An intense Bering Sea storm produced strong damaging wind across the Anchorage area. The storm impact was more severe than usual since it occurred before the ground was frozen and while trees still had leaves on them.
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.
An intense Bering Sea storm produced strong damaging wind across the Anchorage area. The storm impact was more severe than usual since it occurred before the ground was frozen and while trees still had leaves on them. These factors resulted in widespread occurrences of trees blown down across power lines and personal property. Most of Anchorage lost electric power; telephone circuits were down across many parts of Anchorage and Eagle River. Fallen trees crushed several cars and damaged over one hundred residences. Some roofs were partially removed from homes by wind, and a small plane was flipped and severely damaged at Lake Hood. Foresters estimate tens of thousands of trees were lost throughout the Municipality of Anchorage (including the military bases); nearly 6,000 trees were lost on Municipal park land alone. School was canceled across the Anchorage School District because of the power outages.
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 Sep 4, 12:15 PM AKST, 4 hours 25 minutes earlier.
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
115 PM AKDT TUE SEP 4 2012
.ANALYSIS AND UPPER LEVELS...A POWERFUL STORM IS MAKING ITS WAY
ACROSS THE EASTERN BERING SEA AND TOWARD MAINLAND ALASKA THIS
MORNING. THE LATEST OBSERVATION FROM SAINT GEORGE ISLAND SHOWS
A SURFACE PRESSURE OF 972 MB...SO THE CENTRAL PRESSURE OF THE
NEARBY LOW IS LIKELY AROUND 970 MB. STANDARDIZED ANOMALIES ARE
IN THE RANGE OF 4 TO 6 FOR WIND SPEEDS AS THE LOW MOVES ACROSS
THE ALASKA REGION. THIS IS INDICATIVE OF HOW UNUSUAL IT IS TO
HAVE SUCH A STRONG STORM THIS EARLY IN THE SEASON. THE SIZE OF
THE STORM IS ALSO VERY LARGE...WITH GALE FORCE WINDS EXTENDING AT
LEAST 500 MILES IN ANY DIRECTION FROM THE LOW CENTER. IN ADDITION
TO WIDESPREAD STRONG WINDS THIS STORM IS ALSO PRODUCING HEAVY RAIN
ALONG THE FRONTAL SYSTEM...WHICH IS MOVING ONSHORE OF SOUTHWEST
ALASKA EARLY THIS AFTERNOON.
.MODEL DISCUSSION...MODELS REMAIN IN VERY GOOD AGREEMENT WITH
HANDLING OF THIS SYSTEM AND FORECAST CONFIDENCE IS HIGH. THE
LATEST MODELS HAVE TRENDED TOWARD A SLIGHTLY MORE WESTWARD TRACK
OF THE LOW CENTER ALONG THE WEST COAST OF ALASKA WHICH MEANS THE
TIMING OF THE FRONT MOVING THROUGH SOUTHCENTRAL WILL BE A LITTLE
SLOWER.
.SHORT TERM FORECAST...STRONG WINDS AND HEAVY RAIN WILL BE THE
MAIN THREATS FROM THIS STORM. THE HIGHEST IMPACTS FROM WINDS ARE
EXPECTED TO BE IN THE TURNAGAIN ARM AND ANCHORAGE AREA WHERE HIGH
WIND WARNINGS ARE IN EFFECT. WINDS ARE ALREADY INCREASING THROUGHOUT
THE ANCHORAGE AREA. HOWEVER...EXPECT WINDS IN THE ANCHORAGE BOWL
TO COME DOWN LATE THIS AFTERNOON AND EARLY EVENING AS THE FRONT
MOVES INTO THE WESTERN GULF AND THE NORTH-SOUTH PRESSURE GRADIENT
INCREASES DOWN COOK INLET...WHICH SHOULD CAUSE WINDS CURRENTLY
BENDING INTO ANCHORAGE TO INSTEAD REMAIN OUT IN THE INLET. WINDS
ALONG TURNAGAIN ARM AND HIGHER ELEVATIONS WILL CONTINUE TO INCREASE
ALL THE WAY THROUGH THE EVENING HOURS UNTIL THE FRONT MOVES THROUGH
AROUND MIDNIGHT. CONDITIONS CONTINUE TO LOOK FAVORABLE FOR TRAPPING
OF MOUNTAIN WAVES THIS EVENING WHICH WILL BRING SOME STRONGER WINDS
DOWN THE HILLSIDE AND INTO PORTIONS OF EAST ANCHORAGE ALONG THE
MOUNTAINS. WINDS WILL MOVE BACK IN TO ALL OF THE ANCHORAGE BOWL
AS WE APPROACH MIDNIGHT AND THE FRONT MOVES THROUGH. AS HAS BEEN
ADVERTISED THE PAST COUPLE DAYS...WITH LEAVES ON THE TREES AND
FAIRLY SATURATED SOILS THERE IS AN INCREASED LIKELIHOOD OF FALLING
TREES IN THESE HIGH WINDS.
WINDS ELSEWHERE WILL BE STRONGER THAN EXPECTED IN A MORE TYPICAL
WIND EVENT. HOWEVER...WINDS IN THESE AREAS ARE EXPECTED TO REMAIN
BELOW WARNING THRESHOLDS. WINDS WILL DIMINISH RAPIDLY BEHIND THE
FRONT IN MOST LOCATIONS. THE EXCEPTION WILL BE TURNAGAIN ARM AND
HIGHER ELEVATIONS WHERE THE PRESSURE GRADIENT WILL REMAIN QUITE
TIGHT AND SUPPORT STRONG SUB-WARNING LEVEL WINDS THROUGH WEDNESDAY.
AS WAS THE CASE WITH THE SYSTEM THAT MOVED THROUGH THE REGION
YESTERDAY...THERE WILL BE STRONG PRESSURE RISES BEHIN THE LOW
CENTER. THE MAX RISE WILL ONCE AGAIN BE OVER SOUTHWEST ALASKA
WITH WEAKER RISES OVER THE GULF AND SOUTHCENTRAL. THESE PRESSURE
RISES WILL CAUSE WINDSPEEDS TO INCREASE ONCE AGAIN ON WEDNESDAY.
HEAVY RAIN WILL FALL ACROSS MUCH OF THE REGION OUT AHEAD OF THE
FRONT. THE WIDESPREAD STRONG WINDS WILL RESULT IN LIGHTER QPF
AMOUNTS ALONG THE LEE SIDE OF THE MOUNTAINS. AREAS IN UPSLOPE
FLOW WILL SEE ENHANCED RAINFALL AMOUNTS ON THE ORDER OF TWO INCHES
OR MORE...PRIMARILY ALONG THE WESTERN SUSITNA VALLEY AND PRINCE
WILLIAM SOUND AREAS. THE FRONTAL RAIN BAND WILL MOVE THROUGH OVER
ABOUT A 3 TO 6 HOUR PERIOD FOR ANY GIVEN LOCATION. THIS HELPS LIMIT
THE FLOODING POTENTIAL. RIVERS AND STREAMS IN THE SEWARD AREA WERE
RUNNING HIGH AFTER YESTERDAY'S STORM AND A FLOOD WATCH HAS BEEN
ISSUED FOR TONIGHT THROUGH WEDNESDAY AS THE NEXT BATCH OF HEAVY
RAIN MOVES THROUGH.
THIS STORM SYSTEM WILL EXIT TO THE NORTH ON WEDNESDAY WITH IMPROVING
TRENDS EXPECTED ACROSS THE REGION. HOWEVER...ANOTHER UPPER TROUGH
WILL DROP OUT OF THE RUSSIAN ARCTIC AND RAPIDLY TRACK TO THE GULF
OF ALASKA BY LATE FRIDAY. THIS WILL BE A MUCH WEAKER SYSTEM AND WIND
WON'T BE A MAJOR FACTOR...BUT PERIODS OF RAIN AND COOL TEMPERATURES
WILL PERSIST ACROSS THE SOUTHERN MAINLAND THROUGH THE END OF THE
WEEK.
.LONG TERM FORECAST...THE UPPER LEVEL PATTERN WILL REMAIN
PROGRESSIVE THROUGH THE EXTENDED FORECAST PERIOD WITH WEAK TO
MODERATE STORMS MOVING QUICKLY FROM WEST TO EAST ACROSS THE AREA.
AT THIS POINT IT LOOKS LIKE THESE STORMS WILL PRIMARILY REMAIN
ALONG THE SOUTHERN TIER OF THE FORECAST AREA...WHICH MEANS THE
SOUTHERN MAINLAND OF ALASKA MAY SEE A PERIOD OF DRY WEATHER.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 101 125.
MARINE...STORM WARNING...120.
GALE WARNING...125 128 129 130 132 138 140 141 150 155
160 165 170 171 172 175 176 179 180 185.
FIRE WEATHER...NONE.
SEB SEP 121 high wind. Local standard time, as filed.
An unofficial report of wind gust near 130 mph was received. The normal reporting stations in the high wind locations stopped reporting prior to the peak of the event.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2012Every state in 2012This day in weather historyWarnings in Alaska, September 2012
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: 397994.