869
FXUS66 KSGX 152146
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PST SUN DEC 15 2024
SYNOPSIS
DRY WEATHER WILL PREVAIL THIS WEEK. WARMER WEATHER WILL OCCUR
MONDAY. ABOVE AVERAGE TEMPERATURES, LOW HUMIDITY, AND WEAK TO
MODERATE SANTA ANA WINDS WILL PREVAIL TUESDAY THROUGH THURSDAY, WITH
LIGHTER WINDS AND A GRADUAL COOLING TREND FRIDAY THROUGH NEXT
SUNDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SKIES WERE SUNNY AT EARLY AFTERNOON WITH TEMPERATURES MOSTLY IN THE
60S AT LOWER ELEVATIONS, EXCEPT LOWER TO MID 70S IN THE LOWER
DESERTS. LOCAL NORTH TO NORTHEAST WINDS CONTINUED, MAINLY IN THE
FOOTHILLS NORTH AND EAST OF THE INLAND EMPIRE, WITH A FEW GUSTS NEAR
30 MPH.
WEAK RIDGING WILL SPREAD FROM THE EAST PACIFIC EAST TO CALIFORNIA
THIS AFTERNOON AND SHIFT EAST TO SOUTHERN PARTS OF THE DESERT
SOUTHWEST MONDAY AS A TROUGH OF LOW PRESSURE MOVES INTO THE PACIFIC
NORTHWEST. THAT LOW WILL SHIFT EAST VERSUS SOUTH THORUGH THE
NORTHERN ROCKIES AND NORTHERN PLAINS TUESDAY AS ANOTHER RIDGE FORMS
ALONG THE WEST COAST. THIS WILL COMBINE WITH A STRONG SURFACE HIGH
OVER THE NORTHERN ROCKIES WITH A 15-20 MB MSLP GRADIENT, ALBEIT OVER
A BROAD AREA INSTEAD OF CONCENTRATED OVER THE SOCAL MOUNTAINS. SAME
THING WITH THE COLD AIR ADVECTION AT 850 MB WITH MODERATE AMOUNTS
FROM CENTRAL NV THROUGH SOCAL, BUT NOTHING EXTREME. THUS, WE SHOULD
HAVE WEAK TO MODERATE SANTA ANA WINDS TUE-THU, STRONGEST TUE
NIGHT/WED MORNING. HIGH RESOLUTION GUIDANCE SUGGESTS GUSTS 35 TO 50
MPH IN WINDIEST LOCATIONS OF THE SAN BERNARDINO COUNTY MOUNTAINS TUE
NIGHT/WED MORNING, BELOW CAJON PASS AND THE SANTA ANA MOUNTAINS, AND
IN A FEW PARTS OF THE SAN DIEGO COUNTY MOUNTAINS WED. WITH THE UPPER
RIDGE, TEMPERATURES SHOULD BE QUITE HIGH COMPARED TO NORMAL, WITH
SOME LOWER 80S AT LOWER ELEVATIONS, BOTH IN THE LOWER DESERTS AND
VALLEYS.
LATE IN THE WEEK, THE RIDGE WILL MOVE EAST TOWARDS THE ROCKIES
AND/OR PLAINS, THOUGH MODELS/ENSEMBLES HAVE A LOT OF VARIATION IN
THE TROUGH DEVELOPING OFF THE WEST COAST, ESPECIALLY THE SOUTHWARD
EXTENT. MOST LIKELY, THE PRECIPITATION WILL STAY NORTH OF POINT
CONCEPTION WITH THE TROUGH NEXT WEEKEND. BEYOND THAT, THE GENERAL
PATTERN OF THE STORM TRACK HAS PRECIPITATION EVERY FEW DAYS OVER
NORTHERN/CENTRAL CALIFORNIA, BUT WITH LOW CONFIDENCE (BUT NOT ZERO)
FOR ANY PRECIPITATION IN FAR SOUTHERN CALIFORNIA THE WEEK OF XMAS.
AVIATION
152130Z....MOSTLY CLEAR CONDITIONS WITH UNRESTRICTED VIS IS EXPECTED
THROUGH MONDAY AFTERNOON.
MARINE
STRONGER NORTHWEST WINDS EXPECTED IN THE OUTER COASTAL WATERS
STARTING MONDAY AFTERNOON, WITH GUSTS LARGELY NEAR 20 KTS, WITH
ISOLATED GUSTS 20-25 KTS NEAR SAN CLEMENTE ISLAND MONDAY EVENING
THROUGH EARLY TUESDAY MORNING. OTHERWISE, NO HAZARDOUS MARINE
WEATHER EXPECTED THROUGH FRIDAY.
FIRE WEATHER
SANTA ANA WINDS WILL DEVELOP TUESDAY, PEAK TUESDAY NIGHT AND
WEDNESDAY MORNING IN MOST AREAS (MORE LIKE MIDDAY WEDNESDAY IN SAN
DIEGO COUNTY), THEN GRADUALLY WANE WEDNESDAY NIGHT AND THURSDAY.
PEAK GUSTS ARE CURRENTLY PROJECTED IN THE 35-50 MPH RANGE THROUGH
AND BELOW CAJON PASS AND OTHER AREAS ON THE COASTAL SLOPES OF THE
SAN BERNARDINO COUNTY MOUNTAINS, PARTS OF THE INLAND EMPIRE AND
IN/NEAR THE SANTA ANA MOUNTAINS AND FOOTHILLS. RELATIVE HUMIDITY
WILL BE LOW MUCH OF THE WEEK, WITH QUITE A FEW TEENS IN INLAND AREAS
FOR MINIMUMS ALREADY ON MONDAY, MID TEENS TO LOWER 20S TUESDAY, AND
GENERALLY 12-20 PERCENT WEDNESDAY AND THURSDAY. THERE COULD BE SOME
OVERLAP BETWEEN GUSTS GREATER THAN 35 MPH AND HUMIDITY BELOW 15
PERCENT WEDNESDAY, WITH LOCAL STATIONS POTENTIALLY FOR 4-6 HOURS,
BUT MOST LOCATIONS LESS THAN THAT. ELEVATED FIRE WEATHER CONDITIONS
WILL OCCUR ESPECIALLY WEDNESDAY AND THURSDAY, WITH LOCALLY CRITICAL
VALUES. HUMIDITY WILL ONLY SLOWLY INCREASE FRIDAY AND SATURDAY, BUT
WINDS WILL GENERALLY BE LIGHT THEN.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC/FIRE WEATHER...MAXWELL
AVIATION/MARINE...MUNYAN
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