850
FXUS66 KSGX 291041
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
241 AM PST MON DEC 29 2025
SYNOPSIS
DRY AND WARM WEATHER CONTINUES INTO TUESDAY WITH INCREASED SANTA
ANA WINDS ACROSS THE MOUNTAINS AND WESTERN VALLEYS. CLOUDIER SKIES
WILL ENTER THE REGION BY TUESDAY AS LOW PRESSURE SYSTEMS ACROSS
THE PACIFIC MOVE OVER OUR AREA THIS WEEK. THIS WILL BRING CHANCES
FOR PERIODS OF RAIN SHOWERS BY NEW YEAR'S EVE INTO THIS WEEKEND.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..NEW AVIATION DISCUSSION BELOW
NORTH AND EAST WINDS CONTINUE TO BE GUSTY OVERNIGHT WITH WINDS
MAINLY 35-50 MPH ACROSS THE COASTAL SLOPES AND 25-35 MPH ACROSS
THE INLAND EMPIRE AND FOOTHILLS OF ORANGE AND SAN DIEGO COUNTIES.
THESE SANTA ANA WINDS ARE ASSOCIATED WITH A SURFACE AREA OF HIGH
PRESSURE SITUATED OVER THE GREAT BASIN OF WESTERN UTAH. THE
PRESSURE GRADIENT BETWEEN THIS AND OUR AREA WILL CONTINUE TO
STRENGTHEN INTO THE MORNING AND AFTERNOON HOURS, WHERE WINDS WILL
BECOME MOST WIDESPREAD. BY THE AFTERNOON, CHANCES FOR WIND GUSTS
NEAR 20 MPH INCREASE FOR AREAS CLOSER TO THE COAST. WINDS WILL
BECOME MORE LOCALIZED MONDAY NIGHT WITH A SLIGHT RESURGENCE ON
TUESDAY MORNING FOR THE MOUNTAINS AND WESTERN VALLEYS WITH GUSTS
25-45+ MPH. THIS WIND PATTERN WILL ALLOW TEMPERATURES TO ALSO
RISE ACROSS THE REGION TODAY AND TUESDAY. THE BEST CHANCE TO SEE
HIGHS OVER 75 DEGREES WILL BE AREAS OF EAST COUNTY IN SAN DIEGO ON
TUESDAY WITH AROUND A 50-60% CHANCE OF OCCURRENCE.
TAKE IN THOSE CLEAR BLUE SKIES TODAY BECAUSE YOU MAY NOT BE SEEING
THEM MUCH THIS WEEK...! AN AREA OF LOW PRESSURE APPROXIMATELY
1,000 MILES SOUTHWEST OF SAN DIEGO WILL BEGIN TO MOVE NORTHWARD
MONDAY EVENING INTO TUESDAY. SUBTROPICAL MOISTURE ASSOCIATED WITH
THIS SYSTEM IN THE FORM OF MID/HIGH-LEVEL CLOUDS WILL BEGIN TO
OVERSPREAD THE AREA DURING THIS TIME. THE TEMPERATURE FORECAST
WILL BE A BIT TRICKIER WITH THIS AS EXTENSIVE CLOUD COVER MAY
LIMIT PEAK DAYTIME HEATING ON TUESDAY, THOUGH STILL FAIRLY
CONFIDENT IN SEEING HIGHS IN THE 70S WEST OF THE MOUNTAINS AND IN
THE LOWER DESERTS LATE TUESDAY MORNING/AFTERNOON WITH THE DAY
BEING MAINLY DRY.
AS THE SYSTEM MOVES FURTHER NORTH ON WEDNESDAY, CHANCES FOR
MAINLY LIGHT SHOWERS WILL INCREASE THROUGHOUT THE DAY. AROUND NEW
YEAR'S EVE, CHANCES FOR MEASURABLE RAINFALL INCREASE NEAR 60-80%
ALONG AND WEST OF THE MOUNTAINS TO NEAR 40-60% ACROSS THE DESERT
REGIONS. THERE CONTINUES TO BE LOW CONFIDENCE ON EXACT RAIN
AMOUNTS BUT THERE IS INCREASING CONFIDENCE THE HEAVIEST RAIN WILL
FALL SOMETIME LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. GLOBAL
MODELS ARE BEGINNING TO AGREE ON SHOWER CHANCES LOWERING BY LATE
THURSDAY INTO FRIDAY AS THE SYSTEM PASSES TO THE EAST AND ANOTHER
LOW PRESSURE SYSTEM DELAYS OFF THE COAST. NBM CHANCES FOR PRECIP
ARE NEAR 50% AT THIS TIME BUT WOULD NOT BE SURPRISED IF THESE
LOWER SOME IN THE COMING DAYS' FORECAST AS SOME AREAS MAY SEE VERY
LITTLE TO NO RAIN DURING THIS TIME. THE DETAILS ABOUT THE LOW
PRESSURE SYSTEM OFF THE COAST BY LATE WEEK STILL REMAIN UNCERTAIN.
MODELS SHOW A FAIRLY NORTHERLY TRACK WITH THIS FEATURE, SO
CHANCES FOR THE HEAVIEST RAINFALL WILL BE CLOSER TO THE LA BASIN
BY LATE FRIDAY OR SATURDAY.
FOR BOTH OF THESE EVENTS THIS WEEK, SUBTROPICAL MOISTURE FROM THE
SOUTH AND SOUTHWEST WILL KEEP SNOW LEVELS OVER 8,000 WHERE MOST
OF OUR FRIENDS ACROSS THE MOUNTAINS WILL SEE ONLY RAIN. COOLER AIR
WITH A SEMI-ACTIVE WEATHER PATTERN REMAINING IN PLACE, MAY BRING
LOWER SNOW LEVELS AND CONTINUED CHANCES FOR WET WEATHER ACROSS
SOCAL BY NEXT WEEKEND.
AVIATION
291030Z...VFR CONDITIONS CONTINUE THROUGH THE TAF PERIOD WITH FEW-
SCT HIGH CLOUDS AOA 25,000FT. GUSTY WINDS OUT OF THE NORTH TO
NORTHEAST WILL CONTINUE TO GRADUALLY STRENGTHEN THIS MORNING INTO
THE AFTERNOON WITH WIND GUSTS OF 35-45KTS FOR THE COASTAL MOUNTAIN
SLOPES AND MOUNTAIN PASSES WITH 20-30KT GUSTS STRETCHING BELOW
MOUNTAIN PASSES INTO INLAND VALLEYS. LOCALIZED AREAS OF REDUCED VIS
DUE TO BLDU POSSIBLE, ESPECIALLY NEAR THE MOUNTAINS. GUSTY NORTHERLY
WINDS BELOW CAJON PASS COULD PRODUCE CROSSWINDS ON APPROACH/TAKEOFF
WITHIN THE INLAND EMPIRE ALONG WITH 25-35 KTS OF LOW LEVEL WIND
SHEAR. WIDESPREAD MOD UP/DOWNDRAFTS EXPECTED, ESPECIALLY NEAR
MOUNTAINS AND MOUNTAIN PASSES. STRONG OFFSHORE WINDS PREVAIL INTO
THROUGH TUESDAY MORNING.
MARINE
NO HAZARDOUS MARINE WEATHER CONDITIONS EXPECTED THROUGH SATURDAY.
SGX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY UNTIL 1 PM PST TUESDAY FOR SAN BERNARDINO COUNTY
MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE
INLAND EMPIRE-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY
VALLEYS-SAN GORGONIO PASS NEAR BANNING-SANTA ANA MOUNTAINS
AND FOOTHILLS.
PZ...NONE.
PUBLIC...APR
AVIATION/MARINE...ZUBER
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