Issued by NWS Sacramento, CA
000 FXUS66 KSTO 222338 AFDSTO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 335 PM PST SUN NOV 22 2009 .DISCUSSION... ABUNDANT LOW TO MID LEVEL CLOUDINESS ACROSS MUCH OF INTERIOR NORTHERN CALIFORNIA THIS AFTERNOON IN ASSOCIATION WITH LAST NIGHTS SYSTEM. THIS CLOUD MASS HAS BEEN SLOW TO DISSIPATE AND DRIFTING SOUTHWARD THROUGH THE COURSE OF THE DAY. A FEW LIGHT SHOWERS CONTINUE OVER THE SIERRA FOOTHILLS AND MOUNTAINS AND WILL CONTINUE TO DO SO THROUGH THIS EVENING. THE LOW LEVEL STRATUS WILL SLOWLY DISSIPATE THIS EVENING AND TONIGHT...POTENTIALLY MAKING WAY FOR PATCHY FOG TO DEVELOP THROUGH THE VALLEY AND FAVORED MOUNTAIN VALLEYS. WARMING AND DRY TREND WILL BEGIN MONDAY AS HIGH PRESSURE ALOFT BUILDS ALONG THE WEST COAST. SURFACE HIGH PRESSURE WILL SET UP IN THE GREAT BASIN ALLOWING FOR SOME GUSTY WINDS TO BLOW DOWN FAVORED SIERRA CANYONS DURING THE OVERNIGHT HOURS. OTHERWISE...TEMPERATURES WILL BE PLEASANT WITH HIGHS AT OR SLIGHTLY WARMER THAN NORMAL THE NEXT SEVERAL DAYS. .EXTENDED DISCUSSION (THANKSGIVING THROUGH SUNDAY)... THE MODELS ARE IN GOOD AGREEMENT WITH A TROUGH IMPACTING THE NRN CAL ON THU AND INTO FRI. BUT THE GFS...EC AND GEM ARE OFF JUST A BIT ON THE TIMING WITH THE GFS NOW BEING MORE PROGRESSIVE. YESTERDAY THE EC WAS MORE PROGRESSIVE...SO STILL NOT QUITE SURE ON EXACT TIMING. THE HPC SOLUTION USED A BLEND OF THE TWO...BUT FAVORED MORE TOWARD THE EC. SO WENT WITH A CHANCE OF RAIN OVER THE NRN THREE-QUARTERS OF THE FORECAST MOUNTAIN AREAS AND THE NRN HALF OF THE SACRAMENTO VALLEY. THE SACRAMENTO AREA SHOULD STAY DRY WITH VARIABLE CLOUDINESS. JMC && .AVIATION... WEAK FRONTAL SYSTEM MOVING EASTWARD TONIGHT. WINDS WILL REMAIN LIGHT AT 10 KTS OR LESS FOR THE NEXT 24 HRS...TRANSITIONING N TO NWRLY FOR ALL TAF SITES BY 06Z. WINDS WILL BE LIGHTEST OVERNIGHT THRU EARLY MORNING ALLOWING PATCHY FOG TO DEVELOP IN THE CENTRAL VALLEY. MVFR CONDS WITH LOCAL IFR COULD DEVELOP IN THE CENTRAL SAC VALLEY INTO THE SAN JOAQUIN VALLEY AFFECTING THE KSMF-KSAC-KMHR-KSCK TAF SITES. KRDD-KRBL VCNTY SHOULD REMAIN CLEAR WITH NO FOG DUE TO NEARBY DOWNSLOPE FLOW. WINDS ALOFT LIGHT TO MODERATE NORTHERLY. JBB && .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$
