Alert archive / Minnesota / Severe Thunderstorm Watches in 2005

Severe Thunderstorm Watch 310

May 21, 200519 counties in Minnesota

The Storm Prediction Center issued this severe thunderstorm watch at May 21, 2005, 3:15 PM CDT for 19 counties in Minnesota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 21, 2005, 3:15 PM CDT (20:15 UTC)
Expired: May 21, 2005, 9:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Becker County, MN, Beltrami County, MN, Cass County, MN, Clay County, MN, Clearwater County, MN, Crow Wing County, MN, Hubbard County, MN, Koochiching County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Marshall County, MN, Norman County, MN, Otter Tail County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Wadena County, MN, Wilkin County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 148 km from the middle of the area, began a volume at 20:15 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 21, 4:02 PM CDT	Severe Thunderstorm Warning	FGF	Becker, Clay	43 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

Mesoscale Discussion 950May 21, 1:24 PM CDT

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 8.3 hours before the alert went out and 215 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: 1002 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 39 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 212011
SEL0  
SPC WW 212011
MNZ000-220200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 310
NWS STORM PREDICTION CENTER NORMAN OK
315 PM CDT SAT MAY 21 2005

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 

       NORTHERN MINNESOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 315 PM UNTIL
900 PM CDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65
STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES EAST NORTHEAST
OF WARROAD MINNESOTA TO 55 MILES WEST SOUTHWEST OF BRAINERD
MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

DISCUSSION...THUNDERSTORMS INCREASING ALONG FRONT MOVING INTO NWRN
MN.  ALTHOUGH INSTABILITY IS MARGINAL...VERY STRONG DEEP LAYER SHEAR
WITH APPROACH OF NEARLY 100 KT 500 MB WIND MAX EXPECTED TO SUPPORT
SEVERE THUNDERSTORMS AS FRONT MOVES EWD ACROSS NRN MN. PRIMARY
THREAT WILL BE DAMAGING WINDS WITH FAST MOVING STORMS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 25040.


...HALES

490,0933 460,0935 460,0963 490,0962

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 11:37 PM CDT	Mesoscale Discussion	SPC	Clay, Mahnomen, Norman, Pennington, Polk, Red Lake and 1 more	83 min
May 21, 1:08 AM CDT	Mesoscale Discussion	SPC	Big Stone, Clay, Grant, Lac qui Parle, Stevens, Traverse and 1 more	97 min
May 21, 1:35 AM CDT	Severe Thunderstorm Watch	SPC	Becker, Clay, Mahnomen, Marshall, Norman, Pennington and 3 more	7 hr
May 21, 4:52 AM CDT	Mesoscale Discussion	SPC	Becker, Clay, Mahnomen, Marshall, Norman, Pennington and 3 more	83 min
May 21, 7:43 AM CDT	Mesoscale Discussion	SPC	Becker, Clay, Mahnomen, Marshall, Norman, Pennington and 3 more	62 min
May 21, 1:24 PM CDT	Mesoscale Discussion	SPC	Becker, Clay, Clearwater, Kittson, Mahnomen, Marshall and 7 more	66 min

Nearby

Severe Thunderstorm Watches in Minnesota, 2005 Every severe thunderstorm watch in 2005

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.