A series of disturbances across the Northern Rockies led to periods of strong, gusty winds, especially along the Rocky Mountain Front.
Every event with a place to put it; 4 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.
A series of disturbances across the Northern Rockies led to periods of strong, gusty winds, especially along 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 Nov 19, 11:05 AM MST, 3 hours earlier.
Area Forecast Discussion National Weather Service Great Falls MT 1105 AM MST Sun Nov 19 2023 .SYNOPSIS... Minor snow accumulations are expected along the Continental Divide and in the mountains of Southwest Montana through tonight as a series of disturbances cross the Northern Rockies. Periods of strong and gusty winds are expected through the first half of the week, with the strongest winds occurring today through Monday morning and then again Tuesday morning through Tuesday night. Winds will be especially strong along the Rocky Mountain Front. && .UPDATE... Inherited forecast is performing nicely; therefore, no updates are made, at this time. - Fogleman && .DISCUSSION... Today through tonight...primary forecast concerns throughout the period will accumulating snow and strong winds. The H500 pattern over the Northern Rockies will be messy to say the least over the next 24 hours as ridging continues to slide east towards the Mississippi Valley and a series of shortwaves, one lifting northeast from the Pacific Northwest to over the Canadian Prairies and the other diving southeast from Northern California to the Southern Plains, move across the Western CONUS. The tracks of these two shortwaves will keep most locations dry through Monday morning, with the exception of areas along and south of the I-90 corridor in Southwest Montana and across the Continental Divide where predominately light mountain snow and a valley rain/snow mix is expected. Latest NBM probabilistic data only supports a 20% chance for 2" or more of snowfall over Raynolds and Targhee Passes through 12z Monday, with the higher peaks of the Gallatin and Madison Ranges having between a 50-70% chance of seeing 2" or more of snow. While travelers going over these and surrounding mountain passes will undoubtedly encounter some reductions in visibility due to falling snow and minor accumulations on road surface we will forgo any winter highlights given the low snowfall amounts and marginal surface temperatures. A strengthening surface pressure gradient along the Rocky Mountain Front through the day combined with cross barrier flow of 20-40kts will help to drive strong and gusty surface winds across the East Glacier Park Region, Southern Rocky Mountain Front, Northern and Southern High Plains adjacent to the Rocky Mountain Front, and Eastern Glacier/Western Toole/Central Pondera Counties. While most locations across Southwest through North Central Montana can expect to see wind gusts of 20-30kts over the next 24 hours the aforementioned areas across western portions of Central and North Central Montana have a 60+% chance of seeing wind gusts in excess of 48kts, with areas along the immediate eastern slopes of the Rocky Mountain Front having a 30-50% chance of seeing gusts in excess of 64kts. While a period of mountain wave activity spreading east towards the Cut Bank Area is possible during the evening hours tonight, I expect the core of strongest winds to remain along and west of the US Hwy 89 corridor where local High Wind criteria is 75 mph. We will therefor forgo any High Wind highlights at the moment, but should an extended period (outside of a one hit gust) of High Winds become more imminent for areas like Cut Bank then a short lead time High Wind Warning may be needed. Monday through Tuesday...clusters remain in strong agreement with H500 ridging building in over the Northern Rockies through the period, which will bring dry conditions and near (Monday) to above normal (Tuesday) temperatures to Southwest through North Central Montana. High temperatures on Monday will be 5-10 degrees cooler than today in wake of a weak cold front, with temperatures rebounding on Tuesday as the ridge axis moves overhead and downsloping southwest to west surface winds increase. These downsloping southwest to west surface winds will become especially strong and gusty once again along the Rocky Mountain Front, across the Montana Hwy 200 corridor, and in the north-south orientated valleys of Southwest Montana from Tuesday morning through Tuesday night as the surface pressure gradient increases in conjuction with increasing cross barrier flow. While the latest NBM probabilistic data keeps locations below <60% chance of seeing 48kts or greater over this period I am growing concerned that the NBM is not fully grasping the strength of the pressure gradient, especially along the Rocky Mountain Front. We will continue to monitor the deterministic and probabilistic trends for this area especially for any future High Wind highlights. - Moldan Upper-level ridging over western CONUS begins to flatten, as supported by Cluster Analysis, leading to zonal flow aloft, allowing Pacific moisture to stream into the Treasure State. This, in conjunction with a southward advancing cold front from Canada, will ultimately result in below seasonal average temperatures towards the latter end of the week, including Thanksgiving Day, with Friday being the coldest. Afternoon temperatures Thanksgiving Day shows most locations with a temperature spread of a few degrees above and below the freezing mark. Friday's temperature spread is a bit more significant, ranging from the lower teens to just above freezing. Regardless, afternoon temperatures will remain below seasonal average through at least the weekend, maintaining 5 to 10 degrees below seasonal average at most locations. In addition, widespread snowfall will develop Thanksgiving Day and linger into Friday morning. While much of the snowfall will remain in the mountains across North-central and Southwest Montana, many locations at lower elevations may very well experience a white Thanksgiving as well. That said, latest probabilistic guidance has shied away from the previous day's snowfall accumulation, now showing a 60 to 80% chance of at least one inch of snowfall across mountain ranges, while lower elevations show a modest 30% or less of similar accumulation. In fact, many of the model ensembles are suggesting less than an inch of accumulation over the Great Falls vicinity Wednesday night through Thanksgiving Day, down from the almost 2 inches models were hinting at 24 hours ago. Nevertheless, temperatures will be cold enough to retain any snowfall to at least symbolize a white Thanksgiving, which statistically, has only happened 22 out of the last 70 years (dating back to 1953) for Great Falls, 20 out of 61 years (dating back to 1953 apart from 9 years missing) for Helena, and 15 out of 57 years (dating back to 1961 with 5 years missing) for Havre. A White Thanksgiving is classified as a snow depth of at least 1 inch of snow, measured at 5 AM. Needless to say, the probability of a white Thanksgiving tends be on the lower end of occurring. The Climate Prediction Center (CPC) suggests the 8 to 14 day Outlook will have a 33 to 40% chance of below normal temperatures across North-central and Southwest Montana with a 33 to 40% below normal precipitation in Southwest Montana and near normal for North-central Montana. It seems cold and dry will be the trend through early December. - Pierce && .AVIATION... 1105 AM MST Sun Nov 19 2023 (19/18Z TAF Period) MVFR to periodic IFR conditions are expected across Southwestern Montana this afternoon as light rain and mountain snow fall across the area. Visibility should generally remain over 4 miles, but brief periods of lower visibility may be possible if more snow reaches the valley floor. Expect widespread mountain obscuration. Further north, expect VFR conditions to prevail with some mid to high clouds passing overhead and gusty winds. Ludwig Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 54 33 46 30 / 10 10 0 0 CTB 49 30 42 25 / 0 0 0 0 HLN 44 30 45 22 / 20 10 0 0 BZN 41 21 35 13 / 50 40 0 0 WYS 36 16 29 8 / 90 70 0 0 DLN 37 19 38 15 / 50 10 0 0 HVR 52 31 45 22 / 0 10 10 0 LWT 53 30 42 23 / 10 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && http://www.weather.gov/greatfalls
The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
ASOS station KCTB Cut Bank Airport. 40 mph average sustained winds from 205 PM to 305 PM.
ASOS station KCTB Cut Bank Airport measured 58 mph wind gust.
Ambient weather station near 19 WSW Santa Rita measured a 65 mph wind gust. A 60 mph wind gust was measured earlier at this location as well.
Mesonet station DCRM8 Deep Creek RAWS measured 72 mph wind gust. There were other wind gusts that met criteria during this event at Deep Creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyWarnings in Montana, November 2023
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 2026-10-01. Each event’s entry at NCEI: 1143740, 1143739, 1143738, 1143737.