Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 66, NWS Duluth, MN

May 30, 2011Aitkin County, Cass County, Crow Wing County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at May 30, 2011, 11:26 PM CDT for Aitkin County, Cass County, Crow Wing County, Minnesota. It was in force for 49 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 30, 2011, 11:26 PM CDT (04:26 UTC)
Expired: May 31, 2011, 12:15 AM CDT
In force: 49 min
Issued by: NWS Duluth, MN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 70.0 mph

Counties Aitkin County, MN, Cass County, MN, Crow Wing County, MN

The radar

The Duluth radar (KDLH), 133 km from the middle of the area, began a volume at 04:26 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.

Issued	Product	Office	Lasted
May 30, 8:43 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.4 hours before the alert went out and 205 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: 2145 J/kg
Mixed-layer CIN: -246 J/kg
Mixed-layer LCL: 1594 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 234 m²/s²
0-3 km storm-relative helicity: 408 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.8

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 May 30, 8:22 PM CDT, 3 hours 4 minutes earlier.

Area forecast discussion, May 30, 8:22 PM CDT, 3 hours 4 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
822 PM CDT MON MAY 30 2011

.MESOSCALE UPDATE...CONCERNING SEVERE THUNDERSTORM POTENTIAL IN THE
BRAINERD LAKES REGION THRU 1 AM...

SEVERE THUNDERSTORM THREAT WILL INCREASE SIGNFICANTLY AFTER 9 PM
ACROSS CASS AND CROW WING COUNTIES.  THE PRIMARY THREAT WILL BE
DESTRUCTIVE THUNDERSTORM WIND GUSTS IN EXCESS OF 75 MPH.  HAIL UP TO
PING PONG BALL SIZE WILL ALSO BE POSSIBLE WITH THE STRONGEST STORMS.

INTENSE SQUALL LINE HAS DEVELOPED ALONG THE I-29 CORRIDOR IN THE
EASTERN DAKOTAS DURING THE PAST 2 HOURS.. WITH RADAR SIGNATURES
SUGGESTIVE OF EXTREME NON-TORNADIC WIND DAMAGE POTENTIAL /PER LARGE
AREAL COVERAGE OF 80+ KNOT OUTBOUND VELOCITIES ON KABR RADAR WITH
STORM MOVING INTO SW NORTH DAKOTA/.  LARGE SCALE LIFT CONTINUES TO
INCREASE ACROSS CENTRAL AND WESTERN MINNESOTA AT MID EVENING..AS
EVIDENCED BY MID LEVEL ECHO DEVELOPMENT FROM BEMIDJI ALL THE WAY
SOUTHWARD INTO IOWA.

SQUALL LINE IN THE EASTERN DAKOTAS IS EXPECTED TO ACCELERATE
NORTHEASTWARD AFTER 9 PM..AND WHILE BOUNDARY LAYER WILL STABILIZE
SOMEWHAT ACROSS THE BRAINERD/WALKER LAKES REGION..THE SQUALL LINE
WILL BE IN AN ENVIRONMENT CHARACTERIZED BY INTENSE NEAR-SURFACE
SHEAR AND 2000+ J/KG OF MUCAPE.  SUCH AN ENVIRONMENT WILL BE VERY
FAVORABLE FOR THE DEVELOPMENT/PERSISTENCE OF INTENSE BOW ECHOES AND
EMBEDDED LINE VORTICES WHICH MAY HAVE THE POTENTIAL TO PRODUCE
NARROW CORRIDORS OF NON-TORNADIC WINDS IN EXCESS OF 75 MPH.

EXTRAPOLATION OF CURRENT DATA AND LATEST HI-RES MODEL GUIDANCE
SUGGEST THAT SEVERE T-STORM AND HIGH END WIND THREAT WILL DEVELOP
OVER SOUTHERN CASS/CROW WING COUNTIES BETWEEN 10-11 PM..WITH STORMS
PROGRESSING NORTHEASTWARD /ALTHOUGH SLOWLY WEAKENING WITH TIME/
THEREAFTER.
 MILLER

&&

.POINT TEMPS/POPS...
DLH  48  69  46  64 /  70  40  20  10
INL  51  68  43  63 /  70  50  40  10
BRD  64  66  45  71 /  70  20  10   0
HYR  67  76  50  70 /  50  40  10  10
ASX  49  74  47  66 /  50  50  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ140>147.

&&

Hazardous weather outlook, May 30, 3:11 PM CDT, 8 hours 15 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
311 PM CDT MON MAY 30 2011

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-311100-
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-
311 PM CDT MON MAY 30 2011

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

.DAY ONE...THIS EVENING AND TONIGHT

SEVERE THUNDERSTORM WILL DEVELOP BETWEEN 4 AND 7 PM THIS EVENING
ACROSS WESTERN MINNESOTA AND THE EASTERN DAKOTAS.  THESE STORMS WILL
THEN MOVE EAST LATER THIS EVENING AND OVERNIGHT... AFFECTING MUCH
OF THE NORTHLAND.  THE GREATEST THREAT OF SEVERE WEATHER WILL BE
WEST OF A LINE ROUGHLY FROM CRANE LAKE TO GRAND RAPIDS... TO LAKE
MILLE LACS... PARTICULARLY IN THE BRAINERD LAKES REGION NORTHWARD TO
WALKER AND LAKE WINNIBIGOSHISH BETWEEN 9 PM AND 2 AM.  STORMS WILL
THEN CONTINUE TO MOVE EAST OVERNIGHT... REACHING THE MINNESOTA
ARROWHEAD... THE TWIN PORTS... NORTHWEST WISCONSIN AND THE
INTERSTATE 35 CORRIDOR AFTER MIDNIGHT.

THE GREATEST RISK OF DAMAGING THUNDERSTORM WIND GUSTS UP TO 70 MPH
AND HAIL UP TO THE SIZE OF PING PONG BALLS WILL BE ALONG AND WEST OF
HIGHWAY 169 THROUGH AROUND 2 AM. THE THREAT OF TORNADOES IS EXPECTED
TO BE DIMINISHING BY THIS TIME... BUT A TORNADO CANNOT BE ENTIRELY
RULED OUT.  THE THREAT FOR DAMAGING WINDS GREATER THAN 60 MPH AND
HAIL UP TO QUARTER SIZE WILL PERSIST WELL INTO THE NIGHT IN AREAS
ALONG THE INTERSTATE 35 AND HIGHWAY 53 CORRIDORS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SHOWERS AND THUNDERSTORMS WILL CONTINUE TUESDAY ACROSS PARTS OF
NORTHWEST WISCONSIN... AND ALSO ACROSS NORTHERN MINNESOTA WHERE VERY
COLD TEMPERATURES ALOFT MAY RESULT IN SOME SMALL HAIL TUESDAY
AFTERNOON AND EVENING WITH THE STRONGEST THUNDERSTORMS.

THERE IS ANOTHER CHANCE OF THUNDERSTORMS THURSDAY AND FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS EVENING AND
OVERNIGHT TONIGHT.

LSZ121-140>148-311000-
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-
456 AM CDT MON MAY 30 2011

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

.DAY ONE...THIS EVENING AND TONIGHT

GUSTY NORTHEAST WINDS WILL GENERATE BUILDING WAVES TODAY. A SMALL
CRAFT ADVISORY IS IN EFFECT THROUGH THIS EVENING. PLEASE REFER TO
THE LATEST MARINE WEATHER MESSAGE FOR DETAILS.

PERIODIC BOUTS OF THUNDERSTORMS WILL ALSO CONTINUE TONIGHT AND
TUESDAY... ALONG WITH DENSE MARINE FOG ESPECIALLY THIS EVENING
THOUGHT TUESDAY MORNING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THERE IS A CHANCE FOR THUNDERSTORMS AGAIN TUESDAY... AND ANOTHER
CHANCE FOR THUNDERSTORMS FRIDAY INTO SATURDAY.

 MILLER

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB ADDRESS:
HTTP://WWW.WEATHER.GOV/DULUTH (ALL LOWER CASE)

In the hours before

Special weather statement, May 30, 10:20 PM CDT, 1 hour 6 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DULUTH MN
1020 PM CDT MON MAY 30 2011

MNZ018-025-033-034-310400-
CROW WING-NORTH CASS-NORTH ITASCA-SOUTH CASS-
1020 PM CDT MON MAY 30 2011

...LINE OF STRONG TO SEVERE STORMS APPROACHING CASS COUNTY...

AT 1016 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 39 MILES WEST OF
TOWN OF CASS LAKE TO 34 MILES SOUTHWEST OF ESTERDY...MOVING EAST
NORTHEAST AT 50 MPH.

THESE STORMS ARE CAPABLE OF PRODUCING SOME WIND GUSTS OF 40 TO 50
MPH AND SOME HAIL...CONTINUOUS CLOUD TO GROUND LIGHTNING...AND
TORRENTIAL RAIN.

EMBEDDED WITHIN THIS LINE...THERE MAY BE A FEW STORMS CAPABLE OF
PRODUCING STRONGER WIND GUSTS AND SOME LARGE HAIL.

LOCATIONS IMPACTED INCLUDE...
  ESTERDY...            POPLAR...             LEADER...
  OSHAWA...             PHEASANT LAKE...      GULL LAKE...
  TOWN OF CASS LAKE...  WALKER...             SYLVAN...
  PINE RIVER...         PILLAGER...           LENNOX...
  LAKE SHORE...         HACKENSACK...         FORT RIPLEY...

STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN
A STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 2 AM CDT.

LAT...LON 4680 9481 4681 9468 4684 9467 4741 9468
      4742 9443 4779 9443 4785 9421 4615 9410
      4615 9437 4623 9440 4629 9436 4632 9443
      4629 9454 4640 9480

LAMERS

The office that day

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

Issued	Product	Office	Counties	Lasted
May 30, 10:20 PM CDT	Special Weather Statement	DLH	Cass	40 min
May 30, 10:50 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Crow Wing, Itasca	55 min
May 30, 11:52 PM CDT	Special Weather Statement	DLH	Aitkin, Cass, Crow Wing, Itasca, Koochiching	113 min
May 30, 11:55 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton, Cass, Crow Wing, Itasca, Pine and 1 more	65 min
May 31, 12:47 AM CDT	Severe Thunderstorm Warning	DLH	Carlton, Itasca, Pine, Saint Louis	28 min
May 31, 12:55 AM CDT	Areal Flood Advisory	DLH	Aitkin, Crow Wing	4 hr
May 31, 1:25 AM CDT	Special Weather Statement	DLH	Pine	20 min
May 31, 3:42 AM CDT	Small Craft Advisory	DLH		39 hr
May 31, 4:00 AM CDT	Wind Advisory	DLH	Aitkin, Carlton, Cass, Crow Wing, Itasca, Lake and 2 more	18 hr
May 31, 12:10 PM CDT	Special Weather Statement	DLH	Cook	20 min
May 31, 2:25 AM CDT	Special Weather Statement	DLH	Burnett	20 min
May 31, 11:47 AM CDT	Special Weather Statement	DLH	Price	13 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2011 Every severe thunderstorm warning in 2011

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.