427
FXAK69 PAFG 130014
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
414 PM AKDT TUE AUG 12 2025
SYNOPSIS
A COASTAL STORM CONTINUES ALONG THE WEST COAST WITH
HEAVY RAIN AND HIGH SURF. ISSUED A FLOOD WATCH FOR THE SOUTHERN
SEWARD PENINSULA THIS SHIFT FOR HIGH WATER ACROSS RIVERS DRAINING
THE BENDELEBEN MOUNTAINS. NEARLY 2 INCHES OF RAIN HAS FALLEN NORTH
OF NOME IN THE LAST 24 HOURS, AND UP TO 1.5" NORTHEAST OF
KIVALINA. CLOUDS AND PRECIPITATION WILL MOVE EAST THROUGH THE
WEEK, THOUGH RAINFALL AMOUNTS WILL BE MUCH LESS IN THE INTERIOR.
BY FRIDAY, MUCH NEEDED RAINFALL IS EXPECTED ACROSS THE UPPER
TANANA VALLEY.
KEY WEATHER MESSAGES
CENTRAL AND EASTERN INTERIOR...
- TEMPERATURES WARM TUESDAY AND WEDNESDAY WITH HIGHS IN THE UPPER
60S TO LOW 70S.
- A BRIEF PERIOD OF GUSTY SOUTHERLY WINDS THROUGH ALASKA RANGE
PASSES EXPECTED TUESDAY NIGHT INTO WEDNESDAY MORNING WITH GUSTS
UP TO 30 MPH POSSIBLE. STRONGER GUSTS EXPECTED FURTHER WEST.
- ADDITIONAL RAINFALL EXPECTED LATER THIS WEEK ARRIVING FROM THE
WEST LATE WEDNESDAY AND LASTING INTO THE WEEKEND. THE HEAVIEST
RAIN IS EXPECTED THURSDAY AND FRIDAY.
WEST COAST AND WESTERN INTERIOR...
- BERING SEA STORM THROUGH WEDNESDAY MORNING.
IMPACTS:
-2 TO 4 FEET WATER RISES POSSIBLE, HIGHEST IN THE NORTON SOUND.
-WAVE RUN UP AND MINOR BEACH EROSION POSSIBLE.
-HEAVY RAIN EXPECTED MONDAY THROUGH WEDNESDAY WITH 1 TO 2 INCHES
EXPECTED ALONG THE WEST COAST AND 2 TO 4 INCHES POSSIBLE ALONG
SOUTH FACING SLOPES ON THE SEWARD PENINSULA AND THE FAR WESTERN
BROOKS RANGE, HEAVIEST WEST OF KIANA.
-RIVERS/STREAMS EXPECTED TO SEE NOTABLE RISES IN WATER LEVEL.
-WINDS WEAKENING OVERNIGHT TUESDAY NIGHT AND TURNING NORTHERLY
THROUGH THE BERING STRAIT.
TIMING:
-HIGHEST WATER LEVELS EXPECTED THROUGH WEDNESDAY MORNING. TWO
PEAKS ARE EXPECTED, THE SECOND HIGHER PEAK WILL BE TUESDAY
EVENING.
-HEAVY RAIN EXPECTED THROUGH WEDNESDAY.
NORTH SLOPE AND BROOKS RANGE..
- A COASTAL STORM APPROACHES MONDAY BRINGS RAIN THROUGH WEDNESDAY
NIGHT TO THE WESTERN BROOKS RANGE AND CHUKCHI SEA COAST
IMPACTS:
-2.5 TO 3.5 FEET OF WATER RISE ABOVE THE NORMAL HIGH TIDE AT
POINT HOPE. AROUND 2 FEET OF WATER RISE FOR POINT LAY.
-WAVE RUN UP AND MINOR BEACH EROSION POSSIBLE.
-HEAVY RAIN IN THE FAR WESTERN BROOKS RANGE WITH ESTIMATED TOTALS
OF 2 TO 4 INCHES, HEAVIEST WEST OF KIANA.
-STRONG SOUTH WINDS THROUGH BROOKS RANGE PASSES WITH GUSTS UP TO
40 MPH POSSIBLE AT ANAKTUVUK PASS AND UP TO 35 POSSIBLE AT
ATIGUN PASS.
TIMING:
-HIGHEST WATER EXPECTED INTO WEDNESDAY NORTH OF THE BERING
STRAIT, WITH THE PEAK HAVING OCCURRED TUESDAY MORNING.
-HEAVY RAIN IN WESTERN BROOKS RANGE EXPECTED THROUGH WEDNESDAY
-SOUTH WINDS INCREASE PEAK TUESDAY, AND DIMINISH TUESDAY NIGHT.
- COOLER TEMPERATURES WARM TUESDAY WITH HIGHS RISING INTO THE MID
TO UPPER 50S MONDAY AND INTO THE 60S TUESDAY. TEMPERATURES COOL
BACK INTO THE UPPER 40S TO LOWER 50S IN THE LATTER HALF OF THE
WEEK.
FORECAST ANALYSIS AND DISCUSSION
THE UPPER-LEVEL FLOW PATTERN CONTINUES TO EXHIBIT A DIPOLE ACROSS
ALASKA, WITH RIDGING AND HIGH PRESSURE OVER THE EASTERN PORTIONS OF
THE STATE, AND TROUGHING WITH GENERAL STORMINESS AND LOW PRESSURE
ACROSS THE WESTERN PART OF THE STATE. EMBEDDED IN SOUTHWESTERLY FLOW
DOWNSTREAM FROM THE TROUGH AXIS, A STREAM OF MOISTURE AND EMBEDDED
MID-LEVEL DISTURBANCES WILL CONTINUE THEIR ONSLAUGHT ON THE WEST
COAST BRINGING PERIODS OF HEAVY RAIN, AND GUSTY WINDS OF 25-35 MPH
TODAY AND TONIGHT. WIDESPREAD RAINFALL AMOUNTS OF HALF AN INCH TO AN
INCH ARE LIKELY ACROSS AN AREA FROM THE YUKON DELTA, NORTHWARD INTO
THE WESTERN NORTH SLOPE. LOCAL TERRAIN ENHANCEMENTS IN SOUTHERN
PORTIONS OF THE SEWARD AND LISBURNE PENINSULAS MAY RESULT IN
RAINFALL TOTALS AS HIGH AS 2 INCHES BY TONIGHT. THIS WILL BRING THE
POTENTIAL FOR MINOR FLOODING ALONG SMALL CREEKS AND STREAMS THROUGH
FRIDAY MORNING.
ACROSS THE EASTERN TWO-THIRDS OF ALASKA, HIGH PRESSURE TODAY WILL
KEEP CONDITIONS WARM AND SUNNY, WITH HIGHS RANGING FROM THE UPPER
60S TO THE LOW 70S. UPPER-LEVEL CLOUDS WILL STREAM INTO THIS REGION
FROM THE WEST TODAY AND TONIGHT AS THE DISTURBANCE IN THE NORTH
BERING SEA SLOWLY MOVES ONSHORE.
THE STORM SYSTEM IMPACTING WEST ALASKA TODAY WILL SLOWLY MOVE EAST
OVER THE COURSE OF THIS WEEK, PERIODS OF RAIN TO MOST OF CENTRAL AND
NORTHERN ALASKA THROUGH THURSDAY. INCREASING CLOUD COVER AFTER TODAY
WILL ALSO ACT TO MODERATE TEMPERATURES, KEEPING HIGHS STARTING
THURSDAY IN THE UPPER 50S/LOWER 60S. THE ONE EXCEPTION TO THIS TREND
WILL BE THE UPPER TANANA VALLEY AND YUKON FLATS, WHERE TEMPERATURES
MAY REACH INTO THE LOW 70S AGAIN TOMORROW BEFORE THE ARRIVAL OF THE
AFOREMENTIONED STORM SYSTEM. GIVEN PREVAILING SOUTHERLY FLOW AT THE
SURFACE AHEAD OF THIS SYSTEM, SUBSIDENCE DOWNSTREAM FROM THE WHITE
MOUNTAINS WILL ALSO ACT TO MINIMIZE THE AMOUNT OF PRECIPITATION IN
THE YUKON FLATS, KEEPING THIS AREA SUBSTANTIALLY DRIER THAN
SURROUNDING AREAS.
FIRE WEATHER
VERY WET CONDITIONS CONTINUE ACROSS THE WEST COAST
AS A STRONG FRONTAL SYSTEM PUSHES EAST. THIS SYSTEM WILL WEAKEN
QUICKLY AS IT MOVES INLAND, BUT WILL STILL BRING SHOWERS TO THE
INTERIOR ON THURSDAY. THE SYSTEM WILL STALL OVER THE EASTERN
INTERIOR AS A LOW MOVES INTO THE EASTERN GULF OF ALASKA AND LOOKS
TO FINALLY PROVIDE MUCH NEEDED WETTING RAINS TO THE UPPER TANANA
VALLEY FRIDAY AND SATURDAY. UNTIL THEN, RHS WILL REMAIN DOWN NEAR
30% FOR MINIMUMS EAST OF DELTA JUNCTION, WITH WEDNESDAY BEING THE
DRIEST DAY. THUNDERSTORMS ARE NOT EXPECTED OVER THE NEXT WEEK.
BRIEF PERIODS OF SOUTHERLY GAP WINDS GUSTING TO 30 MPH EXPECTED
THROUGH WEDNESDAY NIGHT.
HYDROLOGY
PERIODS OF HEAVY RAINFALL THROUGH WEDNESDAY IN WESTERN ALASKA
WILL CAUSE NOTABLE RISES TO WATER LEVELS, ESPECIALLY ALONG THE
SOUTHERN SEWARD PENINSULA AND FAR WESTERN BROOKS RANGE WHERE 2 TO
4 INCHES OF RAIN IS EXPECTED THROUGHOUT THE EVENT. RIVERS SOURCED
IN THE FAR WESTERN BROOKS RANGE ARE EXPECTED TO RISE
SIGNIFICANTLY TO NEAR BANKFULL WITH A CHANCE FOR MINOR FLOODING.
IMPACTS WILL BE LIMITED BY LOWER WATER LEVELS AHEAD OF THE EVENT.
A FLOOD WATCH IS IN EFFECT FOR THE SOUTHERN SEWARD PENINSULA.
THE MAIN RIVER OF CONCERN IS THE NIUKLUK RIVER. A HYDROLOGIC
OUTLOOK ALSO PROVIDES MORE DETAILS ON HEAVY RAIN IN THE WESTERN
BROOKS RANGE.
EXTENDED FORECAST DAYS 4-7
..FRIDAY AND SATURDAY
UPPER-LEVEL TROUGHING IS EXPECTED TO GENERALLY PREVAIL ACROSS MUCH
OF THE STATE FOR THE BEGINNING OF THIS WEEKEND. THIS PATTERN WILL
BRING WIDESPREAD CLOUDINESS WITH ISOLATED (20-30%) LIGHT RAIN
SHOWERS. HOWEVER, THERE WILL BE TWO AREAS OF ENHANCED PRECIPITATION
CHANCES.
THE FIRST AREA WILL EXTEND FROM THE EASTERN INTERIOR NORTHWARDS TO
THE EASTERN NORTH SLOPE. A MERIDIONAL-ORIENTED FILAMENT OF MID-LEVEL
VORTICITY WILL ACT TO BRING ENHANCED LIFT INTO THIS REGION,
RESULTING IN MORE WIDESPREAD (50% CHANCE) LIGHT RAIN. WITH
TEMPERATURES FRIDAY NIGHT INTO SATURDAY POTENTIALLY DROPPING INTO
THE LOWER-30S AND UPPER-20S, LIGHT SNOW IS POSSIBLE IN THE HIGHER
ELEVATIONS OF THE BROOKS RANGE AND THE FAR EASTERN NORTH SLOPE,
INCLUDING THE DALTON HIGHWAY THROUGH ATIGUN PASS.
THE SECOND AREA WILL PRIMARILY ENCOMPASS THE SEWARD PENINSULA,
LISBURNE PENINSULA, AND ADJACENT AREAS IN THE WESTERN INTERIOR AND
NORTH SLOPE RESPECTIVELY. MEDIUM RANGE GUIDANCE IS IN GENERAL
AGREEMENT OF A SHORTWAVE TROUGH EJECTING OUT OF FAR NORTHEAST RUSSIA
AND QUICKLY MOVING EAST ACROSS THE NORTH BERING SEA/SOUTH CHUKCHI
SEA. FORCING FOR ASCENT AHEAD OF THIS DISTURBANCE WILL BRING A
RATHER LARGE AREA OF SCATTERED RAIN SHOWERS (50% CHANCE) INTO THIS
REGION SATURDAY INTO SATURDAY NIGHT. LOW-LEVEL FLOW LOOKS TO BECOME
SOUTHERLY IN ADVANCE OF THIS DISTURBANCE, SUPPORTING LOCALLY
ENHANCED RAINFALL RATES/AMOUNTS ALONG ANY SOUTHWARD FACING SLOPES.
HIGH TEMPERATURES DURING THIS TIME SHOULD RANGE FROM THE UPPER 50S
TO THE LOW 60S, WITH LOWS IN THE UPPER 30S AND LOW 40S, SLIGHTLY
BELOW CLIMATOLOGICAL AVERAGE.
..SUNDAY AND MONDAY
BY THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK, UPPER-
LEVEL RIDGING AND SOUTHWEST FLOW BUILDS INTO MUCH OF SOUTHERN AND
CENTRAL ALASKA, WITH TROUGHING OVER THE CHUKCHI AND BEAUFORT SEAS
BRINGING WEST FLOW ACROSS THE BROOKS RANGE AND NORTH SLOPE. THIS
FLOW REGIME WILL HELP BRING MOISTURE INTO THE INTERIOR, WITH GENERAL
CLOUDINESS AND ISOLATED RAIN SHOWERS. CONDITIONS ON THE NORTH SLOPE
WILL BE MORE HARSH, WITH GUSTY WINDS OUT OF THE WEST/NORTHWEST AND
OVERCAST, WITH PERIODS OF FOG AND/OR DRIZZLE. MODEL SOLUTIONS BEGIN
TO DIVERGE WITH THE TIMING OF THE NORTHERN SYSTEM DURING THIS TIME
FRAME, WITH THE GFS MORE PROGRESSIVE THAN THE EURO. REGARDLESS, THE
WEATHER PATTERN SHOULD GENERALLY BE UNSETTLED ACROSS MUCH OF CENTRAL
AND NORTH ALASKA, WITH PERIODS OF RAIN AND SLIGHTLY BELOW NORMAL
TEMPERATURES (HIGHS PRIMARILY IN THE 50S AND LOW 60S IN THE LOWER
ELEVATIONS).
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...HIGH SURF RECEED WEDNESDAY AS
WINDS SHIFT NORTH ALONG THE WEST COAST. EXPECTED IMPACTS DAYS 1
AND 2, PLEASE SEE KEY WEATHER MESSAGES.
AFG WATCHES/WARNINGS/ADVISORIES
AK...HIGH SURF ADVISORY FOR AKZ821-822-824-825.
FLOOD WATCH FOR AKZ822.
PK...SMALL CRAFT ADVISORY FOR PKZ801-802-804-808-811-855-858-859.
SMALL CRAFT ADVISORY FOR PKZ803-809.
SMALL CRAFT ADVISORY FOR PKZ805-807-810-853-856.
SMALL CRAFT ADVISORY FOR PKZ806-854.
SMALL CRAFT ADVISORY FOR PKZ816.
SMALL CRAFT ADVISORY FOR PKZ817.
SMALL CRAFT ADVISORY FOR PKZ850.
SMALL CRAFT ADVISORY FOR PKZ852.
CHRIEST
ANALYSIS/EXTENDED: DARRAH
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