Heavy Snow in Alaska, November 26 to 27, 2003

SOUTHEAST ALASKA FORECAST DISCUSSION
1045 AM AST WED NOV 26 2003

.SYNOPSIS...
.SHORT RANGE...A STRONG WEATHER SYSTEM WILL BRING IN LARGE
AMOUNTS OF SNOW TO THE PANHANDLE THROUGH THURSDAY MORNING.  A
DEVELOPING LOW NEAR 52N/141W ATTM WILL SPIN UP RAPIDLY THROUGH
THE DAY AS A STRONG UPPER LEVEL TROF SWINGS OVER THE CENTRAL
GULF.  THERE IS PLENTY OF COLD AIR ASSOCIATED WITH THE TROF AND
A STRONG VORT MAX SO THIS WILL HELP IN THE DEVELOPMENT OF THE
LOW PRESSURE SYSTEM.  THE TRACK OF THE LOW WILL BE OVER THE
CENTRAL TO SOUTHERN CENTRAL PANHANDLE BY 12Z THURSDAY AND INTO
EASTERN BC BY 00Z FRIDAY.  WILL BE ISSUING A HEAVY SNOW WARNING
FOR ZONES 29...26 AND 24 AS THEY COULD RECEIVE BETWEEN 10 AND
12 INCHES BY MORNING.  ALSO ZONES 23...27 AND 28 WILL HAVE A
SNOW ADVISORY AS THEY COULD RECEIVE 4 TO 6 INCHES.  THERE COULD
BE SOME MIXED PRECIP IN THOSE ZONES IF THERE IS WARMER AIR
ASSOCIATED WITH THE THEN WHAT THE NCEP MODELS INDICATE.  AS FOR
THE NORTHERN HALF OF THE FORECAST AREA...THOSE AREAS WILL SEE
3 INCHES OF ADDITIONAL ACCUMULATIONS AS WITH THE CURRENT TRACK
OF THE LOW THERE WILL BE SOME DOWNSLOPING AND NOT AS MUCH SNOW
WILL FALL.

ATTM...THERE ARE SNOW SHOWERS OVER MOST OF THE FORECAST AREA SOME
ISOLATED PLACES OVER THE SOUTHERN HALF ARE REPORTING MIXED RAIN
AND SNOW.  MOST PLACES WILL RECEIVE UP TO 2 INCHES OF SNOW
THROUGH THE DAY AS SNOW SHOWERS WILL PERSIST AS INDICATED ON THE
LATEST RADAR IMAGERY. THE PAYA AREA HAS A SNOW ADVISORY IN EFFECT
AS THE SURFACE LOW IN THE NORTHERN GULF WILL CONTINUE TRACK SNOW
SHOWERS ONSHORE...THEY HAVE RECEIVE 9 INCHES SINCE 12 PM.  THOSE
SHOWERS WILL SLOWLY DISSIPATE BY THIS EVENING AS THE LOW WILL
FALL APART.  THEY COULD RECEIVE UP TO 9 ADDITIONAL INCHES BY
MORNING.

.LONG RANGE...THE UPR TROF WL WKN AND MOV ACRS THE ERN GLF AK AND
SE AK BY THU EVENG AND CONT ON EWD.  THE MAIN UPR LOW OVR WRANGELL
IS WL DRFT SEWD ACRS THE BERING STS AND OVR CNTRL AK THRU SUN.
THE RDG IS MOVG EWD PUSHD BY A STG UPR JTSTRM THAT WL PUSH ACRS
THE SRN GLF AK AND N PAC BY SAT MRNG.  A TROF WL ROT ARND THE
UPR LOW AND PUSH ACRS THE GLF AK THRU SUN NGT.  THIS WL CAUSE THE
JTSTRM TO BCM MORE SWLY THRU MON MORNG.

AS UPR TROF MOVS EWD AND THE RDG PUSHS OVR THE GLF AK THERE WL
ALSO BE A SFC RDG MOV TO XTND NEWD ACRS CNTRL SE AK THRU THU
EVENG.  THERE ALSO SHLD BE A WK HI OVR NW CAN JUST INLD FM CNTRL
SE AK AT THAT TIME.

THE FNTL SYS ASSOCD W/ THE SFC LOW OVR THE BERING STS WL PUSH
RPDLY EWD UNDR STG JTSTRM.  THERE WL BE A LOW DVLPG ON THE FNT AS
IT MOVS OVR NRN GLF AK.  THIS SYS HAS THE POT TO DVLP INTO A STRM
AS IT MOV OVR THE NERN GLF AK THRU FRI MRNG.  THERE WL BE SOME
SGFNT WRM AIR AND MAY CHNG MOST ARES TO RA BY FRI AFTN.  THE
ENTIRE FNTL SYS SHLD PUSH THRU ALL SE AK AND ERN GLF CST BY FRI
NGT.

AS THE UPR TROF ROTS SWD OVR THE GLF AK THERE WL ALSO BE SOME CD
AIR PUSHD OVR THE NWRN GLF AK BY SAT MRNG.  A S/W UPR WV WL MOV
SE OVR THE GLF AK THRU SAT AFT AND PROB DVLP ANOTHER LOW OVR THE
NRN GLF AK.  THE ASSOCD SFC TROF/FNTL SYS WL ROT OVR SE AK SAT
NGT.  ATTM THE SGSTN IS THAT THE AMS WL BE CD ENUF TO PROD SNW
OVR THE ERN GLF CST AND MOST ALL SE AK.

ANOTHER LOW WL DLVP OVR GLF AK SUN AND MOV OVR SE AK MON MRNG AND
PROB AGAIN WL PROB PROD SOME HVY SNOW TO THE NRN HLF OF SE AK.
BYND THIS THE MDLS BCM VERY DIFF...BUT THE ATMOS WL CONT TO BE
ACTV THRU THE PD.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...HEAVY SNOW WARNING FOR TONIGHT...ZONES 24...26...29
         SNOW ADVISORY FOR TONIGHT...23...27...28
         SNOW ADVISORY FOR TODAY...17
MARINE...SCA...OUT SIDE COAST AND ZONES...33...35...36