Red Flag Warning 1, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
238 PM AKDT MON JUL 6 2009

.SHORT TERM...SATELLITE AND OBS TODAY SHOW THAT THE MARINE LAYER
HAS BEEN PUSHED WELL OFF SHORE. THE EXCEPTION TO THIS IS IN THE
SOUTHERN PANHANDLE WHERE SOUTHEASTERLY WINDS ARE PUSHING THE
MARINE LAYER UP CLARENCE STRAIT. OTHERWISE MOST OF THE PANHANDLE
IS DRY AND CLEAR. TEMPERATURES HAVE SHOT UP INTO THE 80S FOR THE
NORTHERN PANHANDLE TODAY AND DUE TO NORTHERLY FLOW DEW POINTS ARE
VERY LOW ESPECIALLY IN PAGY. THE RH FOR PAGY HAS DROPPED AS LOW
AS 11 PERCENT. HAVE ISSUED A RED FLAG WARNING FOR VERY LOW RH FOR
ZONE 18 FOR THIS AFTERNOON AND EVENING.

 NORTHERN LYNN CANAL, CROSS SOUND, AND STEPHENS PASSAGE ARE THE
WINDY SPOTS TODAY WITH SMALL CRAFT WINDS IN STEPHENS AND 20 KT
WINDS IN NORTHERN LYNN AND CROSS SOUND. EXPECT THOSE WINDS TO
DIMINISH THROUGH THE EVENING. ELSEWHERE WINDS ARE RELATIVELY
LIGHT. WINDS WILL PICK UP AGAIN IN NORTHERN LYNN LATE TONIGHT TO
SMALL CRAFT.

 FOR THE REST OF TONIGHT AND TOMORROW, OFFSHORE FLOW OVER MOST OF
THE PANHANDLE WILL KEEP THE NORTHERN AND CENTRAL PANHANDLE DRY
AND CLEAR. THE TROUGH OVER THE SOUTHERN PANHANDLE WILL BRING MORE
MARINE INFLUENCE INTO THE PICTURE KEEPING HIGH TEMPS FOR TOMORROW
DOWN AND POSSIBLY HAVING THE MARINE LAYER CREEP BACK INTO
CLARENCE STRAIT AND THE SOUTHERN OUTER COAST. HIGH TEMPS WILL
ONCE AGAIN BE WARM IN THE NORTHERN PANHANDLE AND THE CONTINUATION
OF DOWNSLOPE WINDS WILL AGAIN BRING DRY CONDITIONS TO THE
NORTHERN PANHANDLE FOR TOMORROW AFTERNOON.

 MODEL AGREEMENT WAS VERY GOOD FOR TODAY. ELECTED TO USE THE NAM
FOR ITS DETAIL AND RESOLUTION. FOR SKY COVER THE GEM WAS THE
MODEL THAT HANDLED IT THE BEST GIVEN THE INFLUENCE FROM THE
MARINE LAYER. STILL HAD TO DO SOME HAND EDITING TO THAT GRID.

.LONG TERM...NOT MUCH CHANGE IN THE LONG TERM PATTERN THROUGH THE
REST OF THE WEEK BUT THERE INDICATIONS THAT THE HOT AND SUNNY
WEATHER WILL COME TO AN END THIS WEEKEND AS ONSHORE FLOW INCREASES
ALOFT. THE OMEGA BLOCK OVER THE GULF WILL KEEP THE PANHANDLE VERY
DRY AND HOT THROUGH THURSDAY WITH TEMPS REACHING RECORD TERRITORY.
THE UPPER HIGH WILL BEGIN TO FLATTEN OUT SOME LATE THIS WEEK INTO
THE WEEKEND AND THAT WILL INCREASE THE ONSHORE FLOW AT MOST
LEVELS. THIS WESTERLY FLOW WILL INCREASE MOISTURE OVER THE AREA AND
THE SURFACE HIGH OVER THE WESTERN GULF WILL DRIFT BACK TO THE EAST
AND WITH A THERMAL LOW IN CANADA WILL INCREASE THE SURFACE ONSHORE
FLOW. THIS WILL ADVECT THE SEA STRATUS BACK OVER THE COASTAL AREAS
LATE TUE NIGHT AND PUSH INLAND WED NIGHT AND MAY GET INTO THE
JUNEAU AREA BY THURSDAY.

THERE IS NO PREICP IN THE FORECAST AS WITH THE STRONG HIGH OVER
THE AREA IT WILL KEEP MOST SHOWERS FROM FORMING. WINDS WILL BE ON
THE LIGHT AS THE HIGH PRESSURE MOVES OVER THE AREA AND THERE WILL
BE NOT MUCH OF A PRESSURE GRADIENT.

USED A BLEND OF THE GFS AND EC THROUGH DAY 4 AS THEY ARE IN GOOD
AGREEMENT BUT FROM THERE THROUGH DAY 7 DID A BLEND OF THE EC AND
HPC AS THERE IS SOME PROBLEMS BETWEEN THE OPERATIONAL MODELS AND
ENSEMBLE MEANS. THE OPERATIONAL MODELS WANT TO PUSH THE UPPER AND
SURFACE HIGH OVER THE PANHANDLE BY THE EARLY WEEKEND BUT THE MEAN
ARE KEEPING THE HIGH FURTHER OFFSHORE. KEEPING THE HIGH OFFSHORE IS
PREFERRED AS THE MODELS USUALLY WANT TO PUSH THE HIGH EAST FASTER
THAN WHAT HAPPENS ALSO THE UPPER HIGH OVER THE GULF IS VERY STRONG
AND DO NOT THINK IT WILL MOVE THAT EASY. SO WITH THAT SAID...THE
ONLY CHANGE TO THE EXTENDED PART OF THE FORECAST WAS TO BRING IN
MORE CLOUDS WITH THE ONSHORE FLOW BUT DID KEEP THE TEMPS IN THE
UPPER 60S TO LOWER 70S AS 850 TEMPS REMAIN BETWEEN 10 AND 15C.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...AREAL FLOOD ADVISORY UNTIL 6 AM AKDT THURSDAY FOR AKZ018.
         RED FLAG WARNING UNTIL 8 PM AKDT THIS EVENING FOR AKZ018.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-031.

&&

EAL/ABJ