High Wind and Dense Fog in California, November 27 to 30, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
935 PM PST SAT NOV 26 2011

.SYNOPSIS...
HIGH PRESSURE PREVAILS OVER THE LOCAL AREA WITH LATE NIGHT THROUGH
EARLY MORNING FOG FORMING OVER THE SAN JOAQUIN VALLEY. MOSTLY SUNNY
SKIES ARE EXPECTED OVER THE FOOTHILLS AND SIERRA NEVADA.

&&

.DISCUSSION...
AN UPPER LEVEL HIGH PRESSURE RIDGE REMAINS ACROSS THE REGION WITH
BANDS OF CIRRUS RIDING ACROSS THE RIDGE OVERHEAD. BENEATH THE HIGH
CLOUDS...MOST VALLEY AREAS HAD CLEARED OF STRATUS AND FOG BY EARLY
THIS AFTERNOON AND TEMPERATURES ACROSS THE CENTRAL CALIFORNIA
INTERIOR WERE ABLE TO CLIMB TO AT OR EVEN SLIGHTLY ABOVE CLIMO.
EXPECT ANOTHER SEASONABLY COOL NIGHT TONIGHT WITH AREAS OF FOG
REDEVELOPING IN THE VALLEY...SOME LOCALLY DENSE. THE FORECAST
LOOKS OK TONIGHT AND NO UPDATE IS PLANNED. FOG DEVELOPMENT WILL BE
MONITORED FOR ANY NECESSARY ADVISORIES.

&&

.PREV DISCUSSION... /ISSUED 210 PM PST SAT NOV 26 2011/

DISCUSSION...AMPLIFYING UPPER RIDGE OVER CA BRINGING DRY WEATHER
AND A WARMING TREND TO OUR AREA. SKIES HAVE GENERALLY CLEARED OUT
AT A RESULT OF SHORTWAVE ENERGY STREAMING ACROSS THE PAC NW AND
NORCAL PROVIDING ENOUGH LIFT ACROSS OUR AREA FOR SOME MIXING TO
TAKE PLACE. THE 12Z WRF/GFS AND 18Z WRF INDICATE THE RIDGE
FLATTENS A BIT ON SUNDAY AS A RESULT OF CONTINUED SHORTWAVE ENERGY
PUSHING INTO THE PAC NW AND NORCAL. WHILE FOG IS EXPECTED TO
REFORM TONIGHT ACROSS THE SAN JOAQUIN VALLEY...DO NOT ANTICIPATE
WIDESPREAD DENSE FOG AND EXPECT SKIES TO ONCE AGAIN CLEAR OUT IN
THE AFTERNOON AS SOME MIXING TAKES PLACE IN RESPONSE TO THE
SHORTWAVE ENERGY TO OUR NORTH. OTHER THAN SOME HIGH CLOUDS AT TIMES
FROM THE UPPER LEVEL MOISTURE STREAMING TO OUR NORTH...EXPECT
SKIES TO REMAIN MAINLY CLEAR ACROSS THE MOUNTAINS AND KERN DESERTS
TONIGHT AND SUNDAY.

THE WRF AND GFS ARE IN GOOD AGREEMENT WITH DROPPING A DRY TROUGH
SOUTHEAST THROUGH THE GREAT BASIN ON MONDAY WHICH WILL BRING A
SLIGHT COOLING TREND TO OUR AREA AS WELL AS PROVIDE ENOUGH MIXING
TO INHIBIT PERSISTENT FOG AND/OR STRATUS OVER THE SAN JOAQUIN
VALLEY. THE RIDGE IS PROGGED TO RE-AMPLIFY ON TUESDAY BEHIND THIS
SYSTEM WHICH RESULT IN WARMING TEMPERATURES OVER THE MOUNTAINS AND
KERN DESERTS WHILE NIGHT AND MORNING FOG MIGHT BE A BIT MORE
PREVALENT OVER OUR AREA ON TUESDAY.

THE MEDIUM RANGE MODELS CONTINUE TO HAVE DIFFICULTY IN COMING TO
AGREEMENT WITH THEIR PROGNOSIS OF ANOTHER UPPER TROUGH WHICH IS
PROGGED TO DEEPEN OVER THE GREAT BASIN ON WEDNESDAY AND THURSDAY.
THE GFS CONTINUES TO BE THE MOST PROGRESSIVE AND KEEP THE MOISTURE
AND STRONGER DYNAMICS WELL TO THE EAST OF OUR AREA AS THE SYSTEM
DROPS SOUTHWARD THE EJECTS THE SYSTEM EAST ACROSS THE DESERTS
SOUTHWEST BY NEXT SATURDAY. THE 12Z ECMWF DROPS THE SYSTEM
SOUTHWARD OVER OUR AREA AND INDICATES A POTENTIAL FOR
PRECIPITATION OVER OUR AREA ON THURSDAY AND FRIDAY BEFORE SLOWLY
PUSHING THE SYSTEM INTO THE DESERT SOUTHWEST ON SATURDAY. THE 12Z
GEM SHOWS A FAIRLY SIGNIFICANT CHANGE FROM IT/S PRIOR RUN AND
DROPS THE LOW SOUTHWARD JUST EAST OF THE SOUTHERN SIERRA NEVADA
RATHER THAN DOWN THE COAST. THIS SOLUTION WOULD NOT BE AS WET AS
THE ECMWF BUT WOULD BE COLDER. BASED ON ENSEMBLE COMPARISONS OF
EACH OF THE MODELS...OUR PREFERENCE IS TO LEAN MORE TOWARD THE GFS
AND COOL TEMPERATURES BELOW SEASONAL NORMALS LATE NEXT WEEK AND
CONFINE PRECIPITATION CHANCES TO A SLIGHT CHANCE OVER THE
MOUNTAINS ON THURSDAY NIGHT AND FRIDAY. THERE IS A POTENTIAL FOR A
STRONG OFFSHORE WIND EVENT OVER THE HIGHER ELEVATIONS LATE NEXT
WEEK AND LATER SHIFTS WILL NEED TO MONITOR THIS. FORECASTER
CONFIDENCE FOR THE EXTENDED PERIOD HOWEVER...REMAINS LOW.

&&

.AVIATION...
IN THE SAN JOAQUIN VALLEY...AREAS IFR IN FOG AND LOW CLOUDS FROM 06Z
THROUGH 20Z SUNDAY...OTHERWISE WIDESPREAD MVFR IN MIST AND HAZE.
VFR CONDITIONS WILL PREVAIL ELSEWHERE ACROSS THE CENTRAL CALIFORNIA
INTERIOR THROUGH 06Z MONDAY.

&&

.AIR QUALITY ISSUES...
ON SUNDAY NOVEMBER 27 2011... FIREPLACE/WOOD STOVE BURNING IS
PROHIBITED IN FRESNO COUNTY.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

PUBLIC...JEB
AVN/FW...BEAN
SYNOPSIS...WP

WEATHER.GOV/HANFORD