Alert archive / Montana / Tornado Watches in 2007

Tornado Watch 473

July 2, 200712 counties in Montana; 6 counties in North Dakota

The Storm Prediction Center issued this tornado watch at Jul 2, 2007, 2:57 PM MDT for 12 counties in Montana; 6 counties in North Dakota. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Jul 2, 2007, 2:57 PM MDT (20:57 UTC)
Expired
Jul 3, 2007, 12:00 AM MDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT, Wibaux County, MT, Burke County, ND, Divide County, ND, Mountrail County, ND, Renville County, ND, Ward County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 55 km from the middle of the area, began a volume at 20:58 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 2, 3:00 PM MDTSevere Thunderstorm WarningGGWSheridan60 min
Jul 2, 3:58 PM MDTSevere Thunderstorm WarningGGWSheridan62 min
Jul 2, 4:30 PM MDTSevere Thunderstorm WarningBISDivide, Williams60 min
Jul 2, 4:59 PM MDTSevere Thunderstorm WarningGGWSheridan28 min
Jul 2, 5:09 PM MDTSevere Thunderstorm WarningGGWPhillips66 min
Jul 2, 5:30 PM MDTSevere Thunderstorm WarningBISDivide, Williams19 min
Jul 2, 6:14 PM MDTSevere Thunderstorm WarningGGWPhillips61 min
Jul 2, 6:15 PM MDTFlash Flood WarningGGWPhillips3 hr
Jul 2, 6:46 PM MDTSevere Thunderstorm WarningGGWValley59 min
Jul 2, 7:15 PM MDTSevere Thunderstorm WarningGGWPhillips60 min
Jul 2, 7:26 PM MDTSevere Thunderstorm WarningGGWPhillips64 min
Jul 2, 7:46 PM MDTSevere Thunderstorm WarningGGWDaniels, Roosevelt, Valley59 min
Jul 2, 8:46 PM MDTSevere Thunderstorm WarningGGWRoosevelt59 min
Jul 2, 8:47 PM MDTSevere Thunderstorm WarningGGWSheridan58 min
Jul 2, 9:41 PM MDTSevere Thunderstorm WarningGGWSheridan41 min
Jul 2, 9:42 PM MDTFlash Flood WarningGGWSheridan3 hr
Jul 2, 9:46 PM MDTSevere Thunderstorm WarningGGWRichland, Roosevelt59 min
Jul 2, 9:59 PM MDTSevere Thunderstorm WarningBISDivide, Williams61 min
Jul 2, 10:45 PM MDTSevere Thunderstorm WarningGGWDawson, Prairie60 min
Jul 2, 11:01 PM MDTSevere Thunderstorm WarningBISWilliams52 min
Jul 2, 11:23 PM MDTSevere Thunderstorm WarningGGWDawson, Prairie, Richland, Wibaux67 min
Jul 2, 11:44 PM MDTSevere Thunderstorm WarningGGWDawson, Prairie46 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

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 9.0 hours before the alert went out and 54 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.

Skew-T log-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 12:00Z on 2007-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1050 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 12:00Z on 2007-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1050 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1631 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
222 m²/s²
Significant tornado parameter
0.0
Supercell composite
-1.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 2, 1:02 PM MDTMesoscale DiscussionSPCBlaine, Chouteau, Daniels, Fergus, Garfield, Golden Valley and 14 more88 min
Jul 2, 2:36 PM MDTSevere Thunderstorm WatchSPCBig Horn, Blaine, Carbon, Carter, Chouteau, Custer and 14 more8 hr
Jul 1, 6:23 PM MDTMesoscale DiscussionSPCAdams, Burleigh, Dickey, Emmons, Grant, Hettinger and 13 more67 min
Jul 1, 8:38 PM MDTMesoscale DiscussionSPCAdams, Bowman, Burleigh, Emmons, Grant, Hettinger and 8 more67 min
Jul 2, 4:59 PM MDTMesoscale DiscussionSPCBarnes, Cass, Dickey, Grand Forks, Griggs, LaMoure and 8 more91 min

Nearby

Tornado Watches in Montana, 2007Tornado Watches in North Dakota, 2007Every tornado 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.