Alert archive / Wisconsin / Mesoscale Discussions in 2017

Mesoscale Discussion 943

June 3, 20176 counties in Michigan; 25 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2017, 3:48 PM EDT for 6 counties in Michigan; 25 counties in Wisconsin. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Jun 3, 2017, 3:48 PM EDT (19:48 UTC)
Expired
Jun 3, 2017, 4:45 PM EDT
In force
57 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 31 counties

Baraga County, MI, Dickinson County, MI, Gogebic County, MI, Iron County, MI, Menominee County, MI, Ontonagon County, MI, Brown County, WI, Calumet County, WI, Clark County, WI, Florence County, WI, Forest County, WI, Iron 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, Portage County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Vilas County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 152 km from the middle of the area, began a volume at 19:49 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, 7.8 hours before the alert went out and 154 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 2017-06-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 33 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 12:00Z on 2017-06-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 square meters per square second.1939Sfc1 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
33 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
1103 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

780 
ACUS11 KWNS 031949
SWOMCD
SPC MCD 031948 
MIZ000-WIZ000-032045-

Mesoscale Discussion 0943
NWS Storm Prediction Center Norman OK
0248 PM CDT Sat Jun 03 2017

Areas affected...Portions of upper Michigan and Wisconsin

Concerning...Severe potential...Watch possible 

Valid 031948Z - 032045Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorms will increase in coverage this afternoon,
with a few storms having the potential for damaging winds and a few
instances of large hail.  Convective trends are being monitored for
potential watch issuance.

DISCUSSION...Gradually increasing forcing for ascent associated with
a passing shortwave trough is yielding isolated convective
development this afternoon across western upper Michigan. Visible
satellite data also indicate growing cumulus underneath mid/upper
clouds over portions of western Wisconsin, aided by weak surface
convergence along/ahead of a cold front. To the south of ongoing
cloud cover, temperatures have warmed into the lower/mid 80s, with
dew points in the lower/mid 60s, yielding upwards of 1000-1500 J/kg
of MLCAPE. Recent KDLH VWP data indicate adequate deep-layer shear,
characterized by relatively straight hodographs. As such, storm
splits and small bowing segments may evolve, with a deepening
boundary layer enhancing the potential for damaging wind gusts.
Additionally, a few instances of large hail will be possible.
Convective trends are being monitored for potential watch issuance.

..Picca/Weiss.. 06/03/2017

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

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

LAT...LON   46509063 46828983 46948844 46568766 46358732 45808714
            45508726 44488789 44088813 44038885 44239012 44989126
            45869123 46159086 46509063

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 3, 4:15 PM EDTSevere Thunderstorm WatchSPCBaraga, Delta, Dickinson, Gogebic, Houghton, Iron and 3 more6 hr
Jun 3, 6:58 PM EDTMesoscale DiscussionSPCAntrim, Benzie, Charlevoix, Delta, Grand Traverse, Leelanau and 5 more92 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.