Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 1633

August 28, 20215 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Aug 28, 2021, 6:09 PM CDT for 5 counties in Minnesota. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Aug 28, 2021, 6:09 PM CDT (23:09 UTC)
Expired: Aug 28, 2021, 7:15 PM CDT
In force: 66 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 471

Counties Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Nicollet County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 135 km from the middle of the area, began a volume at 23:12 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, 11.2 hours before the alert went out and 133 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1550 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 676 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

259 
ACUS11 KWNS 282309
SWOMCD
SPC MCD 282309 
MNZ000-290015-

Mesoscale Discussion 1633
NWS Storm Prediction Center Norman OK
0609 PM CDT Sat Aug 28 2021

Areas affected...Southwest and south-central Minnesota

Concerning...Severe Thunderstorm Watch 471...

Valid 282309Z - 290015Z

The severe weather threat for Severe Thunderstorm Watch 471
continues.

SUMMARY...Areas of intense wind damage (up to 85 mph) are possible
with a bowing complex in southwestern Minnesota.

DISCUSSION...KFSD radar imagery shows an intensifying wind signature
with a bowing complex in southwest Minnesota. A broad area of 90+
kts of outbound velocity is evident within the lowest 6000 ft. With
the complex moving north-northeast at near 50 kts, areas of intense
wind damage are possible. Winds could reach up to 85 mph. The max
intensity of this complex is expected to last for at least the next
hour or two.

..Wendt/Guyer.. 08/28/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MPX...FSD...

LAT...LON   44169581 44519479 44479391 44089386 44029405 43719543
            43679555 44169581

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 27, 9:57 PM CDT	Mesoscale Discussion	SPC	Fillmore, Houston	93 min
Aug 28, 2:17 AM CDT	Mesoscale Discussion	SPC	Big Stone, Stevens, Swift, Traverse	2 hr
Aug 28, 2:32 AM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Traverse	5 hr
Aug 28, 5:42 AM CDT	Mesoscale Discussion	SPC	Benton, Big Stone, Chippewa, Douglas, Grant, Kandiyohi and 11 more	2 hr
Aug 28, 7:08 AM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 13 more	5 hr
Aug 28, 9:39 AM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Chisago, Douglas, Grant, Isanti and 12 more	2 hr
Aug 28, 10:34 AM CDT	Tornado Watch	SPC	Aitkin, Anoka, Benton, Carlton, Carver, Chisago and 14 more	4 hr
Aug 28, 1:13 PM CDT	Mesoscale Discussion	SPC	Anoka, Chisago, Isanti, Kanabec, Pine	2 hr
Aug 28, 2:43 PM CDT	Mesoscale Discussion	SPC	Murray, Nobles, Pipestone, Rock	3 hr
Aug 28, 3:44 PM CDT	Tornado Watch	SPC	Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more	5 hr
Aug 28, 3:57 PM CDT	Severe Thunderstorm Watch	SPC	Cottonwood, Jackson, Murray, Nobles, Rock	7 hr
Aug 28, 5:27 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 22 more	63 min
Aug 28, 5:59 PM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Faribault, Freeborn, Le Sueur and 11 more	6 hr

Nearby

Mesoscale Discussions in Minnesota, 2021 Every mesoscale discussion 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.