Frost Advisory 6, NWS San Diego, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
925 AM PST THU NOV 30 2006

.SYNOPSIS...COLD DRY OFFSHORE FLOW WILL CONTINUE TODAY WITH STRONG
GUSTY WINDS THROUGH THE MOUNTAIN CANYONS AND PASSES. THE WINDS WILL
DECREASE SLIGHTLY THIS AFTERNOON. TONIGHT WILL BE ANOTHER COLD NIGHT
WITH FREEZING TEMPERATURES LIKELY IN THE VALLEYS AND SOME DESERT
AREAS. OFFSHORE FLOW WILL PREVAIL INTO EARLY NEXT WEEK.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES.

THE SANTA ANA WINDS CONTINUE THIS MORNING...BUT THEY ARE NOT AS
STRONG AS THEY WERE LAST NIGHT. THE 1045 MB HIGH OVER UTAH THIS
MORNING WEAKENS TO 1036 MB AT 00Z THIS EVENING...AND THE WINDS WILL
CONTINUE TO DECREASE WITH EBBING THERMAL SUPPORT AND DECREASING
WINDS ALOFT. GIVEN THESE TRENDS...THE HIGH WIND WARNING WILL LIKELY
BE CANCELLED THIS AFTERNOON.

THE OTHER WEATHER CONCERN IS THE FREEZING COLD TEMPERATURES. MORNING
LOWS FELL BELOW FREEZING AT OCEANSIDE TODAY. THE HIGH DESERTS SAW
TEMPERATURES FALL INTO THE TEENS AND 20S...AND EVEN THERMAL IN THE
COACHELLA VALLEY REACHED INTO THE UPPER 20S. BORREGO SPRINGS FELL TO
32 DEGREES.

DEWPOINTS ARE EXCEPTIONALLY LOW THIS MORNING WITH SEVERAL STATIONS
BELOW ZERO IN ORANGE COUNTY. WITH LIGHTER WINDS AND VERY LOW
MOISTURE CONTENT...TONIGHT WILL BE ANOTHER VERY COLD NIGHT WITH
RAPID COOLING AFTER SUNSET. THIS DESPITE THAT FACT THAT WE WILL BE
UNDER WEAK WAA LATE TONIGHT. THE FREEZE WATCHES CURRENTLY IN EFFECT
FOR THE DESERTS AND INLAND VALLEYS WILL LIKELY BE UPGRADED TO
WARNINGS.

ON FRIDAY THE BOUNDARY LAYER TEMPS INCREASE FROM 8C TO 16C AND TEMPS
WILL INCREASE QUICKLY AFTER SUNUP. EXPECT HIGHS TOMORROW TO BE FROM
10 TO 15 DEGREES HIGHER THAN TODAY INLAND FROM THE COAST.

FRIDAY NIGHT...SURFACE HIGH PRESSURE REBUILDS OVER THE GREAT BASIN
BRINGING A REINFORCING SHOT OF OFFSHORE WINDS SATURDAY AND SUNDAY.
THE SUPPORT WONT BE AS STRONG AS WITH THE CURRENT SYSTEM...BUT
STRONG ENOUGH THAT WIND ADVISORIES MAY BE NEEDED. WITH CONTINUING
LOW HUMIDITIES AND PERIODIC OFFSHORE WINDS...RED FLAG WARNING WILL
CONTINUE AS CURRENTLY ADVERTISED.

NO CHANGES TO THE LONG RANGE DISCUSSION...

.LONG RANGE...AIR MASS WILL CONTINUE EXTREMELY DRY SUNDAY AND MONDAY
WITH PREVAILING OFFSHORE FLOW. TUESDAY SHOULD BE A TRANSITION DAY TO
ONSHORE FLOW. CLIMATOLOGY WOULD SUPPORT DENSE FOG NEAR THE COAST
THEN...ANALOGOUS TO WHAT OCCURRED JUST BEFORE THANKSGIVING.
WEDNESDAY THROUGH NEXT THURSDAY...MARINE LAYER SHOULD BECOME DEEPER
AND BETTER ESTABLISHED...HELPING SET THE STAGE FOR CHANCE OF
PRECIPITATION NEXT FRIDAY...DECEMBER 8.

&&

.AVIATION...
OFFSHORE FLOW WILL CONTINUE TO BRING VFR CONDITIONS TO MOST AREAS
WITH A MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES THROUGH
FRIDAY. GUSTY NORTHEAST WINDS WILL DIMINISH THROUGH THE DAY BUT WILL
BE ACCOMPANIED BY MODERATE TO STRONG UP AND DOWN DRAFTS AND LOW
LEVEL WIND SHEAR. THE GUSTY WINDS MAY ALSO PRODUCE AREAS OF BLOWING
DUST WITH ASSOCIATED VISIBILITY RESTRICTIONS THROUGH THIS AFTERNOON.

THERE ARE SOME INDICATIONS THE MARINE LAYER MAY BEGIN TO RECOVER
FRIDAY NIGHT INTO SATURDAY MORNING WHICH MAY RESULT IN PERIODS OF
DENSE FOG WITH LIFR CONDITIONS WHICH COULD IMPACT SOME OF THE
COASTAL AIRPORTS SUCH AS KSAN FRIDAY NIGHT INTO SATURDAY MORNING.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WARNING/WIND ADVISORY FOR MOUNTAINS...INLAND VALLEYS AND
ORANGE COUNTY COASTAL THROUGH 6 PM...SEE LAXNPWSGX.

RED FLAG WARNING FOR THE MOUNTAINS...INLAND VALLEYS AND ORANGE
COUNTY COASTAL AREAS THROUGH SUNDAY. SEE LAXRFWSGX.

FREEZE WATCH FOR THE VALLEYS AND DESERTS TONIGHT. SEE LAXNPWSGX.

&&

PUBLIC...MOEDE
AVIATION...HORTON

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SAN DIEGO CA
400 AM PST THU NOV 30 2006

CAZ042-043-048-050-055-056-057-058-060-061-062-010000-
ORANGE COUNTY COASTAL AREAS-
SAN DIEGO COUNTY COASTAL AREAS-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY VALLEYS-
SAN BERNARDINO COUNTY MOUNTAINS-
RIVERSIDE COUNTY MOUNTAINS-
SANTA ANA MOUNTAINS AND FOOTHILLS-
SAN DIEGO COUNTY MOUNTAINS-
APPLE AND LUCERNE VALLEYS-
COACHELLA VALLEY-
SAN DIEGO COUNTY DESERTS-
400 AM PST THU NOV 30 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ALL OF EXTREME SOUTHWESTERN
CALIFORNIA.

.DAY ONE... TODAY AND TONIGHT.

DAMAGING NORTH TO NORTHEAST WINDS ACROSS MOUNTAINS AND THROUGH AND
BELOW MOUNTAIN PASSES AND CANYONS ARE STILL LIKELY TODAY. A
HIGH WIND WARNING IS IN EFFECT FOR THE MOUNTAINS...INLAND EMPIRE AND
ORANGE COUNTY COASTAL AREAS. A WIND ADVISORY IS IN EFFECT FOR THE
COACHELLA VALLEY AND SAN DIEGO COUNTY VALLEYS. SEE LAXNPWSGX FOR
MORE DETAILS.

HUMIDITY HAS DROPPED WELL BELOW 15 PERCENT AND WILL CONTINUE VERY
LOW THROUGH TONIGHT. COUPLED WITH THE STRONG WINDS...CRITICAL FIRE
WEATHER CONDITIONS ARE PRESENT. A RED FLAG WARNING IS IN EFFECT FOR
THE MOUNTAINS...INLAND VALLEYS AND ORANGE COUNTY. SEE LAXRFWSGX FOR
MORE DETAILS.

IN AREAS PROTECTED FROM THE WINDS...FREEZING TEMPERATURES ARE
POSSIBLE UNTIL 8 AM THIS MORNING. A FREEZE WARNING IS IN EFFECT FOR
THE SAN BERNARDINO COUNTY DESERT AREAS UNTIL 8 AM THIS MORNING. A
FROST ADVISORY IS ALSO IN EFFECT FOR THE COACHELLA VALLEY...THE
INLAND EMPIRE...THE SAN DIEGO COUNTY INLAND VALLEYS...ORANGE
COUNTY...AND THE COASTAL SECTION OF SAN DIEGO COUNTY.

WITH LESS WIND EXPECTED TONIGHT...MORE AREAS MAY EXPERIENCE FREEZING
TEMPERATURES. A FREEZE WATCH IS CURRENTLY IN EFFECT FOR THE VALLEYS
AND THE DESERT AREAS AND MAY BE EXPANDED TO INCLUDE THE COASTAL
SECTIONS TONIGHT. SEE LAXNPWSGX DETAILS.

.DAYS TWO THROUGH SEVEN... FRIDAY THROUGH THURSDAY.

OFFSHORE WINDS MAY INCREASE AGAIN LATE FRIDAY NIGHT AND SATURDAY.
HOWEVER WIDESPREAD DAMAGING WINDS ARE NOT EXPECTED WITH THIS EVENT.

CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE THROUGH SUNDAY. A RED
FLAG WARNING REMAINS IN EFFECT FOR THE MOUNTAINS...INLAND VALLEYS
AND ORANGE COUNTY.

TEMPERATURES MAY CONTINUE TO FALL BELOW FREEZING AGAIN FRIDAY NIGHT
AND SATURDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...SKYWARN WEATHER SPOTTER ACTIVATION
IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT
ANY OBSERVATIONS OF WIND DAMAGE...AND FROST AND FREEZE DAMAGE .

BALFOUR