207 
FPUS66 KSAN 142059
AFDSAN

SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT SAT JUN 14 1997

                           ...SYNOPSIS...
STRONG UPPER-LEVEL LOW PRESSURE WILL GRADUALLY WEAKEN AND MOVE EAST
THROUGH MONDAY. THE VERY DEEP MARINE LAYER WILL BECOME SOMEWHAT MORE
SHALLOW SUNDAY NIGHT AND MONDAY...BRINGING A RETURN TO THE NORMAL
NIGHT AND MORNING LOW CLOUD PATTERN. A FEW THUNDERSTORMS ARE POSSIBLE
SUNDAY ALONG THE EAST SLOPES OF THE MOUNTAINS AND DESERTS AS THERE
WILL BE BETTER SURFACE HEATING AND MORE RESIDUAL MOISTURE.

                          ...DISCUSSION...
RAMSDIS SHOWS THAT SKIES HAVE PARTIALLY CLEARED IN MOST AREAS THIS
AFTERNOON. THE THICKEST CLOUD COVER WAS OVER THE INLAND EMPIRE. THE
MOUNTAINS AVERAGED ABOUT 5 DEGREES WARMER TODAY THAN FRIDAY...BUT
CONVECTION WAS STILL LIMITED TO CUMULUS OVER THE SBD/RIV COUNTY
MOUNTAINS ADJACENT TO THE DESERTS.

IT LOOKS LIKE A GRADUAL TREND TOWARDS FAIR WEATHER THROUGH MONDAY.
THE 850 FLOW BECOMES MORE NORTHWESTERLY...EVEN TONIGHT...BUT FLOW IS
WEAK SO THE MARINE LAYER SHOULD SLOWLY SHRINK TO ABOUT 2000-2500 FEET
BY MONDAY. SOME DRIZZLE COULD STILL OCCUR TONIGHT FROM THE MOUNTAINS
WEST...BUT THE TREND IS DEFINITELY DOWN FOR PRECIP. IN THE
MTNS/DESERTS...A FEW TSTORMS COULD FORM SUNDAY AS 500MB TEMPS REMAIN
AROUND -10C AND THE SURFACE HEATS UP BETTER DUE TO LESS CLOUDS. 700MB
RH VALUES SHOULD REMAIN HIGH ONE MORE DAY. AREAS OF LOW CLOUDS IS
ABOUT ALL TO BE EXPECTED SUNDAY NIGHT/MONDAY MORNING...THOUGH SOME
CUMULUS COULD STILL OCCUR MONDAY OVER HIGHER TERRAIN AS THE WEAK FLOW
MAKES IT DIFFICULT TO REMOVE A LOT OF THE MID-LEVEL MOISTURE.

TEMPERATURES WILL FINALLY INCREASE...ESPECIALLY OVER THE PRESENTLY
UNSEASONABLY COOL MOUNTAINS AND DESERTS. AVN HAS 850 TEMPS RETURNING
TO ABOUT 18C BY MONDAY...WHICH MEANS A RETURN TO MOSTLY 90S IN THE
DESERTS. ANOTHER TROUGH SHOULD AFFECT THE AREA WED/THU...BUT THE
THREE EXTENDED MODELS DIFFER ON POSITIONING. ENS SOLUTIONS SHOW THE
TROUGH TO BE FURTHER WEST THAN THE CURRENT SYSTEM BUT ALL MODELS SHOW
IT TO BE LESS DEVELOPED.

SAN BU 062/069 062/071 062 071100 

MAXWELL