Flash Flood Warning 16, NWS San Diego, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
120 PM PST SUN JAN 27 2008

.SYNOPSIS...PERIODS OF RAIN....SNOW...AND GUSTY WINDS FROM A
POWERFUL WINTER STORM WILL CONTINUE INTO TONIGHT. THE LOW PRESSURE
AREA OFF THE COAST WILL MOVE INLAND THIS EVENING BRINGING COLDER
AIR...LOWER SNOW LEVELS...AND POSSIBLE THUNDERSTORMS. THE RAIN...
SNOW...AND WIND WILL CONTINUE INTO MONDAY AS MOIST...UNSTABLE
NORTHWEST FLOW CONTINUES. DRIER THROUGH MIDWEEK BUT CONTINUED COOL
WITH A CHANCE OF SOME LIGHT RAIN AND SNOW AT TIMES.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

...SPC CONVECTIVE OUTLOOK INCLUDES THE SOUTHERN CA COAST IN A SLIGHT
RISK OF SEVERE THUNDERSTORMS THROUGH THIS EVENING...

LATEST VISIBLE SATELLITE IMAGERY AND RADAR LOOP SHOWS CONVECTION HAS
FIRED TO THE NORTH WITH A TRAILING BAND OF CLOUDS FROM ORANGE COUNTY
OFFSHORE. EXPECT FURTHER DESTABILIZATION THIS AFTERNOON DUE TO
DIABATIC HEATING AND APPROACHING VORT LOBE. A FEW LOW TOPPED
SUPERCELLS COULD DEVELOP WITH HAIL AND STRONG WINDS OVER THE COASTAL
WATERS. ISOLATED WATERSPOUTS AND TORNADOES ARE POSSIBLE AS WELL.
LOOKS LIKE THE BEST FORCING AND INSTABILITY WILL BE OVER NORTHERN
AREAS THIS AFTERNOON INCLUDING LA COUNTY...THE INLAND EMPIRE...AND
PORTIONS OF ORANGE COUNTY...THEN SHIFT SOUTH INTO SAN DIEGO COUNTY
THIS EVENING.

MAIN SUBTROPICAL PRECIPITATION BAND HAS EXITED THE CWA SO ANY
FURTHER PRECIPITATION WILL BE MORE SHOWERY IN NATURE EXCEPT SHER
UPSLOPE FLOW IS ENHANCING AMOUNTS. GUSTY WINDS CONTINUE IN SOME
AREAS...ESPECIALLY OVER THE NORTHERN DESERTS AND DESERT SLOPES WITH
GUSTS IN EXCESS OF 50 MPH. THE ATMOSPHERE WILL CONTINUE TO
DESTABILIZE INTO THIS EVENING WITH AN INCREASING CHANCE OF SHOWERS
AND THUNDERSTORMS INTO TONIGHT.

BASED ON OUR LOCAL WIND PROGRAM AND CONTINUED STRONG SURFACE
PRESSURE GRADIENTS DEVELOPING TO THE GREAT BASIN...WIND ADVISORY
STRENGTH WINDS ARE LIKELY TO CONTINUE THROUGH MONDAY IN THE
MOUNTAINS AND DESERTS WHERE THE WIND ADVISORY WILL LIKELY HAVE TO BE
EXTENDED. SOME STRONG LOCAL GUSTS WILL BE POSSIBLE WEST OF THE
MOUNTAINS AS WELL...ESPECIALLY NEAR CONVECTION THIS EVENING.

STRONG AND MOIST UPSLOPE FLOW WILL CONTINUE TO SUPPORT MODERATE
SNOWFALL RATES IN THE MOUNTAINS THROUGH MON. RESORT TEMPS/DEW POINTS
HAVE ALREADY SLID TODAY AND SHOULD CONTINUE TO FALL OVERNIGHT. 850
MB TEMPS FALL BELOW FREEZING BY MON AFTERNOON BUT SNOW LEVELS SHOULD
LOWER IN CONVECTIVE PRECIPITATION EARLIER. THE WINTER STORM WATCH
FOR THE SAN DIEGO MOUNTAINS HAS BEEN UPGRADED TO A WARNING BASED ON
EXPECTED SNOW AMOUNTS MARGINALLY REACHING CRITERIA AND STRONG SW TO
W WINDS WITH GUSTS TO 60 MPH AT TIMES. STRONG WINDS AND SNOW SHOWERS
WILL CONTINUE IN THE SAN BERNARDINO MOUNTAINS THROUGH MON...SO EVEN
THOUGH THE WSW MAY BE ALLOWED TO EXPIRE AT 10 AM...WIND ADVISORIES
WILL LIKELY BE ISSUED AND INCLUDE THE DESERTS.

MODELS WEAKEN THE UPPER CENTER OFF THE COAST AND BRING IT INLAND
TONIGHT. EXPECT OCCASIONAL MODERATE TO HEAVY RAIN AND SNOW TO
ACCOMPANY THIS SYSTEM INTO MONDAY AS YET ANOTHER VORT MAX DROPS INTO
THE UPPER TROUGH. 500 MB HEIGHTS GRADUALLY RECOVER TUE FOR SOME
DRYING...THEN ANOTHER SYSTEM DROPS SOUTH THROUGH THE MAIN UPPER
TROUGH OVER THE WESTERN U.S. ON WED KEEPING TEMPS ON THE COOL SIDE
AND GUSTY WINDS IN THE MOUNTAINS. ANY PRECIPITATION SHOULD BE LIGHT.
ANOTHER SHOT COMES DOWN THE PIPE FOR GUSTY WINDS AND A SLIGHT CHANCE
OF SOME LIGHT PRECIPITATION FRI.

&&

.AVIATION...
272015Z...THE BAND OF SHOWERS THAT WAS OVER THE AREA THIS MORNING
WAS MOVING SLOWLY TO THE EAST AND AWAY FROM THE AREA THIS AFTERNOON.
THIS BAND OF SHOWERS BROUGHT LOW CEILINGS TO MOST AIRPORT THIS
MORNING. THE CEILINGS AT KPSP AND KTRM CONTINUE TO BE SLOW TO
RECOVER THIS AFTERNOON BUT THE CEILINGS SHOULD RISE AS THE CLOUDS
BREAK UP THROUGH THE AFTERNOON. ADDITIONAL BANDS OF SHOWERS AND
ISOLATED THUNDERSTORMS OFF THE COAST ARE EXPECTED TO MOVE ONSHORE
AND INLAND OVER THE AREA THIS AFTERNOON AND THROUGH THE NIGHT.
SHOWERS CAN BE HEAVY AT TIMES AND MAY PRODUCE LOW CEILINGS AND
VISIBILITIES AT TIMES. SHOWER ACTIVITY SHOULD TAPER OFF DURING THE
AFTERNOON ON MONDAY.

STRONG GUSTY SOUTH TO SOUTHWEST WINDS 20 TO 25 KNOTS WILL CONTINUE
OVER THE AREA WHICH MAY IMPACT SOME OF THE COASTAL AIRPORTS SUCH AS
KSAN...KCRQ AND KSNA THROUGH THE AFTERNOON. EXPECT THE WIND TO
DIMINISH TONIGHT.  HORTON

&&

.MARINE...
272015Z...CONTINUED SMALL CRAFT ADVISORY WINDS EXPECTED OVER THE
COASTAL WATERS THROUGH TONIGHT. AN UNSTABLE AIR MASS WILL MOVE OVER
THIS AFTERNOON AND BRING A CHANCE OF THUNDERSTORMS AND FUNNEL CLOUDS
OR WATERSPOUTS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

FLOOD WARNING FOR THE MOJAVE RIVER...SEE LAXFLWSGX.

FLASH FLOOD WATCH ENTIRE CWA THROUGH THIS EVENING. SEE LAXFFASGX.

WIND ADVISORY UNTIL 10 PM PST THIS EVENING. SEE LAXNPWSGX.

WINTER STORM WARNING FOR THE RIVERSIDE COUNTY...SAN BERNARDINO
COUNTY...AND SAN DIEGO COUNTY MOUNTAINS. SEE LAXWSWSGX.

RIVER STATEMENT FOR AREA RIVER STAGES...SEE LAXRVSSGX.

SMALL CRAFT ADVISORY THROUGH LATE TONIGHT...SEE LAXCWFSGX.     .

MARINE WEATHER STATEMENT FOR POSSIBLE THUNDERSTORMS AND WATERSPOUTS.
SEE LAXMWSSGX.

&&

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

NWS ON THE WEB AT WEATHER.GOV/SANDIEGO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN DIEGO CA
845 PM PST SUN JAN 27 2008

CAZ042-043-048-050-055-056-057-058-060-061-062-281200-
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-
845 PM PST SUN JAN 27 2008

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

A STRONG PACIFIC LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS
INTO MONDAY WITH HEAVY RAIN...GUSTY WINDS...AND MOUNTAIN SNOW.

.DAY ONE... TONIGHT.

* FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 9 AM MONDAY.
  HEAVY RAIN COULD CAUSE DEBRIS FLOWS...ESPECIALLY IN THE BURN
  AREAS. SEE LAXFFASGX FOR DETAILS.

* A WINTER STORM WARNING IS IN EFFECT FOR THE SAN BERNARDINO...
  SAN DIEGO AND RIVERSIDE COUNTY MOUNTAINS TONIGHT. SEE LAXWSWSGX.

* VERY STRONG WINDS ACROSS ALL AREAS TONIGHT. SMALL CRAFT ADVISORIES
  AND GALE WARNINGS ARE IN EFFECT. SEE LAXCWFSGX. WIND ADVISORY ON
  LAND SEE LAXNPWSGX.

.DAYS TWO THROUGH SEVEN... MONDAY THROUGH SATURDAY.

* FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 9 AM MONDAY.
  HEAVY RAIN COULD CAUSE DEBRIS FLOWS...ESPECIALLY IN THE BURN
  AREAS. SEE LAXFFASGX FOR DETAILS.

* STRONG AND GUSTY WINDS OVER THE MOUNTAINS AND DESERTS THROUGH MONDAY
  EVENING.

* A WINTER STORM WARNING IS IN EFFECT FOR THE SAN BERNARDINO...SAN
  DIEGO AND RIVERSIDE COUNTY MOUNTAINS MONDAY. SEE LAXWSWSGX.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER SPOTTER ACTIVATION IS REQUESTED FOR TODAY.

MOEDE