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FXAK67 PAJK 222349
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
349 PM AKDT WED OCT 22 2014

.SHORT TERM...OVERALL THE PATTERN IS RUNNING AS EXPECTED. THE LOW
OVER THE GULF OF ALASKA WILL BE MOVING SOUTHWARD THROUGH THE NEXT
24 HOURS AND NEW LOW WILL BE MOVING NORTH AND START CURVING BACK
TO THE NORTHWEST BY HAIDA GWAII WED NIGHT. A RESIDUAL TROUGH OF
LOW PRESSURE WILL PERSIST OVER THE OUTER COASTAL WATERS BY
THURSDAY AFTERNOON.

THE OLD `PARENT` LOW HEADED SOUTH IS BEING AIDED BY A JET STREAK
(INCREASING TO THE 120-140KT RANGE) HELPING TO DIG THE UPPER LEVEL
THROUGH OVER THE GULF OF ALASKA SOUTHWARD AND IN RESPONSE, THE
DOWNSTREAM PORTION OF THE FLOW WILL BE SHIFTING NORTHWARD FROM THE
WASHINGTON/OREGON COAST BACK TO THE BRITISH COLUMBIA COAST.

A BAND OF STRATI-FORM RAIN IS MOVING OVER THE SOUTHERN PANHANDLE
AS THE SECOND LOW IS TRYING TO ROTATE ABOUT THE FIRST AND MOVE AWAY
FROM HAIDA GWAII. OTHERWISE, SHOWER ACTIVITY IS DIMINISHING OVER THE
NORTHERN PANHANDLE. WINDS AND SEAS ARE SUBSIDING ACROSS THE REGION
AS WELL. THE SMALL EXCEPTION TO THIS WILL BE A SLIGHT INCREASE IN
WINDS OVER THE LYNN CANAL AS THE GRADIENT TIGHTENS WITH THE LOW
APPROACH THE SOUTHERN THIS EVENING.

SOME ISOLATED LIGHTNING HAS BEEN MONITORED OVER THE WATERS AROUND
HAIDA GWAII EARLIER TODAY MOVING TO THE NORTH-NORTHEAST BUT DO
NOT THINK THAT WILL BE IMPACTING SOUTHEAST EAST ALASKA

.LONG TERM...LITTLE CHANGE IN THE EXTENDED RANGE FORECAST. THE
PAIR OF LOWS ROTATING AROUND EACH OTHER DURING THE SHORT RANGE
PERIOD LOOK LIKE THEY WILL COALESCE INTO A VERY WEAK CIRCULATION
SOUTHWEST OF HAIDA GWAII AND FADE AWAY TO THE SOUTHEAST THURSDAY
NIGHT. AS THIS HAPPENS, A WEAK LOW WILL FORM OVER THE FAR NORTH-
CENTRAL GULF AND A BROAD AREA OF WEAK LOW PRESSURE BETWEEN THE TWO
LOWS WILL DOMINATE THE EASTERN GULF THROUGH SATURDAY. THIS LOW
PRESSURE WILL TIGHTEN UP INTO A TROUGH SATURDAY NIGHT THROUGH
SUNDAY. SCATTERED SHOWERS FOR MOST PLACES THROUGH SATURDAY NIGHT,
THEN A CHANCE OF RAIN, PRIMARILY TO THE SOUTH AS LOW LEVEL
OFFSHORE FLOW AIDES IN DRYING OUT THE NORTHERN PANHANDLE.

TROPICAL STORM ANA CONTINUES TO CHURN NORTHWEST OF HAWAII. IR
SATELLITE IMAGERY NOT OVERLY IMPRESSIVE BUT TPW IMAGERY INDICATING
3 OR MORE INCHES OF PRECIPITABLE WATER. CURRENT FORECAST TRACK BY
THE JOINT TYPHOON WARNING CENTER KEEPS THE STORM SOUTH OF 50N
THROUGH MONDAY MORNING. CURRENT GFS IS EVEN FURTHER SOUTH, AS THAT
MODEL IS RUNNING THE SUB-TROPICAL JET IN A VERY ZONAL PATTERN WITH
A VERY CLEAR AND LARGE SEPARATION BETWEEN IT AND THE POLAR JET.
ECMWF AND GEM ARE STILL DIGGING AN UPPER TROUGH MUCH MORE
AGGRESSIVELY, CAUSING A PERTURBATION IN THE SUB-TROPICAL JET. THE
ECMWF THEN PICKS UP THE UPPER LEVEL CIRCULATION OF ANA AND CARRIES
IT FURTHER NORTH THAN GFS, BUT NOT NEARLY AS FAR, NOR AS STRONG, AS
YESTERDAY. IN THAT REGARD, THE MODELS ARE COMING INTO BETTER
ALIGNMENT, BUT THERE IS STILL A LONG WAY TO GO BEFORE THE
EXTENDED RANGE FORECAST CAN BE LABELED "HIGH CONFIDENCE". AS IT
IS, THE CURRENT LONG RANGE FORECAST IS CLOSELY ALIGNED WITH WPC
AND KEEPS THE CENTER OF CIRCULATION OVER HAIDA GWAII AND HECATE
STRAIT NEXT TUESDAY OR LATER. POTENTIAL EXISTS FOR HEAVY RAIN OVER
THE SOUTHERN PANHANDLE, BUT STILL TOO EARLY TO SAY WITH ANY
CERTAINTY AT ALL.

USED ECMWF AS THE FOUNDATION FOR UPDATES TO PRESSURE AND WIND
DIRECTIONS OVER THE GULF THROUGH SATURDAY NIGHT, BLENDED WITH GEM
AND NAM AT TIMES. WIND SPEEDS DURING THIS TIME FRAME DERIVED FROM
NAM. BLENDED CURRENT SREF TO EXISTING POP GRIDS - LITTLE CHANGE TO
THE FORECAST. OVERALL FORECAST CONFIDENCE IS AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-033-036-041-042-051-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ022-043.

&&

$$

BEZENEK/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU








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