Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 1338

July 24, 202115 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2021, 1:10 AM CDT for 15 counties in Minnesota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jul 24, 2021, 1:10 AM CDT (06:10 UTC)
Expired
Jul 24, 2021, 2:45 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 388...389

Counties Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Kandiyohi County, MN, Meeker County, MN, Otter Tail County, MN, Pope County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN

The radar

The Minneapolis radar (KMPX), 190 km from the middle of the area, began a volume at 06:14 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 00:00Z, 6.2 hours before the alert went out and 187 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 2021-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2540 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 2021-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 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
2540 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1098 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.4

Open this sounding in Storm Lab

The text

As transmitted.

628 
ACUS11 KWNS 240611
SWOMCD
SPC MCD 240610 
MNZ000-SDZ000-240745-

Mesoscale Discussion 1338
NWS Storm Prediction Center Norman OK
0110 AM CDT Sat Jul 24 2021

Areas affected...Portions of far eastern SD into west-central MN

Concerning...Severe Thunderstorm Watch 388...389...

Valid 240610Z - 240745Z

The severe weather threat for Severe Thunderstorm Watch 388, 389
continues.

SUMMARY...An isolated strong to severe wind threat should continue
into west-central Minnesota early this morning.

DISCUSSION...A wind gust to 63 mph was recently measured at a
mesonet site in far northeastern SD with a small cluster of storms.
There is convection occurring ahead of this cluster in a low-level
warm advection regime across west-central MN. Still, the airmass
downstream across this region remains somewhat favorable for
surface-based storms, with around 2000 J/kg of MLCAPE present per
latest mesoanalysis estimates. The influence of glancing ascent
associated with an upper-level trough and modestly enhanced
mid-level winds should continue to support storm organization early
this morning. With the mainly linear structure ongoing ahead of a
surface cold front, isolated strong to severe winds gusts should
remain the primary threat in the short term. Some hail may also
occur. It remains unclear how long the severe threat will continue
across MN, as the better boundary-layer instability and potential
for surface-based storms will probably remain slightly to the south
of a convectively reinforced boundary extending across central MN.

..Gleason.. 07/24/2021

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

ATTN...WFO...DLH...MPX...FGF...ABR...

LAT...LON   44879536 45309682 45869650 46229650 46559649 46749605
            46739506 46269450 45119438 44869475 44879536

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 23, 7:44 PM CDTMesoscale DiscussionSPCAitkin, Carlton, Cass, Lake, Saint Louis2 hr
Jul 23, 9:07 PM CDTMesoscale DiscussionSPCLac qui Parle, Lincoln, Lyon, Murray, Pipestone, Redwood and 2 more2 hr
Jul 23, 10:33 PM CDTMesoscale DiscussionSPCBig Stone, Clay, Grant, Otter Tail, Stevens, Traverse and 1 more117 min
Jul 23, 11:22 PM CDTSevere Thunderstorm WatchSPCAnoka, Benton, Big Stone, Chippewa, Douglas, Grant and 16 more4 hr

Nearby

Mesoscale Discussions in Minnesota, 2021Every 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.