Small Craft Advisory 85, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
230 PM AKDT THU AUG 14 2014

.DISCUSSION...
ALOFT...LOW PRESSURE OVER THE BERING SEA AND SOUTHWEST
ALASKA...WITH MODERATE SOUTH TO SOUTHEAST FLOW OVER THE EASTERN
INTERIOR...WHICH BECOMES LIGHTER FARTHER TO THE NORTHWEST OVER
THE STATE. A SHORT WAVE TROUGH IN THIS FLOW MOVING ACROSS NORTON
SOUND AND THE NORTHERN INTERIOR TODAY...WHILE A MOVE VIGOROUS
SHORT WAVE MOVES NORTH OVER THE INTERIOR FRIDAY...CAUSING THE MID
LEVEL FLOW TO WEAKEN GREATLY AS A LOW FORMS EAST OF FAIRBANKS FRI
AFTERNOON THEN MOVES INTO CANADA SAT. THE TROUGH WILL EXTEND FROM
NORTON SOUND TO HUSLIA TO FORT YUKON 4AM SAT AND BY 4PM SAT IT
WILL EXTEND FROM THE BERING STRAIT TO KOTZEBUE TO THE CENTRAL AND
EASTERN BROOKS RANGE. HIGH PRESSURE FAR NORTH OF BARROW WILL DRIFT
EAST AND WEAKEN SOME THROUGH SUN.

SURFACE...WEAKENING OCCLUSION FROM NOME TO BETTLES TO INUVIK IN
CANADA THIS AFTERNOON WILL MOVE TO THE BERING STRAIT TO KOTZEBUE
TO THE EASTERN BROOKS RANGE BY 1AM FRI AND THEN DISSIPATE. SECOND
OCCLUSION ALONG THE NORTH GULF COAST OF ALASKA WILL MOVE NORTH
OVER THE SOUTHERN INTERIOR FRI AND TO THE EASTERN SEWARD PENINSULA
TO THE YUKON FLATS BY 10PM FRI...THEN LIE ALONG THE SOUTHERN
SLOPES OF THE BROOKS RANGE SAT AM AND DISSIPATE LATE SAT. 1024 MB
HIGH FAR NORTH OF BARROW WILL DRIFT EAST TO THE CANADIAN
ARCHIPELAGO THROUGH SUN.

MODELS...THE 12Z NAM IS IN BETTER AGREEMENT WITH THE GFS AND ECMWF
FOR THE SHORT TERM. IN THE MEDIUM TERM THE GFS AND ECMWF ARE
SIMILAR IN HOLDING A RIDGE OVER THE NORTH PACIFIC WITH AN
EXTENSION ACROSS THE SOUTHEASTERN INTERIOR THROUGH THU.

NORTH SLOPE...EAST WINDS CONTINUING WITH LITTLE CHANGE THROUGH THE
WEEKEND. NIGHTTIME AND MORNING FOG ALSO CONTINUING. THE SEVERAL
OCCLUSIONS REACHING THE BROOKS RANGE BEFORE DISSIPATING WILL
PROVIDE SOME SHOWERS TO THE MOUNTAINOUS AREAS...WITH ISOLATED
THUNDERSTORMS POSSIBLE OVER EASTERN HALF.

WESTERN ALASKA...THE FIRST OCCLUSION WILL SPREAD SCATTERED SHOWERS
OVER THE SEWARD PENINSULA...BERING STRAIT...AND THE NORTHEAST
ARCTIC BOROUGH THIS EVENING. EXPECT ISOLATED THUNDERSTORMS ACROSS
THE ENTIRE AREA THIS EVENING WITH SOME CONTINUING OVERNIGHT. AHEAD
OF THE NEXT OCCLUSION EXPECT THUNDERSTORMS AGAIN ON FRI...UP TO
SCATTERED IN EXTENT OVER AREAS SOUTH OF THE ARCTIC CIRCLE.
SHOWERS FOLLOWING BEHIND WITH THE SECOND OCCLUSION ON FRIDAY.

CENTRAL AND EASTERN INTERIOR...THE OCCLUSION MOVING NORTH FROM
SOUTHERN ALASKA WILL CAUSE SOME SUBSTANTIAL RAIN OVER THE EASTERN
AND NORTHERN INTERIOR FRI AND SAT...UP TO 1 INCH OF RAIN IS
POSSIBLE OVER THE UPLANDS FAR NORTH OF FAIRBANKS AND EAST TOWARD
EAGLE FRI AND FRI PM. ALONG THE SOUTHERN SLOPES OF THE EASTERN
BROOKS RANGE 1 TO NEARLY 2 INCHES OF RAIN COULD FALL FRI PM
THROUGH SAT.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.

&&

.FIRE WEATHER...AS NOTED IN PREVIOUS AFD LIGHTNING OVER WESTERN
ALASKA CREATES SOME CONCERN WHERE FUELS ARE DRY...ESPECIALLY THIS
EVENING AND AGAIN FRI AHEAD OF THE SECOND OCCLUSION. OVER THE
EASTERN INTERIOR WINDS WILL BE GUSTY NEAR THE ALASKA RANGE THROUGH
SAT AND HUMIDITIES WILL APPROACH 30 PERCENT BUT THE FUELS ARE NOT
BURNABLE.

&&

.HYDROLOGY...EXPECT SMALL STREAMS WILL RISE LATER FRI AND INTO
SAT BETWEEN FAIRBANKS AND FORT YUKON INCLUDING THE FORTYMILE
AREA...THEN SAT AND INTO SUN ON STREAMS IN THE SOUTHEASTERN BROOKS
RANGE AND UPPER KOYUKUK VALLEYS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

JL AUG 14