Mesoscale Discussion 752

Issued

May 17, 2017, 6:05 PM CDT (23:05 UTC)

Expired

May 17, 2017, 7:00 PM CDT

In force

55 min

Issued by

the Storm Prediction Center

The La Crosse radar (KARX), 159 km from the middle of the area, began a volume at 23:10 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.

303 
ACUS11 KWNS 172305
SWOMCD
SPC MCD 172305 
ILZ000-IAZ000-WIZ000-MNZ000-180000-

Mesoscale Discussion 0752
NWS Storm Prediction Center Norman OK
0605 PM CDT Wed May 17 2017

Areas affected...eastern and northeastern IA...southeastern
MN...southwest WI

Concerning...Tornado Watch 233...234...

Valid 172305Z - 180000Z

The severe weather threat for Tornado Watch 233, 234 continues.

SUMMARY...Scattered to widespread severe gusts are forecast with a
bowing thunderstorm band over eastern portions of IA and this
feature will move into southeastern MN and southwest WI this
evening.

DISCUSSION...A mature and well-developed QLCS arcs from
north-central IA into east-central and southeastern IA and it is
moving north-northeast at 50-55 kt.  The convective band is on the
leading edge of a mid-level dryslot punching northeastward into the
middle-upper MS Valley in the base of a migratory shortwave trough. 
Surface temperatures ahead of the squall line have warmed into the
upper 70s to around 80 degrees F over much of the discussion area. 
Marshalltown IA (KMIW) recorded a measured gust of 60-kt at 2212Z
and Waterloo, IA (KALO) more recently observed a 61-kt gust at
2253Z.  Expecting the QLCS to continue to result in scattered to
widespread severe gusts (60-75 kt).  Single site radar imagery has
also indicated the development of a couple of substantial
mesovortices in the squall line.  A couple of short-track weak
tornadoes are possible with any sustained/stronger mesovortex which
appear to be most likely over northeast IA into adjacent portions of
MN/WI over the next 1-2 hours.

..Smith.. 05/17/2017

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

ATTN...WFO...DVN...ARX...MPX...DMX...

LAT...LON   43059352 43699285 43909169 43059045 41219078 40709211
            41719186 42879259 43059352

Mesoscale Discussions in Iowa, 2017Mesoscale Discussions in Minnesota, 2017Mesoscale Discussions in Wisconsin, 2017Every mesoscale discussion in 2017

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.