362
FXUS66 KSGX 180945
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
245 AM PDT SUN MAY 18 2025
SYNOPSIS
COOL AND CLOUDY WITH CHANCES OF LIGHT RAIN AND DRIZZLE WEST OF
THE MOUNTAINS THIS MORNING. CONDITIONS DRY OFF THIS AFTERNOON AND
REMAIN SO THROUGH THIS WEEK. AS THE LOW PRESSURE TROUGH MOVES
EAST OVER THE NEXT SEVERAL DAYS, A RIDGE DEVELOPS QUICKLY WARMING
TEMPERATURES AND RENDERING A SHALLOWER MARINE LAYER. PERIODS OF
LOCALLY GUSTY OFFSHORE WINDS ARE EXPECTED MONDAY MORNING THROUGH
MONDAY AFTERNOON. TEMPERATURES GO FROM BELOW NORMAL TODAY TO NEAR
OR ABOVE NORMAL TOMORROW. WEDNESDAY AND THURSDAY WILL LIKELY BE
THE WARMEST DAYS, WITH DAYTIME TEMPERATURES REACHING THE MID
NINETYS IN THE INLAND VALLEYS. A LITTLE COOLER FOR NEXT WEEKEND AS
ANOTHER LOW PRESSURE TROUGH MOVES IN FROM THE NORTHWEST.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THIS MORNING...THE MARINE LAYER REMAINS ABOUT 5000 FT DEEP WITH
LOW CLOUDS COVERING MOST OF THE REGION FROM THE MTN SLOPES TO THE
COAST. PERIODS OF LIGHT RAIN OR DRIZZLE CONTINUE AND WILL LIKELY
LAST UNTIL NEAR MIDDAY. ANY ADDITIONAL RAINFALL WILL LIKELY BE
LESS THAN 0.10 INCH. THE WESTERLY WINDS CONTINUE TO WEAKEN AND
ONLY A HANDFUL OF THE WIND- PRONE LOCATIONS ARE REPORTING WIND
GUSTS OF 40 MPH OR MORE THIS HOUR.
A WARMING TREND BEGINS TODAY AS THE LOW PRESSURE SYSTEM MOVES
EASTWARD ACROSS THE GREAT BASIN AND A HIGH PRESSURE RIDGE OVER THE
EASTERN PACIFIC SHIFTS OVER THE WEST COAST. DAYTIME TEMPERATURES
GO FROM MOSTLY BELOW NORMAL TODAY TO ABOVE NORMAL TOMORROW, WITH
INLAND TEMPS REACHING INTO THE 80S AND THE LOWER DESERTS REACHING
THE MID 90S. A SURFACE HIGH FOLLOWING THE LOW PRESSURE SYSTEM
ACROSS THE GREAT BASIN WILL BRING PERIODS OF WEAK OFFSHORE FLOW ON
MONDAY, WITH LOCALLY GUSTY NORTHEAST TO EAST WINDS. MAINLY ALONG
THE FOOTHILLS OF THE SAN BERNARDINO AND SAN JACINTO MTNS, PORTIONS
OF THE IE AND IN THE SANTA ANA MTNS. GUIDANCE HAS TRENDED WEAKER
WITH THE OFFSHORE WINDS AND CURRENTLY SHOW THE WINDS PEAKING
MONDAY MORNING WITH GUSTS OF UP TO 35 MPH. THE OFFSHORE FLOW
WEAKENS BUT HANGS AROUND INTO TUESDAY.
TEMPERATURES CONTINUE TO RISE THROUGH MIDWEEK UNDER BROAD HIGH
PRESSURE RIDGING ALOFT. WED AND THU ARE LIKELY TO BE THE WARMEST
DAYS, WITH DAYTIME TEMPS REACHING THE MID 90S IN THE IE AND SAN
DIEGO COUNTY VALLEYS. GUIDANCE HAS TRENDED LOWER WITH TEMPERATURES
AND THERE IS NOW ONLY ABOUT A 20 PERCENT CHANCE OF EXCEEDING 100
IN THE IE ON WED AND THU.
THE MARINE LAYER WILL BECOME SHALLOWER WITH LESS LOW CLOUDS AND
FOG BECOMING RESTRICTED TO THE IMMEDIATE COAST BY TUESDAY. THIS
WILL LIKELY CONTINUE EACH NIGHT AND MORNING THROUGH THURSDAY.
AS WE APPROACH NEXT WEEKEND, A LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHWEST WILL BRING LOWER TEMPERATURES AND A DEEPER MARINE
LAYER WITH INCREASING LOW CLOUDS DURING THE NIGHTS AND MORNINGS.
FORECAST DETAILS REMAIN UNCERTAIN FOR NEXT WEEKEND DUE TO A LACK
OF CONSENSUS AMONG MODEL SOLUTIONS WITH RESPECT TO THE
TRACK,TIMING AND INTENSITY OF THE APPROACHING SYSTEM.
AVIATION
180900Z...COAST/VALLEYS...SATELLITE SHOWS A FAIRLY EXTENSIVE MARINE
LAYER WITH VARYING BASES 1500-3500FT MSL AND TOPS TO 4500-5500FT.
CLOUDS HAVE PUSHED UP TO THE MOUNTAINS WHERE THE COASTAL SLOPES ARE
SEEING SOME VIS REDUCTIONS, ELSEWHERE, GENERALLY ABOVE 6SM. ON AND
OFF -RA/-DZ FOR SOME SITES, NOT RESULTING IN ANY IMPACTS, BUT MAY
PREVAIL THROUGH THE MORNING. BASES RISE THROUGH THE DAY, WITH SOME
CLEARING EXPECTED FOR THE COASTAL AREAS BUT FURTHER INLAND AND IN
THE VALLEYS, BKN CLOUDS MAY LINGER THROUGH THE AFTERNOON, PRIMARILY
FOR SAN DIEGO COUNTY. LOW CLOUDS REDEVELOP AGAIN TONIGHT WITH AN
EDDY OFF THE COAST, SO SIMILAR BASES EXPECTED TONIGHT WITH A
SHALLOWER MARINE LAYER AND CLEARING LIKELY AFTER 16Z MONDAY.
MOUNTAINS/DESERTS...WEST WINDS WITH GUSTS 35-55KTS OVER THE DESERT
MOUNTAIN SLOPES/FOOTHILLS AND THROUGH PASSES THROUGH ABOUT 12Z,
ESPECIALLY KTRM WHERE GUSTS >25KTS CONTINUE. STRONG UP/DOWNDRAFTS
AND ROTORS OVER AND EAST OF THE MOUNTAINS WITH THESE WINDS. WINDS
WILL GRADUALLY WEAKEN THROUGH THE MORNING, BUT WIDESPREAD GUSTS 25-
35KTS AGAIN AFTER 23Z, WEAKENING BY 06Z MONDAY.
MARINE
WEST-NORTHWEST WINDS GUSTING TO 20KT NEAR SAN CLEMENTE ISLAND
THROUGH THIS MORNING WILL CREATE LOCALLY ROUGH SEAS IN THE FAR OUTER
COASTAL WATERS. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS EXPECTED
THROUGH FRIDAY.
BEACHES
ELEVATED SURF WILL IMPACT BEACHES TODAY THROUGH TONIGHT, PEAKING
THIS AFTERNOON/EARLY EVENING. EXPECTED SURF OF 3-5 FEET WITH SETS TO
6 FEET PRODUCING A HIGH RIP CURRENT RISK.
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...PG
AVIATION/MARINE/BEACHES...ZUBER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page