Alert archive / Wisconsin / Mesoscale Discussions in 2011

Mesoscale Discussion 726

May 11, 20115 counties in Michigan; 8 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 4:19 AM EDT for 5 counties in Michigan; 8 counties in Wisconsin. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: May 11, 2011, 4:19 AM EDT (08:19 UTC)
Expired: May 11, 2011, 5:15 AM EDT
In force: 56 min
Issued by: the Storm Prediction Center

Counties Delta County, MI, Dickinson County, MI, Iron County, MI, Marquette County, MI, Menominee County, MI, Door County, WI, Florence County, WI, Forest County, WI, Kewaunee County, WI, Langlade County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI

The radar

The Green Bay radar (KGRB), 107 km from the middle of the area, began a volume at 08:22 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, 8.3 hours before the alert went out and 108 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 883 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 270 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 11.8

Open this sounding in Storm Lab

The text

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

526 
ACUS11 KWNS 110819
SWOMCD
SPC MCD 110819 
MIZ000-WIZ000-110915-

MESOSCALE DISCUSSION 0726
NWS STORM PREDICTION CENTER NORMAN OK
0319 AM CDT WED MAY 11 2011

AREAS AFFECTED...NRN-NERN WI AND WRN-CENTRAL UPPER MI

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 110819Z - 110915Z

ELEVATED STRONG TO SEVERE STORMS WILL AFFECT PARTS OF NRN-NERN WI
AND WRN-CENTRAL UPPER MI OVERNIGHT INTO EARLY WEDNESDAY MORNING AS
AN ONGOING ACTIVITY TRACKS SEWD REACHING THE NRN EXTENT OF LAKE MI
AROUND 13Z.  GIVEN THE ELEVATED NATURE OF THESE STORMS RESULTING IN
PRIMARILY A HAIL THREAT...A WW DOES NOT APPEAR WARRANTED AT THIS
TIME.  CONVECTIVE TRENDS WILL BE MONITORED FOR ANY FURTHER INCREASE
IN COVERAGE OF STRONGER CORES.

SINCE 07Z...REGIONAL RADAR IMAGERY SHOWED TSTMS INCREASING IN
INTENSITY FROM FAR NORTH CENTRAL WI TO WRN UPPER MI...WITH THE
STRONGEST STORMS AT 0815Z LOCATED OVER ONEIDA COUNTY WI AND WRN IRON
AND WRN MARQUETTE COUNTIES MI.  THIS ACTIVITY APPEARS TO BE
DEVELOPING ALONG AN 850 MB WARM FRONT WHICH PER OBJECTIVE ANALYSES
EXTENDED SEWD FROM FAR NRN MN/ADJACENT ONTARIO THROUGH WRN UPPER MI
AND NERN WI TO CENTRAL AND SRN LOWER MI.  AREA WSR-88D VADS SHOWED A
20-25 KT WLY LLJ EXTENDING INTO WI PROVIDING AN ELEVATED FEED OF
VERY STRONG INSTABILITY AS OBSERVED PER 00Z SOUNDINGS AT CHANHASSEN
MN AND GREEN BAY WI.  CURRENT OBJECTIVE ANALYSIS SHOWED MUCAPE
3000-4000 J/KG ACROSS WI.  ONE OR TWO WEAK MIDLEVEL IMPULSES TOPPING
THE RIDGE OVER THIS REGION PER WATER VAPOR IMAGERY AND LOW LEVEL WAA
SHOULD SUPPORT ADDITIONAL TSTM DEVELOPMENT WITH ACTIVITY TRACKING
SEWD ACROSS CENTRAL UPPER MI AND NERN WI THROUGH 12-13Z.

..PETERS.. 05/11/2011

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

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

LAT...LON   45678961 46728758 46208645 45378643 44568718 44448788
            44988900 45678961

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 2:16 PM EDT	Mesoscale Discussion	SPC	Arenac, Bay, Benzie, Clare, Crawford, Gladwin and 14 more	119 min
May 11, 6:40 PM EDT	Mesoscale Discussion	SPC	Allegan, Berrien, Cass, Saint Joseph, Van Buren	65 min
May 11, 6:56 PM EDT	Severe Thunderstorm Watch	SPC	Allegan, Barry, Berrien, Branch, Calhoun, Cass and 3 more	5 hr
May 10, 9:45 PM EDT	Mesoscale Discussion	SPC	Buffalo, Crawford, Dunn, Eau Claire, Iowa, Jackson and 10 more	90 min
May 11, 1:55 PM EDT	Mesoscale Discussion	SPC	Adams, Columbia, Dane, Dodge, Green, Green Lake and 12 more	65 min
May 11, 2:23 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Calumet, Clark, Columbia, Crawford, Dane and 26 more	6 hr
May 11, 4:38 PM EDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Clark, Columbia, Crawford and 34 more	2 hr

Nearby

Mesoscale Discussions in Wisconsin, 2011 Mesoscale Discussions in Michigan, 2011 Every mesoscale discussion in 2011

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.