Name: Heavy Snow in Alaska, September 29 to 30, 2004
Start: 2004-09-29T21:00
End: 2004-09-30T13:05
Location: Alaska

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

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.

What forecasters said that day

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 29, 12:00 PM AST, 9 hours earlier.

Area forecast discussion, Sep 29, 12:00 PM AST, 9 hours before

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
100 PM ADT WED SEP 29 2004

.DISCUSSION...
.500MB...TROUGH OVER THE WESTERN MAINLAND/AK PEN DIGS SOUTH AS A POOL
OF COLD AIR IS DEPOSITED SOUTH OF UNALASKA TONIGHT. CENTER DEVELOPS
IN THIS REGION AND BECOMES CUT-OFF AS THE REMAINDER OF TROUGH
FLATTENS SOME AND SHIFTS TO OVER CANADA FRI. MAINLAND CONTINUES UNDER
STRONG SOUTHWEST FLOW THROUGH EARLY FRI. RIDGE BUILDS WITH AXIS
EXTENDING FROM SE ALASKA TO TO SEWARD PENINSULA FRI AFTERNOON.

SURFACE...GFS AND MESO ETA FAIRLY REASONABLE IN SYNOPTIC SCALE
PATTERN. GFS MODEL DID A LITTLE BETTER ON THE INITIALIZATION AND
FORECAST TREND LOOKS BETTER...SO THIS MODEL WITH SOME MODIFICATIONS
WILL BE USED IN AFTERNOON FORECAST PACKAGES. ALL MODEL 850 MB TEMP
INITIALIZATIONS WERE AROUND 2C TOO WARM OVER SW AK/SOUTHCENTRAL AT
12Z THIS MORNING. SO WILL SLOW DOWN WARM ADVECTION SOME ON THIS
PACKAGE.

1001 MB CENTER OVER APPROACHING PAEH THIS AFTERNOON MOVES TO OVER THE
CENTRAL MAINLAND TONIGHT AND INTO THE NW TERRITORY OF CANADA THU
EVENING. IN ADVANCE OF LOW...WARM FRONT KICKS NORTH WITH 1000-850MB
THICKNESS VALUES REACHING 1320M AS FAR NORTH AS THE UPPER YUKON
VALLEY EARLY THU. MODELS ARE NOT PICKING UP POCKETS OFF COLD AIR VERY
WELL WHICH CONTINUE TO HOLD OVER THE COPPER RIVER BASIN...SUSITNA
VALLEY...AND KUSKOKWIM VALLEY. EXPECT SNOW WILL BE SLOW TO CHANGE
OVER IN THESE AREAS. COLD ADVECTION ON BACKSIDE OF LOW MOVING THROUGH
THE MAIN SPREADS TO OVER THE EASTERN BERING SEA/WEST ALASKA RANGE THU
MORNING. WITH PASSAGE OF COLD FRONT...SOME CLEARING IS EXPECTED OVER
SW ALASKA THU. BY FRI MORNING...COLD AIR PUSHES AS FAR FAR SOUTH AS
THE BRISTOL BAY COAST...ANCHORAGE BOWL...CENTRAL COPPER RIVER BASIN.
THICKNESS VALUES ARE ONCE AGAIN ON THE RISE THROUGH THE WEEKEND AS
CUT-OFF SOUTH OF THE AK PEN MOVES NORTH AND SOUTH FLOW KICKS IN.

.AER...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 3A,3B,3C,4,5A,5B,6A,6B,8,12A,12A1,12B,13,14,AND 15.
FIRE WEATHER...NONE.

RMC SEP 04

Event by event

1 heavy snow. Local standard time, as filed.

Heavy Snow, Susitna Valley

When: September 29, 9:00 PM AST to September 30, 1:05 PM AST
Where: Susitna Valley forecast zone
Reported by: AWOS,ASOS,MESONET,ETC

A low moved from the southwest Gulf of Alaska into the Susitna Valley Late Wednesday into Thursday. This resulted in a strong push of moisture into the Susitna Valley over the colder air in the northern Susitna Valley. The Orographic lift typical of the "bench" near Chulitna resulted in heavy snow beginning late Wednesday night that continued until the snow changed over to rain Thursday afternoon. The cooperative observer reported that 12 inches of snow fell from 10 p.m. Wednesday night through Thursday morning.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Alaska in 2004 Every state in 2004 This day in weather history Warnings in Alaska, September 2004

Sources

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: 5417299.