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000
FXAK68 PAFC 091334 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
530 AM AKDT SUN MAR 9 2014

CORRECTED WATCH/WARNING SUMMARY

.ANALYSIS AND UPPER LEVELS...
AN UPPER LEVEL TROUGH OVER MUCH OF MAINLAND ALASKA BEGINS TO LIFT
NORTH...AS HIGH PRESSURE ALOFT BUILDS BACK OVER THE GULF AND
SOUTHCENTRAL ALASKA TODAY. AN UPPER LOW SOUTH OF THE CENTRAL
ALEUTIANS INTENSIFIES BEHIND A BUILDING NORTH PACIFIC RIDGE.

AT THE SURFACE...SOME LINGERING SNOW SHOWERS OVER PARTS OF EASTERN
PRINCE WILLIAM SOUND BEGIN TO DISSIPATE AS A 980 MB LOW MOVES INLAND
AND WEAKENS TODAY. STRONG OFFSHORE FLOW REMAINS ALONG THE NORTHERN
GULF COAST AND EASTERN KENAI PENINSULA...AS THE TIGHTENED PRESSURE
GRADIENT BETWEEN THIS GULF LOW AND HIGHER PRESSURE OVER THE MAINLAND
PERSISTS OVER THE AREA. A SIMILAR STORY FOR SOUTHWEST ALASKA...WITH
HIGHER PRESSURE AND PERSISTENT DRY OFFSHORE FLOW COVERING MUCH OF THE
AREA AS DEPICTED BY CURRENT SATELLITE IMAGERY. SOME LINGERING SNOW
SHOWERS HAVE BEEN OBSERVED OVER THE BERING AND EASTERN ALEUTIANS
ASSOCIATED WITH THE REMNANTS OF A WEAKENING FRONTAL BOUNDARY.

.MODEL DISCUSSION...
THE MODELS INITIALIZED WELL AND CONTINUE TO BE IN GOOD SYNOPTIC
AGREEMENT WITH THE OVERALL PATTERN...WITH ONLY A FEW SMALLER SCALE
DISCREPANCIES. THE GFS/NAM SEEM TO AGREE ON A FASTER SOLUTION
WITH THE FRONTAL SYSTEM MOVING THROUGH THE GULF AND INTO THE NORTHERN
GULF COAST DURING THE DAY MONDAY...WHERE THE ECMWF/GEM REMAIN
SLIGHTLY SLOWER WITH THE PROGRESSION OF THIS FRONTAL SYSTEM. WITH THE
SOLUTIONS BEING FAIRLY CLOSE AND THE ECMWF REMAINING SLIGHTLY MORE
CONSISTENT FROM RUN TO RUN...THE ECMWF WAS MAINLY UTILIZED FOR THE
SOUTHCENTRAL AND GULF OF ALASKA FORECAST PACKAGE. THE ONSET AND
AMOUNT OF PRECIPITATION REMAINS DEPENDENT ON THE TIMING OF THIS
FRONTAL SYSTEM MOVING THROUGH THE GULF...POSING A FORECAST CHALLENGE
AND SLIGHTLY LOWERING FORECAST CONFIDENCE. FOR THE WEST...THE NAM WAS
UTILIZED FOR BETTER DETAIL REGARDING THE WINDS ASSOCIATED WITH THE
AFOREMENTIONED INTENSIFYING LOW SOUTH OF THE EASTERN ALEUTIANS
TONIGHT...AND A NORTH PACIFIC LOW SOUTH OF THE CENTRAL ALEUTIANS
TUESDAY.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THE SOUTHWESTERN GULF WILL HAVE A WEATHER FRONT APPROACHING THE
REGION MONDAY MORNING BEFORE REACHING THE NORTHERN GULF BY MONDAY
AFTERNOON. THIS WILL BRING A LARGE SWATH OF MOISTURE/PRECIPITATION
WITH GALE FORCE WINDS. KODIAK WILL HAVE A FEW HOURS OF SNOW EARLY
MONDAY MORNING BEFORE CHANGING TO ALL RAIN BY MIDDAY. THE POSSIBLE
HAZARDS FOR MONDAY THROUGH TUESDAY WILL BE FOR THE EASTERN KENAI FOR
SIGNIFICANT SNOWFALL AMOUNTS ACCOMPANIED BY POSSIBLE BLOWING SNOW
CONDITIONS. AS THE WEATHER FRONT MOVES TOWARDS THE NORTHERN GULF
THERE WILL BE POSSIBLE BLOWING SNOW CONDITIONS FOR THOMPSON PASS.

SOUTHWEST ALASKA...
HIGH PRESSURE AND DRIER OFFSHORE FLOW CONTINUES TO DOMINATE OVER THE
SOUTHWEST MAINLAND THROUGH TOMORROW NIGHT. AS THE LOW SOUTH OF THE
CENTRAL ALEUTIANS BEGINS TO TRACK TO THE NORTHEAST...AN ASSOCIATED
FRONTAL SYSTEM WILL BEGIN MOVE OVER THE AKPEN EARLY MONDAY MORNING.
THIS FRONTAL SYSTEM WILL PRODUCE GUSTY WINDS...ALONG WITH A MIX OF
SNOW AND RAIN OVER MUCH OF THE SOUTHWEST MAINLAND THROUGH LATE
TUESDAY EVENING.

ALEUTIANS/BERING SEA...
THE MAIN SHORT TERM CONCERN FOR THE BERING IS THE POTENTIAL FOR
BLOWING SLOW AND POSSIBLE BLIZZARD CONDITIONS OVER THE EASTERN BERING
AS THE STRONG NORTH PACIFIC LOW PASSES SOUTH OF THE AKPEN TONIGHT AND
TUESDAY. THE BIGGEST THREAT APPEARS TO BE ALONG THE AKPEN BEGINNING
LATE THIS EVENING AS THE FRONT ARRIVES ACCOMPANIED BY SNOW AND STRONG
NORTHEASTERLY WINDS. ONE POTENTIAL LIMITING FACTOR IS THAT
TEMPERATURES WILL BE A LITTLE ON THE WARM SIDE...WITH RAIN POSSIBLY
MIXING IN AT TIMES ALONG THE PACIFIC COAST AS TEMPERATURES REACH THE
MID 30S. HOWEVER...TEMPERATURES SHOULD STAY A LITTLE COOLER IN THE
VICINITY OF COLD BAY AND THUS ALLOW FOR BLOWING SNOW TO DEVELOP...AND
THEREFORE A BLIZZARD WATCH HAS BEEN ISSUED FOR AREAS NEAR COLD BAY
FROM TONIGHT INTO TUESDAY AFTERNOON. BLOWING SNOW WILL ALSO BE
POSSIBLE OVER THE EASTERN ALEUTIANS...HOWEVER THE MOST INTENSE
PRECIPITATION IS EXPECTED TO REMAIN TO THE EAST AND THUS PREVENT
VISIBILITIES FROM REACHING BLIZZARD CRITERIA.

.LONG TERM FORECAST...
A MORE ACTIVE PATTERN WILL COMMENCE WITH THE NORTH PACIFIC LOW MOVING
INTO THE WESTERN GULF OF ALASKA ON TUESDAY AND CONTINUE THROUGH THE
REMAINDER OF THE WEEK AS A SERIES OF LOWS FOLLOW CLOSELY ON THE HEELS
OF THE FIRST SYSTEM WHILE TAKING A VERY SIMILAR TRACK. THIS WILL
GENERALLY RESULT IN A MUCH WETTER PERIOD ACROSS THE SOUTHERN
MAINLAND...WITH STRONG WINDS AT TIMES AS VARIOUS ASSOCIATED FRONTS
ARRIVE ALONG THE NORTHERN GULF COAST. PRECIPITATION TYPE IS EXPECTED
TO REMAIN MOSTLY SNOW ALTHOUGH RAIN COULD MIX IN AT TIMES AS
TEMPERATURES TREND UPWARD...PARTICULARLY ALONG THE COAST.


.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER STORM WATCH 125
         BLIZZARD WATCH 131 181
MARINE...STORM WARNING 119
         GALE WARNING 120 125 130 131 132 138 139 150 155 160 165 170
                      172 174 179 180 181 351 352 412 414
         HEAVY FREEZING SPRAY WARNING 121 129 160 179 180 411 412 414
FIRE WEATHER...NONE

TP/CB/PLD MAR 14