178
FXAK69 PAFG 011447
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
647 AM AKDT WED MAY 1 2024
SYNOPSIS
COOLER AND WETTER TODAY, WARMING AND DRYING ON THU, AND BECOMING
WINDY AND WARMER ON FRI.
A 1022 MB LOW 400 NM NORTHEAST OF DEMARCATION POINT WILL REMAIN
STATIONARY INTO THU AND THEN MOVE TO 300 NM NORTHEAST OF
DEMARCATION POINT BY 4PM FRI. A LOW PRESSURE TROUGH THAT EXTENDS
FROM THAT LOW TO ATQASUK WILL MOVE TO BARTER ISLAND TO POINT HOPE
BY 4AM FRI, THEN MOVE SOUTH ON FRI. THESE FEATURES ARE CAUSING
STRATUS, FLURRIES AND SOME FOG ALONG THE ARCTIC COAST FROM
UTQIAGVIK EAST THAT WILL CONTINUE INTO FRI. THESE FEATURES ARE
ALSO CAUSING NORTHEAST WINDS OF 20 TO 30 MPH OVER THE WESTERN
BROOKS RANGE, THE BERING STRAIT AND ST LAWRENCE ISLAND THAT WILL
CONTINUE INTO FRI.
AN ARCTIC COLD FRONT THAT LIES FROM EAGLE TO FAIRBANKS TO THE
YUKON DELTA WILL MOVE SOUTH TO EAGLE TO NENANA TO THE YUKON
DELTA BY 4PM TODAY, THEN MOVE NORTH TO EAGLE TO GALENA ON THU
AND TO OLD CROW TO THE BERING STRAIT ON FRI. A LOW IN THE
SOUTHEAST BERING SEA WILL MOVE EAST TONIGHT. THIS LOW IS FEEDING
MOISTURE NORTHEAST ALONG THE ARCTIC FRONT. THIS IS CAUSING RAIN
AND SNOW SHOWERS ALONG THIS FRONT TODAY THAT WILL TAPER OFF TO
ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS TONIGHT AS THE LOW
MOVES EAST AND THE MOISTURE FEED ENDS. THERE MAY BE ISOLATED
SHOWERS ALONG THE FRONT THU AM BEFORE ENDING THU PM. RAIN AND
SNOW WILL REDEVELOP ALONG THE ARCTIC FRONT OVER THE WEST COAST AND
NORTHERN INTERIOR ON FRI. SUMMITS OF THE STEESE AND ELLIOT
HIGHWAYS ABOVE 2000 FEET COULD HAVE 2 INCHES OF SNOW TODAY. THIS
FRONT WILL CAUSE TEMPERATURES WELL BELOW NORMAL OVER MOST OF
NORTHERN ALASKA TODAY, WITH BELOW NORMAL TEMPERATURES REMAINING
NORTH OF THE FRONT THU AND FRI.
A THERMAL LOW PRESSURE TROUGH OVER THE ALASKA RANGE WILL REMAIN
IN PLACE THROUGH THU, THEN MOVE JUST NORTH OF THE ALASKA RANGE ON FRI.
TEMPERATURES WILL WARM TO NEAR NORMAL WITH RH FALLING TO 20-30% ALONG
THIS TROUGH ON THU.
MODERATE SOUTHERLY CHINOOK WINDS DEVELOPING ACROSS THE ALASKA RANGE
ON FRI WILL CONTINUE INTO SAT. THIS WILL CAUSE SOUTH WINDS TO GUST
TO 40 MPH ALONG THE NORTH SIDE OF THE ALASKA RANGE FRI INTO SAT,
AND BRING WARMER AND DRIER CONDITIONS TO THE SOUTHERN INTERIOR FRI
AND SAT. THIS WILL BRING THE POSSIBILITY OF RED FLAG CONDITIONS
FROM DELTA JUNCTION SOUTH FRI INTO SAT.
A STRONG LOW SOUTH OF KAMCHATKA WILL MOVE OVER THE WESTERN
ALEUTIANS THU AND TO THE SOUTHEAST BERING SEA ON FRI. THIS WILL
BRING A CHANCE OF RAIN TO SOUTHWEST ALASKA ON FRI. THIS WILL ALSO
CAUSE SOUTHERLY CHINOOK FLOW TO INCREASE ACROSS THE ALASKA RANGE
ON FRI AND CONTINUE INTO SAT.
DISCUSSION
MODELS INITIALIZE WELL ALOFT AT 00Z EXCEPT THAT THE GFS IS 10-20
METERS TOO LOW ON 500 MB HEIGHTS SOUTH OF THE ARCTIC CIRCLE.
MODELS SHOW SIMILAR SOLUTIONS ALOFT THROUGH FRI, WITH AGREEMENT
IN THE LONG WAVE PATTERN THROUGH THE WEEKEND. MODELS SHOW SIMILAR
PATTERNS WITH PRECIP. MODELS VERIFY WELL AT THE SURFACE AT 06Z.
WILL USE A BLEND OF MODELS FOR FEATURES ALOFT, AND FOR PRECIP
THROUGH FRI. WILL USE A BLEND OF THE NAM AND CANADIAN MODELS FOR
SURFACE FEATURES AND WINDS THROUGH FRI. WILL USE A BLEND OF THE
ECMWF AND GFS FOR THE WEEKEND.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.
FIRE WEATHER
AN ARCTIC COLD FRONT THAT LIES FROM EAGLE TO FAIRBANKS TO THE
YUKON DELTA WILL MOVE SOUTH TO EAGLE TO NENANA TO THE YUKON
DELTA BY 4PM TODAY, THEN MOVE NORTH TO EAGLE TO GALENA ON THU
AND TO OLD CROW TO THE BERING STRAIT ON FRI. THERE WILL BE
NUMEROUS RAIN AND SNOW SHOWERS ALONG THIS FRONT TODAY THAT
WILL TAPER OFF TONIGHT. SOME OF THESE SHOWERS COULD BE WET
BETWEEN FAIRBANKS AND EAGLE.
A THERMAL LOW PRESSURE TROUGH OVER THE ALASKA RANGE WILL REMAIN
IN PLACE THROUGH THU, THEN MOVE JUST NORTH OF THE ALASKA RANGE ON FRI.
TEMPERATURES WILL WARM TO NEAR NORMAL WITH RH FALLING TO 20-30% ALONG
THIS TROUGH ON THU AND FRI.
MODERATE SOUTHERLY CHINOOK WINDS DEVELOPING ACROSS THE ALASKA RANGE
ON FRI WILL CONTINUE INTO SAT. THIS WILL CAUSE SOUTH WINDS TO
GUST TO 40 MPH ALONG THE NORTH SIDE OF THE ALASKA RANGE FRI INTO SAT,
AND BRING THE POSSIBILITY OF RED FLAG CONDITIONS FROM DELTA JUNCTION SOUTH
FRI INTO SAT.
HYDROLOGY
RIVER WATCH FLEW THE YUKON RIVER FROM EAGLE TO FORTYMILE RIVER ON
TUESDAY. AN OBSERVER 23 MILES UPSTREAM OF EAGLE SAID THAT THE
YUKON THERE BROKE UP TUESDAY AFTERNOON. ICE BEGAN FLOWING BUT
WITHIN A FEW HOURS HAD STOPPED FLOWING AND AN ICE JAM FORMED.
YUKON ROSE TO NEAR MID-SUMMER HIGH LEVELS AND WAS CONTINUING TO
RISE SLOWLY.
BASED ON THIS REPORT THE YUKON AT EAGLE IS EXPECTED TO BREAKUP
SOMETIME TODAY. DUE TO THE CURRENT RIVER LEVELS AND ICE
CONDITIONS, THE THREAT FOR FLOODING IS DIMINISHED IN THE AREA
AROUND EAGLE. HOWEVER, ICE JAMS CAN STILL POSE A LOCALIZED THREAT
IN THE AREAS IMMEDIATELY AROUND WHERE THEY FORM.
AFG WATCHES/WARNINGS/ADVISORIES
AK...NONE.
PK...BRISK WIND ADVISORY FOR PKZ805.
SMALL CRAFT ADVISORY FOR PKZ806-816.
HEAVY FREEZING SPRAY WARNING FOR PKZ806.
BRISK WIND ADVISORY FOR PKZ807-810-811-817-856-857.
HEAVY FREEZING SPRAY WARNING FOR PKZ816.
GALE WARNING FOR PKZ851.
BRISK WIND ADVISORY FOR PKZ852.
GALE WARNING FOR PKZ854.
JB
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