A potent upper level closed low and associated trough began to dig southeast along the British Columbia Coast during the morning hours of Friday, September 27th, 2019, reaching over Vancouver Island during the evening hours on Friday. By Saturday (September 28, 2019) morning the trough had dug substantially along the Pacific Coast of the United States, with the broad closed low positioned over…
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 potent upper level closed low and associated trough began to dig southeast along the British Columbia Coast during the morning hours of Friday, September 27th, 2019, reaching over Vancouver Island during the evening hours on Friday. By Saturday (September 28, 2019) morning the trough had dug substantially along the Pacific Coast of the United States, with the broad closed low positioned over the western two-thirds of the state of Washington and northern third of Oregon. As the day progressed on Saturday the trough dug even further south into Southern California and began to take on a neutral tilt, all the while the closed low slowly meandered to over the Oregon and Washington borders. This neutrally tilted trough would then persist over the western third of the United States through Sunday (September 29, 2019) evening, with the closed low remaining nearly stationary over the Columbia River Valley of Oregon and Washington over this time frame. This upper level pattern from Friday through Monday (September 30, 2019) allowed for abundant Pacific moisture to be transported east and northeast over the Northern Rockies, which combined with strong easterly and northeasterly upslope flow in the low-to-mid levels and cold air filtering south from Arctic, allowed for widespread snow to develop over North Central and portions of 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 Sep 28, 4:30 AM MST, 1 hour 30 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 530 AM MDT Sat Sep 28 2019 Updated Aviation Discussion .SYNOPSIS... Significant fall storm is underway across the Northern Rockies. This fall storm will bring significant snowfall accumulations to the Rocky Mountain Front and portions of the plains of North Central Montana. Due to the heavy, wet nature of the snow and foliage remaining on trees; widespread tree damage is possible. In addition, powerlines may also fall resulting in power outages, which could last for a prolonged time due to access issues from the depth of the expected snow. && .DISCUSSION... Today through Sunday night...primary forecast concerns continue to be precipitation amounts, snow ratios, and the transition over to snow where the transition has yet to occur; which will all impact snowfall amounts. As of 09z this morning, H500 closed was centered over Western Washington, with ~125-175m height falls overspreading Northern California and the Great Basin as the large H500 trough axis digs southeast into the Western CONUS. Mid-level winds were beginning to strengthen and back from the southeast to northeast over North Central Montana in response to the H700 low moving from the Pacific Northwest and towards the Great Basin. Surface winds over North Central Montana were also increasing and backing to the north to northeast as cold air continues to filter south from Canada, with generally light northerly winds over Southwest Montana. An expansive precipitation shield has been centered over much of North Central Montana for most of the overnight hours, with snow falling along and west of the Interstate 15 corridor and generally rain east of the I- 15 corridor. Over the next 36 hours, expect the H500 low to move very, very slowly to the interior of the Pacific Northwest, which will result in a prolonged period of moist Pacific air being advected northeast over the Northern Rockies. Very favorable upper level dynamics will be in place across the region over this period, especially over Central and North Central Montana where mid-level east to northeast flow will provide upslope conditions along the eastern/northern slopes of the Continental Divide and mountains of North Central Montana. Dynamic cooling and cold air filtering in from Canada will allow rain to transitions to rain/snow and eventually snow over the plains of North Central and valleys of Central Montana throughout the day and evening hours tonight. Some areas could transition much faster where precipitation rates are intense and wet bulbing occurs. How much snow accumulates on the roads today will be dependent on snowfall intensities, but impacts to elevated surfaces likes bridge decks, trees with foliage, and powerlines will occur much faster. With the loss of sunlight this evening and additional cooling, expect a complete transition to snow over all of North Central and Central Montana, with the best accumulating snow expected from tonight and through the day on Sunday as the best forcing arrives from the upper level disturbance. Snowfall amounts have changed very little from previous forecast, as model guidance continues to remain in very good agreement with the evolution of the winter storm. Because of this, have decided to add Hill, Blaine, Choteau, and Fergus Counties to the Winter Storm Warning. While portions of these counties (especially eastern portions) will see lighter snowfall amounts, the mountains and western portions will likely see significant impacts from the heavy, wet snow. Extreme impacts are still expected along the Rocky Mountain Front and portions of the North Central Montana plains through Sunday night due significant accumulations of the heavy, wet snow and strong north to northeast surface winds. Widespread tree damage is possible due to the heavy, wet snow falling onto trees with foliage. Downed power lines are also possible, resulting in widespread power outages that could last days in remote areas where access is limited due to the depth of the snow. Agricultural interests; outdoor recreational interests, including camping and hunting activities; and travel will also be extremely impacted. Blizzard conditions remain possible along the Rocky Mountain Front and immediate eastern plains tonight through Sunday, but have decided to hold onto the Winter Storm Warnings for now given the heavy ,wet nature of the snow, which may not blow around enough to reduce visibilities below 1/4 mile. - Moldan Monday through Saturday...The upper level level low opens up/weakens and lifts out to the northeast Monday but a trough remains in place across the region through Wednesday. Snow wrapping around the upper level low may still be falling Monday morning along the northern border before drier air wraps into the region behind the departing low from the southwest through the day Monday. Outside of areas near the Canadian border Monday morning, a few snow showers are possible at times through Tuesday as weak shortwave energy moves through the upper trough. A chilly airmass remains in place across the region through at least the first half of next week with unseasonably cool daytime temperatures and a high likelihood of record cold overnight low temperatures Monday night and again Tuesday night. With many locations expected to see overnight minimum temperatures in the teens and twenties this may pose a threat to un-winterized outdoor plumbing/irrigation systems. Coldest temperatures are likely to occur across western portions of north-central MT, where a significant snow pack is anticipated to be in place. A brief period of ridging aloft looks to shift across the region late Wednesday through Thursday night, allow temperatures to recover to within 10 degrees of seasonal averages, but still on the cool side. the next Pacific trough moves onto the west coast by Friday and will bring a chance of precipitation and cooling temperatures for the end of the week into next weekend. Hoenisch && .AVIATION... Updated 1530 MDT Sat Sep 28 2019 (12z) Steady precipitation will continue across north-central MT this morning as additional moisture wraps around a deepening upper level low over the Pacific NW. Heaviest precipitation will continue to be focused along the Rocky Mtn front, tapering to scattered showers over SW MT with some periods of lesser precipitation coverage at times today across central MT late this morning through early this evening before precipitation intensifies again this evening. Rain is mixing/changing to snow at all north-central MT terminals this morning with snow continuing, moderate at times at KCTB. Transition to snow will spread south into the SW MT Valleys this afternoon and evening. Mountains/passes will be obscured through the period. Widespread MVFR to IFR conditions at most terminals and periods of LIFR or lower in areas of heavier snow. Hoenisch && .PRELIMINARY POINT TEMPS/POPS... GTF 35 28 33 23 / 100 100 100 90 CTB 30 24 29 23 / 100 100 100 100 HLN 39 29 34 23 / 90 90 100 90 BZN 46 31 39 23 / 60 60 90 70 WEY 42 30 38 18 / 100 80 90 40 DLN 46 28 35 20 / 90 100 90 70 HVR 35 30 36 27 / 100 100 100 100 LWT 36 29 34 23 / 100 100 90 70 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 6 AM MDT Monday Broadwater...Central and Southern Lewis and Clark...Jefferson...Meagher. Winter Storm Warning until 6 AM MDT Monday Eastern Glacier... Eastern Pondera...Eastern Teton...Liberty...Northern Rocky Mountain Front...Southern Rocky Mountain Front...Toole. Winter Weather Advisory from 6 PM this evening to midnight MDT Sunday night Beaverhead...Gallatin...Madison. Winter Storm Warning until 6 AM MDT Monday Cascade...Judith Basin. Winter Storm Warning until 6 AM MDT Monday Blaine...Chouteau... Fergus...Hill. && http://www.weather.gov/greatfalls
11 heavy snow, 4 winter storm, 4 blizzard. Local standard time, as filed.
Northwest Energy reports 462 customers without power in Choteau due to heavy snow falling on trees and power lines.
MDT reports severe driving conditions on Montana highway 200 from Rogers Pass to the highway 434 Junction.
The City of Choteau Public Works Director requested that people stay off the roads due to fallen trees and power lines.
Browning Water Plant went down, which impacted the residents of Browning and East Glacier. The plant was back in operation later that afternoon. Message relayed by Facebook.
A trained spotter at 13 E Lloyd reported 14 inches of snow.
Extreme driving conditions reported along Montana Highway 287 from Choteau to Bowman’s Corner, and Montana Highway 21 from Simms to Augusta.
A trained spotter at 2 SE Lewistown (elevation 4200 ft) reported 9 inches of snow accumulation since 6AM September 28th.
The Blackfeet Nation Tribal council reports that all roads in and out of the Blackfeet Nation Reservation have been closed or are experiencing severe driving conditions.
The Blackfeet Nation Tribal council reports that all roads in and out of the Blackfeet Nation Reservation have been closed or are experiencing severe driving conditions.
A trained spotter at 4 W Utica reports 9 inches of snow since around 6AM on Saturday the 28th. Liquid equivalent total was 1.16 inches.
Public reported 12.5 inches of snow at 1 NNE Havre.
NWS Great Falls (5 WSW Great Falls) reported 19.3 inches for a storm total.
The Rocky Mountain Ranger Station (15 SW Augusta) reported a storm total of 25 inches, with snow drifts up to 3 to 4 feet.
KRTV reported a storm total of 18 inches in Dutton.
Dupuyer Creek SNOTEL (14 SW Dupuyer) reported a 48 hour storm total of 48 inches.
The Badger Pass SNOTEL site reported an estimated snow accumulation of 34 inches.
A trained spotter at 17 WSW Bynum reported a storm total of 46 inches, with estimated 7 foot drifts.
Public reported 22 inches of snow accumulation at Cut Bank, measurements were averaged over 10 locations. Hvy Snow E.Glacier.
BlackFeet Nation Emergency Management reported a storm total of 48 inches, widespread whiteout conditions were being observed at the time of the report.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2019Every state in 2019This day in weather historyWarnings in Montana, September 2019
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: 852191, 852192, 852193, 852195, 851198, 852198, 851197, 852200, 852201, 851196, 851199, 851189, 851195, 851190, 851194, 851200, 851201, 851202, 851203.