AREA FORECAST DISCUSSION

 
 FXUS66 KSTO 242358
 AFDSTO
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE SACRAMENTO CA
 400 PM PST TUE NOV 24 2009
 
 .DISCUSSION...
 HIGH PRESSURE CONTINUES TO DOMINATE OVER INTERIOR NORTHERN 
 CALIFORNIA BRINGING DRY AND MILD WEATHER. DECOUPLING OF THE BOUNDARY 
 LAYER OVERNIGHT ALLOWED PATCHY DENSE FOG TO DEVELOP THIS 
 MORNING...PRIMARILY IN THE SOUTHERN SACRAMENTO AND NORTHERN SAN 
 JOAQUIN VALLEYS AND NEAR THE DELTA. TEMPERATURES THIS AFTERNOON ARE 
 RUNNING NEAR THE LEVELS OF 24 HOURS AGO...THE EXCEPTION BEING 
 TOWARDS THE NORTHERN SACRAMENTO VALLEY WHERE NORTHERLY CHINOOK WINDS 
 HAVE BROUGHT TEMPERATURES UP INTO THE MIDDLE 70S. ELSEWHERE 
 TEMPERATURES ARE RUNNING MAINLY IN THE 60S WITH 50S OVER HIGHER 
 ELEVATIONS. 
 
 MORE OF THE SAME THE NEXT 24 HOURS AS THERE WILL BE LITTLE CHANGE TO 
 THE OVERALL PATTERN. MAY SEE SOME OVERNIGHT FOG FORMATION AGAIN IN 
 THE NORTHERN SAN JOAQUIN AND SOUTHERN SACRAMENTO VALLEYS. HIGHS MAY 
 SEE A DEGREE OR TWO DROP WEDNESDAY OVER TODAY AS A WEAK UPPER 
 DISTURBANCE MOVES THROUGH...THOUGH NO SIGNIFICANT WEATHER IS 
 EXPECTED. SURFACE HIGH PRESSURE OVER THE GREAT BASIN WILL CONTINUE 
 TO BRING GUSTY OVERNIGHT WINDS DOWN FAVORED WEST-FACING SIERRA 
 CANYONS.
 
 THE WEATHER PATTERN WILL CHANGE THANKSGIVING AS THE UPPER RIDGE 
 SHIFTS EASTWARD. A SHORTWAVE CURRENTLY NEAR THE ALASKA PENINSULA 
 WILL ENHANCE AS IT ROUNDS AN ANCHOR LOW OVER THE GULF OF ALASKA. 
 THIS TROUGH WILL BEGIN TO SPREAD PRECIPITATION OVER INTERIOR 
 NORTHERN CALIFORNIA THANKSGIVING EVENING...THOUGH THE BULK OF 
 PRECIPITATION WILL FALL THURSDAY NIGHT INTO EARLY FRIDAY MORNING. 
 MOST OF THE SYSTEMS ENERGY WILL REMAIN NORTH OF THE STATE AND 
 ACCORDINGLY...MOST OF THE PRECIPITATION SHOULD REMAIN NORTH OF 
 INTERSTATE 80 THOUGH CANT RULE OUT A LIGHT SHOWER TOWARDS THE 
 SACRAMENTO METRO AREA. PRECIPITABLE WATER FORECASTS ARE 
 UNIMPRESSIVE...ON THE ORDER OF 0.75 INCHES...AND THUS QPF SHOULD BE 
 LIGHT. WITH SNOW LEVELS ON THE ORDER OF 4000-5500 FT...SNOW 
 ACCUMULATIONS OF PERHAPS AN INCH OR TWO ARE EXPECTED AT THE HIGHER 
 ELEVATIONS. THE SYSTEM WILL CLEAR THROUGH THE AREA FRIDAY SETTING 
 THE STAGE FOR ANOTHER DRY PERIOD. DANG
 
 .EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)...
 RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA INTO EARLY NEXT WEEKEND 
 BRINGING WARMER TEMPERATURES AND DRY WEATHER. NORTH WINDS ARE 
 EXPECTED WITH SURFACE HIGH PRESSURE BUILDING INTO OREGON ON SATURDAY 
 AND THEN SHIFTS INTO NEVADA ON SUNDAY TURNING THE WINDS MORE 
 EASTERLY. RIDGE WEAKENS A BIT ON MONDAY WITH A SHORT WAVE MOVING 
 INTO THE PACIFIC NORTHWEST. THE RIDGE MAY REBUILD OVER THE AREA ON 
 TUESDAY. KEPT THE FORECAST DRY FOR NOW WITH RIDGE REMAINING OVER THE 
 AREA. ALTHOUGH THE MODELS ARE STILL VARIABLE IN POSSIBLY BRINGING A 
 SYSTEM IN MID WEEK NEXT WEEK. 
 
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 .AVIATION...
 VFR CONDS CONTINUE THIS EVENING. HOWEVER...PATCHY FOG WITH MVFR AND 
 LOCAL IFR CONDS COULD DEVELOP OVER PORTIONS OF THE CENTRAL VALLEY 
 NEAR KSMF SOUTHWARD TOWARDS KMOD DURING 12-17Z. IMPROVING CONDS BACK 
 TO VFR AROUND 18Z. LIGHT NORTHERLY WINDS.   JBB
 
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 .STO WATCHES/WARNINGS/ADVISORIES...NONE. 
 
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