Small Craft Advisory 73, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
110 PM ADT WED SEP 13 2006

.DISCUSSION...STRONG UPPER RIDGE EXTENDS N FROM CENTRAL PACIFIC
CENTERED ALONG 150W TO 70-75N. WEAKENING OCCLUDED FRONTAL BAND
STEMMING FROM ABOUT 992 MB LOW JUST NW WRANGEL ISLAND DRAPES S
FROM CHUKOTSK PEN. S THROUGH BERING TO ALEUTIANS. 990 MB LOW
NEAR 50N/165W CURRENTLY HAS TRIPLE POINT MOVING N OVER AK PEN
INTO BRISTOL BAY.

12Z MODELS ALL DEPICTING THESE FEATURES REASONABLY AND ARE IN
GOOD AGREEMENT ON EVOLUTION OF THE PATTERN THROUGH MID-RANGE.

AS 990 MB LOW/FRONTAL BAND S OF AK PEN. MOVES N TONIGHT/THU.
RIDGING AHEAD OF IT WILL FURTHER WEAKEN THE FRONTAL BAND COMING
OFF THE WRANGEL ISLAND LOW. THAT LOW ITSELF WILL BE FILLING AND
LIFTING N AT THE SAME TIME. THIS WILL ACT TO EASE SRLY SURFACE
PRESSURE GRADIENTS...SO GALES AND SMCR WINDS FROM WRN ARCTIC
COAST S TO BERING WILL DIMINISH TONIGHT AND EARLY THU. HEAVY SURF
ADVISORIES AND MARINE WEATHER STATEMENT TO COVER THE HIGH SEAS
WITH THIS WILL EXPIRE AT 12Z. PRECIP. WILL ALSO DIMINISH TONIGHT
ALONG COASTAL MARGINS.

AS TRIPLE POINT AND WARM FRONTAL BAND FROM AK PEN. LOW LIFTS N
TONIGHT...PRECIP. WILL QUICKLY RETURN TO WRN COASTAL AND WRN
INTERIOR ZONES AS FAR N AS PAUN-PAGA 20Z THU AND AS FAR N AS
PAPO-PAFM 06Z FRI. THE STRONG UPPER RIDGE TO THE EAST WILL
NOT ALLOW ANY FURTHER INLAND PENETRATION OF THE MOISTURE THAN
THAT.

WRN ARCTIC COAST MAY SOME SOME SPOTTY -RA FROM THE REMNANTS OF
THE WRANGEL ISLAND FRONTAL BAND MERGING WITH THE WARM FRONTAL
BAND MOISTURE OF THE AK PEN. LOW THU NIGHT INTO FRI. REST OF N
SLOPE TO STAY IN GOOD OFFSHORE SRLY FLOW ALOFT TONIGHT THROUGH
AT LEAST SAT...WITH MID/HIGH CEILINGS AND SOME PATCHY FOG/STRATUS
WHEN WINDS ARE LIGHT.

STRONG UPPER RIDGING OVER CENTRAL AK FORECAST BY MODELS TO PINCH
OFF THU AND FORM BUBBLE HIGH OVER MACKENZIE BAY FRI AS COLD FRONT
AROUND AK PEN. LOW WRAPS N INTO GULF AK. THIS IN TURN WILL CAUSE
UPPER RIDGING TO BULGE AND WEAKEN AND DISSIPATE THE W COAST FRONTAL
BAND LATE FRI/SAT. SOUTHEAST TO SOUTH CHINOOK FLOW WILL ALSO KEEP
INTERIOR WARM AND DRY THU THROUGH SAT. THUS FIRE WEATHER WATCH WAS
ISSUED FOR THU AND FRI FOR ZONES 223/225/226.

UPPER LOW ASSOCIATED WITH THE SURFACE LOW NEAR AK PEN. FORECAST TO
WOBBLE INTO GULF AK SAT/SUN/MON. THIS WILL BEGIN TO COLLAPSE HEIGHT
FIELD OVER INTERIOR BY SUN...FOR A LITTLE COOLING AND REDUCTION IN
GAP FLOW/CHINOOK WIND.

COASTAL HAZARD POTENTIAL DAY 3 AND 4...NONE.
LOW NEAR AK PEN WILL ONLY LIFT AS FAR N AS BRISTOL BAY FRI THEN WEAKEN
AND FILL SAT. SMCR TO MIN GALE WINDS ONLY EXPECTED IN BERING STRAIT
AND OVER MARINE ZONE 210 WITH THIS.

&&

.FIRE WEATHER...
RHS DURING BURNING PERIODS THU AND FRI WILL LIKELY BE NEAR 30 PERCENT.
COMBINED WITH SE TO S WINDS AT LEAST 20-35 MPH AT SAME TIME ZONES 223/
225/226 MAKES FIRE WEATHER WATCH NECESSARY. FUELS ARE RECEPTIVE AFTER
COORD. WITH AK STATE FORESTRY AND AK FIRE SERVICE.

&&

.HYDROLOGY...
NO SIGNIFICANT ISSUES.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR AKZ207-AKZ213.

FIRE WEATHER WATCH FOR AKZ223-AKZ225-AKZ226.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ230-PKZ235.

GALE WARNING FOR PKZ210-PKZ220-PKZ225.
&&

MAR SEP 06