Alert archive / North Dakota / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 591
The Storm Prediction Center issued this severe thunderstorm watch at Aug 13, 2007, 9:48 AM CDT for 24 counties in North Dakota. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 13, 2007, 9:48 AM CDT (14:48 UTC)
- Expired
- Aug 13, 2007, 4:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 24 counties
Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Nelson County, ND, Pembina County, ND, Pierce County, ND, Ramsey County, ND, Ransom County, ND, Richland County, ND, Rolette County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Wells County, ND
The radar
The Fargo/Grand Forks radar (KMVX), 122 km from the middle of the area, began a volume at 14:48 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 9:55 AM CDT | Severe Thunderstorm Warning | FGF | Benson | 65 min |
| Aug 13, 9:58 AM CDT | Severe Thunderstorm Warning | BIS | Pierce | 32 min |
| Aug 13, 10:20 AM CDT | Severe Thunderstorm Warning | BIS | Dickey | 25 min |
| Aug 13, 10:33 AM CDT | Severe Thunderstorm Warning | FGF | Eddy | 57 min |
| Aug 13, 10:38 AM CDT | Severe Thunderstorm Warning | BIS | Wells | 43 min |
| Aug 13, 11:28 AM CDT | Severe Thunderstorm Warning | BIS | Foster | 32 min |
| Aug 13, 11:38 AM CDT | Severe Thunderstorm Warning | FGF | Barnes, Griggs | 67 min |
| Aug 13, 12:42 PM CDT | Severe Thunderstorm Warning | FGF | Cass | 50 min |
| Aug 13, 12:59 PM CDT | Severe Thunderstorm Warning | FGF | Towner | 36 min |
| Aug 13, 1:16 PM CDT | Severe Thunderstorm Warning | FGF | Cavalier, Ramsey | 59 min |
| Aug 13, 1:59 PM CDT | Severe Thunderstorm Warning | FGF | Nelson, Walsh | 61 min |
| Aug 13, 2:15 PM CDT | Severe Thunderstorm Warning | FGF | Ramsey | 30 min |
| Aug 13, 2:33 PM CDT | Tornado Warning | FGF | Grand Forks, Nelson, Walsh | 57 min |
| Aug 13, 3:29 PM CDT | Severe Thunderstorm Warning | FGF | Grand Forks | 61 min |
| Aug 13, 3:40 PM CDT | Tornado Warning | FGF | Grand Forks, Steele, Traill | 65 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Bismarck Municip, ND (KBIS), launched 12:00Z, 2.8 hours before the alert went out and 179 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
- 1500 J/kg
- Mixed-layer CIN
- -501 J/kg
- Mixed-layer LCL
- 788 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 111 m²/s²
- 0-3 km storm-relative helicity
- 262 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 3:16 AM CDT | Mesoscale Discussion | SPC | Divide, Williams | 89 min |
| Aug 13, 8:45 AM CDT | Mesoscale Discussion | SPC | Barnes, Benson, Bottineau, Cass, Cavalier, Dickey and 20 more | 60 min |
| Aug 13, 2:18 PM CDT | Mesoscale Discussion | SPC | Cass, Grand Forks, Nelson, Pembina, Steele, Traill and 1 more | 117 min |
| Aug 13, 2:57 PM CDT | Severe Thunderstorm Watch | SPC | Cass, Grand Forks, Nelson, Richland, Steele, Traill and 1 more | 6 hr |
Nearby
Severe Thunderstorm Watches in North Dakota, 2007Every severe thunderstorm watch in 2007
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.