Alert archive / Minnesota / Special Weather Statements in 2021

Special Weather Statement, NWS Twin Cities, MN

August 20, 2021Swift County, Minnesota

NWS Twin Cities, MN issued this special weather statement at Aug 20, 2021, 5:04 PM CDT for Swift County, Minnesota. It was in force for 41 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 20, 2021, 5:04 PM CDT (22:04 UTC)
Expired
Aug 20, 2021, 5:45 PM CDT
In force
41 min
Issued by
NWS Twin Cities, MN
Hail
0.00 in
Wind
50

County Swift County, MN

The radar

The Minneapolis radar (KMPX), 169 km from the middle of the area, began a volume at 22:05 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.1 hours before the alert went out and 167 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 2021-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 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 2021-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 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
48 J/kg
Mixed-layer CIN
-139 J/kg
Mixed-layer LCL
999 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

964 
WWUS83 KMPX 202204
SPSMPX

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
504 PM CDT Fri Aug 20 2021
 
MNZ054>056-202245-
Chippewa MN-Lac Qui Parle MN-Swift MN-
504 PM CDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of east central Lac qui
Parle, northwestern Chippewa and eastern Swift Counties through 545
PM CDT...

At 504 PM CDT, Doppler radar was tracking a strong thunderstorm near
Milan, or 11 miles northwest of Montevideo, moving northeast at 45
mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
  Benson and Lake Hassel.

This includes the following highways...
 U.S. Highway 12 between mile markers 30 and 53.
 U.S. Highway 212 between mile markers 30 and 38, and near mile
marker 40.
 U.S. Highway 59 near mile marker 107.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
west central Minnesota.

&&

LAT...LON 4541 9579 4542 9546 4541 9529 4489 9567
      4491 9568 4490 9569 4491 9572 4493 9573
      4492 9573 4491 9575 4498 9603
TIME...MOT...LOC 2204Z 210DEG 41KT 4510 9581 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

$$

JLT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 4:47 PM CDTSpecial Weather StatementMPXDouglas28 min
Aug 20, 4:51 PM CDTSpecial Weather StatementMPXTodd39 min
Aug 20, 4:54 PM CDTSevere Thunderstorm WarningMPXDouglas19 min
Aug 20, 5:43 PM CDTSpecial Weather StatementMPXChippewa, Pope, Swift32 min
Aug 20, 5:48 PM CDTSpecial Weather StatementMPXRenville42 min
Aug 20, 5:50 PM CDTSpecial Weather StatementMPXMartin, Watonwan40 min
Aug 20, 6:16 PM CDTSpecial Weather StatementMPXStearns44 min
Aug 20, 6:21 PM CDTSevere Thunderstorm WarningMPXPope, Stearns39 min
Aug 20, 6:53 PM CDTTornado Warning Tornado observedMPXStearns37 min

Nearby

Special Weather Statements in Minnesota, 2021Every special weather statement in 2021

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.