Heavy Snow in Alaska, February 5, 2004

SOUTHEAST ALASKA FORECAST DISCUSSION
1045 AM AST WED FEB 4 2004

.SYNOPSIS...A PERSISTENT LOW ALOFT OVER WESTERN MAINLAND AK WILL
GUIDE A SERIES OF WEATHER SYSTEMS INTO SE AK THROUGH THE MIDDLE
OF NEXT WEEK.

.SHORT RANGE...A FRONTAL WAVE WILL CONTINUE TO SPREAD OVERRUNNING
PRECIP ACROSS THE PANHANDLE INTO EARLY THIS EVENING. STILL EXPECT
A CHANGE OVER TO RAIN TO OCCUR IN MOST AREAS THIS AFTERNOON WITH
GOOD WAA SPREADING ACROSS THE PANHANDLE AND 850 MB FLOW SOUTH TO
SOUTHWEST AROUND 40 KTS. THE EXCEPTION TO THIS WILL BE ZONES 18
AND 19 WHERE PRECIP WILL SHOULD REMAIN ALL SNOW. THE WINDS MAY
BRIEFLY TURN SOUTH LATE THIS AFTERNOON INTO THE EARLY EVENING IN
LYNN CANAL WHICH COULD BRIEFLY WARM TEMPS UP A BIT TO MIX IN SOME
RAIN AT SEA LEVEL BUT SHOULD BE SHORT LIVED AS NORTHERLY FLOW
RETURNS WITH THE APPROACH OF THE NEXT SYSTEM.

A DEVELOPING LOW PRESSURE SYSTEM OVER THE NORTHEAST PACIFIC WILL
MOVE NORTH TONIGHT ACROSS THE CENTRAL GULF AND BE POSITIONED OVER
THE NORTHERN GULF BY 00Z THU. THE LOW WILL CONTINUE TO DEEPEN
INTO THE 970S DURING THIS TIME. THE OCCLUDED FRONT WILL SPREAD
LIGHT TO MODERATE RAINFALL INTO THE PANHANDLE LATE TONIGHT INTO
THU MORNING WITH THE EXCEPTIONS OF ZONE 18 19 AND 29 WHERE COLDER
AIR WILL KEEP PRECIP SNOW. QPF AMOUNTS STILL SUGGEST THE
POTENTIAL FOR WARNING CRITERIA TO BE MET DURING THIS TIME SO WILL
UPGRADE THE WINTER STORM WATCHES TO WARNINGS FOR LATE TONIGHT
INTO THU. THE OCCLUDED FRONT MOVES THROUGH THE PANHANDLE EARLY
THU AFTERNOON WITH A SECOND WRAP CONTINUING TO SPREAD RAIN INTO
THE NORTHERN HALF OF THE PANHANDLE WITH A TRANSITION TO SHOWERS
OVER THE SOUTHERN HALF. EXPECT A GOOD SOUTHERLY FLOW TO DEVELOP
IN LYNN CANAL WITH FROPA SO WILL GO FOR A MIX OF RAIN AND SNOW IN
THE AFTERNOON FOR ZONES 18 AND 19.

THE GRADIENT INCREASES TONIGHT INTO THU ACROSS THE PANHANDLE WITH
THE DEEPENING LOW MOVING NORTH ACROSS THE CENTRAL GULF. A STRONG
SOUTHEAST LOW LEVEL JET OF 50 TO 70KTS EXTENDS ACROSS THE
SOUTHERN PANHANDLE TONIGHT INTO THU MORNING. EXPECT VERY WINDY
CONDITIONS TO DEVELOP OVER ZONES 27 AND 28 TONIGHT AND WILL
UPGRADE THE CURRENT WATCH TO A HIGH WIND WARNING FOR THESE ZONES.
EXPECT ADVISORY LEVEL GUSTS TO DEVELOP IN EXPOSED AREAS IN ZONES
21 22 23 24 25 26 AND 29. GALES WILL DEVELOP OVER THE CENTRAL AND
SOUTHERN INNER CHANNELS ALONG WITH CROSS SOUND. EXPECT GALES OVER
THE NORTHERN OUTSIDE WATERS WITH MINIMAL STORM FORCE WINDS
POSSIBLE OVER MARINE ZONES 41 AND 42.

.LONG RANGE...12Z AVN AND LAST NIGHTS MRF ARE CONSISTENT RUN TO
RUN ON STRENGTH AND LOCATION OF A LOW MOVING NORTH THROUGH THE
EASTERN GULF TONIGHT AND FRIDAY. 971 MB LOW WILL MOVE INLAND
AROUND OR JUST EAST OF PRINCE WILLIAM SOUND...LEAVING A RESIDUAL
SURFACE TROF IN THE NORTHEASTERN GULF THU NIGHT. NEWER AVN IS
WEAKER AND FURTHER WEST WITH THE NEXT LOW THAT WILL FOLLOW IT
INLAND FRIDAY NIGHT. NEW AVN HAS LESS COLD AIR FLOWING INTO THE
GULF FROM SOUTHWESTERN AK. AFTER THAT SURFACE LOWS REMAIN IN THE
WESTERN GULF THROUGH MON NIGHT. TUE AND TUE NIGHT A 978 MB LOW IS
FORECAST TO MOVE THRU THE EASTERN GULF AND INLAND NEAR YAKUTAT.
THIS WOULD BRING WET WARM AND WINDY CONDITIONS WITH A COOL DOWN
WED AS THE COLD AIR WRAPS AROUND BEHIND THE LOW.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...SNOW ADVISORIES FOR TODAY ZONES 17 18 19 AND 25
         HIGH WIND WATCH ZONES 27 AND 28 TONIGHT AND THU
         WINTER STORM WATCH ZONES 18 19 AND 29 TONIGHT AND THU

MARINE...GALES ALL OUTSIDE WATERS AND PKZ022 PKZ033 PKZ035
         STORM WARNING PKZ036
         SCA PKZ011 PKZ021 PKZ031 PKZ032 PKZ034
TAR/

TAR/LN