Alert archive / Minnesota / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 195, NWS Twin Cities, MN

September 20, 2017Swift County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 20, 2017, 12:24 AM CDT for Swift County, Minnesota. It was in force for 21 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
Sep 20, 2017, 12:24 AM CDT (05:24 UTC)
Expired
Sep 20, 2017, 12:45 AM CDT
In force
21 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Swift County, MN

The radar

The Minneapolis radar (KMPX), 159 km from the middle of the area, began a volume at 05:25 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, 12:30 AM CDTHAIL 1.2510 Wnw Sunburg, MNIN SWIFT FALLS ON CR 31.
Sep 20, 12:33 AM CDTTSTM WND DMG5 Wsw Sunburg, MNGRAIN BINS AND SHEDS DAMAGED. POSSIBLE TORNADO.

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 19, 10:36 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 5.4 hours before the alert went out and 156 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 2017-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 246 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 2017-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 274 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
246 J/kg
Mixed-layer CIN
-155 J/kg
Mixed-layer LCL
1179 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
274 m²/s²
0-3 km storm-relative helicity
454 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.2

Open this sounding in Storm Lab

The text

As transmitted.

926 
WUUS53 KMPX 200524
SVRMPX
MNC151-200545-
/O.NEW.KMPX.SV.W.0195.170920T0524Z-170920T0545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
1224 AM CDT WED SEP 20 2017

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Eastern Swift County in west central Minnesota...

* Until 1245 AM CDT

* At 1223 AM CDT, severe thunderstorms were located along a line
  extending from near Clontarf to near De Graff to near Montevideo
  Airport, moving northeast at 70 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. 

* Severe thunderstorms will be near,
  Kerkhoven and Murdock around 1240 AM CDT. 

Other locations impacted by these severe thunderstorms include De
Graff, Swift Falls, and Clontarf.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4541 9572 4542 9550 4541 9526 4519 9524
      4515 9525 4515 9561 4523 9558
TIME...MOT...LOC 0523Z 230DEG 61KT 4542 9563 4528 9553 4501 9567 

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

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 19, 10:55 PM CDTSevere Thunderstorm WarningMPXLac qui Parle50 min
Sep 19, 11:24 PM CDTSevere Thunderstorm WarningMPXStevens, Swift36 min
Sep 19, 11:42 PM CDTSpecial Weather StatementMPXLac qui Parle, Yellow Medicine48 min
Sep 19, 11:50 PM CDTSevere Thunderstorm WarningMPXDouglas, Pope, Stevens55 min
Sep 20, 12:03 AM CDTSpecial Weather StatementMPXSwift57 min
Sep 20, 12:06 AM CDTSpecial Weather StatementMPXMeeker24 min
Sep 20, 12:16 AM CDTSpecial Weather StatementMPXChippewa, Yellow Medicine44 min
Sep 20, 12:42 AM CDTSevere Thunderstorm WarningMPXKandiyohi, Pope, Stearns, Todd33 min
Sep 20, 12:45 AM CDTSpecial Weather StatementMPXBenton, Morrison45 min
Sep 20, 12:51 AM CDTSpecial Weather StatementMPXKandiyohi, Meeker, Renville39 min
Sep 20, 12:55 AM CDTSpecial Weather StatementMPXBrown, Redwood35 min
Sep 20, 1:02 AM CDTSevere Thunderstorm WarningMPXKandiyohi, Meeker, Renville43 min
Sep 20, 1:11 AM CDTSevere Thunderstorm WarningMPXBenton, Morrison, Sherburne, Stearns49 min
Sep 20, 1:15 AM CDTSevere Thunderstorm WarningMPXBrown, Nicollet, Redwood, Renville, Sibley30 min
Sep 20, 1:37 AM CDTSevere Thunderstorm WarningMPXMeeker, Sherburne, Stearns, Wright38 min
Sep 20, 1:41 AM CDTSevere Thunderstorm WarningMPXMcLeod, Renville, Sibley34 min
Sep 20, 1:49 AM CDTSevere Thunderstorm WarningMPXBenton, Kanabec, Mille Lacs, Morrison56 min
Sep 20, 2:00 AM CDTSevere Thunderstorm WarningMPXBenton, Isanti, Mille Lacs, Sherburne45 min
Sep 20, 2:12 AM CDTSpecial Weather StatementMPXAnoka, Hennepin, Wright48 min
Sep 20, 2:36 AM CDTSpecial Weather StatementMPXHennepin, Ramsey, Washington69 min
Sep 20, 2:57 AM CDTSpecial Weather StatementMPXChisago33 min
Sep 20, 3:04 AM CDTSevere Thunderstorm WarningMPXChisago26 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.