000
FXUS66 KMTR 190401
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
901 PM PDT TUE JUN 18 2013

.DISCUSSION...AS OF 9:00 PM PDT TUESDAY...AN UPPER LEVEL LOW IS
CENTERED JUST OFF THE WASHINGTON AND OREGON COASTS. A COOLER
AIRMASS OVER THE AREA CAUSED TEMPERATURES TO DROP ANOTHER 5-10
DEGREES FROM YESTERDAY OVER THE INTERIOR AND 2-4 DEGREES ALONG
THE COAST. THE MARINE LAYER IS NOT IDENTIFIABLE ON THE FT ORD
PROFILER OR THE OAK SOUNDING AS THE AIRMASS HAS REALLY COOLED
ALOFT. THEREFORE THE STRATUS WILL ONLY BE AREAL IN COVERAGE
OVERNIGHT.

THE UPPER LOW WILL MOVE INLAND LATE TONIGHT BUT THE UPPER LOW
WILL REMAIN OVER THE PACIFIC NORTHWEST THROUGH FRIDAY. AN UPPER
LEVEL RIDGE WILL BUILD OFF THE CALIFORNIA COAST THURSDAY BUT
WARMING WILL BE VERY GRADUAL DUE TO THE PROXIMITY OF THE UPPER
LOW. TEMPERATURES ARE ONLY EXPECTED TO GET AS HIGH AS THE LOWER
90S OVER THE WARMEST INTERIOR LOCATIONS FRIDAY BUT SHOULD WARM
INTO THE MID 90S SATURDAY AS THE UPPER LOW MOVES FURTHER EAST.
COOLING IS EXPECTED SUNDAY AND MONDAY AS ANOTHER UPPER LEVEL
TROUGH MOVES THROUGH THE PACIFIC NORTHWEST.

LONG RANGE MODELS BUILD A STRONG UPPER LEVEL RIDGE OVER THE FOUR
CORNERS AREA NEXT TUESDAY AND WEDNESDAY WHICH COULD BRING
SIGNIFICANT WARMING TO THE INLAND AREAS.

SUMMER SOLSTICE WILL OCCUR AT 5:04Z ON JUNE 21...WHICH IS AT
10:04 PM PDT THURSDAY JUNE 20.

&&

.AVIATION...AS OF 5:50 PM PDT TUESDAY...AN UPPER TROUGH
CURRENTLY SWINGING THROUGH THE REGION HAS MIXED OUT THE MARINE
LAYER RESULTING IN MAINLY CLEAR SKIES ACROSS THE DISTRICT TODAY.
ONLY A FEW CLOUDS ALONG THE COAST THIS EVENING. STRATUS TONIGHT
WILL RETURN LATE AND WILL BE PATCHY IN NATURE RESULTING IN AN
EARLY BURN OFF SIMILAR TO THIS MORNING. A STRONG ONSHORE GRADIENT
FORM SFO- SAC IS CURRENTLY AROUND 4.5 MB AND EXPECTED TO
STRENGTHEN TO 5 MB TONIGHT BEFORE DISSIPATING. THEREFORE GUSTY
WINDS WILL PREVAIL THROUGH LATE THIS EVENING IN SOME LOCATIONS.

VICINITY OF KSFO...VFR CONDITIONS WILL PREVAIL THIS EVENING WITH
TEMPORARY MVFR CIGS EXPECTED OVER KSFO0 AS A PATCH OF STRATUS SITS
JUST EAST OF THE RUNWAYS. OTHERWISE PATCHY MVFR CIGS ARE EXPECTED TO
RETURN AFTER 04Z AND 06Z OVER KSFO AND KOAK...RESPECTIVELY. AN
EARLY CLEARING IS ANTICIPATED WEDNESDAY MORNING. A STRONG ONSHORE
GRADIENT WILL MAINTAIN GUSTY WEST WIND AROUND 20 KT WITH GUSTS TO
30 KT POSSIBLE.

KSFO BRIDGE APPROACH...PATCH BROKEN CIGS AROUND 1500 FEET WILL
AFFECT THE APPROACH THIS EVENING. THE THINKING IS THAT THEY WILL
POSSIBLY SCATTER OUT BEFORE REFORMING TONIGHT. CIGS TONIGHT WILL
BE PATCHY WILL CLEAR EARLY WEDNESDAY MORNING. GUSTY WINDS WILL
EASE OVERNIGHT.

MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WILL PREVAIL WITH THE
EXCEPTION OF KMRY THAT WILL SEE A SHORT PERIOD OF BORDERLINE
IFR/MVFR CIGS LATE TONIGHT. AN EARLY CLEARING IS ANTICIPATED
WEDNESDAY MORNING. A STRONG ONSHORE GRADIENT WILL MAINTAIN GUSTY
WEST WIND AROUND 15 KT WITH GUSTS AROUND 20 KT POSSIBLE THROUGH
THIS EVENING. WINDS WILL DIMINISH OVERNIGHT.

VFR THIS MORNING WITH REMAINING
PATCHES OF CLOUDS QUICKLY ERODING. GUSTY WEST WINDS THIS
AFTERNOON. STRATUS TO RETURN THIS EVENING.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY UNTIL 9 PM
             SCA...MRY BAY UNTIL 9 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM

&&

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: CW

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