Gale Warning 127, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
343 PM AKDT FRI MAR 14 2014

.SHORT TERM...CURRENT FRONT MOVING ACROSS LYNN CANAL, AND
ASSOCIATED SOUTHERLY PUSH SHOULD RAISE SKAGWAY WINDS AT ANY TIME
NOW. KEPT STRONG WINDS FOR SKAGWAY BUT CONFIDENCE NOT AS GREAT AS
YESTERDAY. DID DECIDE TO TAKE GALE OUT, BASED ON SLIGHTLY WEAKER
GRADIENTS. CHARACTER OF PRECIPITATION HAS CHANGED TO SHOWERS FOR
MOST PART, BUT KEPT PLANS ON CHANGING IT TO STRATIFORM BEGINNING
LATE TONIGHT FOR THE FAR SOUTHERN ZONES AND FOR THE ENTIRE
PANHANDLE SATURDAY. WESTERLIES HAVE ARRIVED AS SCHEDULED FOR
CROSS SOUND AND CAPE DECISION AND WILL BE COMING SOON TO YAKUTAT
THIS EVENING. MID LEVEL WINDS WILL PICK UP FROM THE SOUTHEAST
LATE TONIGHT OVER THE SOUTHERN AREAS WITH THE APPROACH OF THE LOW
FROM THE SOUTH INTO THE EASTERN GULF. A LITTLE CONCERNED THAT OUR
WINDS WERE A LITTLE LIGHT THROUGH HERE, SO INCREASED THEM TO
15 TO 25 FOR ZONE 27 TONIGHT...BUT HIGHER GUSTS POSSIBLE GIVEN
THE GALE FORCE LOW APPROACHING. THE TREND FOR THE NORTHERN
PANHANDLE IS SOUTHERLY GRADIENTS TURNING NORTH TOMORROW WITH
APPROACHING LOW. WHILE SOUTHERLY AND COASTAL MARINE WINDS
INCREASING TOMORROW.

 NOT REAL CONCERNED ABOUT HYDROLOGY...LEVELS HAVE TAPERED OFF
SINCE DOUSING OF MIDWEEK...YET THE GROUND IS STILL A LITTLE
SATURATED AND STREAM/RIVER LEVELS WILL COME UP SATURDAY...BUT
NONE APPROACHING ACTION STAGE.

 FINALLY THE COLD AIR WILL BEGIN FILLING IN FOR THE SOUTHERN
PANHANDLE FIRST AND QUICKLY SPREAD NORTH AND EASTWARD OVERNIGHT.
THIS WILL SUPPORT SNOW EVEN WHEN TEMPERATURES ARE STILL ABOVE
FREEZING THIS EVENING. DO THINK THERE WILL BE A BREAK IN THE
SHOWERS LATE TONIGHT AS A VORTICITY FEATURE TRANSITIONS INTO
SHARPER RIDGING AHEAD OF THE NEXT SYSTEM. SO EXPRESSED A
DIMINISHING TREND FOR TONIGHT.

 ECMWF MODEL OF CHOICE. CONFIDENCE GOOD TO AVERAGE.

.LONG TERM...MODELS IN PRETTY GOOD AGREEMENT ON THE MAIN SYSTEMS
THAT WILL AFFECT THE AREA THROUGH EARLY NEXT WEEK. NAM WAS AN
OUTLIER ON ITS HANDLING OF THE SAT NIGHT/SUN SYSTEM SO IT WAS
DISREGARDED. ENDED UP USING THE 12Z ECMWF FOR SAT NIGHT THRU TUE
MORNING...THEN TRANSITIONED TO WPC BY TUE NIGHT AND USED IT OUT TO
ITS END.

A LOW WILL MOVE NE INTO THE SRN AREA SAT NIGHT...THEN SHIFT E OF
THE AREA SUN. THIS LOW WILL KEEP PRECIP GOING OVER MUCH OF THE
AREA...AND WITH LOW LEVEL N FLOW OVER THE NRN AREA...CAUSE PRECIP
TO CHANGE BACK TO SNOW SAT NIGHT. OVER THE NRN THIRD. THINK THE
MOST SNOW WILL FALL IN THE PAJN-PAEL CORRIDOR BUT IT WILL LIKELY
REMAIN BELOW ADVY LEVELS. MAIN DRIVER OF PRECIP OVER THE N-CENTRAL
AREA WILL BE DEFORMATION ZONE ON N SIDE OF THE LOW. THE PRECIP
SHOULD TAPER OFF SUN AS LOW MOVES INLAND.

NEXT SYSTEM WILL MOVE INTO THE AREA SUN NIGHT INTO MON. LOWER
LEVEL AIRMASS IS A BIT COOLER AHEAD OF THE OCCLUDED FRONT MOVING
INTO THE ERN GULF LATE SUN NIGHT THEN INTO SE AK MON...AND THIS
WILL ALLOW AT LEAST MIXED PRECIP TO FALL OVER THE NRN AND ERN
AREAS. LOWERED MAX TEMPS A FEW DEGREES FOR MON IN THESE AREAS.
THEN MODELS ARE IN INCREASING AGREEMENT THAT A LOW PRESSURE WAVE
WILL MOVE INTO THE ERN GULF MON NIGHT...BUT DIFFER ON HOW FAR N IT
WILL TRACK ACROSS THE PANHANDLE. THE ECMWF WAS A REASONABLE
COMPROMISE WITH IT...TAKING THE LOW OVER THE NRN AREA LATE MON
NIGHT AND TUE MORNING. THIS SHOULD BRING SOME WARMER AIR NWD BUT
IT IS A TRICKY CALL ON WHERE RAIN/SNOW LINE WILL SET UP. BASICALLY
KEPT IT SIMPLE USING RAIN AND SNOW FOR MOST OF THE NRN AREAS FOR
MON NIGHT INTO TUE MORNING. SRN AREA SHOULD BE RAIN AND MAY GET A
DECENT AMOUNT OF RAIN GIVEN STRENGTH OF LOW LEVEL ONSHORE FLOW. DO
NOT THINK IT WILL LEAD TO ANY HYDRO ISSUES AT THIS POINT HOWEVER.

FOR MIDWEEK ONWARD...TREND IS TOWARD A LITTLE COOLER AND DRIER
PATTERN AS UPPER RIDGE TRIES TO MOVE INTO THE WRN GULF BY LATE
WEEK. THIS WILL DEPEND ON EXACTLY WHERE THE RIDGE SETS UP THOUGH
AS SOME ENERGY COULD DROP DOWN THE FRONT SIDE OF THE RIDGE INTO
THE GULF...WHICH COULD BRING SOME SHOWERY WEATHER TO THE AREA. WPC
WAS TRENDING DRIER AS WELL...SO WAS USING THAT FOR POPS FOR
MIDWEEK ON OUT. DID NOT CHANGE TEMPS AFTER TUE...AND LATER SHIFTS
MAY NEED TO BUMP TEMPS DOWNWARD SOME ESPECIALLY FOR THE NIGHTTIME
PERIODS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 7 PM THIS EVENING TO 1 AM AKDT SATURDAY FOR
     AKZ018.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-022-031-033-035-036-041>043-
     051-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

JWA/RWT