Alert archive / Wisconsin / Mesoscale Discussions in 2017

Mesoscale Discussion 739

May 16, 2017Gogebic County, Iron County, Michigan; 38 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 16, 2017, 6:25 PM CDT for Gogebic County, Iron County, Michigan; 38 counties in Wisconsin. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
May 16, 2017, 6:25 PM CDT (23:25 UTC)
Expired
May 16, 2017, 7:30 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
All 40 counties

Gogebic County, MI, Iron County, MI, Ashland County, WI, Barron County, WI, Bayfield County, WI, Brown County, WI, Buffalo County, WI, Burnett County, WI, Chippewa County, WI, Clark County, WI, Douglas County, WI, Dunn County, WI, Eau Claire County, WI, Florence County, WI, Forest County, WI, Iron County, WI, Jackson County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Portage County, WI, Price County, WI, Rusk County, WI, Saint Croix County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vilas County, WI, Washburn County, WI, Waupaca County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 192 km from the middle of the area, began a volume at 23:26 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 11.4 hours before the alert went out and 220 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, Green Bay/Straub, WI at 12:00Z on 2017-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Green Bay/Straub, WI at 12:00Z on 2017-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1146 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

336 
ACUS11 KWNS 162326
SWOMCD
SPC MCD 162325 
MIZ000-WIZ000-MNZ000-170030-

Mesoscale Discussion 0739
NWS Storm Prediction Center Norman OK
0625 PM CDT Tue May 16 2017

Areas affected...Northern/central Wisconsin and the southern Upper
Peninsula of Michigan

Concerning...Tornado Watch 222...

Valid 162325Z - 170030Z

The severe weather threat for Tornado Watch 222 continues.

SUMMARY...A considerable tornado threat continues across the
discussion area, including significant tornado potential with a cell
currently over Rusk County, WI.

DISCUSSION...A cluster of intense thunderstorms with a history of
strong rotation, significant hail, and tornadoes, has evolved over
the past couple of hours in northwestern and north-central
Wisconsin.  Additional activity has matured west of this cluster
from near DLH southward to about 25 SSE of MSP.  These storms are
moving into a favorable environment for continued significant severe
potential (including tornadoes) over the next 1-2 hours, where
recent objective analyses indicate 2000+ J/kg MUCAPE and 300-400
m2/s2 effective SRH downstream of this complex of storms within an
undisturbed preconvective airmass.  Based on the evolving severe
threat, a new tornado watch and/or spatial extensions to the
existing watch may be needed around/just after 00Z.

..Cook/Guyer.. 05/16/2017

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

ATTN...WFO...MQT...GRB...DLH...ARX...MPX...

LAT...LON   46609217 46759166 46779084 46649039 46448942 46278850
            45948790 45528764 44888766 44478796 44298869 44298990
            44209082 44239168 44439225 44619254 44949278 45739264
            46089252 46609217

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 7:19 PM CDTMesoscale DiscussionSPCCrawford, Dane, Grant, Green, Iowa, Lafayette and 4 more56 min
May 15, 7:52 PM CDTSevere Thunderstorm WatchSPCDane, Green, Iowa, Jefferson, Kenosha, Lafayette and 3 more3 hr
May 15, 9:48 PM CDTSevere Thunderstorm WatchSPCBuffalo, Crawford, Jackson, La Crosse, Monroe, Pepin and 4 more5 hr
May 15, 10:14 PM CDTMesoscale DiscussionSPCJefferson, Kenosha, Rock, Walworth, Waukesha61 min
May 16, 2:13 AM CDTMesoscale DiscussionSPCBuffalo, La Crosse, Trempealeau92 min
May 16, 12:57 PM CDTMesoscale DiscussionSPCBuffalo, Clark, Eau Claire, Jackson, Marathon, Menominee and 7 more2 hr
May 16, 3:32 PM CDTMesoscale DiscussionSPCAdams, Barron, Buffalo, Burnett, Calumet, Chippewa and 33 more88 min
May 16, 4:02 PM CDTTornado WatchSPCAshland, Barron, Bayfield, Buffalo, Burnett, Chippewa and 24 more6 hr

Nearby

Mesoscale Discussions in Wisconsin, 2017Mesoscale Discussions in Michigan, 2017Every mesoscale discussion in 2017

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.