258
FXAK69 PAFG 041411
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
611 AM AKDT THU SEP 4 2025
SYNOPSIS
RAINFALL IS CONTINUING OVER THE WESTERN INTERIOR THIS MORNING.
THE KOYUKUK, KOBUK, AND NOATAK RIVERS REMAIN SLOW TO RECEDE AS
RAIN CONTINUES TO FALL IN THEIR RESPECTIVE HEAD WATERS. THE
EASTERN INTERIOR WILL SEE A WARM AND DRY DAY, BEFORE RAIN BEGINS
TO MOVE INTO THE AREA FROM THE WEST TONIGHT. AN ARCTIC AIRMASS
WILL BEGIN TO MOVE INTO NORTHERN ALASKA THIS EVENING. THIS WILL
BRING A ROUND OF SNOW CHANCES FOR THE NORTH SLOPE TONIGHT, AND
COOLER TEMPERATURES IN THE INTERIOR STARTING FRIDAY.
KEY WEATHER MESSAGES
CENTRAL AND EASTERN INTERIOR...
- SCATTERED RAIN SHOWERS WILL CONTINUE IN THE CENTRAL AND EASTERN
INTERIOR TODAY, BECOMING MORE NUMEROUS OVERNIGHT TONIGHT.
- UP TO 0.25" IS POSSIBLE THROUGH TOMORROW.
- TEMPERATURES WILL WARM TODAY WITH THE TANANA VALLEY IN THE UPPER
60S, AND THE UPPER TANANA VALLEY AND FORTYMILE COUNTRY
APPROACHING 80 DEGREES. WE WILL SEE A COOL DOWN STARTING
TOMORROW WITH AN ARCTIC AIRMASS COMING INTO THE AREA.
- SOUTHERLY GAP WINDS THROUGH THE ALASKA RANGE PASSES WILL
CONTINUE THIS MORNING. WINDY PASS WILL SEE WINDS UP TO 60 MPH,
WHILE ISABELL PASS WILL SEE WINDS UP TO 55 MPH. THEY WILL WEAKEN
BEFORE NOON TODAY.
WEST COAST AND WESTERN INTERIOR...
- RAIN CONTINUES IN THE WESTERN INTERIOR THIS MORNING. RAIN WILL
BECOME SCATTERED THIS AFTERNOON, AND SHOULD BE OUT OF THE
REGION BY 4 AM FRIDAY.
- ADDITIONAL 0.15 TO 0.4 INCHES OF RAIN POSSIBLE.
- UP TO AN 0.5 POSSIBLE FOR ELEVATED AREAS, ESPECIALLY SOUTH
FACING SLOPES.
- A BRIEF DRY SPELL IS EXPECTED FRIDAY MORNING BEFORE THE NEXT
SYSTEM ARRIVES FRIDAY EVENING AND SPREADS TO THE ENTIRE WEST
COAST SATURDAY.
- 0.25 TO 0.75 INCHES OF RAIN POSSIBLE SATURDAY THROUGH SUNDAY.
NORTH SLOPE AND BROOKS RANGE..
- RAIN SHOWERS CONTINUE IN THE BROOKS RANGE TODAY. SOME DRIER
WEATHER IS ANTICIPATED FRIDAY AHEAD OF THE NEXT ROUND OF SHOWERS
SATURDAY AFTERNOON.
- SATURDAY AND SUNDAY COULD SEE ANOTHER INCH OF RAIN ON THE SOUTH
FACING SLOPES.
- WARM TEMPERATURES CONTINUE TODAY ALONG THE NORTH SLOPE. COOLING
TOWARDS NORMAL EXPECTED FRIDAY BEFORE ADDITIONAL WARMING OCCURS
SATURDAY AND SUNDAY.
- SNOW LEVELS FALL ENOUGH THURSDAY NIGHT THAT SOME LIGHT SNOW
ACCUMULATIONS ARE POSSIBLE EAST OF POINT BARROW, GENERALLY UP TO
AN INCH THROUGH FRIDAY. THERE IS A SLIGHT CHANCE FOR UP TO 2
INCHES IN SOME AREAS WITH UP TO 3 INCHES IN THE BROOKS RANGE.
ANY ACCUMULATIONS ARE EXPECTED TO MELT QUICKLY OVER THE WEEKEND.
FORECAST ANALYSIS AND DISCUSSION
VERY LITTLE REMAINS OF THE UPPER LEVEL CIRCULATION FROM THE SYSTEM
MOVING ACROSS THE Y-K DELTA. THIS SYSTEM IS BECOMING MORE OF A
SHORTWAVE TROUGH FEATURE. THIS TROUGH STILL HAS AMPLE UPPER LEVEL
ENERGY, AS WELL AS MOISTURE TO KEEP PRODUCING RAIN ACROSS THE
INTERIOR TODAY AND TOMORROW. SOUTHERLY GAP WINDS WERE STRONGER
THAN ANTICIPATED OVERNIGHT. WHILE THE SURFACE GRADIENT WAS NOT
THAT IMPRESSIVE TO WARRANT A WIND ADVISORY, CONTINUED UPPER LEVEL
ENERGY THROUGH THE NIGHT HAD ENHANCED DOWNSLOPING ALLOWING FOR
STRONGER WINDS. WEAK HIGH PRESSURE WILL BUILD BEHIND THIS TROUGH,
BRINGING SOME DRIER CONDITIONS TO THE WEST COAST AND WESTERN
INTERIOR FRIDAY.
A 982 MB LOW WILL MOVE INTO THE BERING SEA FRIDAY. ANOTHER ROUND
OF SHOWERS WILL ACCOMPANY THIS LOW AS IT MOVES TOWARD THE WEST
COAST. THESE SHOWERS WILL BE WIDESPREAD AND MUCH OF NORTHERN
ALASKA WILL SEE SHOWERS SOMETIME THIS WEEKEND. WITH AN ARCTIC
AIRMASS PERSISTING OVER THE NORTH SLOPE EARLY NEXT WEEK. THE NORTH
SLOPE WILL SEE SNOW SHOWERS STARTING ON MONDAY, AS THE WEAK WARM
FRONT MOVES ONTO THE NORTH SLOPE. THERE IS A WIDE SPREAD OF
UNCERATINITY FOR SNOWFALL AMOUNTS IN THE ENSEMBLES, BUT FOR THE
ARCTIC COASTLINE EAST OF POINT LAY COULD SEE 1 TO 4 INCHES OF
SNOWFALL.
FIRE WEATHER
THE UPPER TANANA VALLEY AND THE FORTYMILE COUNTRY WILL BE THE
PRIMARY AREAS OF CONCERN. RIDGING AND SOUTHERLY FLOW WILL CONTINUE
THROUGH TODAY IN THE FAR EASTERN INTERIOR. THIS WILL KEEP SKIES
MOSTLY CLEAR AND TEMPERATURES WILL WARM TO NEAR 80 DEGREES. WE
WILL SEE SHOWERS MOVE INTO THE TANANA VALLEY BY TONIGHT, AND THEN
INTO THE UPPER TANANA VALLEY TOMORROW MORNING. WE CAN SEE WETTING
RAINS IN THE TANANA VALLEY, BUT NOT IN FORTYMILE COUNTRY AND THE
UPPER TANANA VALLEY. CLOUDS AND AN APPROACHING ARCTIC AIRMASS WILL
COOL TEMPERATURES INTO THE UPPER 50S TO LOW 60S TOMORROW.
HYDROLOGY
THE WET PATTERN CONTINUES INTO THE FORESEEABLE FUTURE WITH
MULTIPLE WAVES OF RAIN CONTINUING TO AFFECT NORTHERN ALASKA.
WATER LEVELS REMAIN HIGH AND A FLOOD WATCH REMAINS IN EFFECT FOR
THE NOATAK, KOBUK, AND KOYUKUK RIVERS. FLOOD ADVISORIES REMAIN IN
EFFECT FOR THE COMMUNITIES OF ALLAKAKET AND KOBUK. WE ARE WATCHING
THE CONDITIONS ON SLATE CREEK NEAR COLDFOOT. HEAVY RAIN IN THE
BROOKS RANGE IS ANTICIPATED TO CAUSE RAPID RISES IN THE RIVER.
WITH ADDITIONAL ROUNDS OF RAIN ANTICIPATED ACROSS THE WESTERN
INTERIOR AND BROOKS RANGE, RIVERS WILL BE SLOW TO RECEDE.
EXTENDED FORECAST DAYS 4-7
WIDESPREAD SHOWERS IN WESTERN ALASKA WILL CONTINUE FROM A
WEAKENING LOW PRESSURE SYSTEM THAT WILL MOVE ONTO THE Y-K DELTA
SUNDAY. THESE SHOWERS WILL MOVE WEST TO EAST, WITH RAIN CHANCES
IN THE EASTERN INTERIOR INCREASING BY SUNDAY NIGHT. THIS SYSTEM
WILL BRING AN ADDITIONAL ROUND OF SNOWFALL FOR THE NORTH SLOPE.
THERE IS MORE MODEL AGREEMENT ON A TUESDAY AND WEDNESDAY STORM.
THE NORTH PACIFIC HIGH IS BEGINNING TO SLOWLY MOVE SOUTH. WITH THE
HIGH MOVING SOUTH, THE LOW PRESSURE ON TUESDAY WILL MOVE
SOUTHEAST INTO THE GULF OF ALASKA. TUESDAY NIGHT WE WILL SEE A
WARM FRONT FROM THIS SYSTEM BEGIN TO WRAP MOISTURE INTO THE
INTERIOR, BRINGING INCREASING CHANCES FOR RAINFALL FROM THE MIDDLE
YUKON TO THE EASTERN ARCTIC COASTLINE.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
AFG WATCHES/WARNINGS/ADVISORIES
AK...FLOOD WATCH FOR AKZ813-814-819-828-831.
PK...SMALL CRAFT ADVISORY FOR PKZ810-856.
DENNIS
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