Alert archive / Minnesota / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 187, NWS Twin Cities, MN

August 18, 2017Brown County, Martin County, Watonwan County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 18, 2017, 7:26 PM CDT for Brown County, Martin County, Watonwan County, Minnesota. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 18, 2017, 7:26 PM CDT (00:26 UTC)
Expired
Aug 18, 2017, 8:00 PM CDT
In force
34 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Brown County, MN, Martin County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 142 km from the middle of the area, began a volume at 00:28 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
Aug 18, 4:51 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.4 hours before the alert went out and 140 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 2017-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2017-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
13 J/kg
Mixed-layer CIN
-140 J/kg
Mixed-layer LCL
1494 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

556 
WUUS53 KMPX 190026
SVRMPX
MNC015-091-165-190100-
/O.NEW.KMPX.SV.W.0187.170819T0026Z-170819T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
726 PM CDT FRI AUG 18 2017

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northwestern Martin County in south central Minnesota...
  Southwestern Brown County in south central Minnesota...
  Western Watonwan County in south central Minnesota...

* Until 800 PM CDT

* At 726 PM CDT, a severe thunderstorm was located over Delft, or 9
  miles north of Windom, moving east at 45 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* This severe thunderstorm will be near,
  Butterfield around 745 PM CDT. 

Other locations impacted by this severe thunderstorm include
Sveadahl, Odin and Darfur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4379 9486 4411 9486 4411 9509 4416 9510
      4420 9470 4377 9470
TIME...MOT...LOC 0026Z 281DEG 39KT 4400 9508 

HAIL...1.00IN
WIND...60MPH
 
$$
AMK
2 follow-up statements
614 
WWUS53 KMPX 190049
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
749 PM CDT FRI AUG 18 2017

MNC015-190058-
/O.CAN.KMPX.SV.W.0187.000000T0000Z-170819T0100Z/
Brown MN-
749 PM CDT FRI AUG 18 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN BROWN COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened. 
Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 100 AM CDT for
south central Minnesota.

LAT...LON 4379 9486 4411 9486 4411 9470 4377 9470
TIME...MOT...LOC 0048Z 281DEG 39KT 4395 9475 

$$

MNC091-165-190100-
/O.CON.KMPX.SV.W.0187.000000T0000Z-170819T0100Z/
Martin MN-Watonwan MN-
749 PM CDT FRI AUG 18 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR NORTHWESTERN MARTIN AND WESTERN WATONWAN COUNTIES...

At 748 PM CDT, a severe thunderstorm was located over Butterfield, or
19 miles east of Windom, moving east at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

this severe thunderstorm will remain over mainly rural areas of
northwestern Martin and western Watonwan Counties, including the
following locations: Sveadahl, Odin and Darfur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4379 9486 4411 9486 4411 9470 4377 9470
TIME...MOT...LOC 0048Z 281DEG 39KT 4395 9475 

HAIL...1.00IN
WIND...60MPH
 
$$
AMK
652 
WWUS53 KMPX 190055
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
755 PM CDT FRI AUG 18 2017

MNC091-165-190105-
/O.EXP.KMPX.SV.W.0187.000000T0000Z-170819T0100Z/
Martin MN-Watonwan MN-
755 PM CDT FRI AUG 18 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MARTIN AND
WESTERN WATONWAN COUNTIES WILL EXPIRE AT 800 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.

A severe thunderstorm watch remains in effect until 100 AM CDT for
south central Minnesota.

LAT...LON 4379 9486 4411 9486 4411 9470 4377 9470
TIME...MOT...LOC 0055Z 281DEG 39KT 4394 9465 

$$
AMK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 7:02 PM CDTSpecial Weather StatementMPXCottonwood28 min
Aug 18, 8:30 PM CDTSpecial Weather StatementMPXMartin30 min
Aug 18, 8:53 PM CDTRiver Flood WarningMPXRedwood3 days

Nearby

Severe Thunderstorm Warnings in Minnesota, 2017Every severe thunderstorm warning in 2017

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.