FXUS66 KSTO 281229
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
430 AM PST SAT NOV 28 2009

.DISCUSSION...
SHOWER ACTIVITY DIMINISHED OVERNIGHT FOR MOST OF OUR CWA. THE 
WRAP-AROUND MOISTURE THAT AFFECTED OUR SIERRA MOUNTAINS CONTINUES TO 
LINGER IN THE VERY SOUTHEASTERN PORTION OF OUR CWA. RADAR AND 
SATELLITE IMAGERY SHOW LIGHT SNOW SHOWERS NEAR THE TAHOE VICINITY 
SOUTHWARD ALONG THE CREST. THOUGH THE MAIN STORM SYSTEM HAS MOVED 
EAST OF OUR CWA...MOISTURE MAY CONTINUE TO WRAP AROUND THE BACK SIDE 
SPREADING OVER THE GREAT BASIN TOWARDS OUR SOUTHEASTERN BORDER. THUS 
HAVE KEPT IN A SLIGHT CHANCE OF LIGHT SNOW SHOWERS THIS MORNING NEAR 
THAT PORTION OF OUR SIERRA CREST. 

THE MAIN WEATHER CONCERN FOR TODAY WILL BE THE INCREASING NORTHERLY 
WINDS. WINDS HAVE BECOME BREEZY THIS MORNING IN PORTIONS OF THE 
CENTRAL VALLEY. OBSERVATIONS SHOW SUSTAINED WINDS AT 15 TO 25 MPH 
WITH GUSTS UP TO 30 MPH. THE NORTHERLY GRADIENT WILL STRENGTHEN 
FURTHER THIS MORNING AND AFTERNOON AS VALLEY GUSTS 
INCREASE...ESPECIALLY ALONG THE WESTERN EDGES OF THE VALLEY. LOCAL 
VALLEY GUSTS TODAY EXPECTED AT 35 TO 45 MPH...LOCALLY HIGHER UP TO 
50 MPH ON THE WESTERN SIDE. GUSTY WINDS ALREADY BEING OBSERVED IN 
THE NORTHERN, CENTRAL AND SOUTHERN SAC VALLEY. WINDS EXPECTED TO 
INCREASE IN THE NORTHERN SAN JOAQUIN VALLEY AS THE MORNING 
PROGRESSES. MOUNTAIN GUSTS HAVE RANGED 30 TO 50 MPH OVERNIGHT AND 
ARE EXPECTED TO STAY GUSTY TODAY. THE NORTHEASTERLY GRADIENT IS 
EXPECTED TO SLACKEN FROM LATE AFTERNOON INTO EARLY EVENING...HOWEVER 
HIGH TERRAIN WINDS WILL ENHANCE LATER TONIGHT AS A STRONG OFFSHORE 
GRADIENT DEVELOPS. 

MADE SLIGHT CHANGES TO THE WIND ADVISORY: EXTENDED ENHANCED VALLEY 
WINDS UNTIL 5 PM TODAY AND INCLUDED THE NORTHERN SAN JOAQUIN VALLEY 
TO THE ADVISORY...KEPT WIND ADVISORY FOR THE SIERRA MOUNTAIN ZONES 
THROUGH SUNDAY MORNING TO ACCOMMODATE THE ENHANCED OFFSHORE FLOW.

BY SUNDAY AFTERNOON...WINDS WILL LESSEN REGION-WIDE AS HIGH PRESSURE 
RIDGING BUILDS OVER NORTHERN CALIFORNIA. THIS RIDGING WILL MAINTAIN 
A MILD WEATHER PATTERN WITH FAIRLY CLEAR SKIES...A GENTLE WARMING 
TREND AND DRY WEATHER THROUGH MIDWEEK.   JBB

.EXTENDED DISCUSSION (WEDNESDAY THROUGH SATURDAY)...MODELS 
INDICATING VARYING SOLUTIONS DURING THE EXTENDED PERIOD. A LOW 
PRESSURE AREA THAT WILL BE OFF THE COAST IS EITHER PROJECTED TO 
SWING WELL SOUTH OF OUR AREA OR MOVE PARTIALLY INTO THE REGION ON 
WEDNESDAY. HAVE CONTINUED THE DRY FORECAST FOR NOW BUT THAT COULD 
CHANGE. THE OTHER HINT OF ANYTHING COMES NEXT FRIDAY WITH A 
SHORTWAVE MOVING INTO THE PACIFIC NORTHWEST. THE GFS IS INDICATING A 
LOW FORMING ALONG THE COAST WHILE THE EUROPEAN KEEP THE SHORTWAVE TO 
THE NORTH. AGAIN HAVE CONTINUED THE DRY FORECAST FOR NOW UNTIL THE 
MODELS CAN COME INTO A BETTER AGREEMENT INTO WHAT IS GOING ON.

&&

.AVIATION...VFR CONDITIONS OVER THE SACRAMENTO VALLEY WITH JUST SOME 
LIGHT LINGERING SNOW SHOWERS CREATING MVFR CONDITIONS ALONG THE 
CREST WHICH WILL END BY AROUND 21Z. NORTH WINDS WILL GRADUALLY 
INCREASE THIS MORNING ACROSS THE VALLEY WITH GUSTS PICKING UP TO 
35-40 KT BETWEEN 16Z-18Z. MOUNTAINS GUSTS 40-45 KT POSSIBLE OVR 
HIGHER TERRAIN AND THROUGH CANYONS THIS MORNING AND AGAIN TONIGHT.

&& 

.STO WATCHES/WARNINGS/ADVISORIES...
...WIND ADVISORY THROUGH 5 PM PST THIS EVENING FOR SACRAMENTO AND    
   NORTHERN SAN JOAQUIN VALLEYS INCLUDING THE DELTA REGION ALONG     
   WITH THE COASTAL RANGE INCLUDING SOUTHWESTERN SHASTA AND LAKE     
   COUNTIES. 
...WIND ADVISORY THROUGH 8 AM PST SUNDAY FOR WEST SLOPE NORTHERN     
   SIERRA NEVADA-WESTERN PLUMAS COUNTY/LASSEN PARK.

&&

$$