EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION NATIONAL
WEATHER SERVICE SAN DIEGO CA
AFDSAN 300 AM PST TUE FEB 29 2000
...SYNOPSIS...
A WEAK PACIFIC STORM WILL MOVE INLAND ACROSS CENTRAL CALIFORNIA
TODAY BRINGING A CHANCE OF SHOWERS TO SOUTHWEST CALIFORNIA THIS
AFTERNOON AND TONIGHT WITH GUSTY WINDS FOR THE MOUNTAINS AND DESERTS.
A SECOND PACIFIC STORM WILL BRING ANOTHER CHANCE OF SHOWERS THURSDAY
AFTERNOON THROUGH FRIDAY MORNING.
...DISCUSSION...
AVN/MRF PREFERRED THRU THE NEXT FIVE DAYS. IN THE NR TERM...ACARS
SOUNDINGS AND RAOBS SHOWED A SUBSIDENCE INVERSION BETWEEN 5K AND 6K FT
MSL WITH SOME LOW CLOUDS BANKED UP ALG THE CSTL SLOPES OF THE
SBD/RIV COUNTY MTNS BLO THIS INVERSION MON EVENING. THESE CLOUDS
HAVE SINCE DISSIPATED. AN EARLY MON EVENING HIGH RESOLUTION ACARS
SOUNDING FROM SNA SHOWED A WK MARINE INVERSION TRYING TO FORM AROUND
1500 FT. COAMPS SHOWS A WK CSTL EDDY THIS MORNING...CONFIRMED WITH
SURFACE REPORTS...WITH BOTH COAMPS AND RUC SHOWING A WK CSTL EDDY
FOR WED MORNING THOUGH DIFFERING ON THE DETAILS FOR WED MORNING.
AREAS NEAR THE CST MAY SEE SOME PATCHY STRATUS...OTHERWISE
INCREASING CLOUDINESS FOR SW CA TODAY AS A WK PAC STORM MOVES INLAND
INTO CNTRL CA. BEST CHANCE FOR SHOWERS WL BE NRN RANGES (SBD/RIV
COUNTY MTNS) THIS AFTERNOON AND EVENING WITH LESSER CHANCES
ELSEWHERE LATE THIS AFTERNOON AND EVENING. AVN 850 MB RH IS
SUPPORTIVE OF A BRIEF PD OF LIGHT SHOWERS LATE AFTERNOON EARLY
EVENING FOR MOST AREAS ALG AND W OF MTNS...BUT AMOUNTS SHOULD BE
LIGHT AWAY FM HIGHER TRRN. QPF WL BE LESS THAN FOR SUN STORM...
QUARTER INCH OR LESS CSTL SXNS TO ONE QUARTER TO LCL ONE HALF INCH
NRN RANGES. WITH SNOW LVLS STARTING OUT LWR THAN FOR SUN STORM...
GREATER PERCENTAGE OF QPF WL GO INTO SNOW FOR NRN RANGES...BUT
PROBABLY NOT SUFFICENT FOR WINTER WEATHER ADV...HENCE HAVE WORDED
LCL SNOW ACCUMULATIONS LESS THAN 4 INCHES ABV 5000 FT FOR SBD/RIV
COUNTY MTNS. THU SYS LOOKS A LTL WETTER...COMPARABLE OR SLIGHTLY
LESS THAN AMOUNTS FOR SUN STORM. EXTENDED MDLS CONTINUE TO ADVERTISE
A MORE SUBSTANTIAL STORM FOR SAT NIGHT AND SUNDAY... LINGERING INTO
MON...BUT THIS IS STILL BEYOND THE CURRENT EXTENDED PD.
SAN 230
.SAN...NONE.
MARTIN