1 flash flood, as filed by the National Weather Service.
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 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 Great Falls, MT wrote its last area forecast discussion before the first event at Jul 15, 2:00 PM MST, 2 hours earlier.
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 300 PM MDT SUN JUL 15 2001 SYNOPSIS...THUNDERSTORMS EXPECTED ACROSS MUCH OF CWA THIS AFTERNOON AND EVENING AS DISTURBANCES PUSH NORTHEAST. POTENTIAL EXISTS FOR SOME SEVERE THUNDERSTORMS AND A WATCH IS IN EFFECT FOR JUDITH BASIN AND FERGUS COUNTIES. COOLER TEMPERATURES AND SCATTERED AFTERNOON THUNDERSTORMS EXPECTED MONDAY AS A LOW PRESSURE TROUGH BEGINS WORKING INLAND. COOLER TEMPERATURES PERSIST INTO TUESDAY. DISCUSSION...ACTIVITY PICKING UP ACROSS CWA WITH ONE LINE OF THUNDERSTORMS MOVING INTO THE CENTRAL CWA...ANOTHER AREA APPROACHING THE SOUTHWEST CWA...AND SOME ISOLATED STORMS OVER THE NORTHEAST CWA. ALL ARE ASSOCIATED WITH A SHORT WAVE THAT IS PUSHING THROUGH COUPLED SOME MODERATELY HIGH INSTABILITY AND A MOIST AIR MASS. THE 18Z MESOETA SHOWS A LINE OF ENERGY EXTENDING FROM THE NORTHERN ROCKIES TO SOUTHEAST MT AT 00Z WITH A TRAIN OF DISTURBANCES WORKING UP INTO CENTRAL AND NORTHERN CWA THIS EVENING. BEST STEERING WINDS FOUND ACROSS SOUTH...STORMS ACROSS NORTHERN CWA MAY BE SLOW MOVING AND CREATE AREAS OF HEAVY RAIN. TRAIN OF DISTURBANCES OVER SOUTHWEST AND CENTRAL CWA COULD ALSO RESULT IN SOME SIGNIFICANT ACCUMULATED RAINFALL. EASTERN CWA WITH HIGHEST INSTABILITIES...MOISTURE AND WIND SHEAR HAS A CHANCE OF SEVERE THUNDERSTORMS. TROUGH THEN PUSHES IN ALONG WA/CANADA BORDER MONDAY. SEVERAL EMBEDDED DISTURBANCE WITH THIS AS WELL...HOWEVER THEY SEEM TO BE STAYING CLOSER TO THE LOW... SWEEPING OVER AREAS WEST OF THE DIVIDE AND JUST BRUSHING THE NORTHWEST CWA FOR ISOLATED TO SCATTERED SHOWERS. HAVE DROPPED TEMPS MONDAY AND TUESDAY A FEW DEGREES AS TROUGH BRINGS IN COOLER AIR. EXTENDED...MRF HAS UPPER TROUGH OVER THE PACIFIC NW ROTATING INTO ALBERTA ON DAY3. ECMWF MODEL NOT AS STRONG AS THE MRF WITH THE PORTION OF THE UPPER TROUGH MOVING OVER MT. BY DAY 5...MRF HAS WEAK UPPER RIDGE BUILDING...WHILE SHORT WAVE TROF SCOOTS ACROSS SOUTHERN CANADA. MRF/ECMWF HAS WEAK TROUGH HANGING BACK TO THE WEST. DAY6 AND DAY7 SHOWS UPPER RIDGE BUILDING BACK OVER MT... WHILE KEEPING WEAK UPPER LOW OFF THE PACIFIC NORTHWEST COAST. IN SHORT...WED LOOKS COOL AND UNSETTLED WITH A RETURN TO WARM TEMPERATURES BY FRIDAY. WILLIAMSON DC CCF NUMBERS GTF EE 051 079 049 077 049 034231 CTB EE 049 077 047 075 047 036211 HLN TE 054 079 051 077 052 032432 BZN TE 049 082 047 079 049 033432 WEY TE 043 078 045 075 046 032432 DLN TE 048 078 045 076 046 032433 HVR EE 055 085 053 081 050 037231 LWT TE 052 081 050 076 048 037342
The national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
Actual event location is Magpie Creek at the point it empties into the north end of Canyon Ferry Lake (location is approximately 20 E of Helena)...Flowing water and mud washed out road at event location...No other damage reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2001Every state in 2001This day in weather historyWarnings in Montana, 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: 5260927.