Alert archive / Wisconsin / Mesoscale Discussions in 2019

Mesoscale Discussion 784

May 24, 20194 counties in Iowa; Houston County, Winona County, Minnesota; 11 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 24, 2019, 9:17 PM CDT for 4 counties in Iowa; Houston County, Winona County, Minnesota; 11 counties in Wisconsin. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: May 24, 2019, 9:17 PM CDT (02:17 UTC)
Expired: May 24, 2019, 11:15 PM CDT
In force: 118 min
Issued by: the Storm Prediction Center

Counties Allamakee County, IA, Clayton County, IA, Fayette County, IA, Winneshiek County, IA, Houston County, MN, Winona County, MN, Adams County, WI, Crawford County, WI, Grant County, WI, Iowa County, WI, Juneau County, WI, La Crosse County, WI, Lafayette County, WI, Monroe County, WI, Richland County, WI, Sauk County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 77 km from the middle of the area, began a volume at 02:16 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

Davenport, (KDVN), launched 00:00Z, 2.3 hours before the alert went out and 177 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 0 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

942 
ACUS11 KWNS 250217
SWOMCD
SPC MCD 250217 
WIZ000-IAZ000-MNZ000-250415-

Mesoscale Discussion 0784
NWS Storm Prediction Center Norman OK
0917 PM CDT Fri May 24 2019

Areas affected...Parts of far northeast Iowa...extreme southeast
Minnesota...southwest Wisconsin

Concerning...Tornado Watch 237...

Valid 250217Z - 250415Z

The severe weather threat for Tornado Watch 237 continues.

SUMMARY...Severe potential continues with sustained supercell
structures currently located across far southwest Wisconsin. Storms
are progressing eastward into an increasingly stable airmass, and
are expected to become increasingly elevated with time.

DISCUSSION...Mutliple supercell structures, occasionally exhibiting
strong low-level rotation, are progressing eastward along a line
from Monroe to Lafayette Counties in far southwest Wisconsin. These
storms are co-located just north of a quasi-stationary baroclinic
zone, where up to 1000 J/kg MLCAPE and effective SRH approaching 400
m2/s2 are in place. As such, any storms that remain rooted within
the boundary layer over the next couple of hours will have the
potential to ingest the copious amounts of available streamwise
vorticity to acquire strong low-level rotation/produce tornadoes.
Otherwise, a stabilizing boundary layer should result in storms
becoming elevated with time, reducing the overall tornado threat.

..Squitieri/Grams.. 05/25/2019

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

ATTN...WFO...MKX...DVN...ARX...DMX...

LAT...LON   42559215 44009187 44018969 42558999 42559215

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 24, 7:00 PM CDT	Mesoscale Discussion	SPC	Allamakee, Black Hawk, Bremer, Buchanan, Chickasaw, Clayton and 5 more	2 hr
May 24, 7:49 PM CDT	Tornado Watch	SPC	Allamakee, Clayton, Fayette, Winneshiek	3 hr
May 24, 8:57 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Des Moines, Dubuque, Jackson and 4 more	2 hr
May 25, 3:24 PM CDT	Mesoscale Discussion	SPC	Appanoose, Davis, Des Moines, Henry, Jefferson, Lee and 2 more	3 hr
May 25, 5:23 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Appanoose, Clarke, Davis, Decatur, Lucas and 7 more	6 hr
May 25, 6:48 PM CDT	Mesoscale Discussion	SPC	Des Moines, Henry, Jefferson, Keokuk, Lee, Louisa and 2 more	57 min

Nearby

Mesoscale Discussions in Wisconsin, 2019 Mesoscale Discussions in Iowa, 2019 Mesoscale Discussions in Minnesota, 2019 Every mesoscale discussion in 2019

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.