Alert archive / Wisconsin / Mesoscale Discussions in 2017

Mesoscale Discussion 474

April 10, 20176 counties in Michigan; 32 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2017, 3:16 AM EDT for 6 counties in Michigan; 32 counties in Wisconsin. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Apr 10, 2017, 3:16 AM EDT (07:16 UTC)
Expired
Apr 10, 2017, 5:15 AM EDT
In force
119 min
Issued by
the Storm Prediction Center
All 38 counties

Alger County, MI, Delta County, MI, Dickinson County, MI, Marquette County, MI, Menominee County, MI, Schoolcraft County, MI, Adams County, WI, Brown County, WI, Calumet County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Door County, WI, Florence County, WI, Fond du Lac County, WI, Forest County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Juneau County, WI, Lafayette County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oconto County, WI, Outagamie County, WI, Portage County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Shawano County, WI, Vernon County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 59 km from the middle of the area, began a volume at 07:19 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 7.3 hours before the alert went out and 62 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 00:00Z on 2017-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Green Bay/Straub, WI at 00:00Z on 2017-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 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
1 J/kg
Mixed-layer CIN
-294 J/kg
Mixed-layer LCL
1327 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
270 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

313 
ACUS11 KWNS 100716
SWOMCD
SPC MCD 100716 
MIZ000-WIZ000-100915-

Mesoscale Discussion 0474
NWS Storm Prediction Center Norman OK
0216 AM CDT Mon Apr 10 2017

Areas affected...southern and eastern Wisconsin into central Upper
Michigan

Concerning...Severe Thunderstorm Watch 137...

Valid 100716Z - 100915Z

The severe weather threat for Severe Thunderstorm Watch 137
continues.

SUMMARY...Local/marginal severe risk -- transitioning toward
primarily hail in most areas -- will persist continue for a couple
more hours across Upper Michigan, and for several more hours farther
south across central and southern Wisconsin.

DISCUSSION...Latest surface analysis and objective analyses reveal a
stable low-level airmass across northeast Wisconsin and into Upper
Michigan, where surface temperatures are currently in the 40s.  As a
result, wind risk with bowing segments moving northeastward across
this area continues to diminish.  Still, ample elevated CAPE and
favorably strong deep-layer shear will support vigorous updrafts --
and associated/local/marginal hail risk for the next couple of
hours.

Farther south across central and southern Wisconsin, a somewhat less
stable boundary layer is indicated ahead of the advancing cold
front.  While gradual surface cooling continues which will further
enhance low-level stability, risk for a locally damaging gust or two
may be possible.  With that said however, convection decreases in
coverage with southward extent.  While CAM guidance (specifically
HRRR runs) suggests some increase in convective coverage possible
over the next couple of hours, overall risk should remain isolated
-- such that new WW across southern and eastern WI will likely not
be required.

..Goss.. 04/10/2017

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

ATTN...WFO...MQT...GRB...MKX...ARX...

LAT...LON   46708781 46848676 46338589 45308685 43818815 42628869
            42569001 43029093 43899101 44998910 45878868 46078813
            46708781

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 1:01 AM EDTSevere Thunderstorm WatchSPCDickinson, Iron, Marquette3 hr
Apr 10, 12:57 PM EDTMesoscale DiscussionSPCAllegan, Berrien, Cass, Kalamazoo, Van Buren3 hr
Apr 10, 2:48 PM EDTSevere Thunderstorm WatchSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 16 more8 hr
Apr 10, 4:25 PM EDTMesoscale DiscussionSPCAllegan, Berrien, Branch, Cass, Kalamazoo, Ottawa and 2 more2 hr
Apr 10, 7:22 PM EDTMesoscale DiscussionSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 18 more53 min
Apr 9, 9:06 PM EDTMesoscale DiscussionSPCBarron, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 8 more54 min
Apr 9, 10:01 PM EDTSevere Thunderstorm WatchSPCBuffalo, Chippewa, Clark, Dunn, Eau Claire, Jackson and 3 more4 hr
Apr 10, 12:32 AM EDTMesoscale DiscussionSPCAdams, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 25 more58 min

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.