Alert archive / Minnesota / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 656

August 27, 20075 counties in Minnesota; 4 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Aug 27, 2007, 6:19 PM CDT for 5 counties in Minnesota; 4 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Aug 27, 2007, 6:19 PM CDT (23:19 UTC)
Expired
Aug 28, 2007, 1:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Carlton County, MN, Cook County, MN, Lake County, MN, Pine County, MN, Saint Louis County, MN, Ashland County, WI, Bayfield County, WI, Douglas County, WI, Iron County, WI

The radar

The Duluth radar (KDLH), 53 km from the middle of the area, began a volume at 23:23 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
10%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 27, 9:10 PM CDTSevere Thunderstorm WarningDLHCarlton, Pine35 min
Aug 27, 11:33 PM CDTSevere Thunderstorm WarningDLHAshland, Bayfield42 min
Aug 28, 12:11 AM CDTSevere Thunderstorm WarningDLHAshland, Iron46 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

International Fa, MN (KINL), launched 12:00Z, 11.3 hours before the alert went out and 175 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, International Fa, MN at 12:00Z on 2007-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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, International Fa, MN at 12:00Z on 2007-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 157 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
44 J/kg
Mixed-layer CIN
-331 J/kg
Mixed-layer LCL
780 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
157 m²/s²
0-3 km storm-relative helicity
178 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 26, 8:04 PM CDTMesoscale DiscussionSPCKittson, Marshall, Pennington, Polk, Red Lake, Roseau116 min
Aug 26, 10:25 PM CDTMesoscale DiscussionSPCBecker, Beltrami, Clay, Clearwater, Koochiching, Mahnomen and 4 more65 min
Aug 27, 1:43 AM CDTMesoscale DiscussionSPCAnoka, Chisago, Dakota, Dodge, Fillmore, Goodhue and 12 more92 min
Aug 27, 7:10 AM CDTMesoscale DiscussionSPCWilkin95 min
Aug 27, 10:14 AM CDTMesoscale DiscussionSPCBecker, Beltrami, Clay, Clearwater, Hubbard, Itasca and 8 more91 min
Aug 27, 12:55 PM CDTMesoscale DiscussionSPCBecker, Clay, Mahnomen, Norman, Otter Tail, Wilkin65 min
Aug 27, 2:29 PM CDTSevere Thunderstorm WatchSPCAitkin, Becker, Beltrami, Cass, Clay, Clearwater and 15 more8 hr
Aug 27, 5:34 PM CDTMesoscale DiscussionSPCAitkin, Becker, Carlton, Cass, Clay, Clearwater and 8 more116 min

Nearby

Severe Thunderstorm Watches in Minnesota, 2007Severe Thunderstorm Watches in Wisconsin, 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.