A band of mid level moisture moving through the region helped isolated afternoon and evening showers develop over a few days.
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 TFX wrote it up.
A band of mid level moisture moving through the region helped isolated afternoon and evening showers develop over a few days.
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 Aug 17, 2:43 AM MST, 1 hour 17 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 343 AM MDT Sat Aug 17 2013 .DISCUSSION... Saturday through Monday...Warm and dry conditions will continue to dominate the short term period as a Ridge of high pressure continues to reside over the four corners region of the Southwestern United States. A shortwave disturbance will flatten the ridge over the area and produce a more zonal flow pattern across the region. This shortwave and associated moisture will bring more moisture and slightly cooler temperatures to the area. However most of the moisture will remain high in the atmosphere with only a slight increase to precipitation chances over the weekend. Temperatures will be cooler than the previous days...however only by 10 degrees or so and still above seasonal averages by 5 degrees or more. This will allow for another day of near critical fire weather...with slightly higher RH values and a better chance of windy conditions. No highlites have been issued for fire weather concerns at this point. Further details can be found in the fire weather discussion. Suk Monday night through Saturday...A flat upper level high pressure ridge will be over the zones Monday night with the jet to the north. A weak shortwave will cross the zones Tuesday but the airmass will remain very dry and most convection should be north of the border. The ridge will sharpen Wednesday and upper level flow over the zones will switch to the southwest. This will allow moisture to move up underneath the ridge and bring some instability across mainly the southwest zones. Moisture will continue to move into the zones from the southwest on Thursday and the airmass will become increasingly unstable with isolated to scattered afternoon thunderstorms spreading across the region. A low pressure trof to the west will be approaching the West Coast Thursday night and move on shore by morning. A shortwave ahead of this trof will keep convection in the forecast through the night. The shortwave will move east of the zones by Friday although the flow aloft will remain unsettled. The airmass will again become unstable in the afternoon along with a chance of thunderstorms through Saturday. Zelzer && .AVIATION... UPDATED 0440Z. Current satellite imagery shows weak upper level trough stretching from southeast Alberta to the ID Panhandle moving faster and bringing greater cloud coverage than forecast models had been indicating. Not a big impact given that ceilings should remain above 10000 ft, but enough to adjust cloud timing and coverage in latest KCTB/KGTF/KHVR Tafs. Have also added mention of VCTS vcnty KCTB tomorrow aftn. Elsewhere, smoke from wildland fires in the western portion of Montana and from eastern Idaho will keep thin layers of high clouds over central and southwest MT overnight and much of tomorrow. Surface winds remaining light through the overnight hours. Waranauskas && .FIRE WEATHER... UPDATED 0945Z. Near critical fire weather conditions are expected again Saturday afternoon over Southwest and South Central Montana. Afternoon humidity will drop to low values of 10 to 15 percent across the lower elevations with slightly higher values across the higher terrain. A weak mid level boundary passing through the region Saturday afternoon could bring somewhat breezy westerly winds, mainly along and near the Continental Divide. Not expecting a major wind shift or strong winds from this boundaries. Breezy winds combined with low humidity could result in critical fire weather conditions Saturday afternoon. Confidence remains high for humidity less than 20 percent and near 50 percent for winds over 15 mph Saturday. As a result, will hold off on fire weather highlights at this time. && .PRELIMINARY POINT TEMPS/POPS... GTF 90 57 88 54 / 10 30 10 10 CTB 86 53 84 50 / 10 10 0 0 HLN 90 58 89 56 / 20 20 10 10 BZN 91 51 89 49 / 10 20 10 10 WEY 84 41 82 38 / 10 10 20 10 DLN 88 50 87 49 / 10 10 10 10 HVR 89 59 87 56 / 10 30 20 0 LWT 87 55 84 53 / 10 30 20 10 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Suk LONG TERM...ZELZER AVIATION...ZELZER weather.gov/greatfalls
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 500 AM MDT SAT AUG 17 2013 MTZ008-012-014-015-048>050-052>055-181100- BEAVERHEAD-CASCADE-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON- SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN- JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 500 AM MDT SAT AUG 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT LOW AFTERNOON HUMIDITY AND BREEZY WESTERLY WINDS WILL RESULT IN AN INCREASED FIRE DANGER ON SATURDAY. CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE DURING THE AFTERNOON AND EARLY EVENING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ009>011-013-044>047-051-181100- NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-CHOUTEAU-TOOLE- LIBERTY-EASTERN PONDERA-BLAINE-FERGUS- 500 AM MDT SAT AUG 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA AND NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
2 high wind. Local standard time, as filed.
Strong winds measuring 50KT (58MPH) were reported 13 miles WSW of St Mary, MT at the Logan Pass visitors center.
Strong winds measuring 60KT (69MPH) were reported 13 miles WSW of St Mary, MT at the Logan Pass visitors center.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2013Every state in 2013This day in weather historyWarnings in Montana, August 2013
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: 474892, 474893.