Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 159, NWS Duluth, MN

September 21, 2007Cass County, Crow Wing County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Sep 21, 2007, 1:50 AM CDT for Cass County, Crow Wing County, Minnesota. It was in force for 68 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 21, 2007, 1:50 AM CDT (06:50 UTC)
Expired
Sep 21, 2007, 2:58 AM CDT
In force
68 min
Issued by
NWS Duluth, MN
Area
Counties, with a storm outline in the text

Counties Cass County, MN, Crow Wing County, MN

The radar

The Duluth radar (KDLH), 152 km from the middle of the area, began a volume at 06:52 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 20, 11:13 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 6.8 hours before the alert went out and 213 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, Minneapolis, MN at 00:00Z on 2007-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1394 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, Minneapolis, MN at 00:00Z on 2007-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 192 square meters per square second.19395878Sfc1 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
1394 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
838 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
192 m²/s²
0-3 km storm-relative helicity
567 m²/s²
Significant tornado parameter
0.0
Supercell composite
24.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Duluth, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 20, 11:26 PM CDT, 2 hours 24 minutes earlier.

Area forecast discussion, Sep 20, 11:26 PM CDT, 2 hours 24 minutes before
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Hazardous weather outlook, Sep 20, 3:26 PM CDT, 10 hours 24 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DULUTH MN
326 PM CDT THU SEP 20 2007

LSZ121-140>148-162-MNZ010>012-018>021-025-026-033>038-WIZ001>004-
006>009-212030-
BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN-
GRAND MARAIS TO TACONITE HARBOR MN-
TACONITE HARBOR TO SILVER BAY HARBOR MN-
SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN-
DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI-
SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI-
OPEN WATERS OF LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI
TO GRAND PORTAGE MN-KOOCHICHING-NORTHERN ST. LOUIS-
NORTHERN COOK/NORTHERN LAKE-NORTHERN ITASCA-CENTRAL ST. LOUIS-
SOUTHERN LAKE/LAKESHORE-SOUTHERN COOK/LAKESHORE-NORTHERN CASS-
SOUTHERN ITASCA-SOUTHERN CASS-CROW WING-NORTHERN AITKIN-
SOUTHERN AITKIN-CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-
ASHLAND-IRON-BURNETT-WASHBURN-SAWYER-PRICE-
326 PM CDT THU SEP 20 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA...
NORTHWEST WISCONSIN AND WESTERN LAKE SUPERIOR.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY AND TONIGHT WEST
OF A LINE FROM BAUDETTE...TO BIGFORK...GRAND RAPIDS...MOOSE
LAKE...AND HINCKLEY. THE MAIN THREAT WILL BE DAMAGING WINDS AND
HAIL.

A WIND ADVISORY IS IN EFFECT THROUGH THIS EVENING FOR WINDS OF 25
TO 30 MPH...WITH GUSTS UP TO 45 MPH...FOR ITASCA...CASS...CROW
WING...AND AITKIN COUNTIES. THIS ADVISORY INCLUDES CASS
LAKE...PINE RIVER...GRAND RAPIDS...AITKIN...AND MILLE LACS. MINOR
WIND DAMAGE AND POWER OUTAGES WILL BE POSSIBLE THROUGH THIS
EVENING.

A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF NORTHEAST MINNESOTA
AND DOUGLAS AND BURNETT COUNTIES IN NORTHWEST WISCONSIN. SHOWERS
AND THUNDERSTORMS...INCLUDING PERIODS OF HEAVY RAIN...WILL PERSIST
OVERNIGHT ACROSS MUCH OF THE REGION. THE THREAT FOR HEAVY RAIN
WILL SHIFT EAST OVER THE NORTHWEST WISCONSIN AREAS AFTER MIDNIGHT.
PLEASE MONITOR THE LATEST FORECAST FOR ADDITIONAL UPDATES
REGARDING THE THREAT OF HEAVY RAIN AND POSSIBLE FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A STRONG COLD FRONT WILL RACE ACROSS THE REGION FRIDAY WITH
THUNDERSTORMS LIKELY. HEAVY RAIN...DAMAGING WIND...AND HAIL ARE
POSSIBLE WITH THESE STORMS. AT THIS TIME...IT APPEARS THE MOST
LIKELY AREA FOR SEVERE THUNDERSTORMS WILL BE FROM THE TWIN PORTS
EAST INTO NORTHWEST WISCONSIN.

THE FLASH FLOOD WATCH CONTINUES INTO FRIDAY AFTERNOON FOR NORTHEAST
MINNESOTA AND A PORTION OF NORTHWEST WISCONSIN. HEAVY RAIN WILL
AGAIN BE POSSIBLE ACCOMPANYING THE COLD FRONT ON FRIDAY. THE LONG
DURATION OF RAIN MAY CAUSE LOCALIZED FLOODING IN THE ALREADY
SATURATED AREAS. PLEASE MONITOR THE LATEST FORECAST FOR ADDITIONAL
UPDATES REGARDING THE THREAT OF HEAVY RAIN AND POSSIBLE FLOODING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING AND
OVERNIGHT.

GRANING

The office that day

Everything else NWS Duluth, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 20, 9:21 PM CDTSevere Thunderstorm WarningDLHPine19 min
Sep 20, 11:56 PM CDTSevere Thunderstorm WarningDLHAitkin, Itasca, Saint Louis38 min
Sep 21, 1:26 AM CDTSpecial Marine WarningDLH64 min
Sep 21, 5:00 AM CDTSevere Thunderstorm WarningDLHCass, Itasca20 min
Sep 21, 5:35 AM CDTSpecial Marine WarningDLH55 min
Sep 21, 6:28 AM CDTSpecial Marine WarningDLH19 min
Sep 21, 6:33 AM CDTSevere Thunderstorm WarningDLHSaint Louis29 min
Sep 21, 6:48 AM CDTSevere Thunderstorm WarningDLHKoochiching42 min
Sep 21, 6:56 AM CDTSevere Thunderstorm WarningDLHPine35 min
Sep 21, 7:22 AM CDTSevere Thunderstorm WarningDLHSaint Louis23 min
Sep 21, 7:28 AM CDTSevere Thunderstorm WarningDLHKoochiching17 min
Sep 21, 7:29 AM CDTSpecial Marine WarningDLH31 min
Sep 21, 7:41 AM CDTSpecial Marine WarningDLH19 min
Sep 21, 7:43 AM CDTSevere Thunderstorm WarningDLHLake, Saint Louis13 min
Sep 21, 7:43 AM CDTSevere Thunderstorm WarningDLHLake, Saint Louis13 min
Sep 21, 7:50 AM CDTSevere Thunderstorm WarningDLHLake, Saint Louis7 min
Sep 21, 7:59 AM CDTSevere Thunderstorm WarningDLHLake26 min
Sep 21, 8:05 AM CDTSevere Thunderstorm WarningDLHKoochiching40 min
Sep 21, 8:20 AM CDTSevere Thunderstorm WarningDLHAitkin25 min
Sep 21, 8:39 AM CDTSevere Thunderstorm WarningDLHKoochiching32 min
Sep 21, 8:54 AM CDTSpecial Marine WarningDLH34 min
Sep 21, 9:23 AM CDTSevere Thunderstorm WarningDLHKoochiching, Saint Louis31 min
Sep 21, 3:29 PM CDTSpecial Marine WarningDLH31 min
Sep 21, 3:43 PM CDTSpecial Marine WarningDLH47 min
Sep 21, 3:56 PM CDTSpecial Marine WarningDLH64 min
Sep 21, 4:30 PM CDTSpecial Marine WarningDLH45 min
Sep 21, 4:56 PM CDTSpecial Marine WarningDLH19 min
Sep 20, 9:58 PM CDTSevere Thunderstorm WarningDLHSawyer, Washburn33 min
Sep 21, 1:25 AM CDTSevere Thunderstorm WarningDLHAshland, Bayfield20 min
Sep 21, 5:35 AM CDTSevere Thunderstorm WarningDLHAshland, Bayfield40 min
Sep 21, 6:09 AM CDTSevere Thunderstorm WarningDLHAshland, Bayfield36 min
Sep 21, 6:41 AM CDTSevere Thunderstorm WarningDLHBurnett, Washburn49 min
Sep 21, 7:04 AM CDTSevere Thunderstorm WarningDLHDouglas30 min
Sep 21, 7:23 AM CDTSevere Thunderstorm WarningDLHIron21 min
Sep 21, 7:37 AM CDTSevere Thunderstorm WarningDLHAshland, Iron38 min
Sep 21, 4:08 PM CDTSevere Thunderstorm WarningDLHAshland, Bayfield52 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2007Every severe thunderstorm warning 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.