Flash Flood Watch 2, NWS San Diego, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
130 PM PST SUN FEB 15 2009

.SYNOPSIS...TODAYS TRANQUIL WEATHER WILL TRANSITION INTO A STORMY
MONDAY WITH WIND...RAIN AND MOUNTAIN SNOW. A STRONG PACIFIC STORM
COULD BRING AN INCH OR MORE OF RAIN TO THE COASTAL BASIN
MONDAY...AND A FOOT OR TWO OF SNOW IN THE SAN BERNARDINO AND
RIVERSIDE COUNTY MOUNTAINS ABOVE 5000 FEET. SHOWERS WILL LINGER
THROUGH TUESDAY...THEN DRY AND WARMER WEDNESDAY THROUGH FRIDAY WITH
WEAK HIGH PRESSURE BUILDING OVER THE SOUTHWEST.

&&

.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.

WILL UPGRADE THE WINTER STORM WATCH TO A WARNING VALID FROM 12Z
MONDAY THROUGH 12Z TUESDAY FOR THE SAN BERNARDINO AND RIVERSIDE
COUNTY MOUNTAINS.

WILL ALSO ISSUE A FLASH FLOOD WATCH FOR MOST OF THE AREA EXCEPT FOR
THE DESERTS VALID FROM 12Z MONDAY UNTIL 02Z TUESDAY.

TEMPERATURES THIS AFTERNOON ARE SHOWING SOME INCREASE OVER SATURDAY
AFTERNOON ESPECIALLY ACROSS THE SAN DIEGO COUNTY MOUNTAINS WHERE
TEMPERATURES ARE RANGING FROM ABOUT 9 DEGREES TO 15 DEGREES ABOVE
SATURDAY UNDER THE WARM ADVECTION TAKING PLACE AHEAD OF THE SYSTEM
MOVING IN FROM THE WEST. SUBTROPICAL MOISTURE CONTINUES TO STREAM
OVER THE AREA FROM THE SOUTHWEST WITH BASES MOSTLY ABOVE 15000 FEET.
THE WESTERN EDGE OF THIS CLOUD SHIELD WAS MOVING INSIDE 120W AS OF
20Z.

THE UPPER LOW CONTINUES TO DIG TO THE SOUTHEAST OFF THE CENTRAL
CALIFORNIA COAST WITH THE ASSOCIATED COLD FRONT TRAILING SOUTHWEST
FROM NEAR MONTEREY TO BEYOND 30N...127W. THE SOUTHERN PART OF THE
FRONT APPEARS TO BE MOVING EAST A LITTLE FASTER THAN THE NORTHERN
PORTION WITH THE FRONT BECOMING MORE NORTH TO SOUTH ORIENTED WITH
TIME. LIGHT STRIKES ARE SHOWING UP ALONG THE FRONT NEAR 30N AS WELL.
SOME DIFFERENCES IN TIMING OF THE FRONT BETWEEN THE 12Z NAM AND THE
12Z GFS MODEL WITH THE NAM BEING A LITTLE SLOWER. THE GFS BRINGS THE
FRONT TO THE COAST AROUND 18Z MONDAY...GIVE OR TAKE A COUPLE HOURS
WHERE AS THE NAM SUGGESTS BETWEEN 21Z AND 00Z. BOTH INDICATE A
SIGNIFANT AMOUNT OF PRECIPITATION AHEAD AND WITH THE FRONT.

THE FOLLOWING RAINFALL ESTIMATES STILL LOOK GOOD...

0.75-1.50 INCHES IN THE SAN DIEGO COAST AND VALLEYS
1-2 INCHES IN ORANGE COUNTY COASTAL PLAIN AND THE INLAND EMPIRE
1.5-3.0 INCHES IN THE RIV/SAN MOUNTAINS
2-4 INCHES IN THE SBD/OC MOUNTAINS AND PALOMAR MOUNTAIN
0.15-0.50 IN THE DESERTS.

THE NAM...GFS AND ECMWF MODELS KEEP FAIRLY DEEP MOISTURE OVER THE
AREA THROUGH TUESDAY WITH THE NAM SUGGESTING THE MOISTURE LASTING
THROUGH WEDNESDAY AS IT SHOWS ANOTHER MINOR SHORTWAVE MOVING THROUGH
TUESDAY NIGHT/WEDNESDAY MORNING. THE GFS SHOWS A MUCH WEAKER BUT
FASTER SHORTWAVE BRUSHING BY LATE TUESDAY. MOISTURE SHOULD DECREASE
ON WEDNESDAY AS A RIDGE BEGINS TO BUILD OVER THE COAST.

THE MEDIUM RANGE MODELS CONTINUE TO SHOW ANOTHER UPPER LOW
DEVELOPING OVER THE EASTERN PACIFIC DURING THE MIDDLE OF THE WEEK
BUT FURTHER OFF THE COAST INDICATING SOME RETROGRESSION TAKING
PLACE. AS THIS LOW DEVELOPS...A RIDGE SHOULD BUILD OVER THE COAST
WHICH HOLDS INTO NEXT WEEKEND SENDING SHORTWAVE TROUGHS NORTHWARD
INTO THE PACIFIC NORTHWEST WHILE KEEPING SOUTHERN CALIFORNIA HIGH
AND DRY. EXPECT SOME WARMING DURING THE LATTER HALF OF THE WEEK AS
WELL. THIS LOW COULD APPROACH THE COAST LATE NEXT WEEKEND BUT WILL
WAIT AND SEE WHAT LATER MODEL RUNS INDICATE.

&&

.AVIATION...
152000Z...UNLESS SOME LOWER CLOUD DECK SNEAKS UP ON US FROM THE
SOUTH...VFR WITH VARIABLE CIGS ABOVE FL100 THROUGH AT LEAST 08Z.
EXPECT DETERIORATING CIGS/VIS BEGINNING AT KSNA BY 12Z...AND
DEVELOPING SOUTH THROUGH KSAN BY 15Z. GUSTY SE WINDS BY 12Z...WITH
SURFACE GUSTS FROM THE SOUTH TO 30 KT POSSIBLE ALONG THE COAST BY
18Z MON. IFR CONDITIONS LIKELY BY 18Z MOST AREAS AND CONTINUING
THROUGH THE AFTERNOON.

&&

.MARINE...
152000Z...WINDS WILL INCREASE OVERNIGHT FROM THE SOUTHEAST BETWEEN
15 AND 25 KT. WINDS WILL CONTINUE TO BUILD OUT OF THE SOUTH ON MON
MORNING TO 25 TO 30 KT WITH GUSTS TO 35 KT POSSIBLE BY LATE MORNING.
A SMALL CRAFT ADVISORY HAS BEEN ISSUED DUE TO THE SHORT-PERIOD WIND
WAVES AND GUSTY WINDS. BEHIND THE FRONT WINDS WILL TURN WESTERLY AND
SLOWLY SUBSIDE MON EVENING. A WEST SWELL WILL ALSO INCREASE...MAINLY
IN THE OUTER WATERS TO 6 TO 8 FEET BY MONDAY AFTERNOON.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

SPECIAL WEATHER STATEMENT.....SEE LAXSPSSGX.

WINTER STORM WARNING FOR SAN BERNARDINO AND RIVERSIDE COUNTY
MOUNTAINS FROM 4 AM MONDAY TO 4 AM TUESDAY...SEE LAXWSWSGX.

FLASH FLOOD WATCH FOR ALL BUT THE DESERT AREAS FROM 4 AM TO 6 PM
MONDAY...SEE LAXFFASGX.

WIND ADVISORY COASTAL AREAS FROM 7 AM TO 4 PM MONDAY...SEE LAXNPWSGX.

SMALL CRAFT ADVISORY FOR THE COASTAL WATERS OFF SAN DIEGO COUNTY IN
EFFECT FROM 1 AM TO 7 PM PST MONDAY...SEE LAXMWWSGX.

&&

PUBLIC...HORTON
AVIATION/MARINE...JAD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN DIEGO CA
900 AM PST SUN FEB 15 2009

CAZ042-043-048-050-055-056-057-058-060-061-062-161200-
ORANGE COUNTY COASTAL AREAS-
SAN DIEGO COUNTY COASTAL AREAS-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY VALLEYS-
SAN BERNARDINO COUNTY MOUNTAINS-
RIVERSIDE COUNTY MOUNTAINS-
SANTA ANA MOUNTAINS AND FOOTHILLS-
SAN DIEGO COUNTY MOUNTAINS-
APPLE AND LUCERNE VALLEYS-
COACHELLA VALLEY-
SAN DIEGO COUNTY DESERTS-
900 AM PST SUN FEB 15 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR
ALL OF EXTREME SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A WINTER STORM WATCH IS IN EFFECT MONDAY. A STRONG PACIFIC STORM
WILL BRING PERIODS RAIN AND LOTS OF MOUNTAIN SNOW. FLASH FLOODING
MAY OCCUR IN THE COASTAL BASIN AND MOUNTAIN SLOPES WITH DEBRIS FLOWS
IN RECENTLY BURNED AREAS. GUSTY WINDS WILL ALSO ACCOMPANY THIS
STORM. SHOWERS WILL LINGER INTO TUESDAY.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER ACTIVATION MAY BE NEED FOR MONDAY.

HORTON