Wind Chill Warning 12, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
243 PM AKST FRI DEC 18 2009

.SYNOPSIS...
A 492 DECAMETER 500 MB ELONGATED LOW RUNS FROM NEAR ANCHORAGE TO
NOME. THIS GRADUALLY GETS PUSHED OFF INTO THE BERING STRAIT
SATURDAY MORNING AS A RIDGE BUILDS INTO THE GULF OF ALASKA. SUNDAY
INTO MONDAY THE RIDGE CONTINUES TO BUILD UP NEAR THE AL CAN BORDER.
THIS ALLOWS FOR A STRONG LOW PRESSURE SYSTEM TO TRACK NORTHWARD
FROM THE ALEUTIANS TOWARDS SAINT LAWRENCE ISLAND INTO THE BERING
SEA SATURDAY NIGHT INTO SUNDAY.

&&

.DISCUSSION...

ACROSS THE INTERIOR SNOW WILL TAPER OFF THIS EVENING FROM SOUTH TO
NORTH. SNOWFALL TOTALS OF 4 TO 6 INCHES WERE COMMON ACROSS THE
CENTRAL INTERIOR. WINDS WILL STAY UP BEHIND THIS...SO ISSUED WIND
CHILL ADVISORIES IN 220...224 AND 226. BLOWING SNOW WILL BE AN
ISSUE OVER SOME OF THE HIGHER SUMMITS AS WELL. PARTIAL CLEARING IS
EXPECTED AND WITH VERY COLD AIR MASS...-29C AT 850...TEMPERATURES
ARE EXPECTED TO FALL RAPIDLY IN THE VALLEYS. THIS COLD IS SHORT
LIVED AS A RIDGE BEGINS TO BUILD IN OVER THE WEEKEND. A STRONG
INVERSION IS EXPECTED TO DEVELOP WITH COLD TEMPERATURES REMAINING
IN THE VALLEYS AND WARMER TEMPERATURES IN THE HILLS ON SUNDAY AND
MONDAY. STRONG SOUTHERLY WINDS ARE EXPECTED THROUGH THE ALASKA
RANGE PASSES SUNDAY NIGHT INTO MONDAY AS WELL.

ACROSS THE NORTH SLOPE TONIGHT LIGHT SNOW IS EXPECTED FROM THE REMNANTS
OF THE FRONTAL SYSTEM THAT MOVED ACROSS THE INTERIOR TODAY. THE
HEAVIEST AMOUNTS WILL BE ALONG THE EASTERN ARCTIC COAST...ALTHOUGH
THEY ARE EXPECTED TO REMAIN BELOW SEVERAL INCHES. SOME CLEARING IS
LIKELY TO BRING COLD TEMPERATURES BEHIND THIS SYSTEM ON SUNDAY
BEFORE THE RIDGE BUILDS IN BRINGING WARMER AIR MONDAY AND
TUESDAY. ON THE WESTERN ARCTIC COAST WINDS WILL PICK UP SUNDAY
NIGHT AND MONDAY AS THE LOW PRESSURE SYSTEM APPROACHES THE IN THE
BERING SEA.

ACROSS THE WEST COAST COLD TEMPERATURES WILL PERSIST TONIGHT WITH
SOME CLEAR AREAS DROPPING TO 45 BELOW. KALTAG IS CURRENTLY AT 40
BELOW. CLOUDY AREAS ARE AROUND 10 TO 20 BELOW. SATURDAY
TEMPERATURES WILL BEGIN TO WARM ACROSS THE REGION AS WARM AIR
MOVES IN AHEAD OF THE SURFACE LOW. THIS LOW PRESSURE IS EXPECTED TO
BRING BLIZZARD CONDITIONS TO ZONES 213 AND 214. A BLIZZARD WATCH WAS
ISSUED FROM SATURDAY EVENING THROUGH SUNDAY EVENING. THERE ARE
SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH THE 12Z ECMWF BEING
STRONGER AND FARTHER WEST. WE WENT CLOSER TO THE GFS AS IT HAS
BEEN MORE CONSISTENT RUN TO RUN AND HANDLED THE RECENT SYSTEM
BETTER THAN THE ECMWF.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FOR AKZ218-AKZ219-AKZ220-AKZ222-AKZ223-
AKZ224-AKZ225-AKZ226.
&&

MKK DEC 09