Southwesterly flow aloft allowed for showers and thunderstorms to develop ahead of a quickly advancing cold front June 15 across Central and North-Central Montana. Not many severe-caliber gusts were observed.
Every event with a place to put it; 11 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.
Southwesterly flow aloft allowed for showers and thunderstorms to develop ahead of a quickly advancing cold front June 15 across Central and North-Central Montana. Not many severe-caliber gusts were observed. Additionally, deep mixing across Southwest Montana ahead of the front allowed for a few strong wind gusts there June 15. Along and behind the front, briefly strong non-convective wind gusts were observed along and adjacent to the Rocky Mountain Front.
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 Jun 15, 10:59 AM MST, 31 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 1159 AM MDT Sat Jun 15 2024 .SYNOPSIS... Showers and thunderstorms through this afternoon will give way to increasing winds, especially along the Rocky Mountain Front from this evening through Sunday morning. Temperatures cool to well below normal for the first half of next week, with widespread precipitation expected across much of the Northern Rockies. && .UPDATE... The primary focus of my update, this morning, is to adjust Probability of Precipitation (POP), generally, reducing POPs through midnight, tonight. Most adjustments were made across portions of north central and central Montana. Aside from this, no significant changes are made, at this time. - Fogleman && .AVIATION... 15/18Z TAF Period A cold front approaching North Central and Southwestern Montana from the west will continue to push into the area this afternoon, bringing a few showers and thunderstorms, along with gusty winds as it moves through, especially along and north of I-90. Watch for turbulence and gusty surface winds as these showers and storms move through, especially east of a line from KGTF to KLWT. Behind this front, winds will be on the increase across the plains, particularly at KCTB where mountain waves may result in 50 kt wind gusts this evening/overnight. Winds will gradually weaken across the area tomorrow. Ludwig Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 545 AM MDT Sat Jun 15 2024/ Today through Sunday...primary forecast concerns throughout the weekend are thunderstorms through early this evening, and the threat for High Winds from this afternoon through Sunday morning along the Rocky Mountain Front. Moist, southwest flow aloft combined with the approach of an upper level jet will lead to increasing coverage of showers and thunderstorms from the late morning through afternoon hours, most notably along the Continental Divide north of the Montana Hwy 200 corridor and across eastern portions of Central and North Central Montana. Nocturnal convection has been on-going most of the night across portions of the CWA, with this convection expected to increase in areal extent by the late morning with the approach of the aforementioned upper level jet. While most thunderstorms are likely to only produce gusty/erratic winds and/or small hail, a few of the storms across eastern portions of Fergus County could become severe and produce damaging wind gusts and large hail. Given this threat, the Storm Prediction Center as placed eastern portions of Fergus County under a Marginal Risk. The other primary concern throughout the period will be the threat for High Winds from the mid-afternoon hours today through Sunday morning along the Rocky Mountain Front. NBM probabilities for wind gusts in excess of 48kts for much of the East Glacier Park Region, Northern and Southern High Plains, and Eastern Glacier/Western Toole/Central Pondera continue to range from 80-90%, with favorable temperature profiles for mountain wave activity from this evening through early Sunday morning. Given these higher probabilities and the likelihood of mountain wave activity, have decided to upgrade the High Wind Watch for the Northern High Plains and Eastern Glacier/Western Toole/Central Pondera, along with adding the East Glacier Park Region and Southern High Plains. Travelers, especially those not used to the strong winds of the Rocky Mountain Front, will need to exercise caution from this afternoon through Sunday. Monday through Wednesday...Ensemble clusters continue to support longwave troughing moving over the Northern Rockies throughout the period, with the leading modes of uncertainty being the amplitude of the trough as it moves over the Great Basin on Monday and then the position and/or timing of the trough on Tuesday and Wednesday as it lifts northeast to over the High Plains. With respect to Monday's uncertainty, main impacts to North Central through Southwest Montana will be just how "cold" and wet conditions will be, with high temperature spreads across lower elevations between the 25th and 75th percentiles being approximately 10-15 degrees from the upper 40s/low 50s (25th percentile) to the upper 50s/low 60s. Additionally, precipitation spreads for Monday and t Monday night range from a couple hundreths over northern and southern portions of North Central and Southwest Montana (respectively) to 0.10"-0.25" elsewhere for the 25th percentiles, with 0.25" to just over 1" for the 75th percentiles. These large spread between temperatures and precipitation also leads to uncertainty with respect to the type of mountain precipitation, with NBM probabilities for 6" or more of snow from Monday through Tuesday generally ranging between 30-50%. Have continued the Winter Storm Watch from Monday through Tuesday given this uncertainty, but regardless if the Watch is upgraded to an Advisory or Warning or cancelled...recreationists should be prepared for cold and raw conditions. Additionally, should higher end snowfall amounts materialize over this timeframe, damage to tree limbs and power outages would be possible given the heavy, wet nature of the snow. High temperatures will warm slightly for Tuesday and Wednesday, but remain below normal. Light precipitation is expected linger through the morning and early afternoon hours on Tuesday, with overall drying conditions expected thereafter. Thursday through next Saturday...Ensemble clusters largely support and unsettled southwest flow regime over the Northern Rockies for the second half of the work week and into next weekend, which would translate to moderating temperatures and daily chances for showers and thunderstorms. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 71 43 66 41 / 60 10 10 40 CTB 64 41 57 35 / 60 20 30 20 HLN 74 42 71 44 / 60 10 20 50 BZN 77 36 67 40 / 60 20 20 30 WYS 71 36 61 36 / 20 10 0 10 DLN 75 34 64 38 / 30 0 10 30 HVR 74 45 63 43 / 60 20 20 20 LWT 74 39 65 39 / 70 20 10 30 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning from 3 PM this afternoon to 9 AM MDT Sunday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains. Winter Storm Watch from Monday morning through Tuesday evening for East Glacier Park Region-Southern Rocky Mountain Front. Winter Storm Watch from Monday evening through Tuesday evening for Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Little Belt and Highwood Mountains-Northwest Beaverhead County. && http://www.weather.gov/greatfalls
The Great Falls radar (KTFX), 144 km away, was scanning. The volume nearest the first event began at 22:02 UTC.
11 high wind, 1 thunderstorm wind. Local standard time, as filed.
Mesonet station MTBWG Browning DOT sensor measured a 70 mph gust.
Mesonet station MTM05 ARC-WTri Conrad measured a 60 mph non-convective gust.
AWOS station KWYS West Yellowstone measured a 58 mph gust. Additionally, there was a report of a tree blown over onto US-191 just north of the Hebgen Lake Rd intersection around 3 PM on the 15th.
Mesonet station GW3478 TCTiber measured a 62 mph gust not associated with convection.
Mesonet station EW1931 measured a 64 mph non-convective gust.
Mesonet station GW4015 Chester 4 NE measured two gusts of 58 mph or greater, including a peak gust of 60 mph. Neither gusts were convective.
Mesonet station MTM09 2.1 W Moccasin measured a 61 mph gust before any thunderstorms were in the area.
ASOS station KDLN Dillon Airport measured a 58 mph gust.
RAWS station FBLM8 Fort Belknap RAWS measured a 59 mph gust while lightning was in the area. Time was estimated using radar given this sensor only reports one time per hour.
ASOS station KCTB Cut Bank Airport measured a 58 mph gust.
Mesonet station DELMT Dellwo (MCSCN) measured a 69 mph gust.
RAWS station TR276 L-C Portable No.1 measured two gusts in excess of 58, including a peak of 68 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2024Every state in 2024This day in weather historyWarnings in Montana, June 2024
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: 1179950, 1179956, 1179948, 1179954, 1179951, 1179955, 1179952, 1179947, 1179958, 1179949, 1179957, 1179953.