Thunderstorm Wind, Idaho
- When
- July 20, 5:05 PM MST
- Where
- Idaho County, Cottonwood
- Reported by
- TRAINED SPOTTER
- Coordinates
- 45.844, -115.467 (the zone’s center; the record gives no point)
Damaging Wind in Idaho, July 20, 2001
0 inch and thunderstorm winds to 65 mph. Large shed was moved off its foundation, two trees blown over, and part of roof blown off.
Where it happened
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.
- 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
- 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 happened
The episode as NWS MSO wrote it up.
Hail between 0.75-1.0 inch and thunderstorm winds to 65 mph. Large shed was moved off its foundation, two trees blown over, and part of roof blown off. Spotter reported one inch of rain fell in 20 minutes.
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 Missoula, MT wrote its last area forecast discussion before the first event at Jul 20, 1:00 PM MST, 4 hours 5 minutes earlier.
Area forecast discussion, Jul 20, 1:00 PM MST, 4 hours 5 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 200 PM MDT FRI JUL 20 2001 .SHORT TERM...WV SHOWS A LONG WAVE TROF OVER THE PACIFIC NORTHWEST WITH NUMBER OF S/WS ROTATING AROUND WITH THE FLOW. OF PARTICULAR INTEREST...IS A STRONG WAVE OVER CENTRAL OREGON WHICH IS PROGGED TO LIFT NORTHEAST BY SATURDAY MORNING. MESO IS VERY CONSISTENT WITH EARLIER RUNS THIS FEATURE. THIS AFTERNOONS CONVECTIVE ACTIVITY WILL CARRY INTO THE OVERNIGHT PERIOD WITH NEGATIVE LIS UNTIL AFTER MIDNIGHT. ADDITIONALLY..A FEW WEAK WAVES IN THE FLOW AND UPPER DIFFLUENCE WILL SUPPORT THIS ACTIVITY. ON SATURDAY...THE TROF AXIS REMAINS OVER EAST WASHINGTON AND OREGON WITH LIS OVER THE FORECAST AREA BETWEEN -2 AND -4. ANOTHER ACTIVE NIGHT AS THE MAIN S/W SHIFTS EAST. EARLY SUNDAY MORNING...THE UPPER FLOW SHIFTS WEST WITH CYCLONIC CURVATURE REMAINING OVER THE NORTHWEST ZONES. WILL GO WITH CHANCE POPS OVER THESE ZONES. SLIGHT CHANCE POPS FOR THE REST OF THE CWA AS S/W RIDGING BUILDS DURING THE DAY. STOLL .EXTENDED...NO REAL CHANGES TO FORECAST TREND. GRADUAL WARMING AND DRYING WILL BE ADVERTISED OVER THE COURSE OF THE FORECAST PERIOD. THE UPPER LEVEL TROUGH BEGINS TO FILL AS IT DRIFT EAST OVER THE NORTHERN ROCKIES REGION DAY3/4 FOR CHANCE POPS. THEN MODELS SUGGEST THAT THE UPPER FLOW BECOMES MORE ZONAL WITH RISING HEIGHTS FOR DECREASING POPS DAY5. BY DAY6/7...MODELS DIVERGE WITH ECMWF7 SHOWING RIDGING AND MRF INDICATING A TROUGH OVER THE REGION. WILL LEAN TOWARD WARM/DRIER ECMWF SOLUTION. MSJ .MSO...FLASH FLOOD WATCH FOR SOUTHERN RAVALLI COUNTY UNTIL MIDNIGHT.
In the hours before
Special weather statement, Jul 20, 12:30 PM MST, 4 hours 35 minutes before
IDZ005>010-MTZ004>007-043-210600- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MISSOULA MT 130 PM MDT FRI JUL 20 2001 ...STRONG THUNDERSTORMS WITH HEAVY RAIN AND HAIL POSSIBLE THIS AFTERNOON AND TONIGHT... DEVELOPING THUNDERSTORMS IN CENTRAL IDAHO THIS AFTERNOON AND MORE ACTIVITY IN WEST CENTRAL MONTANA WILL LIKELY PRODUCE LOCAL DOWNPOURS INTO THIS EVENING DUE TO HIGH ATMOSPHERIC MOISTURE CONTENT. HAIL UP TO HALF AN INCH IN DIAMETER IS ALSO POSSIBLE WITH THESE STORMS ALONG WITH WIND GUSTS TO 40 MPH AND FREQUENT LIGHTNING. PEOPLE ACROSS CENTRAL IDAHO AND WEST CENTRAL MONTANA ARE URGED TO TUNE IN TO LOCAL WEATHER INFORMATION SOURCES FOR THE LATEST INFORMATION AND STATEMENTS ON THIS DEVELOPING WEATHER SITUATION. THUNDERSTORMS ARE EXPECTED TO DIMINISH AFTER MIDNIGHT TONIGHT. HOWEVER...MORE STRONG THUNDERSTORM ACTIVITY IS ANTICIPATED SATURDAY.
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 thunderstorm wind. Local standard time, as filed.
What these are
- Thunderstorm Wind
- Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Heat in Wisconsin, July 20, 2001
- Tornadoes and Hail in Montana, July 20, 2001
- Hail and Damaging Winds in North Dakota, July 20, 2001
- Damaging Wind and Lightning Strike in Georgia, July 20, 2001
- Hail in South Dakota, July 20, 2001
- Flash Flooding in Indiana, July 20, 2001
- Flash Flooding in Montana, July 20, 2001
- Hail and Damaging Wind in Nebraska, July 20, 2001
- High Surf in Hawaii, July 20 to 23, 2001
- Damaging Wind in North Dakota, July 20, 2001
- Damaging Wind in North Dakota, July 20, 2001
- Hail in North Dakota, July 20, 2001
More
Every storm in Idaho in 2001Every state in 2001This day in weather historyWarnings in Idaho, July 2001
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: 5257199.