621
FNUS21 KWNS 101645
FWDDY1
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1044 AM CST TUE DEC 10 2024
VALID 101700Z - 111200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN
CALIFORNIA COAST...
..CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST
CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS CONTINUE
ACROSS SOUTHERN CALIFORNIA THIS MORNING. PEAK WIND GUSTS OF 50-70
MPH (LOCALIZED 80-90 MPH) WITH A FIRE ONGOING IN MALIBU. GUIDANCE
SUGGESTS THAT THE PEAK WINDS HAVE OCCURRED THIS MORNING, WITH
GRADUAL WEAKENING THROUGH THE AFTERNOON. HOWEVER, CRITICAL TO
LOCALLY EXTREMELY CRITICAL CONDITIONS WILL CONTINUE ACROSS THE
MOUNTAINS AND FOOTHILLS THROUGH THE REST OF THE AFTERNOON AND INTO
THE EVENING. SOME LINGERING ELEVATED TO CRITICAL CONDITIONS WILL
CONTINUE INTO WEDNESDAY MORNING. MINOR CHANGES WERE MADE TO BRING
THE CRITICAL TO THE COAST IN VENTURA AND LOS ANGELES COUNTY IN
ALIGNMENT WITH ONGOING SURFACE OBSERVATIONS.
..THORNTON.. 12/10/2024
PREV DISCUSSION
/ISSUED 0102 AM CST TUE DEC 10 2024/
..SYNOPSIS
CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
TODAY ALONG THE SOUTHERN CA COAST, POSING A HIGH-END FIRE WEATHER
THREAT. 06 UTC SURFACE OBSERVATIONS WITHIN THE SOUTHERN CA COASTAL
MOUNTAINS ARE SHOWING WIDESPREAD RH REDUCTIONS INTO THE LOW TO MID
TEENS WITH SUSTAINED WINDS BETWEEN 25-35 MPH AND FREQUENT GUSTS
UPWARDS OF 40-50 MPH (OCCASIONALLY GUSTING TO 60-75 MPH IN A FEW
LOCATIONS). OTHER OBSERVED TRENDS ACROSS THE REGION SUGGEST THAT
WINDS WILL INCREASE THROUGH THE EARLY TO MID-MORNING HOURS (MOST
LIKELY PEAKING DURING THE 12-17 UTC PERIOD). SURFACE PRESSURE OBS
ACROSS NORTHEAST NV ARE REPORTING A 1036 MB SURFACE HIGH WITH
FURTHER PRESSURE RISES TO AROUND 1037-1039 MB EXPECTED THROUGH 15
UTC. ADDITIONALLY, LATEST UPPER-AIR ANALYSES SHOW A LOW TO MID-LEVEL
COLD FRONT PUSHING SOUTH INTO SOUTHERN CA. THE ARRIVAL OF THE
COOLER/MORE DENSE AIR MASS AND STRONGER MID-LEVEL FLOW, ACCOMPANIED
BY FURTHER SURFACE PRESSURE RISES, SHOULD RESULT IN STRENGTHENING
WINDS THROUGH THE MORNING HOURS.
THE OBSERVED LAX-DAG PRESSURE GRADIENT HAS ALSO BEEN TRENDING LOWER
(I.E. STRONGER) THAN DEPICTED BY MOST DETERMINISTIC SOLUTIONS, BUT
GUIDANCE THAT HAS CAPTURED RECENT TRENDS WELL SHOWS INCREASINGLY
WIDESPREAD 60+ MPH WIND GUSTS WITHIN THE SIERRA MADRE, SAN GABRIEL,
AND SAN JACINTO MOUNTAINS BY MID-MORNING. SINGLE-DIGIT RH VALUES
WILL ALSO BECOME MORE COMMON BY THE AFTERNOON HOURS, GIVEN THE
DURATION OF THE DOWNSLOPE WIND EVENT COUPLED WITH THE DIURNAL
HEATING CYCLE. THE PROLONGED NATURE OF THE EVENT IS ALSO PROMOTING
RAPID DRYING OF 1- AND 10-HOUR FUELS, WHICH WILL INCREASE THE FIRE
WEATHER THREAT THROUGH THE DAY. EXTREMELY CRITICAL WIND SPEEDS WILL
GRADUALLY BEGIN TO ABATE AFTER ROUGHLY 20 UTC, AS THE SURFACE HIGH
OVER THE GREAT BASIN BEGINS TO WEAKEN. HOWEVER, WIDESPREAD CRITICAL
FIRE WEATHER CONDITIONS SHOULD STILL PERSIST WELL INTO EARLY
WEDNESDAY MORNING.
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
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