Extreme Cold in Alaska, March 17, 2008

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
431 AM ADT MON MAR 17 2008

.DISCUSSION...
THE NAM AND GFS MODELS HAVE ALMOST IDENTICAL FORECASTS THROUGH
WEDNESDAY MORNING. THE LARGE SCALE PATTERN INCLUDES MODERATE HIGH
PRESSURE OVER THE CHUKCHI SEA AND CHUKOTKA AND MODERATE LOW
PRESSURE OVER THE SOUTHERN MAINLAND OF ALASKA. THE MOST IMPORTANT
FEATURE IN NORTHERN ALASKA IS A STRONG PRESSURES GRADIENT OVER THE
BROOKS RANGE. THE WINDS FROM THIS ALONG WITH COLD ARCTIC AIR ARE
THE REASON WIND CHILL ADVISORIES WERE ISSUED FOR THE NORTHERN
INTERIOR. WIND CHILLS ARE COLD ENOUGH FOR ADVISORIES ON THE
EASTERN ARCTIC COAST...BUT THE BEGINNINGS OF A WEAK LOW PRESSURE
SYSTEM IN THE SOUTHEAST BEAUFORT SEA ARE EXPECTED TO WEAKEN THE
WINDS AND MODERATE THE CHILL FACTORS THERE AT MID DAY TODAY.

POLAR ORBITING SATELLITE IMAGERY FOR EARLY THIS MORNING SHOWS A
THIN BAND OF CLOUDS OVER THE SOUTHEAST INTERIOR. THIS BAND OF
CLOUDS ORIGINATED FROM A LOW JUST SOUTH OF PRINCE WILLIAM SOUND
AND HAVE BROUGHT SOME SNOW TO NORTHWAY. THERE IS NOT ENOUGH OF AN
INFLUX OF MOISTURE FOR MUCH MORE SNOW WITH THIS...SO THE SNOW
THERE IS FORECAST TO END LATER TODAY. THE IMAGERY ALSO SHOWS SNOW
BEARING CLOUDS OVER THE YUKON DELTA AND LOWER YUKON VALLEY...AND
RADAR HAS PICKED UP THE LIGHT SNOW OVER THE MIDDLE TANANA VALLEY.
THE INTERIOR AND WEST COAST NORTH OF ABOUT 65 DEGREES NORTH IS
MOSTLY CLEAR...AS IS THE ARCTIC SLOPE.

THE GFS AND EUROPEAN MODELS FORECAST COLD LOW PRESSURE AND WEAK
CIRCULATION ALOFT OVER MAINLAND ALASKA THROUGH EARLY
THURSDAY...AND THEN FORECAST THIS LOW PRESSURE TO MOVE SOUTHWARD
INTO THE GULF OF ALASKA. THIS PATTERN IS ONE FOR COLDER THAN
NORMAL TEMPERATURES AND FOR ONLY A LITTLE SNOWFALL OVER THE
SOUTHERN INTERIOR. THE FORECAST PATTERN IS A SLOWLY CHANGING ONE
FOR THE REST OF THIS WEEK. STRONGER LOW PRESSURE IS FORECAST TO
REACH BRISTOL BAY AND THE GULF OF ALASKA AT MID WEEK NEXT WEEK. IF
CORRECT...THIS FORECAST PATTERN WILL NOT BRING GREAT CHANGE TO
NORTHERN ALASKA WEATHER FOR MOST OR ALL OF THE WEEK AFTER THIS
ONE.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FOR AKZ203-AKZ204-AKZ218-AKZ219.

BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225.
&&

TF MAR 08