Low pressure caused unseasonably strong gap winds throughout Southcentral Alaska. Due to the unseasonable nature, core partners agreed that there was a concern for impacts with leaves still on the trees.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AFC wrote it up.
Low pressure caused unseasonably strong gap winds throughout Southcentral Alaska. Due to the unseasonable nature, core partners agreed that there was a concern for impacts with leaves still on the trees. Anchorage Forecast Office issued high wind warnings in spite of the fact that winds were not expected to reach criteria.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Anchorage, AK wrote its last area forecast discussion before the first event at Aug 26, 3:30 PM AKST, 10 hours 1 minute earlier.
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ANCHORAGE AK 430 PM AKDT WED AUG 26 2015 .ANALYSIS AND UPPER LEVELS... BROAD BUT FLAT RIDGING OVER THE BERING SEA CONTINUES TO STEER STORMS INTO THE NORTHERN HALF OF THE STATE. A STRONG 150+ KT ZONAL JET MOVING INTO THE BERING IS MAKING FOR A VERY DYNAMIC AND FAST- MOVING WEATHER PATTERN ACROSS MUCH OF THE STATE. SATELLITE IMAGERY AT MIDDAY SHOWS A VIGOROUS SHORTWAVE MOVING EASTWARD ALONG THE BROOKS RANGE...WITH AN ASSOCIATED BAND OF PRECIP EXTENDING SOUTHWARD ACROSS THE COPPER RIVER BASIN AND INTO THE NORTHERN GULF. WIDESPREAD RAIN HAS ENDED ACROSS SOUTHWEST ALASKA AND THE COOK INLET AREA...WITH THE HIGHEST RAINFALL AMOUNTS CONFINED TO THE NORTHERN SUSITNA VALLEY AND ON THE NORTH AND WEST SIDES OF THE ALASKA RANGE. UNSEASONABLY STRONG AND WIDESPREAD WEST AND SOUTHWEST WINDS ARE OCCURRING ACROSS ALMOST ALL OF SOUTHERN ALASKA...AND WILL BE SLOWLY SWINGING AROUND TO A NORTHWEST AND NORTHERLY DIRECTION OVER THE NEXT DAY OR SO. THESE STRONG NORTHWESTERLY WINDS...PARTICULARLY THROUGH AND EAST OF THE ALASKA RANGE...REPRESENT THE PRIMARY FORECAST CHALLENGE TODAY. OVER THE BERING SEA...STRONG HIGH PRESSURE OVER THE NORTH PACIFIC IS KEEPING GUSTY WEST WINDS AND RELATIVELY WARM TEMPERATURES IN PLACE ACROSS THE ALEUTIANS AND SOUTHERN BERING SEA. WIDESPREAD MARINE FOG AND STRATUS REMAIN IN PLACE...PARTICULARLY OVER THE WESTERN ALEUTIANS. WITH THE AFOREMENTIONED STRONG JET LOCATED OVER THE NORTHERN BERING SEA MOST OF THE ACTIVE WEATHER AND RAPIDLY CHANGING CONDITIONS ARE CONFINED TO THE FURTHEST NORTH AND EAST PORTIONS OF THE REGION. && .MODEL DISCUSSION... THE MODELS HAVE COME INTO A BIT BETTER AGREEMENT THAN YESTERDAY. THE KEY EVOLUTION IN THE UPPER LEVELS OVER THE NEXT FEW DAYS WILL BE WHAT IS NOW EXPECTED TO BE TWO SHORTWAVES THAT COME THROUGH SOUTHCENTRAL ALASKA UNDER STRENGTHENING NORTHWEST FLOW. THE 12Z ECMWF TUESDAY WAS THE FIRST MODEL TO SHOW A MUCH FASTER INITIAL WAVE...HAVING BACKED OFF SLIGHTLY TODAY BUT BEING JOINED IN A GENERALLY FASTER TRACK BY THE AMERICAN MODELS (NAM/GFS). THIS WILL INITIATE THE GAP WIND/OUTFLOW PROCESS OVER THE KENAI PENINSULA AND THROUGH THE ALASKA RANGE QUICKER THAN PREVIOUSLY EXPECTED...BUT IT WILL NOT BE UNTIL THE 2ND AND STRONGER WAVE COMES THROUGH EARLY THURSDAY EVENING THAT SURFACE CYCLOGENESIS WILL COMMENCE IN THE GULF AND THE REST OF THE FAVORED GAPS ALONG WITH INTERIOR AREAS LIKE ANCHORAGE AND THE SUSITNA VALLEY WILL EVEN GET IN ON THE GUSTY NORTHWEST WINDS. ONCE NORTHWEST FLOW AT ALL LEVELS IS IN PLACE ACROSS THE STATE ON FRIDAY THERE ARE A FEW MINOR MODEL ISSUES WITH STRENGTH AND TIMING OF WEAK SUPPORTING SHORTWAVES MOVING THROUGH THE OVERALL PATTERN...BUT PINNING DOWN THE DETAILS AT THIS POINT MAY VERY WELL PROVE TO BE AN EXERCISE IN FUTILITY AS TIMING OF WEAK SHORTWAVES MOVING THROUGH A 150 KT JET STREAM WILL ALMOST CERTAINLY BOUNCE AROUND WITH EACH MODEL AND EACH RUN. OVERALL...THE NAM WAS THE PREFERRED MODEL TODAY DUE TO SUPERIOR RESOLUTION IN THE HANDLING OF EXPECTED GAP WINDS AROUND THE REGION. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)... RAINFALL HAS SHIFTED EAST INTO THE COPPER RIVER BASIN AND PRINCE WILLIAM SOUND THIS AFTERNOON AS THE UPPER LEVEL DISTURBANCE CONTINUES TO SHIFT EASTWARD AT A RAPID PACE. ISOLATED SHOWERS WILL REMAIN POSSIBLE THROUGH THE EVENING HOURS ACROSS ANCHORAGE AND THE MATANUSKA VALLEY AS ONE MORE WEAK UPPER LEVEL DISTURBANCES PUSHES THROUGH. THE COPPER RIVER BASIN AND PRINCE WILLIAM SOUND AREAS WILL LIKELY SEE A CONTINUATION OF LIGHT RAIN THROUGH THURSDAY AFTERNOON AS THE STRONG ZONAL JET WILL PUSH TWO STRONG WAVES THROUGH ON THURSDAY AND COMBINE WITH ENOUGH RESIDUAL MOISTURE CURRENTLY BEING ADVECTED INTO THE AREA. RAIN CHANCES THEN BEGIN TO TAPER OFF SIGNIFICANTLY ON FRIDAY AS COLDER AND MUCH DRIER AIR MOVES BACK INTO THE REGION WITH STEEP NORTHWESTERLY FLOW RESIDING OVER THE AREA. AN UNSEASONABLY STRONG WIND EVENT LOOKS POISED TO IMPACT SOUTHCENTRAL ALASKA THURSDAY NIGHT THROUGH EARLY ON SATURDAY. THE COMBINATION OF DECENT COLD AIR ADVECTION ON THE BACK SIDE OF THE UPPER LEVEL TROUGH AND THE LOCATION OF THE UPPER LEVEL JET CREATES A VERY FAVORABLE ENVIRONMENT FOR OUTFLOW WINDS. WINDS WILL STRENGTHEN TO GALE FORCE ACROSS THE BARREN ISLANDS THIS EVENING AND CONTINUE TO OVERSPREAD THE GULF OF ALASKA COME THURSDAY NIGHT. TYPICAL OUTFLOW AREAS(SEWARD...WHITTIER...VALDEZ...AND THOMPSON PASS WILL BE SLIGHTLY DELAYED AS THE STRONGER WINDS WONT DEVELOP UNTIL THURSDAY NIGHT. WHILE NO HIGH WIND WARNING OR WATCHES ARE ANTICIPATED AT THIS TIME...WIND GUSTS ANYWHERE FROM 50 TO 65 MPH ACROSS THE AFOREMENTIONED AREAS APPEAR LIKELY. THE STRONGEST WINDS WILL BE THROUGH THOMPSON PASS AND NEAR WHITTIER WHILE SEWARD AND VALDEZ WILL LIKELY BE CAPPED AROUND 50 MPH. THE REST OF SOUTHCENTRAL ALASKA WILL NOT BE IN THE CLEAR AS WINDS 10 TO 20 MPH WITH GUSTS UP TO 35 MPH IN SOME LOCATIONS (INCLUDING THE ANCHORAGE BOWL) WILL BE POSSIBLE. THIS SET UP IS MORE TYPICAL OF A LATE SEPTEMBER OR EARLY OCTOBER PATTERN...ESPECIALLY WITH THE PUSH OF COLDER AIR BEING ADVECTED SOUTH. ONE LAST THING...IT LOOKS AS IF TEMPERATURES ACROSS EAST ANCHORAGE AND PARTS OF THE MATANUSKA VALLEY WILL DROP NEAR FREEZING THURSDAY NIGHT AND AGAIN FRIDAY NIGHT. THIS WOULD BE UNSEASONABLY EARLY FOR THESE LOCATIONS TO DROP BELOW FREEZING. RIGHT NOW TEMPERATURES ARE FORECASTED BETWEEN 34 AND 36 DEGREES FOR THE MOST VULNERABLE PLACES...SO NO FREEZE WARNING HAS BEEN ISSUED AT THIS TIME. HOWEVER...IF TEMPERATURES ARE EXPECTED TO DROP BELOW FREEZING...A FREEZE WARNING WILL BE ISSUED. && .SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)... A SERIES OF UPPER LEVEL DISTURBANCES WILL TRACK THROUGH THE SOUTHWEST MAINLAND OVERNIGHT TONIGHT AND THROUGH TOMORROW AFTERNOON...KEEPING SCATTERED SHOWERS OVER MUCH OF THE SOUTHWEST MAINLAND AND STEADIER RAINFALLS ALONG THE UPSLOPE AREAS OF THE ALASKA RANGE. THE INITIAL DISTURBANCE WILL BE SLIGHTLY DRIER IN COMPARISON TO THE PREVIOUS SYSTEM THAT EXITED THE SOUTHWEST MAINLAND THIS AFTERNOON...WITH A LESS IMPRESSIVE MOISTURE FEED FROM THE WEST. THE SECOND OF THESE DISTURBANCES WILL USHER IN A DRYING AND COOLING TREND AS NORTHWEST FLOW TAKES HOLD HEADING INTO THE END OF THE WEEK. AS A RESULT...WIDESPREAD GUSTY WINDS WILL CONTINUE AND EVENTUALLY PICK UP ALONG A TIGHTENING NORTHWEST GRADIENT OVER THE MAINLAND THURSDAY MORNING...AND PERSIST THROUGH LATE FRIDAY MORNING. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)... PRECIPITATION WILL GRADUALLY DIMINISH IN COVERAGE ACROSS THE BERING THROUGH THURSDAY NIGHT AS THE PATTERN SLOWLY AMPLIFIES AND THE NORTH PACIFIC RIDGE RETROGRADES WESTWARD. THIS WILL KEEP MOST OF THE RAINFALL CENTERED OVER THE WESTERN TIP OF THE ALEUTIANS AS DEEP SUBTROPICAL MOISTURE CONTINUES TO STREAM NORTHWARD ON THE WESTERN PERIPHERY OF THE RIDGE. HOWEVER...SOME OF THIS MOISTURE AND ENERGY MAKES IT OVER THE RIDGE AND INTERACTS WITH THE NORTHERN ENERGY STREAM...BRINGING SOME GUSTY WINDS AND SHOWERS OVER THE CENTRAL BERING FRIDAY. A FEW SHOWERS WILL ALSO DEVELOP ALONG THE ALASKA PENINSULA AND EASTERN ALEUTIANS IN BRISK NORTHWEST FLOW ACROSS THE EASTERN BERING. OTHERWISE...WIDESPREAD STRATUS AND FOG WILL CONTINUE TO IMPACT MUCH OF THE REGION THROUGH THE END OF THE WEEK BENEATH THE STRONG HIGH. && .LONG TERM FORECAST (DAYS 3 THROUGH 7)... BEGINNING THE EXTENDED PERIOD FRIDAY NIGHT...THE REGION WILL BE UNDER THE INFLUENCE OF AN ELONGATED TROUGH EXTENDING FROM THE NORTH SLOPE OF ALASKA TO THE COAST OF BRITISH COLUMBIA. THE OUTFLOW WIND EVENT WILL BE WINDING DOWN FRIDAY NIGHT AS THE GULF LOW CONTINUES TO WEAKEN AND DRIFT SOUTHEAST. EVENTUALLY WITH TIME...A SHORTWAVE TROUGH IN NORTHWEST FLOW ORIGINATING FROM EASTERN SIBERIA WILL MERGE WITH THE AFOREMENTIONED ARCTIC TROUGH OVER THE NORTH SLOPE SATURDAY AND SUNDAY. THERE UNFORTUNATELY REMAINS MUCH UNCERTAINTY WITH THE DEVELOPMENT OF THIS LOW AS IT MOVES FROM THE NORTHERN BERING SEA TO THE GULF OF ALASKA. THE UNCERTAINTY SEEMS TO LIE IN HOW MUCH SUBTROPICAL ENERGY OVER THE WESTERN BERING MERGES WITH THE DIGGING TROUGH. THE GFS FAVORS A STRONGER SOLUTION AND MORE INTACT MERGER...WHICH BRINGS MORE PRECIPITATION INTO SOUTHWEST ALASKA FRIDAY NIGHT INTO SATURDAY...AND EVENTUALLY INTO SOUTHCENTRAL SATURDAY AFTERNOON AND EVENING. THE WEAKER SOLUTIONS SUCH AS THE ECMWF AND CANADIAN GDPS FAVOR A FARTHER SOUTH TRACK OF THE LOW...AND WEAKER DEVELOPMENT IN THE GULF OF ALASKA. FOR THIS FORECAST...A CONTINUED CONSERVATIVE FORECAST WAS TAKEN FAVORING A WPC ENSEMBLE BLEND ALONG WITH SOME ECMWF. THIS WILL KEEP LOWER END CHANCES FOR PRECIPITATION OVER MAINLAND LOCATIONS...WITH HIGHER CHANCES REMAINING LARGELY OVER THE BERING AND GULF OF ALASKA AS THE LOW SKIRTS THE REGION. THEREAFTER...THERE IS HIGHER CONFIDENCE LEADING INTO MIDWEEK AS SOUTHCENTRAL REMAINS UNDER THE INFLUENCE OF DRY AND COOLER OFFSHORE FLOW...WITH A SLOWLY DEVELOPING FLAT RIDGE OVER THE BERING. PRECIPITATION CHANCES INCREASE AGAIN TOWARDS THE MIDDLE TO END OF NEXT WEEK...WITH A SLOW REBOUND IN TEMPERATURES AFTER THE COOL PERIOD THIS WEEKEND AND EARLY NEXT WEEK. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE. MARINE...NONE. FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...AD SOUTHCENTRAL ALASKA...MC SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP LONG TERM...JA
2 high wind, 1 wildfire. Local standard time, as filed.
Winds fueled a wildfire on Kodiak Island, near the town of Chiniak. Two structures were destroyed and the town was evacuated.
Winds peaked at 63 mph in Whittier. Multiple power outages occurred in Seward and a dock broke loose in Whittier.
At Valdez airport, peak winds reached 75 mph between 1356 and 1535 on 28 Aug 2015. No power outages or damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2015Every state in 2015This day in weather historyWarnings in Alaska, August 2015
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 593757, 593753, 593756.