Area Forecast Discussion
Issued by NWS Fairbanks, AK

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FXAK69 PAFG 272056
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1256 PM AKDT FRI MAR 27 2015

.DISCUSSION...
THE DETERMINISTIC MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE
LARGE SCALE PATTERN UNTIL ABOUT DAY 3 WHEN DIFFERENCES IN
AMPLITUDE/STRENGTH AND PHASE/LOCATION BECOME MORE APPARENT. IN
REGARD TO SENSIBLE WEATHER THOUGH THE SITUATION IS A LITTLE
DIFFERENT...WITH MODELS SHOWING MORE DIFFERENCES EARLIER ON
BEGINNING SATURDAY. MOS TEMPERATURE GUIDANCE HAVE HAD A DIFFICULT
TIME WITH TEMPERATURES...MOST NOTABLY OVER THE INTERIOR. OF
WHICH...THE NAM AND ECMWF MOS GUIDANCE HAVE BEEN GENERALLY COOLER
WITH DAYTIME HIGHS THAN THE GFS AT MOST SITES. THIS IS THE CASE
AGAIN OVER THE INTERIOR TOMORROW AND SUNDAY.

OTHERWISE...MOSTLY CLOUDY SKIES CURRENTLY PERSIST OVER MUCH OF THE
NORTH SLOPE...WEST COAST...AND THE INTERIOR. THE EXCEPTION BEING
THE SEWARD PENINSULA AND WEST OF THE LOWER KOBUK/NOATAK VALLEYS.
WIND ADVISORY WAS EXTENDED UNTIL 4 PM TODAY FOR THE EASTERN
ALASKA RANGE. WINDS THERE ARE STAYING ELEVATED WITH SOME OF THE
FORT GREELY MESONET SITES STILL BLOWING ABOVE WIND ADVISORY
CRITERIA...NOTABLY TEXAS CONDO AND TEXAS RANGE.

BESIDES CLOUDS STICKING AROUND OUR AREA OF RESPONSIBILITY AND
LIGHT SNOW SHOWERS OVER PORTIONS OF THE WEST COAST AND NORTH
SLOPE...GENERALLY QUIET WEATHER WILL PREVAIL THROUGH EARLY
TUESDAY. HOWEVER...DO ANTICIPATE MODERATE WINDS ACROSS PORTIONS OF
THE WEST COAST AND THE ARCTIC COAST BEGINNING THIS WEEKEND INTO
MONDAY.

.ALOFT...CURRENTLY A LONG WAVE TROUGH ENCOMPASSES MUCH OF
ALASKA...EASTERN SIBERIA...AND THE BERING SEA...WITH A MID-LEVEL
LOW EMBEEDED AND CENTERED AROUND SAND POINT. ANOTHER LOW EXISTS
JUST WEST OF THE KAMCHATKA PENINSULA. ELSEWHERE...A RIDGE
PERSISTS OVER SE ALASKA AND THE WEST COAST CONUS. MODELS IN GOOD
AGREEMENT WITH THE EVOLUTION OF THE LONG WAVE TROUGH AND THE SAND
POINT CLOSED LOW. BY SAT...THE CENTER OF SAID LOW WILL HAVE MOVED
TO JUST SOUTH OF KODIAK AND THE RIDGE OVER SE ALASKA WILL BEGIN TO
PUSH EASTWARD INTO BRITISH COLUMBIA. OTHERWISE...NOT MUCH MOVEMENT
IS EXPECTED WITH THE LONGWAVE TROUGH OVERALL DURING THIS PERIOD.

ELSEWHERE...A SHORT-WAVE TROUGH AND VORT LOBE OVER THE WESTERN
ARCTIC COAST WILL BEGIN TO PUSH FARTHER SOUTH TONIGHT AND SAT.
ANOTHER WEAK SHORT-WAVE ASSOCIATED WITH THE LOW OVER SAND POINT
WILL BE MOVING NORTH SAT INTO THE INTERIOR AND WEST COAST. THE
SHORT-WAVE OVER THE WESTERN ARCTIC COAST THEN BECOMES EMBEDDED IN
THE LONGWAVE TROUGH AND DRIFTS SOUTH AND WEST TOWARDS KOTZEBUE
SOUND SUN. THE LOW THAT HAS DRIFTED TO SOUTH OF KODIAK WILL HAVE
WEAKENED BY THEN...AND WILL BECOME AN OPEN WAVE BY EARLY MON
MORNING.

.SURFACE...
SFC ANALYSIS AT 12Z SHOWS A COMPLEX SFC LOW PATTERN...WITH A LOW
CENTER ABOUT 982 MB JUST SOUTH OF THE SHUMAGIN ISLANDS AND ANOTHER
STRONGER CENTER FARTHER SOUTH AT 977 MB IN THE NORTH PACIFIC. THE
NORTHERN CENTER WILL DISSIPATE AND MOVE WESTWARD AS THE SOUTHERN
CENTER STRENGTHENS TO ABOUT 973 MB AND MOVES TO AROUND 400 MILES
SOUTH OF KODIAK BY EARLY SAT MORNING. THIS LOW BY EARLY SUN WILL
HAVE MOVED NORTH TO JUST OFFSHORE SOUTH OF KODIAK AND HAVE
WEAKENED TO ABOUT 985 MB. THE BULK OF THE SENSIBLE WEATHER
ASSOCIATED WITH LOW WILL BE SOUTH OF THE ALASKA RANGE.

MEANWHILE...A SHORT-WAVE TROUGH AND ASSOCIATED VORT LOBE
DESCENDING INTO THE ARCTIC COAST WILL KEEP SNOW CHANCES OVER THE
NORTH SLOPE FROM POINT LAY EAST THROUGH LATE SUNDAY. A WEAKENING
SURFACE TROUGH THAT EXTENDS INTO THE MIDDLE YUKON VALLEY WILL KEEP
SNOW CHANCES IN PORTIONS OF THE WEST COAST AND WESTERN INTERIOR
THE NEXT 30 HOURS. THESE CHANCES WILL BE GENERALLY ALONG AND EAST
OF A LINE FROM DALL POINT TO GOLOVIN TO SHUNGNAK...BUT NORTH OF
THE KUSKOKWIM MOUNTAINS. SNOW CHANCES THEN DIMINISH QUICKLY BEYOND
THAT TIME FRAME OVER THE WEST COAST.

OVER THE INTERIOR...DRY CONDITIONS WILL GENERALLY PREVAIL. SOME
PRECIPITATION MAY SPILL INTO THE SOUTHERN PORTIONS OF THE WESTERN
AND EASTERN ALASKA RANGE ZONES AS THE COMPLEX LOW MOVES NORTH
LATER IN THE PERIOD MONDAY. OTHERWISE...KEPT TEMPERATURES WARM
IN THE SOUTHERN INTERIOR COMPARED TO NAM AND ECMWF STATISTICAL
MOS GUIDANCE. THUS...LEANED TOWARDS THE WARMER GFS BASED ON THE
PAST FEW DAYS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

ET MAR 15



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