, the storm track will remain well to our north and east.
For the second day now, longer range models were forecasting retrogression of the eastern pacific high back towards 160west. Both ECMWF and the GFS have retrogression in their futures. However, the ECMWF retrogrades the upper high all the way to near the date line, while the GFS has it more toward 160west.
The implications are very significant on which model is correct. If the GFS is correct a major snowstorm would be in our future toward the next weekend while if the EC is correct more of the cold air from that storm along with the upper jet would remain to our north. Obviously more time will be needed in determing the long range outlook. The Dweebs feel that by this weeks end, a better handel on the longer term can be expected. One supporting feature to retrogression is a strong spike in the MJO phase space in phase 7. So retrogression is likely. However, the big question is, how much. If there is too much, will just ridge up and stay dry.
Wednesday November 10, 2010
Posted at 8:57 am by Howard
SNOW BEGAN LAST NIGHT MID EVENING AND CONTINUED ON AND OFF IN SHOWERS. THE CURRENT PATTERN, IS SET UP WITH THE EASTERN PACIFIC RIDGE PARKED OUT AT 140W, AND THE DOWN STREAM TROF OVER THE ROCKIES. SHORT WAVE ENERGY IS MOVING ONSHORE NEAR WASHINGTON…..THEN DROPPING SOUTHEAST THEN SOUTH ALONG THE EASTERN SLOPES OF THE SIERRA AND WESTERN NEVADA. THIS IS EVIDENCED BY THE UPPER JET NORTH/SOUTH OVER CALIFORNIA, ATM. EVEN THOUGH WE RECEIVED A FEW INCHES OF SNOW OVER NIGHT AND MAY GET ANOTHER INCH TODAY, THIS IS A DRY PATTERN ASSOCIATED WITH BELOW NORMAL TEMPS.
THE DWEEBS SEE LITTLE CHANGE IN THIS PATTERN FOR AT LEAST A WEEK. THERE HAS BEEN SOME SUGGESTION IN RETROGRESSION IN THE LONG WAVE RIDGE BACK TOWARD 160W BEYOND WEEK ONE. HOWEVER, THAT IS STRICTLY SPECULATION AT THIS POINT, AS THERE IS NOT ENOUGH SUPPORT IN THE ENSEMBLES OF EITHER GLOBAL MODEL.
WHAT IS REALLY NICE TO SEE SO FAR IS THAT THE WESTERN HEMISPHERIC PATTERN FROM THE WEST TO EAST HAS BEEN TO THIS POINT, REALLY PROGRESSIVE, WITH OUT ANY LONG TERM BLOCKING. THIS IS ESPECIALLY TRUE IN THE HUDSON BAY AREA WHERE HEIGHTS HAVE BEEN ACTUALLY HIGHER THEN NORMAL IN THE MEAN. IF YOU LOOK AT THE SSTAS OVER HUDSON BAY, THEY ARE ABOVE NORMAL. THUS NO COLD THERMAL ANCHOR FEEDING BACK INTO THE OVERLYING ATMOSPHERE………SO FAR.
AS WEATHER EXPERT AND RETRIED WSFO LEED TOM CYLKEY ALWAYS SAID, THE TWO BIGGEST INFLUENCES ON MAMMOTH WEATHER IS THE HUDSON BAY LOW FOR WINTER WEATHER….AND THE CONTINENTAL HIGH FOR SUMMERTIME WEATHER. IF THE HUDSON BAY LOW IS WEAK AND PROGRESSIVE, THERE WILL USUALLY BE ENOUGH ADJUSTMENT WAVE IN THE PATTERN TO ALLOW STORMS TO PENETRATE…WELL INTO CA.
HAVE A NICE WEEKEND…IT WILL BE FAIR WITH HIGHS IN THE MID 40S.
LOWS IN THE TEENS AND 20S.
DR HOWARD AND THE DWEEBS…………………………………..:-)