863
FXUS66 KLOX 082024
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
124 PM PDT SAT AUG 8 2026
SYNOPSIS
08/1257 PM.
NIGHT THROUGH MORNING LOW CLOUDS AND PATCHY DENSE FOG WILL BE
COMMON OVER COASTAL AREAS AND THE COASTAL VALLEYS THROUGH THE
WEEKEND. OVER THE INTERIOR AREAS, HAZARDOUS HEAT WILL CONTINUE
THROUGH THIS WEEKEND AND EXPAND INTO THE COASTAL VALLEYS, WITH
NEAR TO ABOVE NORMAL TEMPERATURES AROUND THE BEACHES. OTHER THAN
A SMALL CHANCE FOR MOUNTAIN SHOWERS DURING THE AFTERNOON AND
EVENING HOURS THROUGH EARLY NEXT WEEK, DRY CONDITIONS WILL
PREVAIL.
SHORT TERM (TDY-TUE)
08/1255 PM.
UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED NEAR FOUR-CORNERS
AREA THIS WEEKEND, WITH PEAK HEIGHTS OF AROUND 596 DM TODAY
ACROSS SOUTHERN CALIFORNIA. WHILE THE IMMEDIATE COAST IS BEING
MODERATED BY A SHALLOW MARINE LAYER, AREAS AWAY FROM THE IMMEDIATE
COAST ARE SEEING WARMING TODAY. MOST AREAS ARE EXPECTED TO SEE
PEAK TEMPERATURES TODAY, WITH HIGHS IN THE UPPER 90S TO 109
ACROSS THE INTERIOR (WARMEST IN THE ANTELOPE VALLEY), 90 TO 103
DEGREES IN COASTAL VALLEYS, AND 75 TO 90 DEGREES ACROSS THE
COASTAL PLAIN. THESE TEMPERATURES ARE ABOUT 5 TO 10 DEGREES ABOVE
NORMAL. HEAT ADVISORIES AND EXTREME HEAT WARNINGS REMAIN IN EFFECT
THROUGH SUNDAY FOR MANY AREAS AWAY FROM THE IMMEDIATE COAST, AND
NO CHANGES PLANNED AT THIS TIME. A COOLING TREND WILL TAKE SHAPE
FOR EARLY NEXT WEEK AS 500 MB HEIGHTS DECLINE SOME AS THE UPPER-
LEVEL RIDGE WEAKENS. AN INCREASE IN ONSHORE FLOW WILL BRING A FEW
DEGREES OF COOLING BY MONDAY, WITH MORE PRONOUNCED COOLING ON
TUESDAY.
DUE TO THE RIDGE POSITIONING, THE AREA WILL SIT ON THE FRINGE OF
SUBTROPICAL MOISTURE BEING DRAWN UP BY THE CIRCULATION AROUND THE
HIGH PRESSURE SYSTEM. SOUTHEAST FLOW ALOFT WILL TRANSPORT MARGINAL
AMOUNTS OF MONSOONAL MOISTURE INTO THE REGION. THE LATEST
DETERMINISTIC SOLUTIONS AND SOME OF THE ENSEMBLE MEMBERS SUGGEST
A SLIGHT BUMP UP IN CLOUD COVER AND POSSIBLE CONVECTION FROM
SUNDAY AFTERNOON INTO MONDAY AS WEAK SHORTWAVE IMPULSE MOVES
AROUND THE RIDGE MOVES OVER THE REGION. THERE WILL BE A 5-15
PERCENT CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS, HIGHEST OVER THE LA/VENTURA COUNTY MOUNTAINS
AND ANTELOPE VALLEY. THE LATEST 12Z NAM MODEL DOES INDICATE
AN UPTICK IN ELEVATED INSTABILITY WITH MUCAPE VALUES IN EXCESS
OF 1000 J/KG. AT THIS TIME, THERE IS NOT MUCH FORCING WITH THIS
ENHANCED INSTABILITY. AS A RESULT, MOST LIKELY SCENARIO WILL
BE INCREASING MID LEVEL CLOUDS FOR COASTAL/VALLEY AREAS INTO
ADJACENT COASTAL WATERS, BUT CAN'T TOTALLY RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM IN THESE AREAS (ABOUT 5 PERCENT
PROBABILITY). THIS WILL NEED TO BE MONITORED CLOSELY IN CASE UPPER
LEVEL WAVE (FORCING) STRENGTHENS MORE THAN ADVERTISED. IF
THUNDERSTORMS DO OCCUR, THERE IS THE POSSIBILITY THAT ISOLATED DRY
LIGHTNING MAY CAUSE FIRE STARTS, ADDING TO THE FIRE WEATHER
CONCERN. THE INCREASE IN MONSOONAL MOISTURE ALONG WITH THE WARMER
THAN NORMAL SEA TEMPERATURES WILL ALSO INCREASE HUMIDITIES
ALLOWING FOR WARMER THAN NORMAL OVERNIGHT LOWS AND ADD SOME
HUMIDITY DURING THE DAYTIME TO INCREASE HEAT IMPACTS.
INCREASING ONSHORE FLOW WILL LIKELY BRING A SLIGHTLY STRONGER SEA
BREEZE EACH AFTERNOON AND EVENING AND POSSIBLY GUSTY SOUTHWEST
WINDS DURING THE AFTERNOON AND EVENING HOURS ACROSS INTERIOR
SECTIONS INCLUDING THE ANTELOPE VALLEY. THE STRONGEST ONSHORE
WINDS ARE EXPECTED TO BE ON SUNDAY AND MONDAY, BASED ON PROJECTED
SURFACE PRESSURE GRADIENTS. THE GUSTY WINDS ACROSS THE INTERIOR
IN COMBINATION WITH THE HOT AND DRY CONDITIONS WILL PRODUCE
ELEVATED TO BRIEF CRITICAL FIRE WEATHER CONDITIONS. WITH THE
ENHANCED INSTABILITY OVER THE REGION, THERE IS ALSO AN INCREASED
RISK OF LARGE VERTICAL PLUME GROWTH WITH ANY NEW FIRES ACROSS THE
INTERIOR THIS WEEKEND (SIMILAR TO WHAT WE SAW WITH THE RIDGE FIRE
YESTERDAY).
LONG TERM (WED-SAT)
08/122 PM.
HEIGHTS WILL CONTINUE TO FALL DURING THE EXTENDED PERIOD AS
THE RIDGE OF HIGH PRESSURE WEAKENS AND SHIFTS TO THE EAST.
AN UPPER LEVEL LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP
OFF THE COAST BY WEDNESDAY OR THURSDAY, AND POTENTIALLY LINGER
INTO FRIDAY. AT THE SAME TIME, ONSHORE FLOW WILL INCREASE BOTH TO
THE NORTH AND THE EAST BECOMING STRONGLY ONSHORE IN BOTH
DIRECTIONS IN THE AFTERNOONS. THE MARINE LAYER WILL RESPOND TO
THIS AND LOW CLOUDS WILL LIKELY BEGIN TO EXTEND INTO THE VALLEYS.
LOOK FOR SLOWER THAN NORMAL CLEARING AND SOME WEST FACING BEACHES
MAY SEE ONLY LIMITED CLEARING EACH AFTERNOON AND EVENING.
THE COMBINATION OF A DEEPER MARINE LAYER, STRONGER ONSHORE FLOW,
AND FALLING HEIGHTS WILL BRING COOLING TUESDAY THROUGH THURSDAY.
MAXIMUM TEMPS WILL LARGELY BE BELOW NORMAL BY WEDNESDAY AND
THURSDAY.
PWS WILL REMAIN ELEVATED THROUGH THE PERIOD, HOWEVER. IN
COMBINATION WITH WARMER THAN NORMAL OCEAN TEMPERATURES OFF THE
IMMEDIATE COAST, CONDITIONS WILL CONTINUE TO FEEL A LITTLE
MORE HUMID THAN NORMAL. IT WILL ALSO KEEP OVERNIGHT LOWS A LITTLE
WARMER THAN NORMAL. THE REGION WILL REMAIN ON THE FRINGE OF THE
MONSOONAL MOISTURE THROUGH AT LEAST WEDNESDAY, WITH THE ELEVATED
MOISTURE AND INCREASED INSTABILITY KEEPING THE LOW CHANCE (10 TO
15 PERCENT) OF AFTERNOON MOUNTAIN CONVECTION GOING. IN THE
THURSDAY-FRIDAY TIME FRAME, MEDIUM-RANGE MODELS CONTINUE TO
INDICATE THE POTENTIAL FOR AN UPPER LOW TO DEVELOP OFF THE
CENTRAL CALIFORNIA COAST, EAST OF WHICH LARGE-SCALE ASCENT AND
CONVECTIVE CHANCES COULD MODESTLY INCREASE SOMETIME BETWEEN
THURSDAY AND FRIDAY. AT THIS TIME, THE CONVECTIVE CHANCES
ARE STILL IN THE 5-15 PERCENT RANGE ACROSS THE AREA, WITH THE
HIGHEST CHANCES FOCUSED ACROSS THE CENTRAL COAST. LATEST
ECMWF ENSEMBLE DATE SHOWING A WEAK CONVECTIVE SIGNAL IN THAT
THURSDAY-FRIDAY TIME FRAME WITH A SLIGHTLY UPTICK IN MUCAPE
VALUES. IF CONVECTION WERE TO DEVELOP, THE MAIN CONCERN WOULD BE
THE POTENTIAL FOR ISOLATED DRY LIGHTNING STRIKES WITH MINIMAL
RAINFALL, ADDING TO THE FIRE WEATHER THREAT. THIS WILL NEED TO BE
MONITORED CLOSELY ESPECIALLY CONSIDERING THE DRY FUELS IN PLACE
AFTER THIS PROLONGED HEATWAVE.
ADDITIONALLY, THE STRONG ONSHORE FLOW TO THE EAST WILL PRODUCE
NEAR ADVISORY LEVEL WIND GUSTS ACROSS THE WESTERN ANTELOPE VALLEY
AND THE WESTERN FOOTHILLS EACH AFTERNOON AND EVENING. GUSTY
SUNDOWNER WINDS WILL ALSO BE POSSIBLE EARLY NEXT WEEK IN SOUTHERN
SANTA BARBARA COUNTY.
AVIATION
08/1746Z.
AT 1639Z AT KLAX, THE MARINE LAYER WAS 800 FEET DEEP. THE TOP OF
THE INVERSION WAS AT 3600 FEET WITH A TEMPERATURE OF 27 C.
HIGH CONFIDENCE IN VFR TAFS FOR KPRB, KBUR, KVNY, KPMD & KWJF.
LOW TO MODERATE CONFIDENCE IN REMAINING TAFS DUE TO UNCERTAINTIES
IN COVERAGE AND TIMING OF LOW CLOUDS AND LIFR/IFR CONDS TONIGHT
INTO SUN MORNING. SOME MID-LEVEL MOISTURE AND WARM SEA SURFACE
TEMPS WILL DISRUPT THE FORMATION OF MARINE LAYER. THIS WILL
LIKELY RESULT IN INTERMITTENT CIGS ESPECIALLY FOR KLAX, KSMO, &
KLGB. CIG HEIGHTS ACCURATE WITHIN +/- 200 FT OF CURRENT FORECAST.
KLAX...FAIR CONFIDENCE IN TAF. INTERMITTENT CIGS (007-010)
POSSIBLE 03Z-15Z SUN. NO SIGNIFICANT EAST WIND COMPONENT
EXPECTED.
KBUR...HIGH CONFIDENCE IN VFR TAF. NO WIND ISSUES EXPECTED.
MARINE
08/120 PM.
WINDS AND SEAS ARE EXPECTED TO REMAIN LARGELY BELOW SMALL CRAFT
ADVISORY (SCA) CRITERIA ACROSS THE COASTAL WATERS THROUGH
WEDNESDAY NIGHT. HOWEVER, NORTHWEST WINDS LOCALLY GUSTING TO 20-25
KNOTS IN TYPICALLY WINDY AREAS AROUND AND JUST TO THE NW AND S
OF POINT CONCEPTION CAN BE EXPECTED EACH AFTERNOON AND EVENING
THROUGH SUNDAY.
DENSE FOG MAY AFFECT PORTIONS OF THE COASTAL WATERS EACH NIGHT
THROUGH MORNING THIS WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK.
BEACHES
08/114 PM.
HIGH ASTRONOMICAL TIDES ARE EXPECTED TO AFFECT LOW-LYING BEACHES
SOUTH OF POINT CONCEPTION WITH THE POSSIBILITY OF MINOR COASTAL
FLOODING STARTING WITH THE EVENING HIGH TIDE MONDAY AND CONTINUING
THROUGH AT LEAST WEDNESDAY. AS A RESULT, A COASTAL FLOOD ADVISORY
HAS BEEN ISSUED.
PREDICTED TIDE HEIGHTS OF UP TO 7.5 FEET ARE EXPECTED BETWEEN
ABOUT 8 AND 10 PM EACH EVENING. THESE TIDES, COMBINED WITH A SMALL
INCREASE IN A LONG-PERIOD SOUTHERLY SWELL, COULD RESULT IN MINOR
FLOODING OF SEA WATER AROUND THE TIME OF HIGH TIDE OVER LOW-LYING
COASTAL AREAS SUCH AS PARKING LOTS, BEACHES, AND WALKWAYS. BEACHES
MOST SUSCEPTIBLE TO POTENTIAL MINOR COASTAL FLOODING ISSUES
INCLUDE THOSE AROUND POINT DUME AND NEAR LONG BEACH.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT SUNDAY FOR
ZONES 38-377-381>383. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT SUNDAY FOR ZONES
88-342>345-348-349-351>353-356>358-367>376-378>380-548. (SEE LAXNPWLOX).
COASTAL FLOOD ADVISORY IN EFFECT FROM 6 PM MONDAY TO MIDNIGHT
PDT WEDNESDAY NIGHT FOR ZONES 349-350-354-362-366. (SEE LAXCFWLOX).
PZ...NONE.
PUBLIC...GOMBERG/HALL
AVIATION...SIRARD
MARINE...SIRARD
BEACHES...SIRARD
SYNOPSIS...KL/COHEN
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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