EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
AFDSAN 930 PM PDT THU AUG 5 1999
...SYNOPSIS...
CLOUDS FROM A COASTAL EDDY WILL LINGER THROUGH THE AFTERNOON IN
SOME COASTAL AREAS FRIDAY. A DEEP MARINE LAYER AND STRONG ONSHORE
FLOW WILL KEEP TEMPERATURES BELOW AVERAGE THROUGH SATURDAY.
...DISCUSSION...
COASTAL EDDY GOING STRONG THIS EVENING WITH SOUTHERLY WINDS AT MANY
REPORTING STATIONS. PRESSURE GRADIENTS REMAIN STRONGLY ONSHORE AND
THE CLOUDS SURGED QUICKLY INLAND THIS EVENING. 00Z NKX SOUNDING AND
ACARS DATA SHOW THE INVERSION BASE BETWEEN 1500 AND 2000 FEET.
GIVEN THE COASTAL EDDY...THE STRONG ONSHORE FLOW...AND A DEEPENING
MARINE LAYER...WOULD NOT BE SURPRISED TO SEE DRIZZLE IN SOME AREAS
TONIGHT. THESE FACTORS WILL ALSO LIMIT COASTAL CLEARING FRIDAY.
UPPER LOW OFF THE NORTHERN CALIFORNIA COAST FORECAST TO DRIFT
SOUTHWARD AND DEEPEN FRIDAY. ONSHORE GRADIENTS WILL REMAIN STRONG
FOR ANOTHER DAY OF BELOW AVERAGE TEMPERATURES...ALONG WITH BREEZY
AFTERNOONS IN THE MOUNTAINS AND DESERTS.
00Z MODELS DROP SHORTWAVES INTO THE WEST COAST TROF REINFORCING ITS
POSITION THROUGH THE WEEKEND...KEEPING THE UPPER HIGH OVER THE
SOUTHERN PLAINS FARTHER EAST THAN ORIGINALLY THOUGHT. IF THIS
VERIFIES...A DOMINANT SOUTHWEST FLOW ALOFT WOULD PREVENT MUCH
WARMING THIS WEEKEND...AND NORTHWEST FLOW AROUND PT CONCEPTION
WOULD KEEP THE THREAT OF A COASTAL EDDY GOING INTO SATURDAY.
SAN 0000
.SAN...NONE.
MOEDE