000
FXUS66 KSGX 062144
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
145 PM PST MON FEB 6 2012

.SYNOPSIS...
THE NEXT SYSTEM WILL APPROACH THE CENTRAL CALIFORNIA COASTLINE
TONIGHT...SPREADING PLENTY OF MID AND HIGH LEVEL CLOUDS ACROSS THE
REGION.  THIS SYSTEM WILL TRACK SOUTHEASTWARD ALONG THE CALIFORNIA
COAST ON TUESDAY AND TUESDAY NIGHT...BRING A CHANCE OF RAIN AND
HIGHER ELEVATION SNOW TO THE REGION BY LATE AFTERNOON AND EVENING.
AS THIS LOW TRACK SOUTHWARD AND INTO BAJA ON WEDNESDAY...DRIER
CONDITIONS WILL DEVELOP ACROSS THE REGION...ALONG WITH MODERATE AND
GUSTY NORTHEAST TO EAST WINDS.  THESE DRY AND GUSTY CONDITIONS WILL
CONTINUE THROUGH THE END OF THE WORK WEEK.  ALTHOUGH A COUPLE OF
DISTURBANCES WILL MOVE ACROSS NORTHERN CALIFORNIA THIS
WEEKEND...DRIER CONDITIONS WILL CONTINUE TO PREVAIL ACROSS SOUTHERN
CALIFORNIA.

&&

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

WATER VAPOR IMAGERY CONTINUES TO SHOW SOUTHERN CALIFORNIA SITUATED
UNDER A TRANSITORY RIDGE OF HIGH PRESSURE THIS AFTERNOON...WITH A
LARGE TROUGH OF LOW PRESSURE OVER THE PACIFIC.  THE MAIN LOW
ASSOCIATED WITH THIS TROUGH IS CURRENTLY NEAR 41.5 NORTH AND 144
WEST...WITH A SECONDARY SYSTEM ROUNDING THE BASE OF THE TROUGH.  IT
IS THIS SECONDARY SYSTEM THAT WILL BE THE MAIN WEATHER MAKER FOR
CENTRAL AND SOUTHERN CALIFORNIA OVER THE NEXT 24 TO 36 HOURS.  IN
THE MEANTIME...MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO SPREAD
ACROSS SOUTHERN CALIFORNIA THIS AFTERNOON AND EVENING...WITH A
RELATIVELY MILD NIGHT IN STORE FOR THE REGION.

AS THE FOCUS SHIFTS INTO TUESDAY SYSTEM...MODELS ARE CONTINUING TO
HAVE SOME ISSUES WITH THE POSITION AND TRACK OF THE SYSTEM.  AT THIS
TIME...THE 12Z NAM AND GFS ARE STILL THE FARTHEST NORTH...FORMING
THE LOW NORTH OF POINT CONCEPTION...BEFORE TRACKING IT SOUTHEASTWARD
JUST OFF OR ALONG THE SOUTHERN CALIFORNIA COAST.  MEANWHILE...THE
12Z ECMWF SEEMS TO HAVE SHIFTED THE LOW A LITTLE FURTHER
NORTHWARD...BUT STILL KEEP THE LOW FORMING OVER THE BIGHT...BEFORE
TRACKING OFF TO THE SOUTHEAST.  MEANWHILE...THE 12Z GEM IS STILL THE
OUTLIER...SHOWING THIS SYSTEM FORMING WELL SOUTH.  GIVEN THESE
DIFFERENT PLACEMENTS...IT APPEARS THAT THE WINDS WILL BE SOUTHEAST
OR EVEN EAST OVER SOUTHERN CALIFORNIA FOR A GOOD PORTION OF THE DAY
ON TUESDAY.  THEREFORE...THIS SOME MUCH DRIER AIR FILTERING INTO THE
REGION AHEAD OF THIS SYSTEM WILL PROLONG THE START OF THE
PRECIPITATION.  MOST OF THE MODELS AGREE WITH THIS IDEA...WITH THE
ORANGE COUNTY COAST POTENTIALLY SEEING SOME PRECIPITATION BY
MIDDAY...BUT MOST AREAS NOT SEEING ANYTHING UNTIL THE AFTERNOON OR
EARLY EVENING COMMUTE.

IT ALSO APPEARS THAT THIS INTRUSION OF DRY AIR INTO THE SYSTEM MAY
HELP WEAKEN THE STORM...WITH PRECIPITATION AMOUNTS REMAINING MAINLY
BETWEEN TENTH AND A QUARTER OF AN INCH.  GIVEN THE TRACK OF THE
SYSTEM OFF THE SOUTHERN CALIFORNIA COAST...IT ALSO LOOKS LIKE THE
COASTAL AREAS WILL SEE THE BRUNT OF THE PRECIPITATION.  THERE SHOULD
BE A SUFFICIENT AMOUNT OF COLD AIR WITH THIS SYSTEM TO BRING SOME
HIGHER ELEVATION SNOW TO THE REGION...WITH SNOW LEVELS FALLING TO
AROUND 5500 FEET.  THEREFORE...A LIGHT DUSTING WILL BE POSSIBLE OVER
THE HIGHEST ELEVATIONS...UP TO 3 INCHES LOCALLY AND MAINLY ACROSS
THE SAN BERNARDINO MOUNTAINS LATE TUESDAY AFTERNOON AND EVENING.

ALTHOUGH A FEW LINGERING SHOWERS MAY BE POSSIBLE ON WEDNESDAY
MORNING...MAINLY OVER SAN DIEGO COUNTY...DRIER CONDITIONS WILL BE
DEVELOP.  MODELS ARE ALSO SHOWING THE WINDS TRANSITIONING TO
NORTHEASTERLY DURING THE DAY...WITH GUSTY OFFSHORE WINDS DEVELOPING
THROUGH AND BELOW THE FAVORED CANYONS AND PASSES.  AT THIS POINT IN
TIME...THE SURFACE GRADIENTS ARE ONLY PEAK AROUND 10 MBS BETWEEN
LINDBERGH AND TONOPAH...AND BETWEEN 4 AND 5 MBS BETWEEN LINDBERGH
AND DAGGETT.  THE UPPER LEVEL WINDS ALSO LOOK RELATIVELY WEAK...30
TO 35 KNOTS AT BEST BETWEEN 850 AND 700 MBS.  THEREFORE...THINK THAT
SOME ADVISORY TYPE WINDS MAYBE POSSIBLE...BUT AM NOT OVERLY
IMPRESSED AT THIS TIME.  HOWEVER...THESE WINDS WILL CONTINUE TO BE
POSSIBLE THROUGH FRIDAY.

MODELS ARE SHOWING ANOTHER SYSTEM MOVING ACROSS NORTHERN CALIFORNIA
FOR THIS WEEKEND...AND POTENTIALLY DIGGING INTO THE DESERT SOUTHWEST
SATURDAY NIGHT OR SUNDAY.  EVEN GIVEN THE ISSUES WITH TIMES...IT
LOOKS AS THOUGH THINGS WILL REMAIN DRY ACROSS THE REGION...WITH
COOLER CONDITIONS PREVAILING.

&&

.AVIATION...
062025Z...BKN CLD LYRS IN FL150-200 WILL CONTINUE THROUGH THIS
AFTERNOON. BY 07/00Z...A SCT-BKN STRATUS LAYER WITH BASES AROUND
1000 FT MSL WILL BE NEAR THE IMMEDIATE COAST...BUT THE STRATUS
SHOULD NOT PENETRATE INLAND. THEREFORE...IT DOES NOT APPEAR LIKELY
THAT LOW STRATUS WILL IMPACT THE COASTAL AIRPORTS TONIGHT.
OTHERWISE...BKN-OVC CLD LAYERS AOA FL150 WILL PREVAIL TONIGHT. AFTER
07/12Z...CLDS WILL QUICKLY LOWER TO AROUND 5000 FT MSL TUESDAY
AFTERNOON WITH LIGHT SHOWERS DEVELOPING WEST OF THE MOUNTAINS.

&&

.MARINE...
TRACK OF DEVELOPING LOW PRESSURE SYSTEM EXPECTED TO PRODUCE
SOUTHEAST WINDS GUSTING TO 25 KT OVER THE COASTAL WATERS FOR A BRIEF
PERIOD TUESDAY AFTERNOON. ASSOCIATED SHORT PERIOD WIND WAVES WILL BE
OPPOSING THE BUILDING WEST TO NORTHWEST SWELL. VERY ROUGH TO
HAZARDOUS SEA CONDITIONS COMBINED WITH THE WINDS MAY WARRANT SMALL
CRAFT ADVISORIES...BUT THERE IS HIGH UNCERTAINTY ON THE PRECISE
TIMING AND DURATION OF THE STRONGEST WINDS. THEREFORE...WILL WAIT
FOR SUBSEQUENT MODEL RUNS BEFORE ISSUING SMALL CRAFT ADVISORIES.

HIGH SURF ADVISORIES WILL LIKELY BE NEEDED FOR BOTH ORANGE COUNTY
AND SAN DIEGO COUNTY COASTS WEDNESDAY THROUGH THURSDAY NIGHT DUE THE
WEST-NORTHWEST SWELL CONTINUING TO BUILD.

&&

.FIRE WEATHER...
ALTHOUGH WETTING RAINS ARE EXPECTED WEST OF THE MOUNTAINS AND IN THE
MOUNTAINS ON TUESDAY AFTERNOON AND NIGHT...GUSTY NORTHEAST WINDS AND
DRY CONDITIONS WILL DEVELOP ACROSS SOUTHERN CALIFORNIA BEHIND THE
SYSTEM ON WEDNESDAY.  TEMPERATURES WILL WARM WEDNESDAY THROUGH
FRIDAY...AND HUMIDITIES WILL FALL.  MODERATE TO POOR OVERNIGHT
RECOVERIES WILL ALSO DEVELOP DURING THE OVERNIGHT HOURS.  SOME OF
THE FAVORED SPOTS COULD SEE WIND GUSTS RANGING BETWEEN UP TO 45
MPH.  IF MEANINGFUL RAIN DOES NOT MATERIALIZE ACROSS PORTIONS OF THE
REGION ON TUESDAY AFTERNOON OR TUESDAY NIGHT...FIRE WEATHER CONCERNS
WILL SURFACE AGAIN FOR THE LATTER HALF OF THE WEEK.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC/FIRE...PALMER
AVIATION/MARINE...MOKER

NWS SGX Office Area Forecast Discussion