Area Forecast Discussion
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FXAK67 PAJK 041256
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
456 AM AKDT SAT JUL 4 2015

.SHORT TERM...EARLY MORNING SATELLITE IMAGE SHOWS A HIGH PRESSURE
AREA BUILDS OVER SOUTHEAST ALASKA AND A WARM FRONT MOVES
NORTHWESTWARD ACROSS THE WESTERN AND CENTRAL GULF. THE FRONTAL
PASSAGE WILL CONTINUE TO DRIFT NORTHWESTWARD THROUGH TONIGHT.
UNDERNEATH THE INCREASING SUBSIDENCE...MARINE STRATUS REMAIN NEAR
SHORE FROM CAPE EDGECUMBE NORTHWEST TO NEAR CAPE SUCKLING. PATCHY
FOG DEVELOPED A FEW LOCATIONS...BUT A RAPID DRYING PROCESS
OCCURRED OVERNIGHT AND NO NOTICEABLE FOG EPISODE THIS MORNING. AS
HIGH PRESSURE DOMINATING SOUTHEAST ALASKA...WINDS REMAIN LIGHT AND
VARIABLE. OVERNIGHT TEMPERATURES RANGE FROM THE LOWER 40S INLAND
AREAS TO THE LOWER TO MID 50S ALONG THE COASTAL SECTIONS AND OVER
THE SOUTHERN AREAS.

MODELS REMAIN IN FAIR AGREEMENT WITH THE HIGH PRESSURE CONTINUES
TO DOMINATE SOUTHEAST ALASKA WEATHER THROUGH TONIGHT. AN INVERTED
TROUGH OF LOW PRESSURE DEVELOPING OVER VANCOUVER ISLAND THIS
MORNING WILL EXTEND NORTHWARD TO THE SOUTHERN PANHANDLE BY LATE
TONIGHT. REFRESHED THE INHERITED FORECAST WITH THE NAM12 FOR ITS
GOOD INITIALIZATION AND CONSISTENCY.

A PLENTY OF SUNSHINE WILL BE GRANTED TODAY WITH DAYTIME HIGHS CAN
SOAR UP TO THE UPPER 60S OVER THE NORTHERN PANHANDLE TO THE MID 70S
ACROSS THE SOUTHERN AREAS. HYDER AREA CAN WARM UP TO THE LOWER
80S. NO SIGNIFICANT WINDS...BUT 10 TO 15 KNOTS AFTERNOON SEA
BREEZES. NORTHERN LYNN CANAL WILL AGAIN HAVE DIURNAL SMALL CRAFT
LEVEL SOUTHERLY WINDS LATE THIS AFTERNOON INTO THE EARLY EVENING
HOURS. AS HIGH PRESSURE CONTINUES OVER SOUTHEAST ALASKA...THE
MARINE STRATUS WILL POSSIBLY MOVE CLOSER TO THE PANHANDLE COAST
THIS AFTERNOON...THEN MORE CONFINED OVER THE NORTHERN GULF COAST
TO THE CENTRAL OUTSIDE WATERS THIS EVENING. SOME OF LOW CLOUDS ARE
EXPECTED TO MOVE INTO CROSS SOUND TONIGHT. PATCHY FOG WILL LIKELY
TO DEVELOP ALONG THE IMMEDIATE COASTAL AREAS LATE TONIGHT AND SOME
LOCATIONS IN THE SOUTH CENTRAL AS WELL. OVERNIGHT TEMPERATURES
WILL BE IN THE UPPER 40S TO THE MID 50S.

.LONG TERM...STRONG UPPER RIDGING CONTINUES TO DOMINATE ON SUNDAY
MORNING AND CONTINUES THROUGH TUESDAY. ONLY WIND ISSUES SHOULD BE DIURNAL
OCEAN BREEZES MOST NOTABLE AT CROSS SOUND AND ACCELERATED FLOW AT
CAPE DECISION ALONG WITH THE LOCAL EVENING BREEZES...AND WIDESPREAD
20-25 KT FLOW EAST OF THE GULF RIDGE OVER THE SOUTHERN PANHANDLE
AND ADJACENT WATERS. VERY WARM DAYTIME HIGHS WITH WIDESPREAD 70S
AND A COUPLE SPOTS OF 80 LIKELY ON SUN/MON AS 850MB TEMPS GET UP
TO +15C AND HIGHER...THIS WX WILL LIKELY CONTINUE ON WED FOR THE
SOUTH. ON TUE LATE THE MODEL SOLUTIONS BEGIN TO DIVERGE. SHARP
UPPER RIDGE BEGINS TO GET SQUASHED ON ITS WEST SIDE IN THE GULF AS
STRONG UPPER SOUTHERLY FLOW IMPINGES ON THAT SIDE AS THE UPPER LOW
ROTATES IN THE BERING. GFS SHOWS RIDGING FLATTENING BUT
PREVAILING...WITH MIDDLE CLOUD DECK OVER THE CENTRAL/NORTHERN PANHANDLE...ON
TUE NIGHT WHILE THE EC SHOWS LIGHT RAIN DEVELOPING WITH THE TUE PM
WAVE OVER PORTIONS OF THE NORTHERN PANHANDLE ALONG WITH SOME
CYCLONIC FLOW ALOFT. GEM SOLUTION TENDS TO AGREE WITH THE EC AND
THAT IS THE ROUTE WE STAYED WITH ON THIS FORECAST PACKAGE...WITH
CHANCES OF RAIN OVER THE NORTHERN HALF OF THE PANHANDLE BEGINNING
TUE NIGHT. WE LEANED TOWARDS THE NEW EC BUT DID NOT BUY IT YET
FULL-TILT AS THE INCREASE IN GULF FLOW WAS QUITE MARKED FOR TUE
COMPARED TO PREVIOUS RUNS. UPCOMING NEW RUNS WILL TELL A LOT AS
THIS NEW EC SOLUTION IS CERTAINLY PLAUSIBLE GIVEN RECENT MODEL
PERFORMANCE. FOR THU-FRI WIDESPREAD ONSHORE FLOW IS FORECAST BY
THE MODELS FOR MOST AREAS WITH A COUPLE OF WEAK UPPER
WAVES...LOOKS LIKE A GENERAL OCCASIONALLY WET PERIOD BUT WAY TOO
EARLY TO DECIPHER SYSTEM DETAILS AT THIS POINT. NO EVIDENCE OF ANY
STRONG SYSTEMS/FRONTS AT THIS POINT.

DID NOT CHANGE THE LONG RANGE GRIDS FOR THE MOST PART AS WPC WAS
CHOSEN IN EARLIER SHIFT FOR DAYS 5-8 AND THOUGH CONFIDENCE IS ONLY
AVERAGE DID NOT SEE ENOUGH CONTRARY EVIDENCE TO GO WHOLESALE WITH
THE NEW RUNS. THIS WPC GUIDANCE WAS BASED ON LAST NIGHT`S 00Z EC
RUN. UPDATED DAYS 2-4 THERMODYNAMIC GRIDS WITH AN EC/NAM/INHERITED
BLEND WITH THE NEW MODEL RUNS. BOTTOM LINE... MOST
NORTHERN/CENTRAL ZONES HAVE CHANCES FOR PRECIP FROM TUE PM ONWARD
(TUE FOR YAKUTAT) THROUGH THE END OF THE WEEK. SOUTHERN AREAS DO
NOT APPEAR LIKELY TO GET INTO THE PRECIP THREAT UNTIL THURS/FRI.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.

&&

$$

AHN/WESLEY

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