A fast-moving low pressure system from Saskatchewan with strong winds aloft, combined with a favorable atmosphere to allow most of those strong winds to reach down to the surface, especially across far eastern Montana.
Every event with a place to put it; 1 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 GGW wrote it up.
A fast-moving low pressure system from Saskatchewan with strong winds aloft, combined with a favorable atmosphere to allow most of those strong winds to reach down to the surface, especially across far eastern 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 Glasgow, MT wrote its last area forecast discussion before the first event at Apr 28, 8:30 AM MST, 38 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 930 AM MDT Tue Apr 28 2020 .DISCUSSION... 9 AM Update: Minor tweaks to pops and winds were made to reflect near term guidance and to come in line with recent observations. Current Lake Wind Advisory and fire weather hazards remain in good shape, and will continue to monitor for potential for near high wind in some places with ensembles ranging as high as 50 kts. This would mainly be across usual windy locations such as Malta South, however, in general, do expect a windy day across NE Montana. Radar will continue to be monitored for showers and thunderstorms through the afternoon across the east. Previous Discussion: Synoptic Setup: Desert Southwest contains hot high pressure that is constantly attempting to spring board north as a ridge into the least resistant pathway. The northwest quarter of the CONUS including northeast Montana has zonal flow aloft bringing ridge/trough couplets across in a fairly progressive pattern. Today: Low pressure at the surface sits just northeast over southeast Saskatchewan and is dragging a series of surface troughs along behind and to the south of it. The first one came through yesterday evening taping into strong winds aloft and dragging them down to the surface with convection. The second one is rapidly closing in on northeast Montana from the northwest and has high enough lapse rates to not need convection to drag it to the surface. Model winds are pointing to about 40 to 45 kts at about 850 mbs with this passage whose max should reach us around 15 to 18Z. This makes the gusty winds just short of a high wind for the mid morning to early afternoon. Along with this gusty winds are expected to have enough mixing to drop RH down to near 15 percent behind the trough by the afternoon. For this reason have upgraded Fire Wx Watch to a Red Flag and started it a little earlier at 14Z for a slight safety factor. Tonight through Wednesday: As the PGF slackens and high pressure takes hold, winds will rapidly decrease after dark with fairly light southern winds lasting through Wednesday afternoon. Ridge overhead should also keep things clear to partly cloudy for awhile. Wednesday night to Friday: Ridge will transition to Southwest flow and bring a large disturbance across the region with scattered showers and isolated thunderstorms. Wetting rains may be possible with this activity. Friday night to Saturday night: Ridge with hot air from the Desert Southwest will re-assert dominance. Highs will rise into the lower 70s with mostly clear skies. Sunday onward: While these periods seem climatologically unlikely due to the nature of a PCNW trough pushing too far south into Utah and northern Arizona; They have been consistent the last two nights. If it happens this will lead to an elongated front stretching from northwest to southeast over Saskatchewan to eastern Montana and down into South Dakota that will bring copious rain to northeast Montana. The Utah placement does appear to have low confidence in the ensembles though, so we shall see. GAH && .AVIATION... VFR conditions will prevail today, especially this morning. MVFR ceilings remain a possibility later in the day on the back side of the low pressure system from the north. In addition, scattered showers with isolated thunder will be possible near KGDV and KSDY through 23Z. Winds will be northwest today at 20 to 30 kts, with occasional higher gusts. The winds will tend to decrease during the evening. && .FIRE WEATHER... A Red Flag Warning has been issued for all Fire Weather Zones through 9 PM today. The combination of gusty northwest winds and low relative humidity in the presence of dry fuels will raise critical fire weather concerns. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM MDT this evening for MTZ120-122-134>137. Lake Wind Advisory until 9 PM MDT this evening For Fort Peck Lake for Central and Southeast Phillips...Central and Southern Valley...Garfield...McCone...Petroleum. && weather.gov/glasgow
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
943 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1208 AM TSTM WND GST 13 NW MCCLOUD 47.03N 105.80W
04/28/2020 M57 MPH PRAIRIE MT MESONET
BIG SHEEP MOUNTAIN RAWS SITE. WIND GUST OF 57 MPH
OVERNIGHT.
&&
BMICKELSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
947 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1036 PM TSTM WND GST 8 SW BREDETTE 48.43N 105.44W
04/27/2020 M52 MPH ROOSEVELT MT DEPT OF HIGHWAYS
MCDONALDS MT-13 DOT SITE MTMCD. 52 MPH GUST.
&&
BMICKELSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
955 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0332 AM TSTM WND GST 1 ESE ZORTMAN 47.91N 108.50W
04/28/2020 M50.00 MPH PHILLIPS MT MESONET
ZORTMAN BLM RAWS SITE ALDM8. 50 MPH GUST OVERNIGHT.
&&
BMICKELSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
1000 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 AM TSTM WND GST 11 ENE ZORTMAN 47.96N 108.31W
04/28/2020 M51 MPH PHILLIPS MT DEPT OF HIGHWAYS
MALTA SOUTH US-191 DOT SITE MTMAL. 51 MPH GUST.
&&
BMICKELSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
1003 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0644 AM TSTM WND GST 14 NNW HELL CREEK REC A 47.80N 107.02W
04/28/2020 M50 MPH VALLEY MT MESONET
KING COULEE RAWS SITE KIGM8. 50 MPH GUST.
&&
BMICKELSPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GLASGOW MT
1005 AM MDT TUE APR 28 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0852 PM TSTM WND GST 2 WSW THOENY 48.87N 106.95W
04/27/2020 M51.00 MPH VALLEY MT MESONET
BLUFF CREEK RAWS BLUM8. TIME ESTIMATED FROM RADAR
0856 PM TSTM WND GST GLASGOW 48.20N 106.64W
04/27/2020 M54.00 MPH VALLEY MT OFFICIAL NWS OBS
SUSTAINED WINDS TO 44 MPH, GUSTS TO 54 MPH AT GLASGOW
AIRPORT
0910 PM TSTM WND GST 1 NE SAINT MARIE 48.41N 106.52W
04/27/2020 M50.00 MPH VALLEY MT MESONET
SAINT MARIE MARCO SITE 07MT
1036 PM TSTM WND GST 8 SW BREDETTE 48.43N 105.44W
04/27/2020 M52.00 MPH ROOSEVELT MT DEPT OF HIGHWAYS
MCDONALDS MT-13 DOT SITE MTMCD. 52 MPH GUST.
1208 AM TSTM WND GST 13 NW MCCLOUD 47.03N 105.80W
04/28/2020 M57.00 MPH PRAIRIE MT MESONET
BIG SHEEP MOUNTAIN RAWS SITE. WIND GUST OF 57 MPH
OVERNIGHT.
0332 AM TSTM WND GST 1 ESE ZORTMAN 47.91N 108.50W
04/28/2020 M50.00 MPH PHILLIPS MT MESONET
ZORTMAN BLM RAWS SITE ALDM8. 50 MPH GUST OVERNIGHT.
0500 AM TSTM WND GST 11 ENE ZORTMAN 47.96N 108.31W
04/28/2020 M51.00 MPH PHILLIPS MT DEPT OF HIGHWAYS
MALTA SOUTH US-191 DOT SITE MTMAL. 51 MPH GUST.
0644 AM TSTM WND GST 14 NNW HELL CREEK REC A 47.80N 107.02W
04/28/2020 M50.00 MPH VALLEY MT MESONET
KING COULEE RAWS SITE KIGM8. 50 MPH GUST.
&&
BMICKELSThe Glasgow radar (KGGW), 225 km away, was scanning. The volume nearest the first event began at 21:16 UTC.
2 thunderstorm wind, 1 high wind. Local standard time, as filed.
At the Beaver Hill I-94 DOT site (MTBVR), on the Dawson/Wibaux County line, sustained winds of at least 40 mph each hour, began at 9:08 AM MST, and ended at 3:59 PM MST. Wind gusts in excess of 57 mph also occurred multiple times.
At the Beaver Hill I-94 DOT site (MTBVR), thunderstorm wind gusts of 80 mph were measured from 2:18 PM to 2:24 PM MST.
At the mesonet site 5 ESE Hoyt (MTM28), a wind gust of 60 mph was recorded at 2:30 PM MST.
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, April 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 2026-10-01. Each event’s entry at NCEI: 881811, 881359, 881360.