Alert archive / Minnesota / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 39, NWS Twin Cities, MN

July 9, 2020Dakota County, Washington County, Minnesota; Pierce County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 9, 2020, 5:38 AM CDT for Dakota County, Washington County, Minnesota; Pierce County, Saint Croix County, Wisconsin. It was in force for 24 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 9, 2020, 5:38 AM CDT (10:38 UTC)
Expired
Jul 9, 2020, 6:02 AM CDT
In force
24 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Dakota County, MN, Washington County, MN, Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 60 km from the middle of the area, began a volume at 10:43 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.

What was reported inside it

TimeReportWhereRemark
Jul 9, 5:40 AM CDTHAIL 12 W Hastings, MN
Jul 9, 5:43 AM CDTHAIL 1.25Hastings, MNPICTURE ON TWITTER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 10.6 hours before the alert went out and 62 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 2020-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2332 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 2020-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
2332 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1764 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

853 
WUUS53 KMPX 091038
SVRMPX
MNC037-163-WIC093-109-091115-
/O.NEW.KMPX.SV.W.0039.200709T1038Z-200709T1115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
538 AM CDT Thu Jul 9 2020

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  East central Dakota County in east central Minnesota...
  Southeastern Washington County in east central Minnesota...
  Northwestern Pierce County in west central Wisconsin...
  Southwestern St. Croix County in west central Wisconsin...

* Until 615 AM CDT.

* At 538 AM CDT, a severe thunderstorm was located over Hastings, or
  14 miles southwest of River Falls, moving northeast at 25 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  River Falls, Cottage Grove, Hastings, Hudson, Prescott, Afton,
  Lakeland, Lakeland Shores, Afton State Park, Lake St Croix Beach,
  St Marys Point and Kinnickinnic State Park.

This includes Interstate 94 in Wisconsin near mile marker 1.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4470 9291 4479 9296 4497 9274 4476 9256
TIME...MOT...LOC 1038Z 234DEG 22KT 4477 9288 

HAIL...1.25IN
WIND...60MPH
 
$$

TDH
2 follow-up statements
399 
WWUS53 KMPX 091054
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
554 AM CDT Thu Jul 9 2020

MNC037-091103-
/O.CAN.KMPX.SV.W.0039.000000T0000Z-200709T1115Z/
Dakota MN-
554 AM CDT Thu Jul 9 2020

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL DAKOTA COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4475 9282 4475 9285 4479 9291 4497 9274
      4476 9256 4474 9280
TIME...MOT...LOC 1053Z 234DEG 22KT 4483 9277 

$$

MNC163-WIC093-109-091115-
/O.CON.KMPX.SV.W.0039.000000T0000Z-200709T1115Z/
Washington MN-Pierce WI-St. Croix WI-
554 AM CDT Thu Jul 9 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR SOUTHEASTERN WASHINGTON...NORTHWESTERN PIERCE AND SOUTHWESTERN
ST. CROIX COUNTIES...

At 553 AM CDT, a severe thunderstorm was located near Prescott, or 8
miles west of River Falls, moving northeast at 25 mph.

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

SOURCE...Trained weather spotters reported quarter to half dollar 
         sized hail in Hastings.

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

Locations impacted include...
River Falls, Cottage Grove, Hastings, Hudson, Prescott, Afton,
Lakeland, Kinnickinnic State Park, Afton State Park, Lake St Croix
Beach, St Marys Point and Point Douglas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4475 9282 4475 9285 4479 9291 4497 9274
      4476 9256 4474 9280
TIME...MOT...LOC 1053Z 234DEG 22KT 4483 9277 

HAIL...1.00IN
WIND...60MPH
 
$$

TDH
530 
WWUS53 KMPX 091102
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
602 AM CDT Thu Jul 9 2020

MNC163-WIC093-109-091112-
/O.CAN.KMPX.SV.W.0039.000000T0000Z-200709T1115Z/
Washington MN-Pierce WI-St. Croix WI-
602 AM CDT Thu Jul 9 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON...
NORTHWESTERN PIERCE AND SOUTHWESTERN ST. CROIX COUNTIES IS
CANCELLED...
                
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 has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

LAT...LON 4475 9282 4475 9285 4479 9291 4497 9274
      4476 9256 4474 9280
TIME...MOT...LOC 1100Z 234DEG 22KT 4486 9270 

$$

TDH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 7:15 PM CDTSpecial Weather StatementMPXTodd30 min
Jul 8, 7:33 PM CDTSpecial Weather StatementMPXTodd27 min
Jul 8, 7:44 PM CDTSpecial Weather StatementMPXTodd31 min
Jul 8, 8:24 PM CDTSevere Thunderstorm WarningMPXMille Lacs24 min
Jul 8, 8:35 PM CDTSpecial Weather StatementMPXKanabec25 min
Jul 8, 9:28 PM CDTSpecial Weather StatementMPXKanabec32 min
Jul 9, 12:57 AM CDTSpecial Weather StatementMPXSwift48 min
Jul 9, 1:56 AM CDTSpecial Weather StatementMPXStearns49 min
Jul 9, 2:44 AM CDTSpecial Weather StatementMPXMille Lacs, Morrison46 min
Jul 9, 3:55 AM CDTSpecial Weather StatementMPXCarver35 min
Jul 9, 4:05 AM CDTSpecial Weather StatementMPXIsanti25 min
Jul 9, 4:12 AM CDTSevere Thunderstorm WarningMPXCarver, Scott, Sibley33 min
Jul 9, 4:36 AM CDTSevere Thunderstorm WarningMPXHennepin, Scott24 min
Jul 9, 4:39 AM CDTSpecial Weather StatementMPXChisago51 min
Jul 9, 4:47 AM CDTSevere Thunderstorm WarningMPXBlue Earth, Watonwan23 min
Jul 9, 4:49 AM CDTSevere Thunderstorm WarningMPXAnoka, Hennepin, Ramsey, Washington26 min
Jul 9, 4:58 AM CDTSevere Thunderstorm WarningMPXDakota, Scott14 min
Jul 9, 5:18 AM CDTSpecial Weather StatementMPXRice27 min
Jul 9, 5:20 AM CDTSpecial Weather StatementMPXWashington25 min
Jul 9, 7:44 AM CDTSpecial Weather StatementMPXSteele16 min
Jul 9, 9:55 AM CDTSpecial Weather StatementMPXSteele35 min
Jul 9, 11:45 AM CDTSpecial Weather StatementMPXFreeborn30 min
Jul 8, 11:54 PM CDTSpecial Weather StatementMPXRusk51 min
Jul 9, 5:14 AM CDTSpecial Weather StatementMPXChippewa31 min
Jul 9, 5:15 AM CDTSpecial Weather StatementMPXEau Claire30 min
Jul 9, 5:30 AM CDTSpecial Weather StatementMPXPolk45 min
Jul 9, 5:48 AM CDTSpecial Weather StatementMPXChippewa, Eau Claire42 min
Jul 9, 5:51 AM CDTSevere Thunderstorm WarningMPXSaint Croix13 min
Jul 9, 6:04 AM CDTSevere Thunderstorm WarningMPXPolk, Saint Croix14 min
Jul 9, 6:19 AM CDTSpecial Weather StatementMPXSaint Croix41 min
Jul 9, 7:10 AM CDTSpecial Weather StatementMPXDunn35 min
Jul 9, 7:20 AM CDTSpecial Weather StatementMPXEau Claire25 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2020Severe Thunderstorm Warnings in Wisconsin, 2020Every severe thunderstorm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.