Blizzard in Alaska, March 16, 2008

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SUN MAR 16 2008

.MODEL DISCUSSION...MODELS CONTINUE STREAK OF INITIALIZING WELL AND
RUN TO RUN CONSISTENCY LEADING TO INCREASED CONFIDENCE IN THE SHORT
AND MID TERM SOLUTIONS. LARGEST DIFFERENCES ARRIVE LATER IN THE WEEK
WITH DEVELOPING NPAC LOW. HAVE LEFT FORECAST ALONE BEYOND MID WEEK
UNTIL MODELS COME INTO BETTER AGREEMENT.

.ANALYSIS AND UPPER LEVELS...
THREE HEADED LOW PRESSURE SYSTEM OVER OUR FORECAST DOMAIN WITH MAIN
LOW OVER THE EASTERN ALEUTIANS...A SECONDARY LOW IN THE NORTHEASTERN
GULF...AND A THIRD WEAKER LOW NEAR THE KUSKOKWIM DELTA. UPPER TROF
AXIS IN PROGRESS OF SHIFTING FROM THE EASTERN BERING TO THE NORTHERN
GULF WHERE IT WILL RESIDE THROUGH THE REMAINDER OF THE WEEK.
CHALLENGES ARISE FROM FORECASTING THE TIMING AND IMPACTS OF SEVERAL
SHORT WAVES ROTATING AROUND THE UPPER LOW.

.SHORT TERM FORECAST...
SOUTHCENTRAL...RELATIVELY STRAIGHT FORWARD FORECAST FOR SOUTHCENTRAL
WITH WEAK GRADIENT AT ALL LEVELS AS BROAD TROF MOVES INTO THE
NORTHERN GULF OVERNIGHT. THE PRESSURE AND THERMAL GRADIENT INCREASE
WITH TIME AS THE STACKED LOW BECOMES ESTABLISHED NEAR MIDDLETON
ISLAND. THIS WILL LEAD TO GAP WINDS IN THE NORMAL PLACES AND SNOW
SHOWERS MAINLY CONFINED TO THE COAST. THOMPSON PASS ALREADY SHOWING
SIGNS OF STRONG WIND HEADLINE CRITERIA. ALTHOUGH MODELS TREND TOWARD
A DRYING PATTERN...HAVE TO STEP CAUTIOUSLY AS THIS PATTERN IS
CONDUCIVE TO SURPRISE SNOW EVENTS IN THE ANCHORAGE BOWL. THE UPPER
LOW OVER THE NORTHEASTERN GULF COUPLED WITH WEAK SURFACE LOWS
DEVELOPING AND MEANDERING ABOUT MIDDLETON ISLAND TO PWS CAN VERY
EASILY LEAD TO LIGHT SNOW IN ANCHORAGE. IT WILL BE DIFFICULT TO
PINPOINT BUT BELIEVE AT SOME POINT THIS WEEK WE WILL SEE SOME SNOW.

WEST...COLD AIR WILL BE FILTERING BACK OVER SOUTHWEST ALASKA AND THE
EASTERN BERING SEA AS THE AFOREMENTIONED LOW SHIFTS EAST INTO THE
NORTHERN GULF. AGAIN...TIMING AND STRENGTH OF THE SHORTWAVES WILL BE
THE BIGGEST FORECAST CHALLENGE. WIDESPREAD SNOW OVER THE KUSKOKWIM
DELTA IN THE VICINITY OF THE STRONGEST VORT MAX TODAY. THIS FEATURE
WILL SHIFT SOUTHWARD INTO BRISTOL BAY...LIKELY TAKING THE SNOW WITH
IT. THERE IS SOME CONCERN RIGHT ALONG THE COAST WHERE WINDS HAVE
ALREADY SHIFTED TO THE NORTH AND FRESH SNOW HAS FALLEN OVER THE PAST
24 HOURS. IF WINDS CAN SUSTAIN...WE COULD SEE MORE BLIZZARD
CONDITIONS ALONG THE KUSKOKWIM DELTA COAST. FOR NOW...WILL WORD THE
FORECAST HEAVILY TOWARD THAT BUT HOLD BACK ON ISSUING ANOTHER
BLIZZARD WARNING.

SIMILAR STORY OVER THE ALEUTIANS AND THE PRIBILOFS WHERE SNOW SHOWERS
AND BLUSTERY NORTHERLY WINDS WILL CONTINUE THROUGH AT LEAST MID
WEEK...IF NOT ALL WEEK LONG. WAITING PATIENTLY FOR CIRRUS SHIELD TO
MOVE SOUTH THE PRIBILOFS SO WE CAN GET A BETTER LOOK OF THE SEA ICE.
THE FORECAST FOR THE PRIBILOFS WILL CHANGE DEPENDING ON HOW FAR SOUTH
THE ICE EDGE IS...AT THIS POINT BELIEVE ST PAUL MAY ESCAPE BLIZZARD
CONDITIONS AND JUST SEE SOME BLOWING AND DRIFTING SNOW. ST GEORGE
ISLAND WILL HAVE ENOUGH WATER BETWEEN THEM AND THE ICE TO ALLOW
SHOWERS TO CONTINUE TO DEVELOP...COUPLED WITH THE STRONG WINDS COULD
LEND TO BLIZZARD CONDITIONS. WE ARE WATCHING CLOSELY AND MAY HAVE TO
MAKE A LAST MINUTE DECISION ON A ST GEORGE ISLAND BLIZZARD.

THE EASTERN AND CENTRAL ALEUTIANS WILL SEE NUMEROUS SNOW SHOWERS AND
BLUSTERY WINDS AS WELL. THE FORECAST WILL BE WORDED STRONGLY TOWARD
SNOW AND BLOWING SNOW FOR THE AKPEN AS THE FIRST PUSH OF COLD AIR
ARRIVES MONDAY MORNING AND THEN A SECOND STRONGER PUSH TUESDAY
AFTERNOON. AFTER THAT...THE TIMING BECOMES DIFFICULT BUT THERE IS NO
INDICATION THE PATTERN WILL SHIFT SO WILL KEEP SNOW SHOWERS IN THE
FORECAST THROUGH THE WEEK.

.LONG TERM FORECAST...LONG RANGE MODELS HINTING AT OMEGA BLOCKING
RIDGE DEVELOPING OVER THE WESTERN BERING SEA WHICH WOULD KEEP THE
EASTERN BERING IN COLD NORTHERLY FLOW AND SOUTHCENTRAL IN SEASONAL
COOL TEMPERATURES.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 150 155 160 165 170 172 179.
FIRE WEATHER...NONE.

AB MAR 08