Blizzard Watch 10, NWS Anchorage, AK

383 
WWAK42 PAFC 112354
WSWALU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
354 PM AKDT MON APR 11 2011

AKZ181-121600-
/X.UPG.PAFC.BZ.A.0010.110412T0800Z-110412T1700Z/
/X.NEW.PAFC.BZ.W.0023.110412T0700Z-110412T1600Z/
ALASKA PENINSULA-
INCLUDING THE CITIES OF...COLD BAY...SAND POINT
354 PM AKDT MON APR 11 2011

...BLIZZARD WARNING IN EFFECT FROM 11 PM THIS EVENING TO 8 AM
AKDT TUESDAY FOR THE BERING SIDE...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 11 PM THIS EVENING TO 8 AM AKDT
TUESDAY. THE BLIZZARD WATCH IS NO LONGER IN EFFECT. 

STEADY ONSHORE FLOW AND A BRISK AIRMASS IS YIELDING SNOW SHOWERS
AND BLOWING SNOW ALONG THE ALASKA PENINSULA. A WEAK AREA OF LOW
PRESSURE NEARING THE PRIBILOF ISLANDS WILL MOVE MOVE RAPIDLY SOUTHEAST
TOWARDS THE REGION TONIGHT. THIS FEATURE LOOKS TO ENHANCE THE
PRECIPITATION AND BRING A STEADIER REDUCED VISIBILITY.

ALONG THE BERING SIDE...NORTHWEST WINDS OF 35 TO 45 MPH COUPLED
WITH HEAVIER SNOW SHOWERS WILL REDUCE VISIBILITY TO NEAR ZERO. THE
LOW PRESSURE SYSTEM WILL ROTATE AWAY FROM THE ALASKA PENINSULA
TUESDAY MORNING...ALLOWING PRECIPITATION INTENSITY TO WEAKEN AND
VISIBILITY TO IMPROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITE-OUT
CONDITIONS...MAKING TRAVEL EXTREMELY DANGEROUS. ALL TRAVEL AND
OUTDOOR ACTIVITY IS STRONGLY DISCOURAGED.

&&

$$

JAM

912 
WWAK42 PAFC 120005 CCA
WSWALU

URGENT - WINTER WEATHER MESSAGE...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
404 PM AKDT MON APR 11 2011

AKZ181-121600-
/X.UPG.PAFC.BZ.A.0010.110412T0800Z-110412T1700Z/
/X.COR.PAFC.BZ.W.0023.110412T0700Z-110412T1600Z/
ALASKA PENINSULA-
INCLUDING THE CITIES OF...COLD BAY...SAND POINT
404 PM AKDT MON APR 11 2011

...BLIZZARD WARNING IN EFFECT FROM 11 PM THIS EVENING TO 8 AM
AKDT TUESDAY FOR THE BERING SIDE...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 11 PM THIS EVENING TO 8 AM AKDT
TUESDAY. THE BLIZZARD WATCH IS NO LONGER IN EFFECT. 

STEADY ONSHORE FLOW AND A BRISK AIRMASS IS YIELDING SNOW SHOWERS
AND BLOWING SNOW ALONG THE ALASKA PENINSULA. A WEAK AREA OF LOW
PRESSURE NEARING THE PRIBILOF ISLANDS WILL MOVE RAPIDLY SOUTHEAST
TOWARDS THE REGION TONIGHT. THIS FEATURE LOOKS TO ENHANCE THE
PRECIPITATION AND BRING A STEADIER REDUCED VISIBILITY.

ALONG THE BERING SIDE...NORTHWEST WINDS OF 35 TO 45 MPH COUPLED
WITH HEAVIER SNOW SHOWERS WILL REDUCE VISIBILITY TO NEAR ZERO. THE
LOW PRESSURE SYSTEM WILL ROTATE AWAY FROM THE ALASKA PENINSULA
TUESDAY MORNING...ALLOWING PRECIPITATION INTENSITY TO WEAKEN AND
VISIBILITY TO IMPROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITE-OUT
CONDITIONS...MAKING TRAVEL EXTREMELY DANGEROUS. ALL TRAVEL AND
OUTDOOR ACTIVITY IS STRONGLY DISCOURAGED.

&&

$$

JAM

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT MON APR 11 2011

.MODEL DISCUSSION...

MODELS ARE IN GENERALLY GOOD AGREEMENT. THE 00Z GFS IS COMPLETELY
MISSING THE STEADY SNOW FALLING ON THE SOUTHERN END OF THE KENAI
PENINSULA IN ITS QPF FIELD. THE 00Z EC SEEMS TO BE DOING MUCH BETTER.
WILL STICK TO THE NAM ON THE EAST SIDE FOR THE FORECAST TODAY WITH
RESPECT TO WINDS...WITH THE GFS PREFERRED OUT WEST FOR THE BERING SEA
REGION.

.ANALYSIS AND UPPER LEVELS...

A WEAK AND BAGGY COMPLEX LOW REMAINS NEARLY STATIONARY IN THE GULF OF
ALASKA...GENERATING SHOWERS THROUGHOUT MOST OF THE GULF...ESPECIALLY
THE NORTHERN HALF. ANOTHER STRONGER COMPLEX LOW PRESSURE SYSTEM IS
SITUATED OVER THE FAR NORTHERN BERING INTO WEST CENTRAL ALASKA. A
FAIRLY SHARP DISTURBANCE IS MOVING SOUTH AND EAST TOWARDS THE COOK
INLET REGION TODAY. THE INTERACTION OF THE TWO LOW SYSTEMS IS
GENERATING AREAS OF SNOW OVER THE SOUTHWESTERN KENAI PENINSULA THIS
MORNING. IN THE BERING...NORTHWEST FLOW DOMINATES WITH SHORTWAVE
RIDGING OVER THE ALASKA PENINSULA AREA CURRENTLY WITH A MORE POTENT
DISTURBANCE JUST EXITING FAR NORTHEAST RUSSIA MOVING SOUTHEAST INTO
THE BERING. THIS DISTURBANCE WILL AFFECT THE PRIBILOFS BY MID
AFTERNOON AND THE ALASKA PENINSULA AND EASTERN ALEUTIANS BY MID
EVENING. HIGH PRESSURE AT THE SURFACE AND ALOFT DOMINATES THE CENTRAL
ALEUTIANS...WITH A DISTURBANCE BRUSHING THE FAR WESTERN BERING BUT
GENERALLY REMAINING A NON-FACTOR AS IT MOVES DUE NORTH TOWARDS
NORTHEAST RUSSIA.

.SHORT TERM FORECAST...

SOUTH AND EAST OF THE ALASKA RANGE...

WILL CONTINUE TO WATCH THE SHARP SHORTWAVE OVER THE NORTHERN BRISTOL
BAY REGION APPROACHING THE COOK INLET REGION TODAY BEFORE MOVING BACK
NORTH ACROSS THE ALASKA RANGE TONIGHT AND WEAKENING. THE INTERACTION
OF THIS SYSTEM ALONG WITH THE WEAK GULF SYSTEM WILL KEEP SNOW AND
SNOW AND RAIN SHOWERS IN THE FORECAST...PARTICULARLY ALONG THE KENAI
PENINSULA. FAIRLY COLD TEMPERATURES ALOFT TO THE NORTH AND EAST
SHOULD BRING ABOUT DIURNAL CONVECTION IN THE FORM OF SHOWERS BY THIS
AFTERNOON...ESPECIALLY OVER HIGHER TERRAIN...WITH A WANING TREND
DURING THROUGH THE EVENING AS DAYTIME HEATING IS LOST.

SOUTHWEST ALASKA...

WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL BE CANCELED WITH THE
MORNING PACKAGE ALONG THE COAST OF THE KUSKOKWIM DELTA. NEAR BLIZZARD
CONDITIONS HAVE BEEN REPORTED AT TOKSOOK BAY OVERNIGHT AS A
DISTURBANCE MOVED BY TO THE NORTH AND EAST. EXPECT A RELATIVE LULL IN
WINDS AS A SHARP DISTURBANCE OVER THE NORTHERN BERING MOVES SOUTH AND
EAST TOWARDS THE AKPEN THIS EVENING. THE MAIN CONCERN IS THAT NORTH
WINDS WILL INCREASE ONCE AGAIN AS THIS DISTURBANCE MOVES BY AND WE
WILL NEED TO RE-ISSUE THE ADVISORY THIS AFTERNOON...BUT SINCE THERE
IS TIME TO MAKE THE DECISION WILL DEFER TO THE MORNING FORECASTER.
OTHERWISE...EXPECT CONTINUED ISOLATED SNOW SHOWERS...MAINLY ALONG THE
COAST AND AGAINST NORTHWEST FACING HIGHER TERRAIN SUCH AS THE AHKLUN
AND ALEUTIAN MOUNTAIN RANGES...BUT OTHERWISE GENERALLY PARTLY CLOUDY
SKIES NEAR THE POPULATION CENTERS OF DILLINGHAM AND BETHEL.

BERING SEA REGION...

HIGH PRESSURE WILL DOMINATE THE WESTERN AND CENTRAL ALEUTIANS...SAVE
FOR A BRIEF SHOT AT SOME SNOW THIS MORNING OVER THE FAR WESTERN
ALEUTIANS IN ASSOCIATION WITH A WARM FRONT LIFTING NORTH ACROSS THE
REGION. FROM THE NORTHERN BERING TO THE EASTERN ALEUTIANS AND ALASKA
PENINSULA...SNOW SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON AND
EVENING...EXCEPT FOR MORE STEADY SNOW IN ASSOCIATION WITH A SHARP
DISTURBANCE MOVING SOUTH AND EAST FROM THE NORTHERN BERING. THIS
SYSTEM WILL MOVE RAPIDLY ACROSS THE PRIBILIFS THIS AFTERNOON AND THEN
ACROSS THE ALASKA PENINSULA REGION BY LATE THIS EVENING. THIS SYSTEM
WILL HELP INCREASE THE HEIGHT GRADIENT WITH A NORTHERLY JET STREAK
DEVELOPING OVER THE EASTERN BERING...RESULTING IN CONTINUED COLD
ADVECTION SNOW SHOWERS AND GUSTY NORTHERLY WINDS OVER THE EASTERN
BERING THROUGH TUESDAY NIGHT.

.LONG TERM FORECAST...

A VERY SPRING-LIKE PATTERN ON TAP FOR THE GULF AND SOUTHCENTRAL
REGION WEST THROUGH THE CENTRAL BERING IN THE EXTENDED PERIOD. HIGH
PRESSURE ALOFT OVER THE BERING WILL BUILD NORTH OVER THE BERING
STRAIT REGION WITH EASTERLY FLOW OVER THE GULF AND SOUTHERN BERING
REGION. ONLY AREA OF REAL UNCERTAINTY SYNOPTICALLY IS THE POSSIBLE
ARRIVAL OF A SYSTEM FROM THE WEST INTO THE WESTERN ALEUTIANS
APPROACHING THE WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES...150 155 160 165 170
         HVY FRZG SPRY...150 155 160 165 179
FIRE WEATHER...NONE.

CC APR 11