Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 677

May 3, 20124 states

The Storm Prediction Center issued this mesoscale discussion at May 3, 2012, 2:53 PM CDT for 4 states. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
May 3, 2012, 2:53 PM CDT (19:53 UTC)
Expired
May 3, 2012, 4:00 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 23 counties

Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Kane County, IL, Lake County, IL, McHenry County, IL, Ogle County, IL, Winnebago County, IL, LaPorte County, IN, Porter County, IN, Berrien County, MI, Columbia County, WI, Dane County, WI, Dodge County, WI, Jefferson County, WI, Kenosha County, WI, Milwaukee County, WI, Racine County, WI, Rock County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 26 km from the middle of the area, began a volume at 19:56 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, 7.9 hours before the alert went out and 187 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 2012-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 321 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 2012-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 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
321 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
565 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
220 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

511 
ACUS11 KWNS 031953
SWOMCD
SPC MCD 031953 
INZ000-MIZ000-ILZ000-WIZ000-032100-

MESOSCALE DISCUSSION 0677
NWS STORM PREDICTION CENTER NORMAN OK
0253 PM CDT THU MAY 03 2012

AREAS AFFECTED...SRN WI...NRN IL...SRN LAKE MI

CONCERNING...SEVERE THUNDERSTORM WATCH 230...

VALID 031953Z - 032100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 230
CONTINUES.

SUMMARY...STRONG/SEVERE THUNDERSTORMS WILL PERSIST ACROSS THE NRN
HALF OF WW230.

DISCUSSION...TRANSITORY MCV HAS PROGRESSED ACROSS SRN WI AND HAS
LOST ITS IDENTITY OVER CNTRL LAKE MI.  IN THE WAKE OF THIS FEATURE
STRONG/SEVERE THUNDERSTORMS TRAIL SWWD ACROSS CNTRL LAKE MI AND SRN
WI.  GIVEN THE DEEP SWLY FLOW ACROSS THIS REGION THERE APPEARS TO BE
SOME AIR MASS RECOVERY INTO THE SWRN FLANK OF THE ONGOING
CONVECTION.  LATEST VIS IMAGERY SUPPORTS THIS TREND WITH NEW
UPDRAFTS FORMING ACROSS SCNTRL WI.  NEW TSTMS WILL LIKELY EVOLVE
ACROSS SRN WI OVER THE NEXT FEW HOURS WITH SUBSEQUENT MOVEMENT
EXPECTED TO TRAIL CURRENT ACTIVITY.  WITH TIME NEW STORMS MAY
DEVELOP INTO NRN IL AS BOUNDARY LAYER WARMS/DEEPENS.

..DARROW.. 05/03/2012

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

ATTN...WFO...IWX...LOT...MKX...DVN...

LAT...LON   43738952 43318654 41428652 41858952 43738952

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 3, 1:07 PM CDTSevere Thunderstorm WatchSPCBoone, Cook, DeKalb, DuPage, Kane, Kendall and 5 more6 hr
May 3, 3:53 PM CDTMesoscale DiscussionSPCBrown, Bureau, Cass, DeWitt, Fulton, Greene and 22 more37 min
May 3, 4:20 PM CDTTornado WatchSPCBureau, Cass, Champaign, DeWitt, Ford, Fulton and 26 more8 hr
May 3, 6:22 PM CDTMesoscale DiscussionSPCCook, DeKalb, DuPage, Kane, Kendall, Lake and 1 more23 min
May 3, 6:41 PM CDTSevere Thunderstorm WatchSPCBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more5 hr
May 3, 6:42 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, DeWitt, Fulton, Greene and 17 more63 min
May 2, 11:51 PM CDTMesoscale DiscussionSPCManistee, Mason, Oceana54 min
May 3, 10:34 AM CDTMesoscale DiscussionSPCArenac, Bay, Clare, Clinton, Genesee, Gladwin and 28 more86 min
May 3, 11:41 AM CDTSevere Thunderstorm WatchSPCAlcona, Alpena, Antrim, Arenac, Bay, Benzie and 23 more5 hr
May 3, 1:35 PM CDTSevere Thunderstorm WatchSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 27 more8 hr
May 3, 1:39 PM CDTMesoscale DiscussionSPCAntrim, Arenac, Bay, Benzie, Clare, Crawford and 18 more66 min
May 3, 3:33 PM CDTMesoscale DiscussionSPCAllegan, Barry, Bay, Calhoun, Cass, Clinton and 15 more57 min
May 3, 5:57 PM CDTMesoscale DiscussionSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 28 more63 min
May 2, 7:38 PM CDTMesoscale DiscussionSPCAdams, Buffalo, Jackson, Juneau, La Crosse, Monroe and 4 more37 min
May 2, 7:47 PM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Clark, Jackson, Juneau, La Crosse and 3 more5 hr
May 3, 8:43 AM CDTMesoscale DiscussionSPCAdams, Brown, Buffalo, Calumet, Clark, Columbia and 26 more92 min

Nearby

Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Indiana, 2012Every 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.