Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 892

May 24, 20124 counties in Michigan; Houston County, Minnesota; 21 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 24, 2012, 6:41 PM EDT for 4 counties in Michigan; Houston County, Minnesota; 21 counties in Wisconsin. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2012, 6:41 PM EDT (22:41 UTC)
Expired
May 24, 2012, 8:45 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 26 counties

Baraga County, MI, Gogebic County, MI, Houghton County, MI, Iron County, MI, Houston County, MN, Adams County, WI, Clark County, WI, Eau Claire County, WI, Florence County, WI, Forest County, WI, Iron County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Monroe County, WI, Oneida County, WI, Portage County, WI, Price County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Vilas County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 174 km from the middle of the area, began a volume at 22:42 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, 10.7 hours before the alert went out and 176 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 2012-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2072 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

634 
ACUS11 KWNS 242241
SWOMCD
SPC MCD 242241 
MIZ000-WIZ000-MNZ000-250045-

MESOSCALE DISCUSSION 0892
NWS STORM PREDICTION CENTER NORMAN OK
0541 PM CDT THU MAY 24 2012

AREAS AFFECTED...PORTIONS OF SERN MN/NWRN WI/WRN UPPER MI

CONCERNING...TORNADO WATCH 295...

VALID 242241Z - 250045Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 295 CONTINUES.

SUMMARY...BROKEN LINE OF STORMS CONTINUES MOVING ACROSS NWRN AND W
CENTRAL WI AND ADJACENT FAR SERN MN -- WHERE THREAT FOR DAMAGING
WINDS AND HAIL ALONG WITH AN ISOLATED TORNADO OR TWO CONTINUES.

DISCUSSION...A BAND OF STRONG/LOCALLY SEVERE STORMS CONTINUES SHIFT
EWD ACROSS THE UPPER MS VALLEY/WRN UPPER GREAT LAKES
REGION...THROUGH AN ENVIRONMENT FEATURING MODEST INSTABILITY /AOB
500 J/KG MIXED-LAYER CAPE/ BUT VERY STRONG FLOW ALOFT.  WITH A
RELATIVELY DRY/DEEP BOUNDARY LAYER AND FLOW ALOFT INCREASING TO 50
KT FROM THE SSW ROUGHLY 1 KM AGL PER AREA VWPS...THREAT FOR
STRONG/DAMAGING WINDS REMAINS EVIDENT WITH THE MORE ROBUST STORMS. 
DEGREE OF 0-1 KM SHEAR IS ALSO SUPPORTIVE OF LOW-LEVEL
ROTATION...THOUGH FAIRLY LARGE SURFACE DEWPOINT DEPRESSIONS/HIGH
CLOUD BASES SUGGEST THAT TORNADO THREAT WILL REMAIN ISOLATED.

..GOSS.. 05/24/2012

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

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

LAT...LON   47218808 46788780 43538983 43509180 44789139 46309064
            47218808

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 7:33 AM EDTMesoscale DiscussionSPCIron57 min
May 24, 2:34 PM EDTMesoscale DiscussionSPCGogebic, Iron116 min
May 24, 3:22 PM EDTTornado WatchSPCBaraga, Gogebic, Houghton, Iron, Ontonagon5 hr
May 24, 4:06 PM EDTMesoscale DiscussionSPCCrawford, Grant, Iowa, Richland114 min
May 24, 4:30 PM EDTSevere Thunderstorm WatchSPCCrawford, Grant, Iowa, Lafayette, Richland, Sauk4 hr
May 24, 6:42 PM EDTMesoscale DiscussionSPCCrawford, Grant, Iowa, Lafayette, Richland, Sauk2 hr

Nearby

Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Michigan, 2012Mesoscale Discussions in Minnesota, 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.