Area Forecast Discussion
Issued by NWS San Diego, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KSGX 020440
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PDT WED OCT 1 2014

.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT AND OFFSHORE FLOW WILL BRING GUSTY WINDS
TO THE MOUNTAINS AND VALLEYS LATE TONIGHT INTO THURSDAY AND VERY
WARM TO HOT WEATHER THURSDAY THROUGH SUNDAY. A COOLING TREND WILL
OCCUR EARLY NEXT WEEK AS ONSHORE FLOW REDEVELOPS AND BRINGS SOME
STRATUS AGAIN TO THE COAST AND THE UPPER HIGH WEAKENS...THOUGH HOT
WEATHER WILL STILL OCCUR IN SOME INLAND AREAS THROUGH ABOUT TUESDAY.
CONTINUED COOLING WILL OCCUR THE MIDDLE OF NEXT WEEK AS THE UPPER
HIGH WEAKENS FURTHER.

&&

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

SKIES WERE MOSTLY CLEAR THIS EVENING...WITH THE PATCHES OF STRATUS
ALONG THE SAN DIEGO COUNTY COAST HAVING MOSTLY DISSIPATED BY
MID-EVENING. 00Z NAM/LOCAL WRF INDICATE THAT THE BOUNDARY LAYER
RELATIVE HUMIDITY WILL MOSTLY BE HIGH OVERNIGHT ONLY ALONG THE
BEACHES AND OFF THE COAST...SO STRATUS WILL BE QUITE LIMITED
OVERNIGHT.

THE MAIN EVENT WILL BE THE OFFSHORE FLOW...WHICH WILL BE MODERATE
STRENGTH THURSDAY AND SOMEWHAT WEAKER FRIDAY AND SATURDAY. GRADIENTS
WILL BE UP TO 10 MB FROM SOUTHERN NEVADA TO THE SO-CAL COAST THU
WITH RATHER LIMITED COLD AIR ADVECTION IN THE LOW-LEVELS. 00Z FWIS
SHOWS GUST POTENTIAL IN THE 45 MPH RANGE BELOW PASSES AND CANYONS.
THE PREVAILING FLOW WILL MOSTLY BE FROM THE EAST VERSUS
NORTH/NORTHEAST...SO HIGHEST WINDS COULD BE IN THE SAN DIEGO COUNTY
MOUNTAINS. WIND ADVISORY CURRENTLY COVERS THE INLAND EMPIRE AND THE
SAN BERNARDINO COUNTY MOUNTAINS...THOUGH THIS LOOKS RATHER MARGINAL.
GIVEN THAT MOST OF THE WIND IN SAN DIEGO COUNTY WILL BE IN THE
MOUNTAIN LOCATIONS THAT TYPICALLY RECEIVE HIGHER WINDS...LIKE SILL
HILL...WILL NOT EXPAND THE WIND ADVISORY THERE. TEMPS ALOFT WILL
INCREASE WITH THE BUILDING HIGH...WITH 850 MB TEMPS WEST OF THE
MOUNTAINS...AIDED BY COMPRESSIONAL HEATING...AROUND 20-21 C THU AND
22-23 C FRI. THEREFORE...WE SHOULD HAVE A LOT OF HIGH TEMPS IN THE
90S WEST OF THE MOUNTAINS...WITH HIGHEST TEMPS FRIDAY...WHEN TEMPS
OVER 100 WILL OCCUR IN PARTS OF THE VALLEYS AND INLAND ORANGE
COUNTY...WITH ONLY MINOR CHANGES SATURDAY. LOCAL WRF AND CANSAC WRF
INDICATE THAT THERE SHOULD BE SEA BREEZES EACH DAY FRI/SAT WHICH
SHOULD MODERATE THE TEMPERATURES SOMEWHAT NEAR THE IMMEDIATE COAST.
HEAT ADVISORY LOOKS GOOD FOR NOW.

THE NORTHWEST-SOUTHEAST ORIENTED UPPER HIGH OVER CALIFORNIA WILL
CONTINUE THROUGH SUNDAY AS A BROAD TROUGH COVERS THE EASTERN US. A
LOW OFF THE COAST WILL APPROACH MONDAY AND WEAKEN THE HIGH AND
RESULT IN COOLING. THE LOW COULD MOVE THROUGH AROUND MID-WEEK BUT
SHOULD NOT BE STRONG...JUST ENOUGH FOR SOME DEEPENING OF THE MARINE
LAYER AND TEMPS LOWERING TO NEAR NORMAL.

&&

.AVIATION...
020300Z...COASTS/VALLEYS...MOSTLY CLEAR IN ORANGE COUNTY TONIGHT.
PATCHY COASTAL STRATUS OVER COASTAL SAN DIEGO COUNTY THROUGH 14Z
WITH SCT010-015 BECOMING SCT-BKN005-010 THROUGH 13Z. SKIES CLEARING
BY 16Z. AFT 16Z...CLEAR WITH UNRESTRICTED VIS THROUGH THURSDAY
NIGHT.

NORTHEAST WINDS WITH SFC GUSTS 25-35 KT...LOCALLY AS HIGH AS 45
KT...WILL DEVELOP BELOW THE CAJON AND BANNING PASSES AND SANTA ANA
FOOTHILLS LATE TONIGHT...INCLUDING NEAR KONT. LLWS AND MOD UDDFS
POSSIBLE NEAR THE COASTAL FOOTHILLS OF THE SAN BERNARDINO AND SANTA
ANA MTNS WITH THESE WINDS. WINDS WILL WEAKEN EARLY THU AFTERNOON.

MOUNTAINS/DESERTS...NE TO E WINDS WITH SFC GUSTS 35-45 KT DEVELOPING
THROUGH THE PASSES...CANYONS...AND COASTAL SLOPES OF THE MTNS AS
WELL AS THE FAR N COACHELLA VALLEY BY 02/12Z...WEAKENING BY EARLY
THU AFTERNOON.

&&

.MARINE...
800 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY.

&&

.BEACHES...
A LONG PERIOD SOUTH-SOUTHWEST SWELL ARRIVING IN THE COASTAL WATERS
LATE THURSDAY WILL GENERATE ELEVATED SURF EARLY FRIDAY MORNING
THROUGH SUNDAY. SURF OF 3 TO 5 FEET WITH SETS TO 6 FEET IS EXPECTED
ALONG SOUTH AND SOUTHWEST FACING BEACHES OF ORANGE AND SAN DIEGO
COUNTIES. STRONG RIP CURRENTS AND LONGSHORE CURRENTS WILL CREATE
HAZARDOUS SWIMMING CONDITIONS AT MOST AREA BEACHES. A BEACH HAZARDS
STATEMENT IS IN EFFECT FRIDAY THROUGH SUNDAY.

&&

.FIRE WEATHER...FROM PREVIOUS DISCUSSION...
HIGH PRESSURE ALOFT AND OFFSHORE FLOW WITH LOCALLY GUSTY NORTHEAST
WINDS WILL BRING MUCH WARMER AND DRIER CONDITIONS FOR THURSDAY
THROUGH SUNDAY. STRONGEST WINDS...WITH LOCAL GUSTS TO AROUND 40
MPH...ARE EXPECTED FOR LATE TONIGHT INTO THURSDAY MORNING...FOLLOWED
BY GRADUAL WEAKENING FRIDAY AND SATURDAY. FRIDAY AND SATURDAY WILL
BE THE WARMEST DAYS...ESPECIALLY INLAND WHERE TEMPERATURES OF 95 TO
105 DEGREES ARE POSSIBLE. SLOW COOLING MAY BEGIN NEAR THE COAST ON
SUNDAY AS WEAK ONSHORE FLOW RETURNS. HUMIDITIES WILL FALL
THURSDAY...REACHING THE MID TEENS BY LATE MORNING FOR INLAND AREAS.
EXPECT LOWEST DAYTIME HUMIDITIES OF 5 TO 10 PERCENT FOR INLAND AREAS
FRIDAY AND SATURDAY WITH POOR OVERNIGHT RECOVERY. HUMIDITIES ARE
EXPECTED TO SLOWLY RECOVER FOR SUNDAY INTO EARLY NEXT WEEK AS WEAK
ONSHORE FLOW RETURNS. WHILE MORE WIDESPREAD AREAS MEETING RED FLAG
WARNING CRITERIA IS NOT EXPECTED...WARNING CRITERIA WILL LIKELY BE
MET IN SOME LOCATIONS ON THURSDAY...MAINLY BELOW THE CAJON
PASS...WEST OF THE BANNING PASS...PORTIONS OF THE COASTAL FOOTHILLS
OF THE SANTA ANA MOUNTAINS...AND PORTIONS OF THE SAN DIEGO
FOOTHILLS. REGARDLESS...THERE WILL BE AN ELEVATED THREAT FOR
WILDFIRES THURSDAY INTO SUNDAY.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT FROM LATE THURSDAY NIGHT THROUGH LATE
     SUNDAY NIGHT FOR THE ORANGE COUNTY COASTAL AREAS...SAN
     DIEGO COUNTY COASTAL AREAS.

     HEAT ADVISORY FROM 11 AM FRIDAY TO 8 PM PDT SATURDAY FOR THE
     ORANGE COUNTY COASTAL AREAS...RIVERSIDE COUNTY MOUNTAINS...
     SAN BERNARDINO COUNTY MOUNTAINS...SAN DIEGO COUNTY COASTAL
     AREAS...SAN DIEGO COUNTY MOUNTAINS.

     WIND ADVISORY FROM 2 AM TO 2 PM PDT THURSDAY FOR THE SAN
     BERNARDINO COUNTY MOUNTAINS...SAN BERNARDINO AND RIVERSIDE
     COUNTY VALLEYS-THE INLAND EMPIRE.

     HEAT ADVISORY FROM 11 AM FRIDAY TO 8 PM PDT SUNDAY FOR THE SAN
     BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE...
     SAN DIEGO COUNTY VALLEYS...SANTA ANA MOUNTAINS AND
     FOOTHILLS.

PZ...NONE.

&&

$$

PUBLIC...MAXWELL
AVIATION/MARINE/BEACHES...MOEDE
FIRE WEATHER...PG





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.