A series of strong, wet storm systems hit Southcentral Alaska in mid-September. Each storm followed nearly the same track along the Alaska Peninsula then along the Bering Sea coast, setting up a strong moist fetch into the Southcentral Alaska.
Every event with a place to put it. Tap one for its entry below.
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.
A series of strong, wet storm systems hit Southcentral Alaska in mid-September. Each storm followed nearly the same track along the Alaska Peninsula then along the Bering Sea coast, setting up a strong moist fetch into the Southcentral Alaska. This resulted in widespread flood damage over a large area. Storm total precipitation ranged from 21 to 27 inches along the eastern Kenai Peninsula, while further inland between 6-12 inches of rain fell along the Talkeetna Mountains north to the headwaters of the Nenana River. A large number of roads and bridges were affected; damage to the Alaska Railroad was severe enough to shut down the rail service for several days. Almost 60 homes were either severely damaged or destroyed and over 700 other homes were either affected or sustained minor damage; most of the damage occurred along the Little Susitna River and Willow Creek. State estimates of damage to individual property approached $3.5 million, public infrastructure exceeded $19 million statewide, and the military base in Anchorage sustained an addition $3.5 million in flood damages. There was one fatality associated with the flooding. On September 24, a 51 year old man died while attempting to cross a swollen creek on his ATV.
In addition to flooding, the storms brought strong east and southeast wind to an area from southeast Prince William Sound, to Cordova, through Portage Pass, along Turnagain Arm and along the Anchorage. The first strong storm resulted in wind through the Chugach Mountains with an unofficial peak wind of 120 mph measured by a spotters home weather system in Bear Valley. In the other wind-prone locations, peak wind was generally around 70 to 75 mph, with 90 mph in reported in Portage Valley.
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 20, 4:55 AM AKST, 5 hours 5 minutes earlier.
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
555 AM AKDT THU SEP 20 2012
.ANALYSIS AND UPPER LEVELS...
THE AMPLIFIED UPPER LEVEL PATTERN CONTINUES AS A LONGWAVE TROUGH
EXTENDS THROUGH THE BERING SEA AND INTO THE NORTHERN PACIFIC...WITH A
STRONG RIDGE OVER WESTERN CANADA. MUCH OF THE SOUTHERN MAINLAND
REMAINS IN DEEP LAYER SOUTHERLY FLOW BETWEEN THESE TWO FEATURES AS
SUBTROPICAL MOISTURE CONTINUES TO STREAM NORTHWARD FROM THE NORTHERN
PACIFIC...BRINGING SIGNIFICANT RAINFALL TO MUCH OF SOUTHCENTRAL
ALASKA...PARTICULARLY ALONG THE GULF COAST. ELSEWHERE...THE LARGE
UPPER LOW THAT WAS OVER THE WESTERN BERING YESTERDAY IS NOW LOCATED
ABOUT 350 MILES SOUTH OF THE CENTRAL ALEUTIANS AND PROGRESSING
EASTWARD THROUGH THE NORTHERN PACIFIC.
.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM REGARDING A SHORTWAVE
TROUGH AND ASSOCIATED SURFACE LOW THAT WILL MOVE NORTHWARD ACROSS
SOUTHCENTRAL AK TODAY AND TONIGHT. MODELS REMAIN IN REASONABLE
AGREEMENT INTO THE MID TERM IN HANDLING THE UPPER LOW IN THE NORTHERN
PACIFIC DESPITE SOME DIFFERENCES IN STRENGTH AND POSITION...SHOWING A
GENERAL CONSENSUS IN DEEPENING THE SYSTEM AND BRINGING IT NORTHWARD
INTO THE WESTERN GULF OF ALASKA ON SATURDAY.
.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
WIDESPREAD RAIN WILL CONTINUE THROUGH TONIGHT AS A SHORTWAVE TROUGH
EMBEDDED IN THE BROAD SOUTHERLY FLOW MOVES OVER SOUTHCENTRAL AK. AN
ASSOCIATED SURFACE LOW WILL MOVE INLAND JUST WEST OF KODIAK ISLAND
THIS AFTERNOON AND TRACK QUICKLY NORTHWARD...FOLLOWING A PATH VERY
SIMILAR TO THE LOW THAT MOVED THROUGH THE AREA YESTERDAY. MUCH OF
SOUTHCENTRAL WILL SEE A TEMPORARY BREAK FROM PRECIPITATION AND
PERHAPS SOME SUNSHINE ON FRIDAY AS UPPER LEVEL RIDGING MOVES
THROUGH...ALTHOUGH RAIN WILL PERSIST ALONG THE GULF COAST WITH
CONTINUED ONSHORE FLOW. RAIN WILL RETURN TO THE REST OF THE AREA THIS
WEEKEND AS THE LARGE UPPER LOW MOVES INTO THE GULF OF ALASKA.
SOUTHWEST ALASKA...
RAIN WILL RETURN TO THE BRISTOL BAY REGION AND EASTERN PORTIONS OF
THE LOWER KUSKOKWIM VALLEY THIS AFTERNOON AS THE SURFACE LOW MOVES
ASHORE WEST OF KODIAK ISLAND. RAIN WILL THEN OVERSPREAD ALL OF THE
SOUTHWEST MAINLAND THIS WEEKEND AS THE SYSTEM CURRENTLY OVER THE
NORTHERN PACIFIC APPROACHES SOUTHERN ALASKA.
ALEUTIANS/BERING SEA...
A RELATIVELY BENIGN PATTERN WILL CONTINUE ACROSS THE BERING SEA AND
ALEUTIANS THROUGH FRIDAY AS THE LARGE UPPER LOW REMAINS WELL SOUTH OF
THE CHAIN. RAIN WILL THEN MOVE BACK IN FROM WEST TO EAST THIS WEEKEND
AS ANOTHER LOW MOVES OFF OF THE KAMCHATKA PENINSULA.
.LONG TERM FORECAST...
MODELS CONTINUE TO SUGGEST A PATTERN CHANGE MAY BE IN STORE TOWARDS
THE END OF THE WEEK AS THE BROAD UPPER LEVEL TROUGH THAT HAS BEEN
DOMINATING THE BERING SEA SHIFTS EASTWARD OVER MAINLAND
ALASKA...WHICH WOULD LIKELY KEEP SOUTHERN ALASKA COOL AND WET INTO
THE EXTENDED TERM.
.HYDROLOGY...
GIVEN THE LARGE AMOUNTS OF RAIN ALREADY RECEIVED ACROSS SOUTHCENTRAL
ALASKA IN THE PAST FEW DAYS LEADING TO SATURATED GROUND AND LOCAL
STREAMS AND RIVERS ALREADY AT BANKFULL LEVELS...FLOODING CONCERNS
WILL CONTINUE ALONG THE GULF COAST AND INTO ANCHORAGE AND THE MAT-SU
VALLEY AS RAIN PERSISTS ACROSS THE AREA THROUGH THURSDAY NIGHT.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WARNING 125 131 135 145
FLOOD WATCH 121
FLOOD ADVISORY 101 111
MARINE...GALE WARNING 120 125 130
FIRE WEATHER...NONE
CB SEP 12The national radar mosaic for the moment the first event began.
3 flood. Local standard time, as filed.
Ship Creek Above the Glenn Highway crested at 7.13ft at 21:15 AKDT.|Damages occurred on the Eagleglen and Moose Meadows golf courses.
The Kenai River at Skilak crested at 15.56ft on 9/26/12 at 15:15 AKDT; the Kenai River at Soldotna crested at 12.53ft on 9/26/12 at 13:15 AKDT.
Flood waters from the Lowe River closed the Richardson Highway east of Valdez from milepost 12 to milepost 16.
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: 427525, 427524, 406781.