Flood, Upr Tanana Vly Fortymile
- When
- July 10, 6:00 PM AKST to July 12, 6:00 AM AKST
- Where
- Upr Tanana Vly Fortymile County, Chicken
- Cause
- Heavy Rain
- Deaths
- 0 direct, 1 indirect
- Reported by
- Department of Highways
- Coordinates
- 64.070, -141.950
Flood in Alaska, July 10 to 12, 2010
An area of low pressure moved out of the Gulf of Alaska and to the Alaska-Yukon border on the 11th. As the low moved southeast and into the southern Yukon moisture wrapped around the low and produced heavy rainfall across the Fortymile County.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 1
- 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 happened
The episode as NWS AFG wrote it up.
An area of low pressure moved out of the Gulf of Alaska and to the Alaska-Yukon border on the 11th. As the low moved southeast and into the southern Yukon moisture wrapped around the low and produced heavy rainfall across the Fortymile County. Rainfall amounts of 3.2 inches were observed at Chicken and O'Brien Creek, which is over one quarter of the average annual rainfall in just a little over one day.|The heavy rain caused the Fortymile River at the Taylor Highway bridge to rise 22 feet and the river crested at 94.5 feet. This surpassed the previous record of 92.4 ft on May 3, 1979 and may have surpassed the all-time record observed in 1964. Unfortunately, there are no records of the peak crest in 1964. The crest observed on O'Brien Creek which is a tributary of the Fortymile River was the highest on record. Due to the areal extent and distribution of the rainfall over the region and the resulting flood damage, this suggests that the flood was likely one of the highest floods on record for the Fortymile River basin and its tributaries. |The heavy rain washed out parts of the Taylor Highway and stranded 20 to 30 people. Seven portions of the road were completely washed out for several hundred feet, and multiple mud slides took out parts of the road. A U.S Customs Agent was missing and presumed dead after searchers found his U.S. Government Vehicle in O'Brien Creek. The Alaska State Troopers stated the driver evidently failed to negotiate a corner and his vehicle went down a 200-foot embankment and ended up i the creek.
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 Fairbanks, AK wrote its last area forecast discussion before the first event at Jul 10, 2:21 PM AKST, 3 hours 39 minutes earlier.
Area forecast discussion, Jul 10, 2:21 PM AKST, 3 hours 39 minutes before
NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 321 PM AKDT SAT JUL 10 2010 .DISCUSSION... FAIRLY DYNAMIC PATTERN DEVELOPING FOR NORTHERN ALASKA. A DEEP LOW ALOFT VCNTY KODIAK ISLAND MOVES ENEWD NEXT COUPLE OF DAYS..TO BE OVER NORTHERN BC BY MON MORNING. A TRAILING LOW WILL BE JUST EAST OF KODIAK TUE. MEANWHILE...COLD LOW ALOFT JUST THIS SIDE OF THE POLE WILL DRIFT SOUTH NEXT SEVERAL DAYS...WITH CRCLN ASSOCIATED WITH THIS FEATURE COVERING MOST OF THE CWA BY LATE TUE. MODELS..NO DOUBT CORRECTLY..DEEP THE LOW CENTER NORTH OF 75N...THOUGH REASONABLY COLD AIR FOR MID-JULY SPILLS SOUTH INTO THE NORTH SLOPE AND WESTERN BROOKS RANGE BY LATE TUE. THE MID-RANGE LOOKS FEATURE MORE WLY FLOW ALOFT...AND IN MOST AREAS LOW LEVEL TEMPS BACK UP TOWARD NORMAL BY NEXT WEEKEND. NORTH SLOPE...FOG EXPECTED TO RETURN TONIGHT. A COUPLE OF FRONTS WILL PASS BY NEXT COUPLE OF DAYS...WITH 850 MB TEMPS FALL BELOW ZERO OVER NEARLY ALL THE SLOPE BY MONDAY. FLURRIES BECOME POSSIBLE...THOUGH MOST AREAS THE COLD AIR WILL COME IN AFTER THE PCPN ENDS. STILL...NORTH OF 70N...FLURRIES OUT OF THE STRATUS IS POSSIBLE. WEST COAST....MARIE STRATUS/FOG HAS BEEN INCREASING TODAY OVER THE SOUTHERN CHUKCHI SEA AND WE EXPECT THIS TO BE ADVECTED EASTWARD INTO KOTZEBUE SOUND IN THE LOW LEVEL WESTERLY FLOW. MEANWHILE...THUNDER WILL NOT AS CONCENTRATED THIS EVENING AS FRIDAY..BUT ISOLATED STORMS INLAND. COLD FRONT MOVING SOUTHWARD SUN/SUN NIGHT MOVING TOO QUICK TO BRING TOO MUCH RAIN BUT WILL BRING WINDS UP THROUGH THE BERING STRAIT. INTERIOR...COPIOUS RAINFALL SEEMS LIKELY IN THE UPPER TANANA VALLEY TONIGHT AND TOMORROW AS LOW ALOFT PLOWS RIGHT THRU THE NE GULF OF ALASKA AND INTO SRN BC. FOLLOWING THE LOW THERE IS NO COLD AIR TO ADVECT IN...SO REMAINING WARM AND PROBABLY UNSTABLE CENTRAL INTERIOR UNTIL COOLER AIR ARRIVES FROM THE NORTHWEST EARLY NEXT WEEK. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... RAIN FROM THE CENTRAL INTERIOR WWD LIKELY ESPECIALLY WIDESPREAD ENOUGH TO DAMPEN FIRES THAT HAVE BEEN REINVIGORATED IN THE HOT WEATHER. && .HYDROLOGY... NONE NOW. IF NAM PCPN COMES CLOSE TO VERIFYING IN THE UPPER TANANA VALLEY...COMBINED WITH HIGH FREEZING LEVELS...THERE MAY BE SOME ISSUES EARLY NEXT WEEK. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ210-PKZ215-PKZ220-PKZ225. && RT JUL 10
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 flood. Local standard time, as filed.
The people who died
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flood, Upr Tanana Vly Fortymile | 2010-07-12 | 56 | Male | Unknown | Indirect |
What these are
- Flood
- Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Lightning Strike in Arizona, July 10, 2010
- Flash Flooding and Flood in Massachusetts, July 10, 2010
- Tornado and Flash Flood in Minnesota, July 10, 2010
- Flash Flood and Flood in Pennsylvania, July 10, 2010
- Lightning Strike in Louisiana, July 10, 2010
- Flash Flooding and Hail in Kansas, July 10, 2010
- Hail and Damaging Winds in Nebraska, July 10, 2010
- Flash Flooding and Hail in South Dakota, July 10, 2010
- Hail and Damaging Winds in Wisconsin, July 10, 2010
- Tornadoes and Hail in Minnesota, July 10, 2010
- Lightning Strike in Colorado, July 10, 2010
- Flash Flood and Hail in South Dakota, July 10, 2010
More
Every storm in Alaska in 2010Every state in 2010This day in weather historyWarnings in Alaska, July 2010
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: 236250.