000
FXUS66 KSGX 071136
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
335 AM PST WED JAN 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BRING SLOW WARMING TODAY FOLLOWED BY SLOW COOLING
THURSDAY AS THE HIGH PRESSURE BEGINS TO WEAKEN. A TROUGH OF LOW
PRESSURE MOVING THROUGH FROM THE NORTHWEST ON EARLY FRIDAY WILL
BRING COOLING WITH GUSTY ONSHORE WINDS AHEAD OF THE TROUGH AND GUSTY
OFFSHORE WINDS BEHIND THE TROUGH. PERIODS OF MODERATE TO LOCALLY
STRONG OFFSHORE FLOW AND WARMING WILL FOLLOW FOR THE WEEKEND THROUGH
EARLY NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH FRIDAY)...
HIGH PRESSURE...SUCH AS IT IS...WILL PEAK TODAY BRINGING SOME MINOR
ADDITIONAL WARMING FOLLOWED BY MINOR COOLING FOR THURSDAY AS THE
HIGH PRESSURE BEGINS TO WEAKEN. SOME HIGH CLOUDS WILL CONTINUE AT
TIMES THE NEXT FEW DAYS. AS WEAK ONSHORE FLOW RETURNS...SOME PATCHY
STRATUS MAY DEVELOP NEAR THE COAST LATE TONIGHT INTO THURSDAY
MORNING. THE NAM HAS TRENDED SLOWER WITH THE STRATUS RETURN. FOR
THURSDAY NIGHT AND FRIDAY...A WEAK TROUGH OF LOW PRESSURE MOVING BY
TO THE NORTH WILL BRING A PERIOD OF STRONGER ONSHORE FLOW THURSDAY
EVENING WITH A BRIEF PERIOD OF DEEPENING OF THE MARINE LAYER AND A
GREATER RETURN OF COASTAL STRATUS. BEHIND THE TROUGH...THE FLOW WILL
TRANSITION TO OFFSHORE FRIDAY. STRATUS THAT DEVELOPS THURSDAY
EVENING SHOULD BEGIN TO SCATTER OUT FROM THE NORTH BY FRIDAY
MORNING. THE TROUGH SHOULD ALSO BRING SOME COOLING FOR FRIDAY. THE
MODELS ARE TRENDING A LITTLE MORE INLAND WITH THE TRACK OF THIS
TROUGH. THIS SHOULD GREATLY MINIMIZE THE ALREADY SLIM CHANCES FOR
PRECIPITATION WITH THIS TROUGH PASSAGE.
&&
.LONG TERM (SATURDAY THROUGH TUESDAY)...
THE CONSISTENT ECMWF REMAINS THE PREFERRED SOLUTION. PERIODS OF
MODERATE TO LOCALLY STRONG OFFSHORE FLOW AND BUILDING HIGH PRESSURE
ALOFT FOR THE WEEKEND THROUGH EARLY NEXT WEEK SHOULD BRING WARMING
WITH STRONG GUSTY WINDS AT TIMES THROUGH AND BELOW PASSES AND
CANYONS. ADVISORY STRENGTH WINDS...WITH WARNING STRENGTH WINDS IN
THE WINDIER LOCATIONS BELOW THE CAJON PASS AND IN THE SANTA ANA
MOUNTAINS AND FOOTHILLS...ARE EXPECTED TO DEVELOP FRIDAY...AND
CONTINUE AT TIMES INTO SUNDAY OR MONDAY.
&&
.AVIATION...
071100Z...VFR OVER THE AREA TODAY THROUGH THU...EXCEPT SOME 3-5SM
VIS RESTRICTION AND PATCHY 1SM VALLEY FOG BETWEEN 08Z AND 16Z IN THE
MORNINGS WEST OF THE MOUNTAINS. PRESSURE GRADIENTS AND SEA BREEZE
WILL BE WEAK SO SFC WINDS WILL BE MOSTLY UNDER 10 KT. AN INCREASE IN
ONSHORE FLOW WITH A DEEPER MARINE LAYER IS EXPECTED THU PM AND EVE.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
