Storm Warning 26, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
606 AM AKST FRI NOV 29 2013

.SHORT TERM...EARLY MORNING SATELLITE LOOP REVEALS A RIDGE OF
HIGH PRESSURE OVER BRITISH COLUMBIA AND A LOW IN THE NORTHERN
GULF...SLOWLY MOVES OVER THE NORTHERN PANHANDLE. A COLD FRONT
ASSOCIATED WITH THE LOW SWEEPS THE NORTHEASTERN GULF COAST WITH
NUMEROUS SNOW SHOWERS OVER YAKUTAT AREA. BEHIND THE RIDGE OF HIGH
PRESSURE...ANOTHER LOW MOVES INTO THE EASTERN GULF. TIGHTENED
SOUTHERLY PRESSURE GRADIENT PRODUCES STRONG WIND OVER SKAGWAY
AREA WITH SOLID SMALL CRAFT LEVEL WINDS ACROSS NORTH TO SOUTH
ORIENTED INNER CHANNELS. EXCEPT THE NORTHEASTERN GULF
COAST...MARITIME AIR MASS MAINTAINS PRECIPITATION AS RAIN AND
RELATIVELY WARM TEMPERATURES OVER SOUTHEAST ALASKA WITH OVERNIGHT
LOWS MOSTLY IN THE UPPER 30S TO THE LOWER 40S.

 MODELS REMAIN IN FAIR AGREEMENT WITH THE LOW ACROSS THE NORTHERN
PANHANDLE THIS MORNING WILL CONSOLIDATE WITH THE LOW IN THE
EASTERN GULF OVER THE CENTRAL PANHANDLE THIS AFTERNOON. THE
RESULTANT LOW WILL THEN MOVE INTO NORTHERN BRITISH COLUMBIA
THROUGH TONIGHT. A WEAK LOW WILL DEVELOP IN THE NORTHERN GULF
TONIGHT. AN ARCTIC HIGH PRESSURE AREA OVER ALASKA INTERIOR WILL
CONTINUE TO EXPAND EASTWARD INTO THE YUKON. REFRESHED THE
INHERITED FORECAST PACKAGE WITH THE 06Z RUN NAM TO MAINTAIN A
MAXIMUM CONTINUITY FROM THE PREVIOUS SYNOPTIC PATTERN.

 AS THE LOWS CONSOLIDATING OVER THE CENTRAL PANHANDLE THIS
AFTERNOON...PRESSURE GRADIENT WILL RELAX AND EXPECT THE STRONG
WINDS OVER SKAGWAY AREA AND ACROSS MOST OF THE INNER CHANNELS
WILL DECREASE THROUGH LATE THIS MORNING. THE EXPANDING ARCTIC
HIGH OVER NORTH OF THE PANHANDLE WILL BEGIN PRODUCING NORTHERLY
PRESSURE GRADIENT WITH INCREASING OFFSHORE FLOW OVER THE NORTHERN
PANHANDLE. WINDS WILL SHIFT TO THE NORTH THIS AFTERNOON AND
CONTINUE TO INCREASE AND BECOME SMALL CRAFT LEVEL LATE AFTERNOON
THEN GALE FORCE INTO THE EARLY EVENING. POSTED FREEZING SPRAY FOR
LYNN CANALS AND STRONG WIND HEADLINE FOR THE SKAGWAY AREA.

 EXCEPT YAKUTAT AREA WHERE DAYTIME HIGHS REMAIN BELOW
FREEZING...TEMPERATURES WILL STEADY IN THE UPPER 30S OVER THE
NORTHERN AND CENTRAL PANHANDLE AND MOSTLY IN THE LOWER TO MID 40S
ACROSS THE SOUTHERN AREAS. WITH ARCTIC AIR MASS ENTRAINMENT FROM
THE NORTH UNDER INCREASING OFFSHORE FLOW...OVERNIGHT TEMPERATURES
WILL SIGNIFICANTLY DROP DOWN TO THE LOWER TO MID TEENS OVER THE
NORTHERNMOST PANHANDLE...MOSTLY IN THE 20S ACROSS THE CENTRAL
PANHANDLE AND IN THE LOWER TO MID 30S OVER THE SOUTHERN ZONES.
WITH INCREASING OFFSHORE FLOW...POPS WILL CONTINUE TO SUBSIDE
THIS AFTERNOON INTO TONIGHT.

 &&

 .LONG TERM...FORECAST REMAINS ON TRACK FOR BRIEF BUT STRONG
ARCTIC OUTBREAK BEGINNING SATURDAY. AT ISSUE IS A STRONG SURFACE
HIGH THAT WILL BEGIN TO BUILD EAST AND SOUTH STARTING TODAY. THE
RIDGE WILL SHOVE AN AREA OF LOW PRESSURE WHICH CURRENTLY EXTENDS
FROM THE GULF TO BRITISH COLUMBIA TO THE SOUTH. PART OF THIS LOW
WILL BE LEFT BEHIND IN THE NORTHERN GULF AND ACT TO ACCENTUATE
THE RESULTING NORTHERLY/OFFSHORE PRESSURE GRADIENT. ON SATURDAY,
A LOW WILL TRACK NORTHEAST ACROSS THE SOUTHERN GULF AND UNDER THE
RIDGE AS IT ENTERS CANADA. THIS WILL INCREASE THE NORTHERLY
PRESSURE GRADIENT EVEN MORE AND CORRESPONDS TO THE PERIOD OF TIME
WHEN WINDS WILL BE AT THEIR MAXIMUM INTENSITY. STRONG WIND IN
SKAGWAY THROUGH AT LEAST SATURDAY NIGHT AND A HIGH WIND WARNING
THERE IS NOT OUT OF THE QUESTION. ALSO AM EXPECTING STRONG WINDS
IN DOWNTOWN JUNEAU/DOUGLAS THIS WEEKEND AND INTO EARLY NEXT WEEK.
HAVE STORM FORCE WINDS IN NORTHERN LYNN CANAL WITH MAX GALES IN
SOUTHERN LYNN AND SOLID GALES OVER VARIOUS OTHER INNER CHANNELS.
WINDS OUT OF TAKU INLET AS WELL AS OTHER PASSES NEAR TH THE COAST
MOUNTAINS WILL BE PARTICULARLY FIERCE. ON THE OUTSIDE, OUTFLOW WIND
PLUMES OUT OF CROSS SOUND AS WELL AS THE COASTLINE EAST OF YAKUTAT
FORECAST TO PEAK AT 40 TO 45 KTS OUT OF THE NORTHEAST SATURDAY
NIGHT THROUGH SUNDAY NIGHT.

COLD AIR FROM THE ALASKAN INTERIOR AND NORTHWESTERN CANADA WILL
ACCOMPANY THE RIDGE AS IT BUILDS SOUTH AND EAST. OVERNIGHT LOWS
WILL TAKE AN ABRUPT TURN FOR THE COLDER BEGINNING IN THE SHORT
TERM AND REMAIN IN THE MIDDLE TEENS AS FAR SOUTH AS PETERSBURG
THROUGH MID WEEK. LOOK FOR SINGLE DIGIT LOWS SINGLE DIGITS OVER
THE FAR NORTHERN INNER CHANNELS AND MENDENHALL VALLEY THROUGH
SUNDAY NIGHT. DAYTIME HIGHS FOR THE UPCOMING WEEK WILL ALSO SAG
WELL BELOW NORMAL FOR THIS TIME OF THE YEAR. VERY COLD
TEMPERATURES AND HOWLING NORTHERLY WINDS WILL RESULT IN WIND
CHILLS DOWN AS LOW AS -35 DEGREES NEAR WHITE PASS THIS WEEKEND SO
TRAVELERS USING THE KLONDIKE HIGHWAY SHOULD TAKE NOTE AND EXERCISE
DUE CAUTION.

USED NAM EARLY ON, FOLLOWED BY A NAM/ECMWF BLEND, THEN STRAIGHT EC
THROUGH WEDNESDAY FOR PRESSURE AND WIND. FINISHED UP WITH WPC. NO
CHANGES TO POP, SNOW, OR QPF. FORECAST CONFIDENCE IN VERY STRONG
WINDS AND WELL BELOW NORMAL TEMPERATURES IS HIGH.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 AM AKST EARLY THIS MORNING FOR AKZ018.
         STRONG WIND FROM NOON AKST TODAY THROUGH LATE SATURDAY NIGHT FOR
     AKZ018.
MARINE...GALE WARNING FOR PKZ012.
         SMALL CRAFT ADVISORY FOR PKZ011-013-022-031-033>036-041-042.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ043-051-052.

&&

AHN/FRITSCH