Heavy Snow in Alaska, March 19, 2006

SOUTHEAST ALASKA FORECAST DISCUSSION
1130 AM AST SAT MAR 18 2006

.SHORT RANGE...ARCTIC AIR STILL IN PLACE OVER SOUTHEAST ALASKA
ALTHOUGH A BIT WARMER OVERALL THAN LAST COUPLE OF DAYS. THIS
MORNING SHOULD BE END OF THE RECORD COLD.  NOW FOR THE NEW
FUN...A WEATHER FRONT SPREADING ACROSS THE EASTERN GULF OF ALASKA
THROUGH THIS AFTERNOON AND THROUGH THE PANHANDLE REGION SUNDAY
NIGHT.  WITH FAIR PRECIPITATION AMOUNTS EXPECTED AND THE COLD AIR
SLOWLY WARMING...HAVE UPGRADED THE WINTER STORM WATCHES TO
WARNINGS FOR MAJORITY OF THE NORTHERN PANHANDLE  AMOUNTS OF
AROUND 6 INCHES FOR THE SITKA ZONE AND POTENTIALLY 1 TO 2 FEET IN
SOME OF THE NORTHERN ZONES.  SOME CONCERN OVER THE LYNN CANAL
REGION AS THEY RE NOT IN THE WARNING SET UP AT THIS
TIME...SUSPECT I WILL AT LEAST END UP WITH THEM IN ADVISORY
LEVELS SUNDAY. WILL ALSO GO WITH ADVISORY FOR WRANGELL AND
PETERSBURG AREA SUNDAY...THEY ARE A LITTLE CLOSER TO THE WARMER
AIR AND WILL CHANGE OVER A BIT MORE READILY.  THE PORTIONS OF THE
SOUTHERN WARNING ZONES ALSO LIKELY TO CHANGE OVER OR MIX.

EXPECT A TRANSITION TO SHOWERS BEHIND THE MAIN FRONT FOR SUNDAY
NIGHT FOR MOST AREAS.

WINDS WITH THE SYSTEM ARE ALSO RATHER STRONG LEADING TO STORMS IN
SOME IN MARINE ZONE 052 AND PERHAPS OFFSHORE (310) WITH GALES THE
REST OF THE OUTER AREAS AND A COUPLE OF THE INNER CHANNEL AREAS.

.LONG RANGE...THE OPERATIONAL FORECASTING MODELS LOOK FAIRLY
SIMILAR THROUGH MID-WEEK...AFTER THAT THEY DIVERGE ON A SOLUTION
SO CONFIDENCE AFTER DAY 4 IS ON THE LOW SIDE. THE 500 MB LOW OVER
THE BRISTOL BAY AREA SUNDAY NIGHT WILL LIFT NORTH INTO THE
INTERIOR AND OVER THE ARCTIC BY MONDAY NIGHT. THE MAIN TROF WILL
DIG SOUTHEAST AS A LONG WAVE RIDGE BUILDS OVER THE BERING
EXTENDING INTO RUSSIA. AS THE TROF MOVES INTO THE WESTERN GULF A
LOW WILL SPIN UP IN THE SOUTHERN GULF/NORTH PACIFIC MONDAY NIGHT.
THIS LOW WILL CONTINUE SLOWLY ON ITS SOUTHEAST TRACK ACROSS THE
NORTH PACIFIC AS A UPPER RIDGE OF HIGH PRESSURE OVER CENTRAL
BRITISH COLUMBIA BUILDS OVER THE PANHANDLE TUESDAY. THE HIGH WILL
DRIFT NORTH TO BE OVER SOUTHEASTERN YUKON/NORTHWEST TERRITORY AND
REMAIN QUASI-STATIONARY THROUGH THE END OF THE WEEK.

A WEAK SURFACE LOW WILL DRIFT INTO THE WESTERN GULF SUNDAY
NIGHT/MONDAY MORNING AND BEGGING TO DEVELOP WITH THE UPPER TROF
DIGGING SOUTH. THIS LOW WILL DEEPEN TO 975 MB AS IT DRIFTS INTO
THE CENTRAL GULF BUT WILL SLIDE SOUTHEAST AND INTO THE EASTERN
PACIFIC THROUGH WEDNESDAY NIGHT.

FOR SOUTHEAST ALASKA...SHOWERS WILL PERSIST THROUGH MONDAY NIGHT
AS THE UPPER LEVEL FLOW WILL REMAIN ONSHORE WITH A SHORTWAVE
MOVING OVER THE AREA THROUGH THE DAY. PRECIP TYPE WILL BE THE
MAIN FORECASTING ISSUE AS THE PANHANDLE WILL CONTINUE TO WARM UP
FROM THE DEEP FREEZE. THINK THERE WILL BE RAIN SHOWERS FOR THE
SOUTHERN THIRD AND COASTAL AREAS...MIXED RAIN AND SNOW SHOWERS
FOR THE CENTRAL PANHANDLE AND SNOW SHOWERS FOR THE NORTHERN
AREAS.

THE WINDS WILL NOT BE THAT SIGNIFICANT THROUGH THE EARLY WEEK BUT
THEY WILL BEGIN TO BACK AROUND TO THE EAST TUESDAY. THIS ALONG
WITH OFFSHORE WINDS ALOFT WILL BEGIN TO DRY SOUTHEAST ALASKA OUT
THROUGH TUESDAY. DRY CONDITIONS WILL PERSIST MOST OF THE WEEK BUT
THE FAR SOUTHERN AREAS COULD SEE SOME SHOWERS THROUGH THE END OF
THE WEEK. MOISTURE AND MID-LEVEL ENERGY WRAPPING AROUND THE
VERTICALLY STACK LOW IN THE EASTERN PACIFIC COULD MAKE ITS WAY
OVER THE AREA.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...WINTER STORM WARNINGS FOR AKZ017-020>025 VARIOUS TIMES
STARTING THIS AFTERNOON/EVENING TO SUNDAY EVENING

MARINE...STORM PKZ052
      ...GALE WARNING 011-021-022-035-041>043-051
      ...SMALL CRAFT REMAINDER OF AREA.

BMB/ABJ