Alert archive / Minnesota / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 16, NWS Duluth, MN

May 25, 2008Cass County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at May 25, 2008, 5:25 PM CDT for Cass County, Minnesota. It was in force for 50 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: May 25, 2008, 5:25 PM CDT (22:25 UTC)
Expired: May 25, 2008, 6:15 PM CDT
In force: 50 min
Issued by: NWS Duluth, MN
Area: Storm-based polygon

County Cass County, MN

The watch it was issued in

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

Issued	Product	Office	Lasted
May 25, 2:45 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 10.4 hours before the alert went out and 196 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 783 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 73 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 May 25, 4:20 PM CDT, 1 hour 5 minutes earlier.

Area forecast discussion, May 25, 4:20 PM CDT, 1 hour 5 minutes before

AREA FORECAST DISCUSSION...MESOSCALE UPDATE
NATIONAL WEATHER SERVICE DULUTH MN
420 PM CDT SUN MAY 25 2008

.MESOSCALE UPDATE CONCERNING SEVERE THUNDERSTORM POTENTIAL FROM THE
BRAINERD LAKES REGION EASTWARD TO NORTHWEST WISCONSIN...

CONVERGENCE ALONG PACIFIC FRONT/DYLINE LOCATED FROM LAKE OF THE
WOODS SOUTHWARD TO JUST WEST OF WILLMAR CONTINUES TO STRENGTHEN..
WITH NUMEROUS ATTEMPTS AT SUSTAINED DEEP CONVECTION JUST TO THE WEST
OF THE DLH WESTERN CWA BORDER.  HOWEVER..THUS FAR..THESE UPDRAFTS
HAVE APPARENTLY NOT BEEN ABLE TO BECOME WELL-ROOTED INTO THE
NEAR-SURFACE LAYER..DESPITE SEVERAL STRONG UPDRAFT PULSES.  DEEP
LAYER SHEAR VECTORS ARE ORIENTED AT ABOUT A 70 DEGREE ANGLE TO THE
BOUNDARY..WHICH WOULD TYPICALLY FAVOR DISCRETE STORM MODE..BUT THUS
FAR..STORM ORGANIZATION APPEARS TO BE LACKING. THERE IS ALSO SOME
QUESTION REGARDING HOW FAR EAST THE SEVERE THREAT WILL EXIST AT
LEAST THRU 6 PM..AS VIZ SAT IMAGERY STILL INDICATES STABLE ROLL
CLOUDS TO THE NORTHEAST OF I94. IN ADDITION..THE TWO BEST STORMS
THUS FAR IN TERMS OF LONGEVITY AND STRUCTURE HAVE BEEN LEFT
MOVERS..SUGGESTING THAT HODOGRAPHS IN THIS AREA POSSESS SOME
ANTI-CYCLONIC CURVATURE. AT LEAST IN THE SHORT TERM..THE PRIMARY
SEVERE THREAT IN AREAS FROM LAKE WINNIBIGOSHISH SOUTHWARD TO THE
BRAINERD LAKES AREA APPEARS TO BE LARGE HAIL WITH A SOMEWHAT LESSER
THREAT OF DAMAGING WINDS..AS LEFT MOVERS ARE TYPICALLY PROLIFIC HAIL
PRODUCERS..SUPPORTED BY RECENT REPORT OF NEAR GOLF BALL SIZE HAIL
FROM SMALL LEFT MOVING CORE JUST NW OF LEECH LAKE.

MEANWHILE..VERY SIGNIFICANT SEVERE THREAT APPEARS TO BE FOCUSSING
ALONG AND JUST NORTH OF NORTHWARD RETREATING OUTFLOW BOUNDARY FROM
MORNING CONVECTION THAT EXTENDS FROM THE NW SUBURBS OF THE MSP METRO
AREA..EASTWARD INTO WCENT WI. INTENSE SUPERCELL HAS DEVELOPED OVER
WRIGHT COUNTY AT THE LEADING EDGE OF STRONG DRY PUNCH INTO SW MN
WHERE OUTFLOW BOUNDARY INTERSECTS THE ADVANCING DRYLINE. AT THIS
TIME..THE OUTFLOW BOUNDARY REMAINS SOUTH OF BURNETT/WASHBURN/SAWYER/
PHILLIPS COUNTIES..BUT LATEST SHORT RANGE MODEL GUIDANCE IS STILL
INSISTENT THAT THE OFB WILL RETREAT NWD BY 00-02Z..ALLOWING MUCH
MORE ROBUST SURFACE BASED INSTABILITY TO SURGE NWD INTO THE
AFOREMENTIONED AREAS. IF THIS DOES IN FACT TRANSPIRE..A MUCH MORE
SIGNIFICANT SEVERE WEATHER THREAT WILL EXIST BETWEEN 6-9 PM.
HOWEVER..ANOTHER POSSIBLE SCEANRIO IS FOR ADDITIONAL STORMS TO THE
WEST OF THE EXISTING SUPERCELL TO MERGE AND DEVELOP INTO AN MCS
WHICH WOULD THEN LIKELY PROPAGATE ESEWD..AND REMAIN MAINLY SOUTH OF
THE DULUTH CWA IN NW WI.
 MILLER

&&

.DLH WATCHES/WARNINGS/ADVISORIES...

MN...NONE.
WI...NONE.
LS...NONE.

Hazardous weather outlook, May 25, 11:49 AM CDT, 5 hours 36 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1149 AM CDT SUN MAY 25 2008

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-261700-
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-
1149 AM CDT SUN MAY 25 2008

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS ARE LIKELY THIS
AFTERNOON AND EVENING. TORNADOES ARE ALSO POSSIBLE. THIS IS A VERY
VOLATILE SITUATION AND EVERYONE SHOULD CLOSELY MONITOR THE WEATHER
VIA YOUR FAVORITE SOURCE OF WEATHER...OR KEEP YOUR ALL HAZARD
WEATHER RADIO IN ALERT MODE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY NIGHT THROUGH SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT.

LSZ121-140>148-261700-
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-
1149 AM CDT SUN MAY 25 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS ARE LIKELY THIS
AFTERNOON AND EVENING. TORNADOES ARE ALSO POSSIBLE. THIS IS A VERY
VOLATILE SITUATION AND EVERYONE SHOULD CLOSELY MONITOR THE WEATHER
VIA YOUR FAVORITE SOURCE OF WEATHER...OR KEEP YOUR ALL HAZARD
WEATHER RADIO IN ALERT MODE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS ARE LIKELY THIS
AFTERNOON AND EVENING. TORNADOES ARE ALSO POSSIBLE. THIS IS A VERY
VOLATILE SITUATION AND EVERYONE SHOULD CLOSELY MONITOR THE WEATHER
VIA YOUR FAVORITE SOURCE OF WEATHER...OR KEEP YOUR ALL HAZARD
WEATHER RADIO IN ALERT MODE.

CLC

In the hours before

Local storm report, May 25, 12:00 PM CDT, 5 hours 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
1200 PM CDT SUN MAY 25 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1159 AM     HAIL             4 S GRANTSBURG          45.72N 92.68W
05/25/2008  M0.75 INCH       BURNETT            WI   AMATEUR RADIO

&&

CCHRIST

Local storm report, May 25, 1:03 PM CDT, 4 hours 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
103 PM CDT SUN MAY 25 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 PM     HAIL             1 N SPOONER             45.84N 91.89W
05/25/2008  E0.88 INCH       WASHBURN           WI   TRAINED SPOTTER

            NICKEL-SIZED HAIL.

0100 PM     HAIL             SPOONER                 45.82N 91.89W
05/25/2008  M0.88 INCH       WASHBURN           WI   TRAINED SPOTTER

&&

BETTWY

Local storm report, May 25, 1:37 PM CDT, 3 hours 48 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
137 PM CDT SUN MAY 25 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0136 PM     HAIL             8 E HAYWARD             46.01N 91.31W
05/25/2008  M0.75 INCH       SAWYER             WI   AMATEUR RADIO

&&

CCHRIST

Local storm report, May 25, 3:19 PM CDT, 2 hours 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
319 PM CDT SUN MAY 25 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0255 PM     HAIL             11 SW MERCER            46.05N 90.22W
05/25/2008  M0.75 INCH       IRON               WI   TRAINED SPOTTER

            CEDAR COVE CABINS.

&&

BETTWY

Local storm report, May 25, 3:19 PM CDT, 2 hours 6 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE DULUTH MN
319 PM CDT SUN MAY 25 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0250 PM     HAIL             9 SW MERCER             46.05N 90.18W
05/25/2008  M0.75 INCH       IRON               WI   TRAINED SPOTTER

            CEDAR COVE CABINS.

&&

BETTWY

The office that day

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

Issued	Product	Office	Counties	Lasted
May 25, 11:08 AM CDT	Severe Thunderstorm Warning	DLH	Pine	67 min
May 25, 4:24 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching	66 min
May 25, 4:42 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching	13 min
May 25, 4:55 PM CDT	Severe Thunderstorm Warning	DLH	Itasca	19 min
May 25, 5:20 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching	55 min
May 25, 5:52 PM CDT	Tornado Warning	DLH	Cass	23 min
May 25, 6:08 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching	67 min
May 25, 6:11 PM CDT	Tornado Warning	DLH	Cass, Itasca	41 min
May 25, 6:17 PM CDT	Severe Thunderstorm Warning	DLH	Itasca, Saint Louis	31 min
May 25, 6:51 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching	24 min
May 25, 12:12 PM CDT	Severe Thunderstorm Warning	DLH	Burnett, Washburn	33 min
May 25, 12:38 PM CDT	Severe Thunderstorm Warning	DLH	Burnett, Sawyer, Washburn	52 min
May 25, 1:25 PM CDT	Severe Thunderstorm Warning	DLH	Ashland, Sawyer	50 min
May 25, 2:08 PM CDT	Severe Thunderstorm Warning	DLH	Ashland, Iron	67 min
May 25, 2:50 PM CDT	Severe Thunderstorm Warning	DLH	Iron	25 min
May 25, 3:19 PM CDT	Severe Thunderstorm Warning	DLH	Iron, Price	29 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2008 Every severe thunderstorm warning in 2008

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.