Small Craft Advisory 22, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
221 PM AKDT SUN MAY 24 2015

.DISCUSSION...
ALOFT...HIGH AMPLITUDE RIDGE FROM WESTERN CANADA TO NORTH OF
PRUDHOE BAY WILL PERSIST THROUGH WED WITH SEVERAL SHORT WAVE
TROUGHS MOVING NORTH DURING THIS TIME. THE FIRST SHORT WAVE
TROUGH IS FROM POINT LAY TO ANCHORAGE AND WILL DRIFT NORTH AND
EAST TO DISSIPATE BY 4PM MON FROM BARROW TO NEAR FAIRBANKS. A
SECOND SHORT WAVE TROUGH IS SOUTH OF NORTHWAY 4PM SUN AND IT WILL
MOVE TO THE FAR EASTERN BROOKS RANGE 4PM MON. LOW OVER THE
SOUTHEAST BERING SEA WILL DRIFT NORTHWEST AND WEAKEN INTO A TROUGH
WHICH WILL MOVE TO THE BERING STRAIT BY 10 PM MON WHICH EXTENDS TO
A LOW AT KODIAK ISLAND. THIS LOW THEN MOVES TO THE NORTHERN
PANHANDLE WED AM WHICH CAUSES THE SOUTHEAST FLOW OVER THE
INTERIOR TO DIMINISH WHILE A NEW LOW MOVES INTO THE BERING SEA AND
BRINGS ANOTHER ROUND TO SOUTHERLY FLOW TO THE WEST COAST OF
ALASKA.

SURFACE...1026 MB HIGH OVER THE BEAUFORT SEA WILL BUILD TO 1034 MB
THROUGH WED AND EXPAND TO THE WEST AND SOUTHEAST. WEAKENING
OCCLUSION FROM POINT LAY TO ANCHORAGE WILL DISSIPATE BY 10 PM
TONIGHT. WEAK COLD FRONT FROM THE BERING STRAIT TO BETHEL WILL
DRIFT NORTH AND WEST. THERMAL TROUGH FROM NEAR POINT LAY TO FORT
YUKON TO NEAR NORTHWAY WILL PERSIST THROUGH MON THEN REFORM TO LIE
FROM TANANA TO EAGLE TO DAWSON CANADA ON TUE. LOW PRESSURE CENTER
SOUTHWEST OF SHEMYA MOVING TO THE NORTH CENTRAL BERING SEA
THROUGH WED AND WEAKENING TO 992 MB. ASSOCIATED OCCLUSION WILL
MOVE TO THE BERING STRAIT WED AM AND EXTEND SOUTHEAST TO THE YUKON
DELTA.

MODELS...AGREE WELL IN SHORT TERM WITH MAIN FEATURES. IN EXTENDED
PERIODS FAVOR THE WPC SOLUTION OF USING THE ENSEMBLE MEANS OF THE
ECMWF AND GFS FOR THE WEEKEND AS THE OPERATIONAL RUNS BREAK DOWN
THE RIDGING OVER AK TOO FAST IT SEEMS.

NORTH SLOPE...WINDS DIMINISHING OVERNIGHT. EXPECT STRATUS TO HANG
ON FOR A FEW DAYS GIVEN THE PERSISTENT EAST FLOW. IS POSSIBLE
THERE WILL BE ENHANCED SHOWER ACTIVITY OVER EASTERN BROOKS RANGE
MON NIGHT AND TUE AM WITH SHORT WAVE MOVING NORTH OVER INTERIOR.
ACTUAL LOCATION FROM MODELS IS VARIED AND GIVEN THE SHOWERY NATURE
THERE MAY BE LITTLE BASIN WIDE COVERAGE. THIS MAY HOWEVER AFFECT
THE ALREADY HIGH RIVERS DRAINING THE BROOKS RANGE.

WESTERN ALASKA...THE WEAK WEATHER FRONTS AND SHORT WAVE TROUGH
WILL PROVIDE ONLY ISOLATED TO SOMETIMES SCATTERED SHOWERS THROUGH
WED...MOST FAVORED AREAS ARE OVER INLAND AREAS NEAR THESE FEATURES
WHERE DAYTIME HEATING CAN PRODUCT DIURNAL SHOWERS. ON WED MORE
SHOWERS MOVING INTO COASTAL AREAS FROM INCOMING OCCLUSION.

CENTRAL AND EASTERN INTERIOR... THE BEST THOUGH LIMITED CONVECTION
WILL REMAIN OVER THE NORTHEAST SECTIONS WHERE ISOLATED
THUNDERSTORMS ARE EXPECTED...MAYBE SCATTERED ON MON WITH THE SHORT
WAVE TROUGH MOVING NORTH. SOME SHOWERS OVER THE FORTYMILE AREA AND
THE BROOKS RANGE COULD BE ENHANCED WITH LOCAL AMOUNTS UP TO A
HALF INCH. THE SHOWERY COVERAGE MAY RESULT IN LITTLE EFFECT ON A
BASIN...NONETHELESS SOMETHING TO WATCH.

&&

.FIRE WEATHER... HOT AND DRY CONDITIONS HANGING ON THIS AFTERNOON
AND EVENING OVER THE EASTERN INTERIOR...BUT OVER THE CENTRAL
INTERIOR A COOLER AIRMASS IS MOVING IN WITH HIGHER AFTERNOON
HUMIDITIES FOR TODAY AND MONDAY FOR ZONES 221...222...AND 225.
THIS TREND WILL OCCUR OVER THE EASTERN INTERIOR ON MONDAY. BEST
INSTABILITY TODAY LIES NE OF EAGLE TO ARCTIC VILLAGE SO EXPECT
ISOLATED THUNDERSTORMS THIS AFTERNOON/EVENING...THOUGH VERY FEW
STRIKES. AS THE HIGHER HUMIDITIES WORK THEIR WAY OVER THE INTERIOR
THE MON AND TUE THE NORTHEAST PORTION WILL AGAIN HAVE THUNDERSTORMS
BUT SHOULD BE WET FOR THE MOST PART.

&&

.HYDROLOGY...HAVE CANCELLED ADVISORIES ON THE KUPARUK AND COLVILLE
RIVERS...BUT CONDITIONS WILL PERSIST FOR SOME TIME ALONG THE
DALTON HIGHWAY. EXPECT SOME IMPROVEMENT SOON FOR THE PORCUPINE
RIVER AT AND ABOVE FORT YUKON.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FOR AKZ220-AKZ223-AKZ224-AKZ226.

FLOOD WATCH FOR AKZ203-AKZ220.

FLOOD WARNING FOR AKZ203-AKZ220.

SMALL CRAFT ADVISORY FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ240-PKZ245.
&&

MAY 15