Blizzard in Alaska, January 9 to 10, 2007

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
410 AM AST TUE JAN 9 2007

.DISCUSSION...

...SUMMARY...
BIG PATTERN CHANGE TOWARD WETTER AND MUCH WARMER WEATHER IS UNDERWAY.
THE TRANSITION LINE IS A STRONG FRONT MOVING EAST THROUGH THE
EASTERN BERING/ALEUTIANS TODAY. THIS FRONT WILL CONTINUE TO PROGRESS
EAST...BRINGING WITH IT SIGNIFICANT PRECIPITATION AND MUCH WARMER
TEMPERATURES. THIS NEW PATTERN WILL STICK AROUND FOR AT LEAST A WEEK.

...MODELS...
MODELS ARE IN GOOD AGREEMENT WITH ALL MAJOR FEATURES THROUGH THE
FORECAST PERIOD. CERTAINLY SOME UNCERTAINTY WITH THE TIMING OF THE
SHORTWAVES IN THE MOIST SOUTHWEST FLOW FROM THURSDAY AFTERNOON AND
BEYOND...BUT THERE IS HIGH CONFIDENCE IN THE OVERALL PATTERN OF WARM
AND WET. THE LARGEST MODEL CONCERN IS JUST HOW WARM TEMPERATURES GET
FROM BRISTOL BAY OVER TO THE GULF COAST FROM LATE WEDNESDAY
ONWARD...AND HOW FAR NORTH THE RAIN SNOW LINE CAN MAKE IT.

...SOUTHCENTRAL FORECAST SOUTH AND EAST OF THE ALASKA RANGE...
COLD OFFSHORE FLOW IS PRESENT OVER SOUTHCENTRAL TODAY. TEMPERATURES
THIS MORNING HAVE BEEN THE COLDEST OF THE SEASON SO FAR FOR MANY
AREAS. SOME VISIBILITY RESTRICTIONS ARE PRESENT FROM SOME FREEZING
FOG AND ICE FOG. WITH THE PRESSURE GRADIENT LIGHTENING UP TODAY OVER
SOUTHCENTRAL AS THE LOW OVER THE NORTHEAST GULF MOVES SOUTHEAST INTO
THE PANHANDLE...EXPECT THESE AREAS OF FOG TO CONTINUE INTO TONIGHT.
HOWEVER...THERE WILL ALSO BE PLENTY OF CLEAR SKIES AROUND...WITH THE
SUN LIKELY VISIBLE TODAY EVEN IN AREAS WHICH HAVE SOME FOG. THE
PRESSURE GRADIENT MENTIONED ABOVE IS LEADING TO SOME GUSTY WINDS
THROUGH THE USUAL CHANNELED AREAS. THIS HAS LED TO SOME DANGEROUS
WIND CHILLS IN PLACES SUCH AS BROAD PASS AND THOMPSON PASS. AS THE
PRESSURE GRADIENT RELAXES LATER TODAY...EXPECT THE WINDS IN
CHANNELED TERRAIN TO DIE DOWN. A WARM FRONT WILL PROGRESS NORTHEAST
THROUGH THE WESTERN GULF ON WEDNESDAY...BRINGING THE BIG CHANGE TO
WARMER TEMPERATURES...AND THE FIRST IN A SERIES OF MOIST WEATHER
SYSTEMS TO SOUTHCENTRAL. AS MENTIONED BEFORE...RAIN VS SNOW WILL BE
A CHALLENGE FROM WEDNESDAY ONWARD. FOR KODIAK...EXPECT PRECIP TO
START OUT AS SNOW WEDNESDAY...BUT CHANGE OVER TO RAIN WEDNESDAY
NIGHT AND STAY MOSTLY RAIN THROUGH THE WEEKEND. FOR THE KENAI
PENINSULA TO CORDOVA...PRECIPITATION SHOULD FALL AS SNOW THROUGH
THURSDAY...BUT THEN THINGS GET MORE CHALLENGING FROM THURSDAY NIGHT
ONWARD. THE CHANCE DOES EXIST FOR SIGNIFICANT RAIN FALLING ON TOP OF
THE SNOWPACK IN THESE AREAS FROM THURSDAY NIGHT INTO EARLY NEXT
WEEK. FROM ANCHORAGE NORTH...PRECIP SHOULD FALL MOSTLY AS SNOW.
DOWNSLOPE WILL PROBABLY PLAY A ROLE FOR ANCHORAGE AND PALMER TO KEEP
SNOW FROM BEING HEAVY...BUT THE NORTHERN SUSITNA VALLEY HAS A GOOD
CHANCE OF GETTING A LOT OF SNOW. IT WILL NOT BEING SNOWING OR
RAINING QUITE THE WHOLE TIME FROM WEDNESDAY ONWARD...BUT SYSTEMS
WILL CERTAINLY BE MOVING THROUGH QUITE FREQUENTLY IN THIS PATTERN.

...SOUTHWEST MAINLAND FORECAST...
THE STRONG FRONT OVER THE EASTERN BERING WILL BEGIN TO BRING
ACCUMULATING SNOW TO THE COAST WEST OF BETHEL BY THIS
AFTERNOON...ALONG WITH STRONG WINDS. THUS...A BLIZZARD WARNING IS
BEING ISSUED WITH THIS MORNING PACKAGE BEGINNING THIS AFTERNOON FROM
HOOPER BAY TO CAPE NEWENHAM. THE FRONT WILL MOVE ONSHORE THE WEST
COAST TONIGHT INTO WEDNESDAY...WITH DRAMATICALLY WARMER
TEMPERATURES...ABUNDANT PRECIPITATION...AND STRONG WINDS.
PRECIPITATION SHOULD SPREAD EAST TO MCGRATH BY WEDNESDAY AFTERNOON.
ENOUGH WARM AIR SHOULD MOVE INTO THE BRISTOL BAY AREA TO CHANGE
PRECIP OVER TO RAIN FOR SOME AREAS WEDNESDAY AFTERNOON OR WEDNESDAY
NIGHT. PERSISTENT SHORTWAVES IN SOUTH TO SOUTHWEST FLOW WILL
DOMINATE THE AREA THROUGH AT LEAST NEXT WEEKEND...WITH FREQUENT
BOUTS OF SNOW...MIXED WITH RAIN AROUND BRISTOL BAY.

...BERING SEA/ALEUTIAN FORECAST...
A STRONG WARM FRONT OVER THE EASTERN BERING/ALEUTIANS TODAY HAS
TURNED THE PRECIP MOSTLY OVER TO RAIN BEHIND THE FRONT. OUT TOWARD
THE CENTRAL AND WESTERN ALEUTIANS...ALTHOUGH THE HEAVIEST
PRECIPITATION AND STRONGEST WINDS HAVE TAPERED OFF AS THE FRONT HAS
MOVED EAST...AREAS OF RAIN PERSIST. WITH A STRONG LOW ANCHORED OFF
THE KAMCHATKA PENINSULA OVER THE NEXT FEW DAYS...EXPECT UNSTABLE
SOUTHWEST FLOW AND PERSISTENT RAIN...MIXED WITH SNOW AT TIMES...OVER
THE ENTIRE REGION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNINGS 131 155 161.
         HIGH WIND WARNING 185.
MARINE...STORM WARNINGS 155 160 165 170 171 172 180 410.
         GALE WARNINGS 120 121 129 130 138 150 175 176 179 185.
         HEAVY FREEZING SPRAY WARNINGS 120 121 125 129 130 132 138
         140 350.

FOISY JAN 07