Surface low pressure diving southeastward across North-central Montana and Central Montana resulted in strong wrap around northwesterly winds across the eastern plains April 13. The strongest gusts were across Toole co and vicinity as well as in Fergus co.
Every event with a place to put it; 5 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 TFX wrote it up.
Surface low pressure diving southeastward across North-central Montana and Central Montana resulted in strong wrap around northwesterly winds across the eastern plains April 13. The strongest gusts were across Toole co and vicinity as well as in Fergus co.
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 Apr 12, 7:48 PM MST, 1 hour 12 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Great Falls MT 848 PM MDT Sat Apr 12 2025 .KEY MESSAGES... - Scattered rain showers continue through this evening with a few thunderstorms expected over Southwest Montana. - A fast moving weather system will bring a period of wet accumulating snow and gusty northwesterly winds to the Central Montana island ranges tonight into Sunday. - Dry and milder conditions return Monday and Tuesday before a more active and cooler weather pattern re-develops mid to late next week. && .UPDATE... No significant updates needed to the tonight/Saturday portion of the forecast. Main adjustment was to decrease the chance for additional showers and isolated thunderstorms for the remainder of this evening, as the line of showers and storms has mostly moved into Eastern Montana. Radar echoes are currently detecting the main push of rain and snow along and behind the cold front just north of the Canadian border. This is generally on track with the forecast timing, which moves the area of precipitation into mainly North Central and Central Montana overnight and east out of the area by late Saturday afternoon. No adjustments needed either to the Winter Weather Advisories and the High Wind Warning. -Coulston && .DISCUSSION... /Issued 528 PM MDT Sat Apr 12 2025/ - Meteorological Overview: A moist southwesterly flow aloft is maintaining scattered to broken mid- and higher level clouds over the Northern Rockies and scattered showers over central and southwestern areas. The combination of diurnal instability and forcing from an approaching trough will continue to initiate a few thunderstorms through the late afternoon hours, mostly for southwestern locations east of I15 and south of I90. Not expecting a whole lot out this storm activity aside from gusty winds up to 40 mph, some rain/snow/graupel, and a few lightning strikes. Then a low pressure system races southeastward through Central/North- central Montana and brings a quick round of wet snow and gusty northwesterly winds tonight into Sunday. H700/H500 temperatures quickly fall to around -15C/-30C while a 40 to 50 kt northwesterly winds wrap around the the mid- level low. While this is a favorable setup for snow over and near the central MT island ranges, its short residence time will prevent optimal snowfall totals from being realized. Regardless, the combination of the winds and snow should exert short term impacts tonight and Sunday morning. Ensembles favor weak ridging to return Monday and Tuesday for warming temperatures and dry conditions. This boosts most lower elevation high temperatures into the 60s and 70s by Tuesday before unsettled conditions return once again for the second half of the week. Ensembles remain in good agreement with a broad, splitting trough moving over the western CONUS to close out the workweek; however, there are conflicting solutions on how deep the northern extent of the trough digs and whether or not it splits and sends a significant portion of moisture and energy southward into the Great Basin. - RCG - Forecast Confidence & Scenarios: Snow and winds tonight into Sunday... Probabilistic guidance continues to favor higher end probabilities (80%+) for 2 inches of snow or more in the Glacier National Park area and over the Little Belts/Bears Paw Mountains. In fact, the probabilities for 6 inches of snow or more have increased to over 70% over the Little Belts. While the dynamics explained in the paragraphs above support this, the speed of the system and the downward trend of the deterministic don't. I decided to place winter weather advisories in areas with the highest confidence for impactful snowfall persisting for at least 4 to 6 hours, resulting in the Little Belts and the Bears Paws going in the advisory while leaving the Glacier National Park area out for now. The lower elevations of Judith Basin County were also added due to the Armington Junction area lying within the area of heaviest snowfall potential. The combination of snow and northwesterly winds gusting over 40 mph at times may cause short term impacts including slushy/slippery roads, significantly reduced visibility, and isolated power outages. The heaviest snow should fall late tonight into Sunday morning. The strongest winds are expected over the Sweet Grass Hills and for areas east of a Great Falls to Havre line. A high wind warning was sent out for central and eastern Fergus County where there is a 70to 90% chance for wind gusts over 55 mph. - RCG A return to unsettled conditions for the second half of next week... Recent ensembles have started to latch on to a colder and wetter solution for the second half of next week, but the 'splitting trough' set up vastly increases uncertainty, especially 5 to 6 days away from the said event. - RCG && .AVIATION... 13/00Z TAF Period Scattered rain showers will continue to push through and east of a KEKS, to KBZN, to KLWT line through 03z Sunday; with these showers predominately producing low-VFR CIGS, although temporary MVFR CIGS are possible beneath the heaviest showers. Focus and concern then shift northwest to North Central and Central Montana beyond 04z Sunday as a fast moving disturbance moves over Northern Montana through Sunday morning. VFR conditions early this evening will degrade to IFR/MVFR at the KCTB, KHVR, KGTF, and KLWT terminals as precipitation spreads southeast behind the disturbance, with CIGS lowering rapidly and remaining at these IFR/MVFR conditions for 6 to 9 hours. Lowest VIS due to falling and blowing snow over this timeframe is expected at the KLWT terminal where VIS has a 30% chance of falling to LIFR, mainly between 09-18z Sunday. Mountain obscuration will persist through 18-21z Sunday before gradually improving thereafter. - Moldan Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 33 49 29 59 / 80 60 0 0 CTB 29 46 26 59 / 90 30 0 0 HLN 34 50 30 61 / 40 40 0 0 BZN 27 47 23 57 / 40 30 0 0 WYS 17 43 14 54 / 30 10 0 0 DLN 25 48 25 60 / 10 0 0 0 HVR 32 50 26 57 / 80 80 0 0 LWT 29 42 26 51 / 70 80 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to 9 AM MDT Sunday for Bears Paw Mountains and Southern Blaine-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Snowy and Judith Mountains. High Wind Warning from 3 AM to 3 PM MDT Sunday for Fergus County below 4500ft-Snowy and Judith Mountains. && http://www.weather.gov/greatfalls
The national radar mosaic for the moment the first event began.
4 high wind, 1 winter weather. Local standard time, as filed.
Snotel equipment at Onion Park estimated 9 inches new snow. This was an isolated instance of snow of 9 inches.
Two sensors measured gusts in excess of 58 mph, including the DOT sensor at Inverness, which measured a 62 mph gust.
Multiple mesonets measures gusts in excess of 58 mph, including mesonet sensor GW3546 Whitlash 7 South which measured a 98 mph gap wind following cold front passage.
Mesonet station MTM90 Big Sandy SW measured a 61 mph gust.
Multiple sensors in eastern and southeastern Fergus county in lee of terrain measured strong winds and wind gusts, including MDT sensor Beacon Hill, which measured a peak gust of 68 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2025Every state in 2025This day in weather historyWarnings in Montana, April 2025
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: 1257909, 1257895, 1257902, 1257876, 1257882.