Winter Storm Watch 3, NWS San Diego, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1003 AM PST FRI JAN 29 2016

.SYNOPSIS...
WARM AND DRY TODAY UNDER WEAKENING HIGH PRESSURE. A LOW PRESSURE
SYSTEM OFF THE WEST COAST ON SATURDAY WILL MOVE INLAND THROUGH
SOUTHERN CALIFORNIA ON SATURDAY NIGHT AND SUNDAY BRINGING
COOLING...STRONG GUSTY WEST WINDS...WITH LOCALLY HEAVY
PRECIPITATION...MOSTLY ON SUNDAY. SHOWERS WILL DECREASE SUNDAY
NIGHT. FOR NEXT WEEK...HIGH PRESSURE ALOFT WILL STRENGTHEN NEAR
THE WEST COAST BRINGING DRY WEATHER WITH A WARMING TREND.

&&

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

AT 9 AM PST...WATER VAPOR SATELLITE IMAGERY DISPLAYED WET...ZONAL
FLOW OVER NORTHERN CA/OREGON...AND NW FLOW ALOFT OVER SW CA. 580
DM H500 HEIGHTS OVER THE REGION AND WEAK OFFSHORE SURFACE FLOW
WILL HELP INLAND HIGH TEMPERATURES RISE 5 TO 10 DEG F ABOVE NORMAL
TODAY...WITH LOCAL AREAS OF THE MOUNTAINS RISING UP TO 20 DEG F
ABOVE SEASONAL NORMALS. PATCHY FOG MAY DEVELOP TONIGHT ALONG THE
COAST AS THE MARINE LAYER REDEVELOPS WITH LOWERING HEIGHTS ALOFT.

A SHORTWAVE TROUGH MOVING ACROSS THE REGION LATE SATURDAY WILL
INCREASE ONSHORE FLOW...AND CREATE GUSTY WESTERLY WINDS IN THE
MOUNTAINS AND DESERTS. GUSTS TO AROUND 60 MPH ARE POSSIBLE NEAR
MOUNTAIN RIDGES AND ALONG DESERT MOUNTAIN SLOPES LATE SATURDAY
THROUGH EARLY SUNDAY. LIGHT PRECIPITATION OF A FEW HUNDREDTHS IS
POSSIBLE...MAINLY OVER THE MOUNTAINS...DURING THE PERIOD. LIGHT
SNOWFALL IS EXPECTED ABOVE 7000 FT.

A DEEPER...MORE SIGNIFICANT TROUGH WILL MOVE ACROSS THE REGION
SUNDAY THROUGH EARLY MONDAY. THIS WILL CREATE STRONG WESTERLY
WINDS ACROSS MOST AREAS THROUGH THE PERIOD...AND MODERATE TO
HEAVY PRECIPITATION OVER AND WEST OF THE MOUNTAINS AS THE FRONT
MOVES SOUTHEAST. HIGH-RES MODELS SHOW HEAVIER PRECIP BEGINNING IN
NORTHERN AREAS MID SUNDAY AFTERNOON AS PRECIPITABLE WATER VALUES
RISE TO JUST ABOVE ONE INCH...AND DEVELOP PRECIP TO THE SE
THROUGH SUN EVENING. H850 WINDS AROUND 50 KT MAY CREATE GUSTY
WINDS EVEN ALONG THE COAST AND IN THE VALLEYS AS THE FRONT PASSES.
WESTERLY GUSTS NEAR 75 MPH ARE POSSIBLE IN THE MOUNTAINS AND
DESERTS...AND 35 MPH IN THE VALLEYS AND ALONG THE COAST. ISOLATED
GUSTS AROUND 45 MPH...OR LOCALLY HIGHER...ARE POSSIBLE IN THE
VALLEYS AND ALONG THE COAST AS THE FRONT MOVES SOUTHEAST. AREAS
OF BLOWING DUST ARE POSSIBLE IN THE DESERTS BEFORE PRECIP BEINGS.

...FORECAST STORM TOTAL PRECIP (IN) LATE SAT THROUGH EARLY MON...
DESERTS.........0.25 TO 0.50
COAST/VALLEYS...0.50 TO 1.00
MOUNTAINS.......1.50 TO 2.50...WITH LOCALLY GREATER AMOUNTS

SNOW LEVELS WILL START OUT AROUND 7500 FT SAT NIGHT...LOWER TO
6000 FT SUNDAY MORNING...4500 FT SUNDAY EVENING AND 3500 FT
MONDAY MORNING.

...FORECAST STORM TOTAL SNOWFALL (IN) LATE SAT THROUGH EARLY MON...
3500 TO 4000 FT...TRACE TO 1
4000 TO 5000 FT...2 TO 5
5000 TO 6000 FT...3 TO 10
6000 TO 7000 FT...8 TO 16
ABOVE 7000 FT.....10 TO 20

LOWER HEIGHTS ALOFT WILL DROP HIGH TEMPERATURES 5 TO 15 DEG F
BELOW SEASONAL NORMALS SUNDAY THROUGH TUESDAY. PRECIP SHOULD END
EARLY MONDAY MORNING...WITH GUSTY WINDS SLOWLY DIMINISHING MONDAY
AFTERNOON.

WEAK RIDGING AND SURFACE OFFSHORE FLOW WILL CREATE DRY AND WARMER
WEATHER FOR THE MIDDLE OF NEXT WEEK...WITH HIGHS CLOSER TO
NORMAL THROUGH THE PERIOD.

&&

.AVIATION...
291600Z...SCT-BKN150-200 THROUGH THIS EVENING. OCNL SCT005-010 ALONG
THE COAST AND OVER THE COASTAL WATERS TODAY. BTWN 02-06Z...BKN004-
008 DEVELOPING NEAR THE COAST...THEN MOVING 15-20 MI INLAND BTWN 06-
14Z. LOCAL VIS AOB 2SM POSSIBLE OVER HIGHER COASTAL TERRAIN AND
COASTAL MESAS...INCLUDING KCRQ AND KMYF.

&&

.MARINE...
AT 8 AM...THE SAN CLEMENTE BASIN BUOY REPORTED A 9 FOOT SWELL AT 21
SECONDS. THIS LARGE LONG-PERIOD WEST-NORTHWEST SWELL WILL PRODUCE
SEAS OF 9-12 FEET OVER THE OUTER COASTAL WATERS TODAY AND TONIGHT.

SUNDAY AFTERNOON THROUGH MONDAY NIGHT...A STRONG COLD FRONT MOVING
THROUGH THE REGION WILL BRING NORTHWEST GALE-FORCE WIND GUSTS OF 35-
45 KT. THE STRONG WINDS AND A LARGE SHORT-PERIOD SWELL FROM 14-18
FEET WILL RESULT IN DANGEROUS BOATING CONDITIONS FOR SUNDAY
AFTERNOON THROUGH MONDAY NIGHT. THE MARINE WEATHER STATEMENT
(LAXMWSSGX) HAS THE DETAILS.

&&

.BEACHES...
800 AM...A HIGH SURF ADVISORY IS IN EFFECT THROUGH 10 PM
SATURDAY. SURF WILL RANGE FROM 6-10 FEET WITH SETS TO 12 FEET AT THE
BEACHES IN NORTHERN ORANGE COUNTY AND SOUTHERN SAN DIEGO COUNTY.
THERE WILL ALSO BE STRONG RIP CURRENTS AND BEACH EROSION.

A LARGER WEST-NORTHWEST SWELL OF 14-18 FEET IN THE OUTER WATERS.WILL
BRING ANOTHER ROUND OF HIGH SURF AND STRONG RIP CURRENTS LATE SUNDAY
INTO MONDAY.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
 ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 10 PM PST SATURDAY FOR ORANGE COUNTY
     COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.
&&

PUBLIC...JJT
AVIATION/MARINE/BEACHES...MOEDE