Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 060423
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
922 PM PDT SUN JUL 5 2015

.SYNOPSIS...

LOW PRESSURE OFF THE CENTRAL CALIFORNIA COAST...AND HIGH PRESSURE
OVER THE INTERIOR SOUTHWEST STATES KEPT A SOUTHERLY FLOW OF MID-
LEVEL MOISTURE OVER THE REGION TODAY. THE HIGHER MOISTURE WILL
DECREASE AS THE UPPER LOW APPROACHES THE COAST AND MOVES INLAND
THROUGH FRI...MAINTAINING A DEEP MARINE LAYER WITH WIDESPREAD NIGHT
AND MORNING LOW CLOUDS...AND BELOW AVERAGE DAYTIME TEMPERATURES WEST
OF THE MOUNTAINS. CLOUDS MAY NOT COMPLETELY CLEAR SOME BEACHES EACH
DAY.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

SCATTERED SHOWERS AND THUNDERSTORMS OCCURRED PRIMARILY IN THE SAN
BERNARDINO COUNTY MOUNTAINS AND HIGH DESERTS...ALONG WITH A FEW
CELLS FURTHER SOUTH INTO THE RIVERSIDE AND SAN DIEGO COUNTY
MOUNTAINS. ACTIVITY HAS FINALLY DISSIPATED IN OUR AREA
ATTM...ALTHOUGH THERE CONTINUES TO BE SOME PERSISTENT CONVECTION
OVER FAR EASTERN SAN BERNARDINO COUNTY. A FEW OF THE STORMS IN OUR
SAN BERNARDINO COUNTY AREAS BECAME QUITE STRONG BETWEEN ABOUT 3 TO 6
PM SUNDAY AFTERNOON...WITH HEAVY RAIN...FREQUENT LIGHTNING...AND
POSSIBLY SOME SMALL HAIL...ALTHOUGH WE WEREN`T ABLE TO CONFIRM
IF ANY HAIL OCCURRED WITH THOSE STORMS.

FOR MONDAY...HI RES MODELS INDICATE THAT ATMOSPHERIC MOISTURE WILL
GENERALLY DIMINISH SOMEWHAT...ALTHOUGH INSTABILITY WILL STILL BE
SUFFICIENT TO GENERATE ISOLATED CONVECTION. THEREFORE ALTHOUGH OUR
POPS FORECAST IS A BIT LOWER...WE`RE STILL EXPECTING TO SEE ISOLATED
CONVECTION OVER THE SAN BERNARDINO COUNTY MOUNTAINS AND DESERTS.

OTHERWISE...THE MARINE LAYER HAS BECOME QUITE DEEP WITH A STRONG
INVERSION OF ABOUT 8 DEGREES CELSIUS...ALTHOUGH NOT QUITE AS STRONG
AS THE LAST KNKX SOUNDING...COASTAL STRATUS IS RAPIDLY EXPANDING
INTO THE VALLEYS ATTM. THROUGH WEDNESDAY THE ONSHORE GRADIENTS WILL
PICK UP SUBSTANTIALLY AS AN UPPER LEVEL TROUGH DEEPENS OFF THE
CALIFORNIA COAST. THIS PATTERN SHOULD MAXIMIZE THE COASTAL INVERSION
AROUND WEDNESDAY...WITH TEMPERATURES A BIT BELOW NORMAL FOR MOST
AREAS. SOME DRIZZLE MAY ACCOMPANY THE LOW CLOUDS LATE AT NIGHT AND
IN THE MORNING...ESPECIALLY ALONG THE MESAS AND COASTAL SLOPES.

...REMAINDER OF THE PREVIOUS DISCUSSION (ISSUED AT 127 PM PDT)...

CONFIDENCE FOR NEXT WEEK DIMINISHES AS THE LATEST GFS/ECMWF MODEL
SOLUTIONS DIVERGE SLIGHTLY. THE 12Z GFS MODEL IS TRENDING MORE
TOWARD STRENGTHENING THE SUBTROPICAL RIDGE OVER THE ROCKIES EARLY
NEXT WEEK...BUT KEEPS A TROUGH AND SW FLOW ALOFT OVER CA. THE 12Z
ECMWF DEVELOPS A BROADER HIGH OVER THE SW WHICH RESULTS IN HIGHER
HEIGHTS/THICKNESS OVER SOCAL AND A RETURN OF SOME MONSOONAL MOISTURE
ALOFT. BOTH SOLUTIONS LOOK DRY...AND PLACE THE MEAN RIDGE AXIS
CLOSER TO THE ROCKIES.

&&

.AVIATION...

060330Z...COAST/VALLEYS...BKN/OVC015-020 TOPS 030 SPREADING DEEP
INTO THE VALLEYS TONIGHT. LOCALLY LOWER CLOUD BASES AND 2-4SM VIS
FROM 11Z-17Z MONDAY WITH LOCAL DRIZZLE AND FOG.

VALLEY AIRPORTS WILL CLEAR THROUGH 19Z MONDAY...BUT THE COASTAL
AIRPORTS OF KSAN AND KCRQ MAY NOT CLEAR AT ALL. KSNA COULD HAVE
SCT020 CONDITIONS FOR A FEW HOURS BETWEEN 19-24Z.

MTNS/DESERTS...MOSTLY CLEAR TONIGHT. ISOLATED SHOWERS AND
THUNDERSTORMS FORMING MONDAY BTWN 18-24Z OVER THE MOUNTAINS AND HIGH
DESERTS...ESPECIALLY VCNTY KL35...WITH BASES 10000 FT MSL AND TOPS
TO 40000 FT MSL. LOCAL WEST SFC WINDS 15-25 KT WITH GUSTS TO 35 KT
IN THE SAN GORGONIO PASS AND DESERT MOUNTAIN SLOPES MONDAY AFTERNOON
THROUGH EVENING.

&&

.MARINE...

830 PM...NO HAZARDOUS WEATHER IS EXPECTED THROUGH THURSDAY.

&&

.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...JMB
AVIATION/MARINE...MOEDE
PREVIOUS DISCUSSION...JAD


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