EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
AFDSAN 320 AM PST TUE MAR 5 2002
.SYNOPSIS...HIGH PRESSURE WILL WEAKEN OVER SOUTHWEST CALIFORNIA
THROUGH WEDNESDAY WITH A COOLING TREND SPREADING INLAND FROM THE
COAST AND A RETURN OF COASTAL LOW CLOUDS AND FOG. A PACIFIC TROUGH
OF LOW PRESSURE WILL BRING A CHANCE OF LIGHT SHOWERS WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT. FAIR AND A LITTLE WARMER FOR FRIDAY THROUGH
THE WEEKEND.
.DISCUSSION...THOUGH THE AVN WAS WELL-INITIALIZED OVR THE ERN PAC...
GENERALLY PREFER THE WKR ETA AS THE AVN HAS HAD TOO MUCH AMPLITUDE
WITH RECENT SYSTEMS. BOTH MDLS ARE SIMILAR IN TIMING AND GENERAL
TRACK OF SHORTWAVE FEATURES TO AFFECT SW CA WED/THU...THOUGH.
ETA SHOWS A WK CST EDDY THIS MORNING. MON EVENING ACARS SOUNDINGS
SHOWED THE BASE OF THE MARINE INVERSION NR 500 FT WITH A TOP NR
1200. AS SHOWN BY TEMPERATURE/DEWPOINT SPREADS...LWR LVLS ARE STILL
FAIRLY DRY...EVEN AT THE CST. SOME PATCHY STRATUS IS POSSIBLE THIS
MORNING FM THE CST INLAND TO THE MESAS. WITH THE LOW INVERSION
HEIGHT...ANY FOG COULD BE LCLLY DENSE ALG THE CST. ETA ALSO SHOWS A
WK CSTL EDDY TONIGHT INTO WED MORNING. STRATUS SHOULD SPREAD QUICKLY
INLAND OVR SRN CSTL SXNS EARLY THIS EVENING...REACHING THE VLYS LATE
TONIGHT.
THE SYSTEM FOR WED/THU APPEARS SIMILAR TO MANY THAT HAVE AFFECTED SW
CA THIS WINTER. LEAD SHORTWAVE MOVES INLAND ACROSS CENTRAL AND SRN
CA WED AND WED NIGHT WITH ONLY WK DYNAMICS FOR SW CA. BEST CHANCES
FOR RAIN WITH THIS SHORTWAVE WL BE ACROSS ORANGE COUNTY AND THE
INLAND EMPIRE NORTH...MAINLY LATE AFTERNOON WED INTO WED NIGHT WITH
LESSER CHANCES FARTHER S WED NIGHT. FOR LATE THU INTO THU
NIGHT...ONE SHORTWAVE MOVES INLAND ACROSS CNTRL CA WITH A
SECOND...WKR SHORTWAVE...MOVG INLAND ACROSS NRN BAJA THU NIGHT.
THOUGH SW CA IS ON THE FRINGES OF BOTH OF THESE SHORTWAVES...THE
BEST CHANCES FOR RAIN LATE THU INTO THU NIGHT SHOULD BE ACROSS THE
SOUTHEAST HALF OF THE FORECAST AREA...MAINLY SAN DIEGO COUNTY.
OVERALL RAINFALL AMOUNTS SHOULD BE FAIRLY LOW WITH LIGHT SNOWFALL
POSSIBLE AT THE HIGHER ELEVATIONS. ANOTHER WKR SYSTEM MAY AFFECT
PORTIONS OF SRN CA LATE SUN OR EARLY MON. FOR NOW...WL RETAIN THE
CURRENT PARTLY CLOUDY WORDING.
.SAN...NONE.
MARTIN