AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
911 PM CST TUE DEC 2 2008
.UPDATE...
WILL PUSH TIMING OF PCPN BACK A BIT TNGT SERN ZONES BUT NO
DRASTIC CHANGES MADE.
&&
.DISCUSSION...
MAIN REASON FOR EVENING AFD UPDATE WAS TO MENTION THAT 00Z NAM
SOLUTION NOT TOTALLY BOUGHT. MODEL HAS BEEN INCONSISTENT IN QPF
GENERATION ACROSS THE OAX CWA AND 00Z RUN JUST SPREAD A LTL INTO
FAR NRN ZONES LATE TNGT AND THAT WAS IT. MEANWHILE STLT SHOWED
VIGOROUS UPR TROUGH MOVG ACROSS RCKY MTNS GENERATING OCNL LTG
STRIKES OVR SERN WY/NRN CO WITH TROUGH AND STRONG 850-700
FRONTOGENESIS GENERATING SHOWERS IN SWRN NEBR WHICH WERE NOT
PICKED UP AT ALL BY 00Z NAM. 00Z RUC QPF WAS MORE BULLISH/FTHR S
THAN NAM WITH 0.10 AROUND KOFK BY 12Z WED. ALSO LAST EVENINGS 4KM
NAM COMPOSITE REFLECTIVITY OUTPUT DID HINT AT SWRN NEBR ACTIVITY
IN ADDITION TO SD SNOW AREA AND IT SPREAD/DVLPD RETURNS SE THRU
OMA/LNK AREA BY 03/12Z. THUS NO MAJOR CHANGES ATTM TO FORECAST.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 308 PM CST TUE DEC 2 2008/
SHORT TERM...TONIGHT THROUGH FRIDAY.
SNOW CHANCES/AMOUNTS TONIGHT...THEN TEMPERATURES THROUGH
FRIDAY...ARE THE PRIMARY SHORT TERM FORECAST CONCERNS.
POTENT MID LEVEL SHORT WAVE WAS DROPPING INTO THE CENTRAL ROCKIES
THIS AFTERNOON...LED BY 120M HEIGHT FALLS AS PER MORNING RAOB
DATA. SIGNIFICANT DRYING WAS OCCURRING IN THE WAKE OF THIS WAVE
OVER NORTHERN CALIFORNIA AS SHOWN ON WATER VAPOR LOOPS...AND PLUME
OF MID LEVEL MOISTURE WAS BEGINNING TO SURGE NORTHEAST INTO
COLORADO AHEAD OF THE SYSTEM. OTHERWISE NOT MUCH AVAILABLE
MOISTURE WAS NOTED ON MORNING UPPER AIR CHARTS...CAUSING A BIT OF
CONCERN FOR PRECIPITATION GENERATION ACROSS THE CWA TONIGHT.
HOWEVER...APPARENT STRENGTH OF SYSTEM AS NOTED ON WATER VAPOR
IMAGERY SUGGESTS SUFFICIENT MOISTURE WILL WORK INTO THE SYSTEM
PRIOR TO ITS ARRIVAL IN OUR AREA.
AT THE SURFACE...PRESSURES HAVE BEEN LOWERING THIS AFTERNOON IN THE
HIGH PLAINS WITH SYSTEM APPROACHING. A COLD FRONT WAS SETTLING SOUTH
TO THE NEBRASKA/SOUTH DAKOTA BORDER AS OF MID AFTERNOON...WITH
SOUTHWEST FLOW AHEAD OF IT HELPING TO WARM TEMPS INTO THE 50S ACROSS
MUCH OF THE CWA. HOWEVER 30S AIR WAS SURGING SOUTH THROUGH NORTHERN
SOUTH DAKOTA...AND SHOULD ARRIVE IN OUR NORTHERN CWA BY MIDNIGHT.
Bookmarks