000
FXUS66 KSGX 071114
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
415 AM PDT SUN SEP 7 2008
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN SLOWLY BRINGING A SLOW COOLING TREND TO
SEASONAL TEMPERATURES THROUGH MID WEEK. THE MARINE LAYER WILL DEEPEN
AND THE COASTAL CLOUDS WILL BECOME MORE EXTENSIVE DURING THE NIGHTS
AND MORNINGS OVER THE NEXT FEW DAYS. MID LEVEL MOISTURE IN SOUTHEAST
FLOW ALOFT WILL BRING SOME AFTERNOON CLOUDS TO THE MOUNTAINS THE
NEXT FEW DAYS WITH A SLIGHT CHANCE OF THUNDERSTORMS FOR MONDAY AND
TUESDAY AFTERNOONS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A TROUGH OF LOW PRESSURE ALONG THE CALIFORNIA COAST WILL SLOWLY
AMPLIFY THROUGH TUESDAY. THIS WILL BRING SLOW COOLING AND STEADY
SLOW DEEPENING OF THE MARINE LAYER WITH NIGHT AND MORNIGN COASTAL
STRATUS EXTENDING INLAND INTO THE WESTERNMOST SAN DIEGO COUNTY
VALLEYS THIS MORNING AND INTO LOWER PORTIONS OF THE INLAND VALLEYS
BY TUESDAY MORNING. FOG COULD BE LOCALLY DENSE NEAR THE MESAS AND
OTHER HIGHER COASTAL TERRAIN THIS MORNING.
MID LEVEL MOISTURE CONTINUES CENTERED AROUND 600 MB IN SOUTHEAST
FLOW ALOFT. WHILE THERE`S BEEN SUFFICENT MOISTURE FOR CLOUDS OVER
THE MOUNTAINS THE PAST FEW AFTERNOONS...THUNDERSTORMS HAVE REMAINED
SOUTH OF THE BORDER. WHILE MOST MODELS SHOW LITTLE OR NO
PRECIPITATION IN THE MOUNTAINS THE NEXT FEW DAYS...THE LOCAL
WORKSTATION VERSION OF THE WRF WITH THE NAM INITIALIZATION DOES SHOW
INCREASING QPF ON THE DESERT SLOPES OF THE MOUNTAINS THE NEXT FEW
DAYS. WHILE THIS APPEARS OVERDONE...THIS MAY INDICATE JUST ENOUGH
INCREASE IN MOISTURE AND INSTABILITY ALONG THE DESERT SLOPES OF THE
MOUNTAINS TO SUPPORT A FEW THUNDERSTORMS MONDAY AND TUESDAY
AFTERNOONS.
&&
.LONG TERM (WEDNESDAY THROUGH SATURSDAY)...
WEAK UPPER TROUGHING WILL MOVE SLOWLY SOUTHWARD ALONG THE CALIFORNIA
COAST BRING SLOWLY COOLING AND DRYING. BY LATE IN THE WEEKEND...THE
TROUGH MAY WEEKEN WITH SLOW WARMING AND A SLOW DECREASE IN THE
MARINE LAYER DEPTH.
&&
.AVIATION...
071030Z...MARINE LAYER IS SHALLOW...LESS THAN 1000 FT DEEP. AREAS OF
STRATUS AND FOG WILL CONTINUE THROUGH 16Z WITH BASES AT/BELOW 800 FT
MSL AND VSBYS BELOW 1 MILE AT TIMES OVER THE MESAS AND HIGHER
COASTAL TERRAIN. SOME LOCAL NEAR ZERO VSBYS WILL OCCUR. CLEARING
WILL OCCUR BETWEEN 15Z AND 17Z...THOUGH LOCAL SCT-BKN CONDITIONS
WILL OCCUR NEAR THE IMMEDIATE COAST. THE MARINE LAYER SHOULD DEEPEN
TONIGHT...WITH STRATUS BASES LIKELY TO BE ABOVE 1000 FT MSL THEN.
ABOVE THE MARINE LAYER...MODERATE AMOUNTS OF MID-LEVEL MOISTURE WILL
RESULT IN SCATTERED CUMULUS TODAY...MAINLY AFTER 18Z...AND WITH
BASES ABOVE 9000 FT MSL. ANY TSTORMS SHOULD REMAIN OVER BAJA
CALIFORNIA AGAIN. OTHERWISE...UNLIMITED VSBYS AND CIGS ARE EXPECTED
THROUGH MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MAXWELL
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
