Brisk Wind Advisory 26, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
429 PM AKDT TUE MAR 24 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A "DOUBLE" UPPER LOW WITH ONE CENTER JUST SOUTH OF THE
SOUTHWEST GULF AND ANOTHER OVER THE EASTERN ALEUTIANS. THESE HAVE
SIMILAR STRENGTHS ALOFT...BUT AT THE LOWER LEVELS THE ONE SOUTH OF
THE GULF IS BY FAR THE STRONGER AND MORE IMPORTANT LOW. ALSO
ASSOCIATED WITH THE GULF LOW IS AND EAST-WEST FRONT STRETCHED
ACROSS THE SOUTHERN GULF...AND A STRONG JET ALOFT TO THE SOUTHEAST
OF THE LOW. THERE IS A RIDGE OF HIGH PRESSURE OVER SOUTHERN AND
CENTRAL ALASKA AND ANOTHER (WEAK) RIDGE OVER THE WESTERN BERING
SEA.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT. THERE
ARE SOME SLIGHT DIFFERENCES IN TIMING/LOCATION OF THE GULF LOW
WHEN IT NEARS KODIAK WEDNESDAY NIGHT INTO THURSDAY...BUT THIS DOES
NOT CREATE ANY MAJOR FORECAST PROBLEMS. THEREFORE THE FORECAST
CONFIDENCE IS A BIT HIGHER THAN NORMAL.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...

CLEAR AND COOL CONDITIONS ARE EXPECTED TONIGHT OVER THE INLAND
ZONES...WITH CLOUDS ALONG THE COAST. A FRONT APPROACHING THE GULF
COAST WILL INDUCE SOME WIND IN CHANNELED TERRAIN ON WED...WITH
RAIN MIXING WITH SNOW WED AFTERNOON AND EVENING. DOWNSLOPING WEST
OF THE KENAI AND CHUGACH MOUNTAINS WILL KEEP ANCHORAGE AND MUCH OF
THE WESTERN KENAI DRY THROUGH WED. ON THU THE UPPER LEVEL FLOW
BECOMES MORE SOUTHERLY AND THIS WILL ALLOW DOWNSLOPED AREAS TO
RECEIVE PRECIPITATION. RAIN WILL BE PREDOMINANT ALONG THE
COAST...BUT TEMPERATURES WILL COOL ENOUGH AT NIGHT INLAND TO ALLOW
FOR A MIX WITH SNOW.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
HIGH PRESSURE ALOFT OVER THE MAINLAND HAS STARTED TO GIVE WAY TO
CLOUD COVER AHEAD OF AN APPROACHING FRONT FROM THE NORTH PACIFIC...WITH
CLOUDS CURRENTLY SPILLING OVER INTO THE BRISTOL BAY AREA. THE
PRECIPITATION PRODUCED BY THIS SYSTEM WILL INITIALLY AFFECT THE
KUSKOKWIM DELTA AND BRISTOL BAY COASTAL AREAS THROUGH TONIGHT.
THEN BY EARLY TOMORROW MORNING A FRONTAL BOUNDARY WILL SPREAD
INTO BRISTOL BAY BRINGING RAIN FROM THE ALASKA PENINSULA NORTHWARD
INTO INTERIOR BRISTOL BAY...WHILE AREAS IN THE LEE OF THE ALEUTIAN
RANGE SHOULD REMAINED DRIER IN DOWNSLOPE CONDITIONS. GUSTY
EASTERLY WINDS OVER THE BRISTOL BAY ZONE WILL CONTINUE TO INCREASE
THROUGH THE EVENING...AS THE NORTH PACIFIC LOW CLOSES IN ON THE
ALASKA PENINSULA AND FURTHER TIGHTENS UP THE GRADIENT OVER THE
AREA. THE GUSTY WINDS OVER THE BRISTOL BAY AREA WILL PEAK BY
TOMORROW MORNING BEFORE SLOWLY DIMINISHING THROUGH THURSDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
MOST OF THE BERING WILL REMAIN UNDER THE BROAD CYCLONIC FLOW OF
A PERSISTENT UPPER LOW THROUGH THE LATTER HALF OF THIS WEEK. THIS
PATTERN WILL BRING SNOW SHOWERS FROM THE PRIBILOF ISLANDS AND
WESTWARD...WHILE THE EASTERN ALEUTIANS AND ALASKA PENINSULA WILL
SEE RAIN SHOWERS AND WARMER TEMPERATURES. A FRONTAL BOUNDARY
ASSOCIATED WITH A NORTH PACIFIC LOW WILL MOVE INTO THE EASTERN
BERING SEA BY TOMORROW BRINGING SNOW...RAIN...AND REDUCED
VISIBILITIES CAUSED BY BLOWING OVER THE PRIBILOF ISLANDS.

&&

.LONG TERM FORECAST (THURSDAY THROUGH MONDAY)...
A GALE FORCE NORTH PACIFIC LOW CONTINUES TO TRACK SOUTH OF
KODIAK ISLAND WITH AN ASSOCIATED WEATHER FRONT MOVING INTO
SOUTHWESTERN GULF BY WEDNESDAY. THIS LOW PRESSURE SYSTEM WILL
STALL OUT OVER KODIAK ISLAND BEFORE DISSIPATING BY THURSDAY
AFTERNOON. THIS FRONTAL SYSTEM WILL INCREASE THE PRESSURE
GRADIENTS FOR THE SOUTHCENTRAL REGION. LOOK FOR GUSTY WINDS
TO DEVELOP FROM WESTERN PRINCE WILLIAM SOUND...THROUGH TURNAGAIN
ARM INTO THE ANCHORAGE BOWL. THESE WINDS WILL DIMINISH BY LATE
THURSDAY NIGHT DUE TO THE WEAKENING OF THE PRESSURE GRADIENTS.
THE BULK OF THE PRECIPITATION WILL REMAIN ALONG THE NORTH GULF
COASTLINES WITH THIS WEATHER FRONT THROUGH FRIDAY. THE UPSTREAM
FLOW WILL REMAIN SOUTHERLY AND CONTINUE TO BRING WARMER
TEMPERATURES TO SOUTHCENTRAL REGION. THE GULF WILL HAVE SHOWERY
PRECIPITATION HEADING INTO THE WEEKEND...EXCEPT FOR CHANCES OF
RAIN INCREASING FOR INTERIOR SOUTHCENTRAL WITH THE CONTINUED
SOUTHERLY FLOW THROUGHOUT THE LOWER LEVELS. THIS WILL COINCIDE
WITH ANOTHER NORTH PACIFIC LOW ENTERING THE GULF BY SATURDAY JUST
SOUTH OF KODIAK ISLAND. THIS WILL RESULT IN THE SAME WEATHER
PATTERN AS THE PREVIOUS LOW PRESSURE SYSTEM FOR THE GULF AND
SOUTHCENTRAL REGION CONTINUING THROUGH THE EARLY PART OF NEXT
WEEK.

FOR THE BERING SEA AND THE ALEUTIANS...THEY WILL REMAIN IN
PERSISTENT NORTHERLY FLOW THROUGH THE WEEKEND. THE EASTERN BERING
SEA/ALEUTIANS AND THE BRISTOL BAY AREA WILL RECEIVE THE EFFECTS
FROM THE NORTH PACIFIC LOW AS IT STALLS OVER THE KODIAK ISLAND
AREA. THE PRECIPITATION WILL SPREAD OVER INTO THE EASTERN BERING
SEA/ALEUTIANS THROUGH THE WEEK. THIS PATTERN WILL BEGIN AGAIN WITH
THE NEXT LOW TRACKING TOWARDS KODIAK ISLAND BY SATURDAY. THE
TEMPERATURES WILL REMAIN WELL ABOVE FREEZING ALONG THE EASTERN
ALEUTAINS AND THE BRISTOL BAY AREA. BY MONDAY A SERIES OF WEAK
WAVES WILL ENTER THE WESTERN ALEUTIANS AND MOVE EASTWARD ALONG THE
ALEUTIAN CHAIN. THIS WILL BRING WARMER TEMPERATURES WITH RAIN TO
THE WESTERN/CENTRAL BERING SEA AND ALEUTIANS THROUGH
TUESDAY...EXCEPT FOR A WINTRY MIX FARTHER NORTH IN THE BERING SEA
WITH THE COOLER TEMPERATURES.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES...119 132 136 137 139 150 155 160 165 179
STORMS...120 130 131 138
FIRE WEATHER...RED FLAG WARNING ZONE 111.

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...DS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...PD