Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 1586

August 24, 202132 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Aug 24, 2021, 1:10 AM CDT for 32 counties in Minnesota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Aug 24, 2021, 1:10 AM CDT (06:10 UTC)
Expired
Aug 24, 2021, 2:45 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%
All 32 counties

Anoka County, MN, Benton County, MN, Carver County, MN, Chippewa County, MN, Dakota County, MN, Douglas County, MN, Grant County, MN, Hennepin County, MN, Isanti County, MN, Kanabec County, MN, Kandiyohi County, MN, Le Sueur County, MN, McLeod County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Nicollet County, MN, Otter Tail County, MN, Pope County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Wright County, MN, Yellow Medicine County, MN

The radar

The Minneapolis radar (KMPX), 120 km from the middle of the area, began a volume at 06:12 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 6.2 hours before the alert went out and 117 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 2021-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 501 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 2021-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
501 J/kg
Mixed-layer CIN
-147 J/kg
Mixed-layer LCL
1780 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

662 
ACUS11 KWNS 240610
SWOMCD
SPC MCD 240610 
MNZ000-240745-

Mesoscale Discussion 1586
NWS Storm Prediction Center Norman OK
0110 AM CDT Tue Aug 24 2021

Areas affected...Portions of central/southern MN

Concerning...Severe potential...Watch possible 

Valid 240610Z - 240745Z

Probability of Watch Issuance...60 percent

SUMMARY...The potential for scattered damaging winds and isolated
severe hail may continue with storms moving eastward this morning.
Watch issuance is possible.

DISCUSSION...An organized MCS is ongoing from southeastern SD into
northeastern SD early this morning. The northern segment of this
line is moving quickly eastward around 40-45 kt, and should reach
the eastern edge of Severe Thunderstorm Watch 459 within the next
60-90 minutes. A wind gust to 91 mph was recorded at 0533Z at a
mesonet site in association with the MCS along the ND/SD border.
While winds that high may not be occurring over a large area, there
appears to be potential for at least scattered severe/damaging winds
around 60-70 mph to continue through the early morning hours into
parts of central/southern MN. A surface front is located across this
region, with dewpoints generally in the mid 60s to low 70s to its
south. This front may try to lift northward some over the next
couple of hours, but the faster northern segment of the MCS may move
along or just north of this boundary given its quick eastward
motion. Regardless, continued lift from a southerly low-level jet
and strong deep-layer shear will likely continue to support the
intensity and longevity of this line into central/southern MN where
an unstable airmass resides. If current convective trends continue,
then a downstream Severe Thunderstorm Watch will probably be needed.

..Gleason/Thompson.. 08/24/2021

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

ATTN...WFO...DLH...MPX...FGF...FSD...

LAT...LON   46589663 46529472 46099302 45669290 44599296 44229325
            44299443 44419543 44619639 45179602 46029620 46589663

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 24, 2:17 AM CDTSevere Thunderstorm WatchSPCAnoka, Benton, Big Stone, Brown, Carver, Chippewa and 34 more7 hr
Aug 24, 3:00 AM CDTMesoscale DiscussionSPCAnoka, Benton, Big Stone, Brown, Carver, Chippewa and 35 more2 hr
Aug 24, 5:00 AM CDTMesoscale DiscussionSPCAnoka, Carver, Dakota, Hennepin, Kandiyohi, McLeod and 8 more90 min
Aug 24, 6:00 AM CDTMesoscale DiscussionSPCDodge, Faribault, Fillmore, Freeborn, Houston, Mower and 5 more90 min
Aug 24, 7:10 AM CDTMesoscale DiscussionSPCBlue Earth, Chisago, Dakota, Dodge, Fillmore, Freeborn and 13 more95 min
Aug 24, 12:44 PM CDTMesoscale DiscussionSPCHouston91 min

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.