Flood in Alaska, September 10 to 11, 2011

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
324 PM AKDT FRI SEP 9 2011

.SHORT TERM...THE RAIN SHOWERS WILL CONTINUE TO END IN A S TO
N SEQUENCE TONIGHT. THE STRONGEST WINDS FOR THE INNER CHANNELS OF
THE PANHANDLE INCLUDE LYNN CANAL AND THE VICINITIES OF PAGY AND
PAHN. THE SHOWERS WILL CONTINUE TO END IN A SE TOWARD NW SEQUENCE
WITH THE LAST HOLDOUT OF SCATTERED SHOWERS SATURDAY WILL BE IN THE
YAKUTAT ZONE.

ON THE GOES IR THE REMAINS OF THE LOW THAT MADE LANDFALL 1008 MB
THAT MADE LANDFALL NEAR YAKUTAT CAN STILL BE FOUND IN SRN YUKON
TRRTY AS A COMPLEX OF VORT FEATURES. CONVECTIVE BANDS CAN STILL BE
IDENTIFIED IN THE NRN PNHDL. THE UPPER LEVEL SUPPORT IS PROVIDING
A STRONG LOW PRESSURE TROUGH THAT EXTENDS S INTO NRN LYNN CANAL.

A WEAK SFC RIDGE IS EXTENDING NW ALONG THE PNHDL AND IS ALREADY
BEGINNING TO CUT OFF A WEAK SFC HIGH THAT BY 12Z SHOULD BE ABOUT
1026 MB IN CNTRL SE AK. THE SATURATED GROUND AND THE DIMINISHING
CLOUD COVERAGE WILL AID RADIATIONAL FOG DEVELOPMENT IN MOST OF
THE PUBLIC ZONES OVERNIGHT. THE EXCEPTIONS SHOULD BE IN THE NRN
PNHDL INCLDG PAGY AND PAHN, WHERE THE LAST CIGS WILL BE PERSISTING
AS WELL AS THE STRONGEST REMAINING WINDS FOR THE INNER CHANNELS.

THE ONLY AREAL FLOOD ADVISORY STILL IN EFFECT IS FOR ZONE 26, AND
IS SPECIFICALLY FOR THE VICINITY OF THE THE STIKINE RIVER. THIS
RAISED STAGE HAS BEEN FED BY THE CONDITIONS UPSTREAM IN ADJACENT
CANADA AND THE STAGE SHOULD BE FALLING ENOUGH THAT THE ADVISORY
IS STILL SCHEDULED TO END AT 06Z THIS EVENING.

&&

.LONG TERM...OVERALL MODEL CONSENSUS IS FAIRLY GOOD UNTIL MID
WEEK. A RIDGE OF HIGH PRESSURE HOLDS OVER SOUTHEAST ALASKA AND FAR
EASTERN GULF OF ALASKA. WITH A BUBBLE HIGH ALONG THE NORTHEAST
GULF COAST. MODELS AGREEING THAT THERE IS A LOW MOVING OUT OF THE
NORTH CENTRAL PACIFIC ALONG 150W THAT WILL CURVE TO THE NORTHWEST
LATE SUNDAY AND HEADED INTO BRISTOL BAY AREA LATE MONDAY NIGHT.
WITH A BROAD RIDGE STILL HOLDING OVER THE SOUTHEAST ALASKA STILL
IN PLACE. A WEAKENING FRONT FROM THE LOW HEADED TO BRISTOL BAY
WILL BE TRYING TO MOVE OVER THE PANHANDLE MONDAY NIGHT... WHILE A
LARGER FRONT MOVES INTO THE PANHANDLE TUESDAY NIGHT.

ONLY MINIMAL CHANGES DONE TO THE FORECAST PACKAGE FROM WEDNESDAY
ONWARD. THROUGH TUESDAY THERE WAS A NUDGE TOWARDS THE OPERATIONAL
GFS SOLUTION BUT WITH THE SIMILAR PATTERN MODEL CHOICE COULD HAVE
BEEN A PICK ONE SET UP.

THERE DOES SEEM TO BE A 36 TO 72 HOUR BREAK IN PRECIPITATION ACROSS
THE PANHANDLE FROM SUNDAY TO LATE TUESDAY. A BIT OF SUNSHINE MAY
EVEN MAKE AN EXTENDED APPEARANCE OTHER THAN JUST A BREAK IN THE
CLOUDS. THE POTENTIAL FROM SOME AREAS OF FOG ACROSS THE PANHANDLE
SATURDAY NIGHT...ALTHOUGH DID NOT COVER VERY HARD IN THE CURRENT
FORECAST.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...AREAL FLOOD ADVISORY UNTIL 10 PM AKDT THIS EVENING FOR AKZ026.
MARINE...GALE WARNING FOR PKZ012-022.
         SMALL CRAFT ADVISORY FOR PKZ051.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

JBT/BEZENEK