Heavy Rain, Chouteau
- When
- August 21, 9:56 AM MST to August 26, 9:56 AM MST
- Where
- Chouteau County, 6.93 mi S of Shonkin
- Reported by
- COOP Observer
- Coordinates
- 47.530, -110.580
Heavy rain, measuring over 8.34 inches storm total, was reported.
Widespread and at times moderate to heavy rainfall affected North-Central Montana as a broad, potent low pressure system with plenty of moisture and energy moved east over the Northern Rockies. Periods of rain and isolated thunderstorms also affected the region.
Every event with a place to put it. 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 TFX wrote it up.
Widespread and at times moderate to heavy rainfall affected North-Central Montana as a broad, potent low pressure system with plenty of moisture and energy moved east over the Northern Rockies. Periods of rain and isolated thunderstorms also affected the region. Total rainfall amounts generally ranged from 1 to 2 inches over North-Central Montana with only 0.25 to 0.75 inches across Southwest Montana.
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 21, 8:41 AM MST, 1 hour 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 941 AM MDT Thu Aug 21 2014 .UPDATE... A weather disturbance aloft will be moving through the forecast area today and expect showers and a few thunderstorms ahead of it. Have left the high chances of precipitation in the forecast but have changed wording from rain showers likely to occasional rain showers as do not expect precipitation to last any more than a couple of hours at any one location. Have removed the mention of thunderstorms over the northwest forecast zones as do not see enough instability for thunderstorms. Behind the weather disturbance should see a little sunshine over western portions of southwest Montana this afternoon so have changed the sky forecast to reflect that. Generally left most high temperatures for today alone as some guidance was indicating warmer than currently forecast highs while other guidance was indicating cooler than currently forecast highs. Did raise highs for today at Great Falls and Havre slightly as had fairly high confidence in warmer temperatures. First glance at the this mornings NAM model run shows wet forecast for Friday through Saturday is on track. Blank && .AVIATION... UPDATED 1140Z. Broad upper level trough will remain over the Pacific Northwest and Northern Rocky Mountains through Friday morning. An associated Canadian cold front will continue to push south through the region with northerly surface winds prevailing through the period. Mid level moisture and low level upslope flow across North Central Montana will fuel scattered to numerous showers through the period. MVFR/IFR conditions will prevail over North Central Montana with VFR/MVFR conditions expected in Southwest Montana. Mountain obscurations will be widespread across the region. mpj && .PREV DISCUSSION... /ISSUED 540 AM MDT Thu Aug 21 2014/ Today through Saturday...An upper level low pressure system is slowly moving through the region...while a Canadian cold front has pushed southward through the CWA. The end result is scattered showers and isolated thunderstorms will continue to move through the region today. The precipitation has not been as widespread as previously thought over North Central MT so far. However...because humidities are so high...passing areas of precipitation are possible in most areas today. Thus pops remain high for today...even though overall QPF amounts will generally not be significant today...and a widespread all day rain is not expected either. The scattered precip continues tonight...again with high pops mainly for the event. On Friday...as the upper level trof comes close to Central MT...and a surface low develops over the Central Rockies...better upslope conditions are expected to develop over Central/North Central MT. Thus Friday night through Saturday...a band of widespread precipitation is expected to move through the region. The heaviest precip is expected over the Rocky Mountain Front and the Central Mountain ranges...with 1.50 to 2.50 inches possible in the mountains...at lower elevations 1.00 to 1.50 inches will be possible. Precip amounts will generally be less than 1.00 inches in Southwest MT. In terms of snow...the latest forecast models indicate snow levels should generally be above 7500 feet in the Glacier Park region. For now...I will leave the snow level down to the currently forecasted snow level near 6500 feet in case latter model runs bring down some colder air. In either case...snow accumulations of 1 to 2 inches will be possible at mountain peaks over Glacier Park Friday into Saturday. In terms of temperatures...well below normal temperatures are expected through Saturday. There is the potential that temperatures could be a few degrees cooler than forecasted highs should clouds/precip continue for several hours during the afternoon hours. Brusda Saturday Night through Thursday...A slow moving upper level trough will remain over the region through the weekend until at least Tuesday. Models are in decent agreement on details through Monday morning keeping a good likelihood of precipitation over the region Saturday evening then a chance of showers into Monday. Solutions once again diverge as a jet streak moves over the ridge in the Gulf of Alaska and moves south along the British Columbia coast. The ECMWF depicts a stronger and faster jet thereby digging further south along the west coast and elongating the trough southwestward while the GFS reinforces the trough over the Northern Rockies. GFS solution drives the trough eastward and places Montana into a generally dry northwest to westerly flow aloft. Meanwhile, the ECMWF develops a closed low over the west coast then drifts this feature eastward through the Great Basin and Wyoming with wrap around moisture being advected into Southwest Montana. At this time the GFS is more in keeping with previous forecasts so have continued to trend the forecast towards a warmer and dryer solution. mpj && .PRELIMINARY POINT TEMPS/POPS... GTF 66 51 64 52 / 70 60 90 100 CTB 61 49 58 49 / 70 60 90 90 HLN 68 53 65 52 / 60 60 90 100 BZN 69 51 67 49 / 50 60 80 80 WEY 60 45 61 40 / 40 40 50 40 DLN 69 48 65 45 / 40 50 80 70 HVR 69 55 66 55 / 70 50 80 80 LWT 62 50 60 51 / 70 60 80 90 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && weather.gov/greatfalls www.twitter.com/NWSGreatFalls www.facebook.com/NWSGreatFalls
The national radar mosaic for the moment the first event began.
27 heavy rain. Local standard time, as filed.
Heavy rain, measuring over 8.34 inches storm total, was reported.
Heavy rain, measuring 3.60 inches storm total, was reported.
Heavy rain, measuring 3.00 inches storm total, was reported.
Heavy rain, measuring 1.99 inches storm total, was reported.
Heavy rain, measuring 8.50 inches storm total, was reported.
Heavy rain, measuring 6.74 inches storm total, was reported.
Heavy rain, measuring 8.06 inches storm total, was reported.
Heavy rain, measuring 1.26 inches in 24 hours, was reported.
Heavy rain, measuring 1.40 inches in 24 hours, was reported.
Heavy rain, measuring 2.23 inches in 24 hours, was reported.
Heavy rain, measuring 8.22 inches storm total, was reported. Lowland flooding was seen.
Heavy rain, measuring 5.89 inches storm total, was reported.
Heavy rain, measuring 2.41 inches storm total, was reported.
Heavy rain, measuring 7.50 inches storm total, was reported.
Heavy rain, measuring 3.70 inches in 24 hours, was reported.
Heavy rain, measuring 4.60 inches in 18 hours, was reported.
Heavy rain, measuring over 1.05 inches in 12 hours, was reported.
Heavy rain, measuring 5.00 inches, was reported.
Heavy rain, measuring 1.00 inches in 12 hours, was reported.
Heavy rain, measuring 2.32 inches storm total, was reported.
Heavy rain, measuring 0.80 inches in 12 hours, was reported.
Heavy rain, measuring 2.69 inches in 18 hours, was reported.
Heavy rain, measuring 1.88 inches in 12 hours, was reported.
Heavy rain, measuring over 1.13 inches in 6 hours, was reported.
Heavy rain, measuring 2.00 inches in 11 hours, was reported.
Heavy rain, measuring over 1.00 inches in 1 hour, was reported.
Heavy rain, measuring over 2.00 inches in 24 hours, was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2014Every state in 2014This day in weather historyWarnings in Montana, August 2014
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: 536581, 536547, 536574, 536567, 536576, 536569, 536578, 536537, 536539, 536541, 536570, 536571, 536572, 536573, 536562, 536544, 536538, 536564, 536540, 536579, 536543, 536561, 536552, 536535, 536549, 536534, 536531.