This winter storm had a favorable combination of moisture and cold arctic air. An upper level low off the west coast extended a piece of energy into the region Friday through the weekend.
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.
This winter storm had a favorable combination of moisture and cold arctic air. An upper level low off the west coast extended a piece of energy into the region Friday through the weekend. This low provided ample pacific moisture and enhanced lift from an upper level warm front. Meanwhile, a cold front pushed from north to south and brought rapidly cooling temperatures along with strong gusty winds. The hardest hit area was north and west of a Helena to Havre line, where the presence of a barrier jet enabled blizzard conditions to develop. The end result was widespread snow for three days, with areas of blowing snow, and sub-zero temperatures once the snow ended.
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 Mar 12, 10:55 PM MST, 5 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 1155 PM MDT Thu Mar 12 2020 Updated Aviation Discussion .SYNOPSIS... A major winter storm is expected to impact portions of the Northern Rockies, especially the plains of Central and North Central Montana to end the work week and through the weekend. Snow, blowing snow, and cold temperatures are expected to accompany this storm. Motorist should be prepared for hazardous driving conditions, especially from Friday through Saturday && .UPDATE... The evening update has been published. Snow showers over the Little Belts and the eastern portions of the CWA will continue to wind down for the remainder of the evening into the overnight. Then the focus turns to the winter storm, which moves in from northwest to southeast tonight through Saturday night. No changes were made to the current winter weather headlines but the situation will continue to be monitored for the potential of blizzard conditions along and west of the I15 corridor northwest of Great Falls to the Canadian border. && .AVIATION... Updated 1155 PM MDT Thu Mar 12 2020 (13/06Z TAF Period) VFR conditions will begin to degrade toward MVFR/IFR from north to south late tonight into Friday morning for central and north-central MT while VFR conditions continue through Friday morning for SW MT terminals. Snow will spread south to central MT terminals by around 18z Friday with NE to E winds increasing and leading to blowing snow at times, especially at KCTB Friday afternoon but likely to also impact KGTF, KHLN and KLWT late Friday afternoon and Friday night. Mountian obscurations and aircraft icing will increasingly become more widespread, especially for areas receiving snow. Hoenisch && .PREV DISCUSSION... /ISSUED 617 PM MDT Thu Mar 12 2020/ Rest of this afternoon through Saturday night...biggest concern and focus with the afternoon forecast was on the major winter storm set to impact the region beginning late tonight and persisting through much of the day on Saturday, only to be followed by record to near record low temperatures Saturday night/Sunday morning across North Central and Central Montana. First, not to be ignored or slept under the proverbial rug of the "major winter storm", is the on-going snow showers over North Central and Central Montana this afternoon. These snow showers, which are being drive by a combination of moist, northwest flow aloft and steep low-level lapse rates, will likely continue into the late evening hours before gradually decreasing in areal coverage. Brief reductions in visibility and some accumulations on road surfaces are the primary impacts with these showers, but given the scattered nature and briefness of said showers we will continue to just highlight through Special Weather Statements. As the showers gradually dissipate in coverage this evening over the plains of Central and North Central Montana, expect snow to begin to fill in along the Rocky Mountain Front around midnight as the low level flow becomes more east to northerly. Snow will spread south (east) along (away from) the Rocky Mountain Front Friday morning through Friday afternoon, continuing into Saturday morning/afternoon. Of biggest concern with today's forecast issuance is the potential for blizzard condtions, especially along and west of the Interstate 15 corridor. For these areas, a push of pressure 6hr rises of 3-6mb along the Rocky Mountain Front combined with H850 winds of 25-35kts is expected to lead to a prolonged period strong and gusty northerly winds. The one question that remains is whether or not a sustained period of blizzard condtions can be observed, but given uncertainty and that the onset of the winds are still 18-24hrs out I will defer possibly upgrading (to a Blizzard Warning) to future shifts should trends continue. Regardless of if a Blizzard Warning is needed, I have continued to message within the current Winter Storm Warning that near-blizzard conditions are possible and could lead to hazardous conditions for both driving and ranching interests. Otherwise, snowfall amounts continue to remain relatively steady across the region, with the only major change being an increase in amounts along and west of Interstate 15. Finally, a very cold night is expected Saturday night/Sunday morning as a strong surface high settles over the area, with the potential for record or near-record temperatures. - Moldan Sunday through next Thursday...The low pressure area will continue to move south along the Pacific coast Sunday through Tuesday, which will help decrease the snow across the area. High pressure at the surface will also start to slowly exit the area to the east, relaxing the surface pressure gradient and allowing the winds to decrease. However, cold air will remain in place over much of the area due to the expected widespread snow cover. Temperatures over the plains could potentially fall into the teens below zero Sunday night and Monday night, with even colder temperatures possible if skies clear out and winds stay light. A weak westerly flow aloft will then reside over the forecast area through the middle of the week, keeping much of the area dry with only gradually warming temperatures. Daytime temperatures should warm above freezing in Southwest Montana, but they should remain below freezing over the plains. - Coulston && .PRELIMINARY POINT TEMPS/POPS... GTF 18 24 0 8 / 20 100 100 100 CTB 12 14 -8 3 / 80 100 100 100 HLN 20 29 4 14 / 10 70 80 90 BZN 17 33 15 28 / 0 20 40 70 WYS 2 34 17 36 / 10 0 60 80 DLN 19 35 18 35 / 0 0 20 60 HVR 16 24 9 18 / 50 70 100 100 LWT 16 25 12 20 / 40 90 90 90 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from noon Friday to 4 PM MDT Saturday Broadwater...Jefferson. Winter Storm Warning from 9 AM Friday to 4 PM MDT Saturday Central and Southern Lewis and Clark...Meagher. Winter Storm Warning from 9 AM Friday to 4 PM MDT Saturday Blaine...Cascade...Chouteau...Fergus...Hill...Judith Basin... Liberty. Winter Storm Warning from midnight tonight to 4 PM MDT Saturday Eastern Glacier...Eastern Pondera...Eastern Teton...Northern Rocky Mountain Front...Southern Rocky Mountain Front...Toole. && http://www.weather.gov/greatfalls
13 winter storm, 5 blizzard, 2 heavy snow. Local standard time, as filed.
The Cut Bank Airport estimates a two day total of 12 inches of snow accumulation. Snow depth was only 4 inches due to blowing and drifting.
Storm total 8.2 inches of snow accumulation measured at the Havre Airport.
A storm total of 11.4 inches of snow accumulation measured at Loma.
The Great Falls Airport measured a storm total of 11.5 inches of snow accumulation.
Poor visibility and slippery road conditions may have contributed to a multi vehicle crash on US highway 12 near mile marker 58. There were two fatalities in this collision.
Severe winter driving conditions were reported on US highway 89 from mile marker 31 to 62.
Severe winter driving conditions were reported on US highway 89 from mile marker 23 to 31.
The public estimates 14 inches of snow accumulation at 5 SW Stanford.
Severe winter driving conditions reported on interstate 15 from mile marker 247 to 257.
Montana highway 200 was closed from mile marker 200 to the highway 279 junction due to severe winter driving conditions.
A COOP observer at 12 E Ledger measured 12 inches of snow accumulation.
Blizzard conditions were reported at the Cut Bank Airport from 5 am to 1135 am MST.
The blizzard conditions observed in the Eastern Glacier and Southern Rocky Mountain Front zones will be used to verify blizzard conditions over the southern portion of the Northern Rocky Mountain Front zone due to similar synoptic setup and lack of reporting stations in that particular area.
The blizzard conditions observed in the Eastern Glacier zone will be used to verify blizzard conditions over the Eastern Pondera zone due to similar synoptic setup and lack of reporting stations in that particular area.
AWOS site at 6 NNE Fairfield (Hotel K1HM) reports blizzard conditions from 6 am to 11 am MST. The blizzard conditions may have began earlier but there was a station outage during the overnight hours.
An AWOS station at 9 NNE Augusta (Foxtrot (K1FM) reported blizzard conditions from 6 am to 12 pm. The blizzard conditions may have begun earlier but there was a station outage during the overnight hours.
A coop observer at 1 NW Choteau measured 13 inches of snow accumulation.
A trained spotter at 1 SW Helena measured 12 inches of snow accumulation.
A storm total of 12 inches of snow accumulation was measured at 3 ENE Dutton.
A snow accumulation of 13 inches measured at the Grass range COOP.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Winter Storm, Broadwater | 2020-03-13 | 25 | Female | Vehicle/Towed Trailer | Indirect |
| Winter Storm, Broadwater | 2020-03-13 | 11 | Female | Vehicle/Towed Trailer | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2020Every state in 2020This day in weather historyWarnings in Montana, March 2020
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: 875727, 875718, 875720, 875723, 882919, 882922, 882923, 875721, 882921, 882920, 875726, 875735, 882924, 882925, 875733, 875734, 875729, 875724, 875725, 875722.