Three to five inches of rain caused a significant 100+ year flash flood over the higher terrain of northeast Okanogan County on the evening of July 12. The weather pattern showed an upper level high pressure ridge over the western United States with monsoonal moisture extending northward into Washington.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 OTX wrote it up.
Three to five inches of rain caused a significant 100+ year flash flood over the higher terrain of northeast Okanogan County on the evening of July 12. The weather pattern showed an upper level high pressure ridge over the western United States with monsoonal moisture extending northward into Washington. Early in the evening, a band of northward-moving thunderstorms developed over northeast Okanogan County which continued to re-generate on its southern flank for 2-3 hours. Excessive rainfall and flash flooding were the result. The worst flash flooding occurred along a stretch of the Oroville-Chesaw Road. Three separate drainages contributed to the event: an unnamed creek that flows from Fletcher Mountain, Dry Creek and Tonasket Creek. A "wall of mud" blasted across Oroville-Chesaw Road where the unnamed creek crosses under the road (one mile east of its intersection with Molson Road), washing a van into the raging creek around 915 PM PDT. A 56-year old grandmother in the van pushed her granddaughter out in time for the granddaughter to escape injury. The grandmother could not escape the van and was presumably washed away inside it. The grandmother is missing and assumed dead (direct). Her body was never found in the deep mud. Significant damage occurred in this rural part of Okanogan County. Eden Valley Road was completely washed out. A bridge along Dry Gulch Road was washed out. Damage to other county roads in the vicinity was extensive. At the Eden Valley Guest Ranch, fences and other farm implements were washed away. A grain bin was washed 30 feet away from its foundation. Water rose high enough to cause damage to parked vehicles. Mud filled another grain bin, a basement, garage, shop and barn. Much of the damage in the area was not covered by flood insurance.
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 Spokane, WA wrote its last area forecast discussion before the first event at Jul 12, 1:30 PM PST, 5 hours 55 minutes earlier.
EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 PM PDT THU JUL 12 2001 A COOLER MORE UNSETTLED PATTERN HAS SET UP OVER THE INLAND NORTHWEST. THE WEAK BROAD TROUGH REMAINS OFF THE WASHINGTON COAST THIS AFTERNOON WITH SOUTHWESTERLY FLOW OVER WASHINGTON AND IDAHO. WITH TEMPERATURES IN THE 80S AND DEWPOINTS IN THE 50S THE ATMOSPHERE HAS BECOME UNSTABLE THIS AFTERNOON AND A FEW SHOWERS AND THUNDERSTORMS ARE BEGINNING TO DEVELOP AT THIS TIME. THE AREA OF MOST INSTABILITY IS OVER OUR SOUTHEASTERN ZONES AND STRONGEST AND MOST NUMEROUS STORMS WILL BE IN THIS REGION THROUGH THE NIGHT...BUT ALL AREAS MAY SEE SHOWERS AND A THUNDERSTORM OR TWO. AS THIS WAVE PASSES OUT OF THE AREA TONIGHT THE CONVECTIVE ACTIVITY SHOULD DIE DOWN. ANOTHER WEAKER WAVE WILL PASS THROUGH THE EASTERN ZONES ON FRIDAY FOR A CHANCE OF SHOWERS AND THUNDERSTORMS...BUT THE COLUMBIA BASIN AND EAST SLOPES SHOULD REMAIN DRY. ON SATURDAY THE ATMOSPHERE BECOMES A BIT MORE STABLE WITH ONLY A SLIGHT CHANCE OF PRECIPITATION...MAINLY EASTERN ZONES. THERE SHOULD BE LITTLE CHANGE IN TEMPERATURES OVER THE NEXT FEW DAYS WITH BOTH HIGHS AND LOWS NEAR NORMAL. CC .EXTENDED...MODELS CONVERGED MAINLY ON A MORE OPEN TROUGH SOLUTION THROUGH THE NORTHWEST...WITH ECMWF LOOKING STRONGEST. SHORTWAVES ROTATING SOUTHEAST ALONG THE WEST SIDE OF THE TROUGH AFFECT THE REGION SUNDAY/MONDAY AND AGAIN WEDNESDAY. RIDGING ACROSS SOUTH CENTRAL PLAINS SLOWS THE EASTWARD PROGRESS MIDWEEK. COLDEST AIR ALOFT REMAINS IN CANADA WITH BEST INSTABILITY HELD ALOFT AND ONLY TO AROUND 700 MB ACROSS THE NORTHEAST. WHILE KEEPING UNSETTLED SHOWERY CONDITIONS...THUNDER MENTION WILL BE LIMITED TO MOUNTAIN ZONES NORTHEAST THROUGH CENTRAL PANHANDLE. SLIGHTLY COOLER THAN NORMAL TEMPERATURES AND SLIGHTLY WARMER WEDNESDAY/THURSDAY. JR ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 058/083/058/081 3221 CQV 055/087/055/086 3222 SPT 050/080/051/079 4332 COE 055/083/054/082 3221 WWP 053/078/054/076 4332 LWS 066/089/065/089 3332 PUW 058/083/057/081 3221 EAT 066/089/065/087 2000 MWH 062/088/061/088 2000 .GEG...NONE.
The national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
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 |
|---|---|---|---|---|---|
| Flash Flood, Okanogan | 2001-07-12 | 56 | Female | Vehicle/Towed Trailer | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2001Every state in 2001This day in weather historyWarnings in Washington, July 2001
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: 5259482.