Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 109, NWS Grand Forks, ND
NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 6, 2021, 11:30 PM CDT for Becker County, Clearwater County, Mahnomen County, Minnesota. It was in force for 45 min. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Sep 6, 2021, 11:30 PM CDT (04:30 UTC)
- Expired
- Sep 7, 2021, 12:15 AM CDT
- In force
- 45 min
- Issued by
- NWS Grand Forks, ND
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 50.0 mph
Counties Becker County, MN, Clearwater County, MN, Mahnomen County, MN
The radar
The Fargo/Grand Forks radar (KMVX), 129 km from the middle of the area, began a volume at 04:29 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 6, 11:59 PM CDT | HAIL 1.25 | 4 N Ponsford, MN | REPORTS OF LARGE HAIL, HEAVY RAIN, AND VERY STRONG WINDS ACROSS EAST CENTRAL ROUND LAKE AND NORTHEAST PINE POINT TOWNSHIPS. HAIL WAS MAINLY NICKEL TO QUARTER SIZED WITH NUMEROUS LARGER STONES MIXED IN. LARGE HOLES WERE LEFT IN BEAN LEAVES, AND IN THE GROUND IT |
| Sep 7, 12:14 AM CDT | TSTM WND DMG | 4 Ssw Two Inlets, MN | LARGE BRANCHES BROKEN DOWN ONTO ROADWAYS ACROSS SOUTHERN PORTIONS OF TWO INLETS STATE FOREST. TIME ESATIMATED BASED ON RADAR. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
International Fa, MN (KINL), launched 00:00Z, 4.5 hours before the alert went out and 243 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 133 J/kg
- Mixed-layer CIN
- -170 J/kg
- Mixed-layer LCL
- 1566 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- 364 m²/s²
- 0-3 km storm-relative helicity
- 441 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
133 WUUS53 KFGF 070430 SVRFGF MNC005-029-087-070515- /O.NEW.KFGF.SV.W.0109.210907T0430Z-210907T0515Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Grand Forks ND 1130 PM CDT Mon Sep 6 2021 The National Weather Service in Grand Forks has issued a * Severe Thunderstorm Warning for... Southern Mahnomen County in northwestern Minnesota... Northern Becker County in northwestern Minnesota... South central Clearwater County in northwestern Minnesota... * Until 1215 AM CDT. * At 1130 PM CDT, a severe thunderstorm was located over southwestern White Earth Nation, or 22 miles north of Detroit Lakes, moving east at 55 mph. HAZARD...Half dollar size hail. SOURCE...Radar indicated. IMPACT...Damage to vehicles is expected. * This severe thunderstorm will be near... White Earth around 1135 PM CDT. Tulaby Lake and Many Point Lake around 1150 PM CDT. Other locations in the path of this severe thunderstorm include Bad Medicine Lake, Long Lost Lake and Two Inlets. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Prepare immediately for large hail and deadly cloud to ground lightning. Seek shelter inside a well-built structure. Stay away from windows. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4705 9607 4723 9606 4724 9522 4697 9522 TIME...MOT...LOC 0430Z 273DEG 47KT 4714 9595 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...1.25 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...<50 MPH $$ BH
1 follow-up statement
469 WWUS53 KFGF 070449 SVSFGF Severe Weather Statement National Weather Service Grand Forks ND 1149 PM CDT Mon Sep 6 2021 MNC005-029-087-070515- /O.CON.KFGF.SV.W.0109.000000T0000Z-210907T0515Z/ Mahnomen MN-Becker MN-Clearwater MN- 1149 PM CDT Mon Sep 6 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT FOR SOUTHEASTERN MAHNOMEN...NORTHEASTERN BECKER AND SOUTH CENTRAL CLEARWATER COUNTIES... At 1149 PM CDT, a severe thunderstorm was located over southeastern White Earth Nation, or 24 miles northeast of Detroit Lakes, moving east at 55 mph. HAZARD...Half dollar size hail. SOURCE...Radar indicated. IMPACT...Damage to vehicles is expected. Locations impacted include... Long Lost Lake, Bad Medicine Lake and Two Inlets. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Prepare immediately for large hail and deadly cloud to ground lightning. Seek shelter inside a well-built structure. Stay away from windows. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4702 9574 4723 9573 4724 9522 4697 9522 TIME...MOT...LOC 0449Z 273DEG 47KT 4713 9558 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...1.25 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...<50 MPH $$ BH
The office that day
Everything else NWS Grand Forks, ND issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 6, 9:06 PM CDT | Special Weather Statement | FGF | Beltrami | 24 min |
| Sep 6, 9:17 PM CDT | Severe Thunderstorm Warning | FGF | Beltrami | 18 min |
| Sep 6, 9:50 PM CDT | Severe Thunderstorm Warning | FGF | Mahnomen, Norman | 20 min |
| Sep 6, 10:32 PM CDT | Special Weather Statement | FGF | Hubbard | 43 min |
| Sep 6, 11:19 PM CDT | Special Weather Statement | FGF | Mahnomen | 41 min |
| Sep 7, 12:07 AM CDT | Severe Thunderstorm Warning | FGF | Becker, Hubbard, Wadena | 38 min |
Nearby
Severe Thunderstorm Warnings in Minnesota, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.