783
FXAK69 PAFG 181521
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
721 AM AKDT THU JUN 18 2026
SYNOPSIS
WARM TEMPERATURES WITH RELATIVELY DRY CONDITIONS CONTINUE ACROSS
THE AREA THROUGH THIS WEEKEND, WITH HIGHS WIDELY IN THE 60S AND
70S IN THE INTERIOR AND SOUTHERN NORTH SLOPE AND THE 50S (UPPER
40S IN COLDER SPOTS) IN COASTAL AREAS. MOVING INTO THE WEEKEND,
THE WARMEST SPOTS (ESPECIALLY THE YUKON FLATS) COULD REACH INTO
THE MID 80S. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
TODAY IN INLAND AREAS BUT WILL INCREASE IN COVERAGE FROM FRIDAY
INTO THE WEEKEND. SATURDAY EVENING INTO SUNDAY, A COLDER AIR MASS
WILL BRUSH ALONG THE ARCTIC COAST AND COOL TEMPERATURES DOWN A BIT
WHILE BRINGING SOME LIGHT PRECIPITATION, BUT IT WILL NOT IMPACT
TEMPERATURES SOUTH OF THE BROOKS RANGE. THERE WILL BE BETTER
CHANCES FOR MORE NUMEROUS SHOWERS IN THE SOUTHERN INTERIOR TO
OCCUR DURING THIS SAME TIME FRAME.
KEY WEATHER MESSAGES
CENTRAL AND EASTERN INTERIOR...
- WARMER TEMPERATURES IN THE MID TO UPPER 70S TODAY. EXPECT HIGHS
IN THE UPPER 70S AND LOW 80S IN THE CENTRAL INTERIOR BY FRIDAY
WITH MID TO UPPER 80S EXPECTED IN THE YUKON FLATS AND PORTIONS
OF THE EASTERN INTERIOR THIS WEEKEND.
- SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY BUT WILL
BECOME MORE PREVALENT FRIDAY INTO THE WEEKEND.
- HIGHEST PROBABILITY FOR THUNDERSTORMS IN THE INTERIOR IS FRIDAY
AND SATURDAY.
WEST COAST AND WESTERN INTERIOR...
- TEMPERATURES REMAIN SEASONABLY COOL ALONG THE COAST WITH HIGHS
IN THE 50S TO LOW 60S THROUGH THE WEEKEND. HIGHS IN THE INTERIOR
IN THE 60S TO NEAR 70 TODAY WILL RISE INTO THE MID TO UPPER 70S
BY THE WEEKEND.
- SHOWERS AND THUNDERSTORMS TODAY WILL GRADUALLY MOVE EAST BY THE
WEEKEND. ISOLATED THUNDERSTORMS WILL BE POSSIBLE TODAY IN THE
WESTERN INTERIOR.
- THUNDERSTORMS PERSIST ON FRIDAY IN THE WESTERN INTERIOR, MOSTLY
FROM MCGRATH TO HUSLIA EAST. A FARTHER EAST PROGRESSION PERSISTS
ON SATURDAY WITH MOST STORMS SOUTH AND EAST OF RUBY.
NORTH SLOPE AND BROOKS RANGE...
- A WARMING TREND CONTINUES IN THE AREA. EXPECT HIGH TEMPERATURES
TO INCREASE THROUGH FRIDAY, REACHING INTO THE 50S TO NEAR 60 FOR
PORTIONS OF THE COAST, 60S TO MID 70S IN THE PLAINS, AND 70S TO
NEAR 80 FOR THE VALLEYS OF THE BROOKS RANGE.
- A COLD FRONT ARRIVES SATURDAY AFTERNOON WITH COOLING
TEMPERATURES AND CHANCES FOR RAIN FROM WEST TO EAST THROUGH
SUNDAY.
- THUNDERSTORMS WILL BE AROUND THE BROOKS RANGE AND ARCTIC PLAIN
EACH DAY THROUGH THE WEEKEND WITH THE MOST ABUNDANT COVERAGE
BEING SATURDAY AND SUNDAY AFTERNOONS.
FORECAST ANALYSIS AND DISCUSSION
A 557 DAM UPPER-LEVEL LOW OVER THE CHUKCHI SEA IS GRADUALLY
SHIFTING SOUTHWARD (AND IS MERGING WITH A LOW TO ITS WEST) AS
RIDGING IN NORTHWEST CANADA EXPANDS WESTWARD. WITH THAT BEING THE
CASE, SURFACE TEMPERATURES IN THE INTERIOR ON WEDNESDAY WERE ABLE
TO REACH INTO THE 60S AND 70S ACROSS MOST OF THE AREA, WITH
SOMEWHAT COOLER TEMPERATURES IN NEAR-COASTAL PORTIONS OF WESTERN
ALASKA. AS THE RIDGE EXPANDS WESTWARD, 850 MB TEMPERATURES WILL
RISE INTO THE UPPER SINGLE DIGITS TO LOW DOUBLE DIGITS, AND
SURFACE HIGHS WILL REACH INTO THE UPPER 70S TO LOW 80S. IN SOME OF
THE WARMEST INTERIOR VALLEYS (ESPECIALLY THE YUKON FLATS), MID
80S WILL BE POSSIBLE, WITH 850 MB TEMPERATURES RISING TO NEAR 14 C.
A SERIES OF SHORTWAVE TROUGHS WILL CROSS OVER THE ALASKA RANGE
FROM THE SOUTH AND WILL OFFER MULTIPLE OPPORTUNITIES FOR
CONVECTIVE SHOWERS AND THUNDERSTORMS IN THE INTERIOR AND ON THE
NORTH SLOPE, ESPECIALLY MOVING INTO LATE WEEK AND THE WEEKEND,
WHEN MODEL PROGNOSIS SUPPORTS THE PRESENCE OF SEVERAL HUNDRED J/KG
OF SURFACE-BASED CAPE AND LIS OF AROUND −1 TO −3 C. FROM SATURDAY
EVENING INTO SUNDAY, SHOWERS IN THE SOUTHERN INTERIOR COULD
BECOME MORE NUMEROUS AS A SHORTWAVE TROUGH CROSSES THE ALASKA
RANGE.
FIRE WEATHER
FAIRLY ACTIVE THUNDERSTORM DAYS CONTINUE THIS WEEK ACROSS NORTHERN
ALASKA AS UPPER LEVEL RIDGING SETTLES OVER THE STATE. ISOLATED
THUNDERSTORMS ARE EXPECTED TO MAINLY IMPACT MUCH OF THE WESTERN
INTERIOR AND BROOKS RANGE THIS AFTERNOON, WITH VERY ISOLATED
THUNDERSTORMS POSSIBLE IN PORTIONS OF THE NORTH SLOPE AND WHITE
MOUNTAINS. GOING INTO FRIDAY, THUNDERSTORM COVERAGE SHIFTS EASTWARD
TOWARDS THE CENTRAL/EASTERN INTERIOR WITH SCATTERED THUNDERSTORMS
EXPECTED THROUGH THE WEEKEND. THUNDERSTORMS MAY STILL DEVELOP ACROSS
THE WESTERN INTERIOR AND BROOKS RANGE THIS WEEKEND, BUT WILL BE MORE
ISOLATED IN NATURE. GIVEN THE UPTICK IN EXPECTED THUNDERSTORM
ACTIVITY THIS WEEKEND, IT WILL BE ESPECIALLY IMPORTANT TO STAY
WEATHER AWARE AS MIDNIGHT SUN/SUMMER SOLSTICE FESTIVITIES ARE HELD
OUTDOORS. AS WITH ALL THUNDERSTORMS, GUSTY WINDS, HEAVY RAIN, AND
FREQUENT LIGHTNING ARE POSSIBLE WITH THE STRONGEST STORMS.
BESIDES THUNDERSTORMS, THERE IS HIGH CONFIDENCE IN WARM SUMMER-LIKE
TEMPERATURES THROUGH THE REST OF THE WEEK. ACROSS THE
CENTRAL/EASTERN INTERIOR, HIGHS WILL BE MID TO UPPER 70S TODAY WITH
WIDESPREAD UPPER 70S AND LOW 80S EXPECTED FRIDAY THROUGH SUNDAY. THE
WESTERN INTERIOR WILL REMAIN SLIGHTLY COOLER WITH HIGHS IN THE LOW
TO MID 70S THROUGH FRIDAY, THEN POTENTIALLY SEEING A FEW SPOTS REACH
THE UPPER 70S BY THE WEEKEND. MIN RHS WILL LARGELY REMAIN ABOVE
CRITICAL THRESHOLDS THROUGH THE REST OF THE WEEK WITH THE EXCEPTION
OF THE YUKON FLATS AND TANANA VALLEY AS VALUES BOTTOM OUT AROUND 20%
TO 25% BY FRIDAY. WINDS ARE EXPECTED TO REMAIN FAIRLY LIGHT THROUGH
THE WEEKEND, OUTSIDE OF SOME GUSTY OUTFLOW WINDS.
EXTENDED FORECAST DAYS 4-7
THE EXTENDED FORECAST PERIOD BEGINS WITH A SEASONABLY WEAK CLOSED
LOW OVER THE ALASKAN PENINSULA AND AN UNSEASONABLY STRONG ARCTIC LOW
CENTERED NEAR THE NORTH POLE. THE ARCTIC LOW SENDS A WEAK TROUGH
ACROSS THE NORTH SLOPE THIS WEEKEND, WHICH ALSO HELPS SHIFT THE WEAK
COLD FRONT ACROSS THE INTERIOR DURING THE EXTENDED PERIOD. THIS
FRONT IS SHIFTING UNDER A WEAK RIDGE AXIS EXTENDING WEST ACROSS
INTERIOR ALASKA FROM WESTERN CANADA THAT DOESN'T MOVE MUCH THROUGH
THE MIDDLE OF NEXT WEEK. MORE IMPORTANTLY, THIS FRONT FOCUSES SHOWER
AND THUNDERSTORM POTENTIAL ALONG AND EAST OF THE BOUNDARY. THERE IS
GOOD MODEL AGREEMENT THAT THIS FRONTAL BOUNDARY WILL BE ORIENTED
ROUGHLY NORTH-SOUTH BETWEEN MCGRATH AND BETTLES SATURDAY AFTERNOON
BEFORE SHIFTING TO BE MORE WEST-EAST ORIENTED FROM MCGRATH TO EAGLE
BY MONDAY AFTERNOON. THE SUMMER SOLSTICE PROVIDES PLENTY OF
INSOLATION TO FUEL THUNDERSTORM ACTIVITY SO FREQUENT LIGHTNING AND
GUSTY WINDS ARE EXPECTED WITH THE STRONGEST STORMS, DESPITE RATHER
WEAK SYNOPTIC SCALE FORCING. THE LATEST 00Z GUIDANCE CONTINUES TO
SUGGESTS A MORE ROBUST EASTERLY WAVE BY THE MIDDLE OF NEXT WEEK, BUT
CONFIDENCE IN THAT FEATURE IS LOW AT THIS TIME.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
PREV DISCUSSION
/ISSUED 354 PM AKDT WED JUN 17 2026/
HYDROLOGY
MOST OF THE CONCERN FROM THE RECENT HEAVY RAIN IN THE BROOKS RANGE
HAS DIMINISHED. WE'LL NOTICE SOME HIGHER WATER IN ALLAKAKET
TOMORROW AS WELL AS ON THE COLVILLE RIVER. BUT OBSERVED VALUES
HAVE BEEN NEAR BANKFULL. WE STILL HAVE A FLOOD ADVISORY FOR THE
COLVILLE RIVER AND UMIAT WILL BE SEEING CRESTING WATER OVER THE
NEXT 36 HOURS. THIS WATER WILL CONTINUE TO MOVE DOWNRIVER TOWARDS
NUIQSUT WITH MINOR FLOODING OF LOW-LYING AREAS POSSIBLE.
AFG WATCHES/WARNINGS/ADVISORIES
AK...NONE.
PK...NONE.
DS
EXTENDED - EK
FIRE WEATHER - SANTIAGO
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