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strong early season storm: incoming
By ccrossen | October 8, 2009
Latest model runs show much more confidence for a solid hit on Tahoe. Doesn’t look like we’ll get much snow, but a lot of rain Monday evening through Thursday. Snow levels will begin high, drop to about 7,000 but then head up to 10,000. This is going to be a “major precipitation event.”
MONDAY THROUGH THURSDAY…
AFTER A FEW DAYS OF WAVERING ON THE INCOMING STORM NEXT WEEK…THE LATEST MEDIUM RANGE GUIDANCE AND ENSEMBLE DATA HAVE LOCKED ON TO A HIGH CONFIDENCE MAJOR PRECIPITATION EVENT FOR THE SIERRA AND PARTS OF WRN NV. AN UNUSUALLY STRONG PACIFIC JET CONTAINING REMNANT TROPICAL TYPHOON MOISTURE…AND A VERY STRONG UPPER LOW MOVING ACROSS THE ERN PACIFIC APPEAR TO BE COMING TOGETHER TO SLAM DIRECTLY INTO THE SIERRA. THE TIMING OF THIS SYSTEM BASED ON THE LATEST DATA WOULD INDICATE THE LIGHTER PRECIP BEGINNING LATE MON AFTN-MON EVE WITH THE BULK OF THE MOISTURE OCCURRING FROM TUESDAY THRU TUES NIGHT. SFC PRESSURE AND 500 MB HEIGHT ANOMALIES ARE OFF THE CHARTS FOR THIS TIME OF YEAR WITH THE PROJECTED VALUES 4 TO 6 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT…POPS HAVE BEEN RAISED SIGNIFICANTLY FROM THE PREV FCST FROM MON NGT THRU WED…INCLUDING SOME CATEGORICAL POPS OVER 80 PERCENT IN THE SIERRA AND FAR WRN NV FOR TUESDAY-TUES NIGHT.
FOR THE MOST PART…THIS WILL BE A RAIN EVENT FOR THE SIERRA EXCEPT FOR THE HIGHEST ELEVATIONS. INITIAL WET BULB EFFECT COOLING MON EVE MAY ALLOW FOR A SHORT PERIOD OF SNOW DOWN TO 7000-7500 FT…BUT AS THE MAIN MOISTURE SURGE ARRIVES THE SNOW LEVELS WILL LIKELY RISE QUICKLY TO WELL ABOVE 8000 FT AND COULD BE AROUND 10000 FT AT TIMES ON TUESDAY. MODEL QPF PROJECTIONS ARE ALSO VERY IMPRESSIVE WITH BULLS-EYES WEST OF THE SIERRA CREST ADDING UP TO 6-10 INCHES DURING THE DURATION OF THIS EVENT. DEEP MOISTURE AND BROAD AREA OF INSTBY WOULD FAVOR A SIGNIFICANT PERIOD OF SPILLOVER RAIN INTO THE WRN NV VALLEYS FOR MUCH OF TUESDAY AND TUES NIGHT. THE INTENSITY OF THE PRECIP IS PROJECTED TO WIND DOWN ON WEDNESDAY ESPECIALLY IN THE LOWER ELEVATIONS. EVEN THOUGH THIS SYSTEM IS STILL SEVERAL DAYS AWAY…THE POTENTIAL IS HIGH FOR …. SEVERAL INCHES OF RAIN POSSIBLE IN THE SIERRA AND ERN CA FOOTHILLS FROM THIS SYSTEM.
PRECIP WILL CONTINUE TO DECREASE FROM WED NGT THRU THURSDAY WITH LINGERING SHOWERS RESTRICTED TO PARTS OF ERN CA NEAR THE CREST…AS THE STORM LIFTS OUT AND RIDGE APPROACHES FROM THE WEST.
Topics: Tahoe Snow Report |