Alert archive / Minnesota / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 154, NWS Twin Cities, MN

September 20, 20186 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 20, 2018, 6:41 PM CDT for 6 counties in Minnesota. It was in force for 34 min. 13 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
Sep 20, 2018, 6:41 PM CDT (23:41 UTC)
Expired
Sep 20, 2018, 7:15 PM CDT
In force
34 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Anoka County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Ramsey County, MN, Washington County, MN

The radar

The Minneapolis radar (KMPX), 57 km from the middle of the area, began a volume at 23:42 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
Sep 20, 6:50 PM CDTTSTM WND DMGFarmington, MNTREES AND POWER LINES DOWN.
Sep 20, 6:51 PM CDTTSTM WND DMG6 Wnw Randolph, MNTREES AND POWER LINES DOWN.
Sep 20, 6:53 PM CDTTSTM WND DMGWest St. Paul, MNTREES DOWN.
Sep 20, 6:59 PM CDTTSTM WND DMGRandolph, MNTREES AND POWER LINES DOWN.
Sep 20, 7:00 PM CDTTSTM WND DMGHampton, MNTREES AND POWER LINES DOWN.
Sep 20, 7:02 PM CDTTSTM WND DMGCannon Falls, MNCORRECTS PREVIOUS TSTM WND DMG REPORT FROM CANNON FALLS. PHOTOS OF LARGE, HEALTHY TREES UPROOTED AND SIGNIFICANT DAMAGE TO OUTBUILDINGS. RELAYED VIA TWITTER BY TV METEOROLOGIST.
Sep 20, 7:02 PM CDTTSTM WND DMGCannon Falls, MNTWEET WITH PHOTOS SHOWING TREES DOWN ON ROADS AND HOUSES ONE MILE SOUTH OF MAYO HOSPITAL.
Sep 20, 7:02 PM CDTTORNADO3 Ene Randolph, MNEF0 TORNADO TRACKED EASTWARD 3.5 MILES ON THE NORTH SIDE OF CANNON FALLS.
Sep 20, 7:03 PM CDTTSTM WND DMGCannon Falls, MNMANY TREES AND POWER LINES DOWN. POSSIBLY A CONTINUATION OF THE TORNADO TO THE SOUTHWEST.
Sep 20, 7:05 PM CDTTSTM WND DMGCannon Falls, MNNUMEROUS TREES DOWN. POWER OUT IN CANNON FALLS.
Sep 20, 7:15 PM CDTTSTM WND DMG7 Nw Red Wing, MNSOME TREES AND POWER LINES DOWN AROUND PRAIRIE ISLAND INDIAN COMMUNITY.
Sep 20, 7:17 PM CDTTORNADO7 Ene Miesville, MNEF0 TORNADO TRACKED 3.9 MILES FROM NEAR PRAIRIE ISLAND EAST ACROSS THE MISSISSIPPI RIVER TO THE SOUTH SIDE OF DIAMOND BLUFF, WI.
Sep 20, 7:20 PM CDTTSTM WND GST 636 E Miesville, MNMESONET STATION MN047, RED WING 4W.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Sep 20, 3:33 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.7 hours before the alert went out and 60 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 12:00Z on 2018-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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 12:00Z on 2018-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 195 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
18 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
461 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
195 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

974 
WUUS53 KMPX 202341
SVRMPX
MNC003-037-049-053-123-163-210015-
/O.NEW.KMPX.SV.W.0154.180920T2341Z-180921T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
641 PM CDT THU SEP 20 2018

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Southeastern Hennepin County in east central Minnesota...
  Dakota County in east central Minnesota...
  Northwestern Goodhue County in southeastern Minnesota...
  Southeastern Anoka County in east central Minnesota...
  Washington County in east central Minnesota...
  Ramsey County in east central Minnesota...

* Until 715 PM CDT.

* At 641 PM CDT, severe thunderstorms were located along a line
  extending from Coon Rapids to Webster, moving east at 50 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Minneapolis, St. Paul, Northfield, Red Wing, Bloomington, Eagan,
  Woodbury, Coon Rapids, Burnsville, Blaine, Lakeville and Apple
  Valley.

This includes the following highways...
 Interstate 35 between mile markers 130 and 133.
 U.S. Highway 8 in Minnesota between mile markers 0 and 2.
 U.S. Highway 61 between mile markers 96 and 104.

This includes  Treasure Island Casino.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in The Twin Cities.

&&

A Tornado Watch remains in effect until 1100 PM CDT for south
central, southeastern and east central Minnesota. A Tornado Watch
also remains in effect until midnight CDT for west central Wisconsin.

LAT...LON 4519 9327 4530 9302 4530 9275 4519 9277
      4511 9274 4506 9280 4503 9276 4497 9277
      4494 9275 4490 9278 4482 9277 4475 9281
      4464 9262 4451 9261 4447 9327
TIME...MOT...LOC 2341Z 260DEG 45KT 4515 9330 4454 9334 

HAIL...0.75IN
WIND...60MPH
 
$$

JLT
1 follow-up statement
648 
WWUS53 KMPX 210009
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
709 PM CDT THU SEP 20 2018

MNC003-037-049-053-123-163-210018-
/O.EXP.KMPX.SV.W.0154.000000T0000Z-180921T0015Z/
Hennepin MN-Dakota MN-Goodhue MN-Anoka MN-Washington MN-Ramsey MN-
709 PM CDT THU SEP 20 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HENNEPIN...
DAKOTA...NORTHWESTERN GOODHUE...SOUTHEASTERN ANOKA...WASHINGTON AND
RAMSEY COUNTIES WILL EXPIRE AT 715 PM CDT...
    
The storms which prompted the warning have weakened below severe 
limits. Therefore, the warning will be allowed to expire. However 
gusty winds and heavy rain are still possible with these 
thunderstorms.

A Tornado Watch remains in effect until 1100 PM CDT for south
central, southeastern and east central Minnesota. A Tornado Watch
also remains in effect until midnight CDT for west central Wisconsin.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
The Twin Cities.

Remember, a Tornado Warning still remains in effect for Dakota 
county until 730 PM. 

LAT...LON 4519 9327 4530 9302 4530 9275 4519 9277
      4511 9274 4506 9280 4503 9276 4497 9277
      4494 9275 4490 9278 4482 9277 4475 9281
      4464 9262 4451 9261 4447 9327
TIME...MOT...LOC 0008Z 260DEG 45KT 4520 9285 4459 9290 

$$

JLT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 12:13 PM CDTSpecial Weather StatementMPXBrown, Nicollet32 min
Sep 20, 12:53 PM CDTSpecial Weather StatementMPXBrown37 min
Sep 20, 1:33 PM CDTSpecial Weather StatementMPXLe Sueur, Scott42 min
Sep 20, 1:49 PM CDTSpecial Weather StatementMPXDakota26 min
Sep 20, 2:07 PM CDTSpecial Weather StatementMPXRice, Washington38 min
Sep 20, 2:31 PM CDTSpecial Weather StatementMPXRamsey119 min
Sep 20, 2:46 PM CDTRiver Flood WarningMPXRedwood9 days
Sep 20, 3:00 PM CDTSpecial Weather StatementMPXYellow Medicine30 min
Sep 20, 3:24 PM CDTSpecial Weather StatementMPXRenville36 min
Sep 20, 4:50 PM CDTSpecial Weather StatementMPXRamsey85 min
Sep 20, 5:21 PM CDTSpecial Weather StatementMPXHennepin, Ramsey54 min
Sep 20, 5:30 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Faribault, Martin, Watonwan45 min
Sep 20, 5:51 PM CDTSpecial Weather StatementMPXCarver, Le Sueur, Nicollet, Sibley24 min
Sep 20, 5:54 PM CDTAreal Flood WarningMPXAnoka, Carver, Dakota, Hennepin, Ramsey, Scott and 2 more3 hr
Sep 20, 5:59 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Faribault, Waseca46 min
Sep 20, 6:13 PM CDTSevere Thunderstorm WarningMPXCarver, Dakota, Hennepin, Ramsey, Scott47 min
Sep 20, 6:15 PM CDTSevere Thunderstorm WarningMPXCarver15 min
Sep 20, 6:19 PM CDTTornado WarningMPXLe Sueur, Rice, Waseca41 min
Sep 20, 6:23 PM CDTSevere Thunderstorm WarningMPXFreeborn, Le Sueur, Rice, Steele, Waseca52 min
Sep 20, 6:40 PM CDTTornado WarningMPXGoodhue, Rice, Steele35 min
Sep 20, 6:49 PM CDTTornado Warning Tornado observedMPXDakota, Goodhue, Rice41 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2018Every severe thunderstorm warning in 2018

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.