Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 1208

June 18, 201211 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2012, 2:49 PM CDT for 11 counties in Wisconsin. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Jun 18, 2012, 2:49 PM CDT (19:49 UTC)
Expired: Jun 18, 2012, 4:15 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Brown County, WI, Calumet County, WI, Kewaunee County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Waupaca County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 39 km from the middle of the area, began a volume at 19:52 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 12:00Z, 7.8 hours before the alert went out and 41 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: 67 J/kg
Mixed-layer CIN: -387 J/kg
Mixed-layer LCL: 1455 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 382 m²/s²
0-3 km storm-relative helicity: 524 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

055 
ACUS11 KWNS 181950
SWOMCD
SPC MCD 181949
WIZ000-MIZ000-182115-

MESOSCALE DISCUSSION 1208
NWS STORM PREDICTION CENTER NORMAN OK
0249 PM CDT MON JUN 18 2012

AREAS AFFECTED...NERN/CNTRL WI

CONCERNING...SEVERE THUNDERSTORM WATCH 406...

VALID 181949Z - 182115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 406
CONTINUES.

SUMMARY...PORTIONS OF WW 406 CENTERED OVER NERN WI ARE BEING
CONSIDERED FOR REPLACEMENT WITH A TORNADO WATCH. THIS MAY BE
REQUIRED IF MORE INTENSE/SUSTAINED SUPERCELLS BECOME NOTED.

DISCUSSION...SEVERAL SEMI-DISCRETE CELLS WERE PREVALENT WITHIN A
WSW/ENE-ORIENTED PRE-FRONTAL CONFLUENT BAND FROM 40 W CWA TO NEAR
ESC. REMNANT OUTFLOW BOUNDARY/COMPOSITE WARM FRONT INTERSECTS THIS
ACTIVITY FROM MARATHON TO SHEBOYGAN COUNTIES. ALTHOUGH THE HODOGRAPH
IS FAIRLY STRAIGHT-LINE...STRONG LOW-LEVEL SPEED SHEAR REMAINS NEAR
THIS JUXTAPOSITION /AROUND 35 KT FROM 0-1 KM IN THE GRB VWP DATA/.
ADDITIONAL SHOWERS FORMING S OF THE ONGOING ACTIVITY WOULD LIKELY
POSE THE GREATEST RISK FOR DEVELOPING SUSTAINED LOW-LEVEL
MESOCYCLONES...WHICH MAY BE SUFFICIENT FOR A TORNADO THREAT DURING
THE NEXT FEW HOURS.

..GRAMS.. 06/18/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MQT...GRB...

LAT...LON   45308877 45488796 45288769 44888728 44358742 44068787
            43998838 44048886 44288952 44738974 44928971 45308877

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 7:27 PM CDT	Mesoscale Discussion	SPC	Pierce, Polk, Saint Croix	93 min
Jun 17, 7:57 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Barron, Buffalo, Burnett, Chippewa, Clark and 21 more	8 hr
Jun 17, 10:55 PM CDT	Mesoscale Discussion	SPC	Buffalo, La Crosse, Pierce, Trempealeau	95 min
Jun 18, 1:28 AM CDT	Mesoscale Discussion	SPC	Adams, Buffalo, Chippewa, Clark, Columbia, Dunn and 22 more	62 min
Jun 18, 11:40 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Buffalo, Calumet, Clark, Door and 27 more	2 hr
Jun 18, 12:24 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Buffalo, Calumet, Clark, Door and 29 more	8 hr
Jun 18, 3:50 PM CDT	Mesoscale Discussion	SPC	Door, Kewaunee	85 min
Jun 18, 6:00 PM CDT	Mesoscale Discussion	SPC	Brown, Calumet, Door, Green Lake, Kewaunee, Manitowoc and 7 more	60 min

Nearby

Mesoscale Discussions in Wisconsin, 2012 Every mesoscale discussion in 2012

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.