Area Forecast Discussion
Issued by NWS San Diego, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KSGX 201038
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
340 AM PDT SUN APR 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING INLAND WARMING THROUGH MONDAY WHILE THE
MARINE LAYER KEEPS COASTAL AREAS COOLER WITH AREAS OF NIGHT AND
MORNING LOW CLOUDS AND FOG. FOR TUESDAY AND EARLY WEDNESDAY...A
TROUGH OF LOW PRESSURE WILL MOVE INLAND ALONG THE WEST COAST
BRINGING COOLING...DEEPENING OF THE MARINE LAYER...AND STRONG GUSTY
WEST WINDS IN THE MOUNTAINS AND DESERTS. WEAKER WINDS AND MODEST
WARMING FOR THURSDAY AND FRIDAY. THEN ANOTHER STRONGER TROUGH OF LOW
PRESSURE NEXT WEEKEND WILL BRING COOLING AND GUSTY WINDS WITH LESS
CERTAINTY ON CHANCES FOR PRECIPITATION.

&&

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

.SHORT TERM (TODAY THROUGH TUESDAY)...
THROUGH MONDAY...HIGH PRESSURE ALOFT WILL BRING INLAND WARMING AND A
SHALLOWER MARINE LAYER. RECENT AIRCRAFT SOUNDINGS SHOW MULTIPLE
INVERSIONS...ONE NEAR 2500 FEET AND A SECOND LOWER ONE NEAR 1500
FEET. WITH HIGH PRESSURE ALOFT STRENGTHENING...THE LOWER INVERSION
SHOULD BECOME DOMINANT DURING THE NEXT 24 HOURS. PATCHY LOW CLOUDS
AND FOG EARLY THIS MORNING WILL INCREASE SOMEWHAT IN COVERAGE AND
EXTEND INLAND INTO THE WESTERN VALLEYS. FOR TONIGHT INTO MONDAY
MORNING...STRATUS COVERAGE IS EXPECTED TO BE GREATER...BUT NOT
EXTEND QUITE AS FAR INLAND.

FOR TUESDAY...A TROUGH OF LOW PRESSURE WILL MOVE INLAND ALONG THE
WEST COAST...STRENGTHENING THE ONSHORE FLOW. THIS WILL BRING
COOLING...DEEPENING OF THE MARINE LAYER INTO THE INLAND
VALLEYS...AND STRONG GUSTY WEST WINDS IN THE MOUNTAINS AND DESERTS.
THE BULK OF THE GUIDANCE SUPPORTS ADVISORY STRENGTH WIND GUSTS IN
THE MOUNTAINS AND DESERTS TUESDAY AFTERNOON AND EVENING WITH
ISOLATED STRONGER GUSTS POSSIBLE.

&&

.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
MODEST WARMING AND WEATHER WINDS FOR WEDNESDAY THROUGH FRIDAY UNDER
WEAK HIGH PRESSURE ALOFT. FOR NEXT WEEKEND...A STRONGER TROUGH OF
LOW PRESSURE WILL MOVE INLAND ALONG THE WEST COAST WITH CONTINUING
DIFFERENCES IN TIMING AND AMPLITUDE (STRENGTH). IT WILL BRING
COOLING...DEEPENING OF THE MARINE LAYER...AND GUSTY WEST WINDS FOR
THE MOUNTAIN AND DESERTS. THERE IS GREATER UNCERTAINTY REGARDING
PRECIPITATION POTENTIAL. FOR THOSE MODEL SOLUTIONS WITH GREATER
AMPLITUDE...PRECIPITATION WOULD EXTEND SOUTHWARD INTO SOUTHERN
CALIFORNIA. FOR THOSE WITH LESSER AMPLITUDE...THE PRECIPITATION
WOULD MOSTLY REMAIN NORTH OF POINT CONCEPTION.

&&

.AVIATION...
201015Z...COAST/VALLEYS...AREAS OF STRATUS WILL OCCUR WITHIN 20 MI
OF THE COAST THROUGH 18Z. BASES WILL BE 1000 TO 1500 FT MSL WITH
TOPS TO 2000 FT. MOST VIS WILL REMAIN ABOVE 5 MI. LOCAL STRATUS WILL
CONTINUE ALONG THE COAST THIS AFTERNOON...THEN STRATUS WILL DEVELOP
AGAIN THIS EVENING WITHIN 15 MI OF THE COAST...WITH SLIGHTLY LOWER
BASES AND SOME VIS REDUCTIONS TO 2 TO 4 MI...LOCALLY LOWER.

MTNS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH TONIGHT.

&&

.MARINE...
WEST TO NORTHWEST WINDS WILL STRENGTHEN TUESDAY AS A TROUGH OF LOW
PRESSURE MOVES ACROSS CALIFORNIA. THE WINDS PEAK TUESDAY NIGHT WITH
GUSTS OF 25-30 KT OVER THE OUTER WATERS...AND GUSTS OF 15-25 KT OVER
THE INNER WATERS. THESE WINDS WILL COMBINE WITH A 6-8 FOOT
SHORT-PERIOD SWELL TO BRING HAZARDOUS SEAS FOR SMALL CRAFT OVER THE
OUTER WATERS. A SMALL CRAFT ADVISORY WILL LIKELY BE ISSUED FOR
TUESDAY/TUESDAY NIGHT...ESPECIALLY IN THE OUTER WATERS. CONDITIONS
WILL IMPROVE SOMEWHAT WEDNESDAY.

&&

.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...17
AVIATION/MARINE...MAXWELL











USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.