Alert archive / Wisconsin / Mesoscale Discussions in 2012
Mesoscale Discussion 938
The Storm Prediction Center issued this mesoscale discussion at May 28, 2012, 12:00 PM CDT for Jo Daviess County, Stephenson County, Illinois; Clayton County, Dubuque County, Iowa; 40 counties in Wisconsin. It was in force for 60 min.
The area
The outline as issued.
The facts
- Issued
- May 28, 2012, 12:00 PM CDT (17:00 UTC)
- Expired
- May 28, 2012, 1:00 PM CDT
- In force
- 60 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 44 counties
Clayton County, IA, Dubuque County, IA, Jo Daviess County, IL, Stephenson County, IL, Adams County, WI, Brown County, WI, Calumet County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Forest County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, Lafayette County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oconto County, WI, Outagamie County, WI, Portage County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Shawano County, WI, Sheboygan County, WI, Vernon County, WI, Washington County, WI, Waukesha County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI
The radar
The La Crosse radar (KARX), 128 km from the middle of the area, began a volume at 17:00 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, 5.0 hours before the alert went out and 130 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.
- Mixed-layer CAPE
- 42 J/kg
- Mixed-layer CIN
- -178 J/kg
- Mixed-layer LCL
- 1757 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 133 m²/s²
- 0-3 km storm-relative helicity
- 158 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
174
ACUS11 KWNS 281701
SWOMCD
SPC MCD 281700
WIZ000-ILZ000-IAZ000-MNZ000-281800-
MESOSCALE DISCUSSION 0938
NWS STORM PREDICTION CENTER NORMAN OK
1200 PM CDT MON MAY 28 2012
AREAS AFFECTED...IA..WI...IL
CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY
VALID 281700Z - 281800Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...STRONG TO SEVERE TSTMS ARE EXPECTED TO DEVELOP AHEAD OF A
COLD FRONT MOVING INTO AREAS OF EXTREME ERN IA...MUCH OF WI...AND
NRN IL THROUGH THE AFTERNOON. A WATCH IS POSSIBLE ACROSS SOME OR
MOST OF THESE AREAS WITHIN THE NEXT HOUR OR TWO.
DISCUSSION...STRONG ASCENT ACCOMPANYING THE SHORT WAVE TROUGH MOVING
INTO ERN MN AND IA WILL LIKELY AID CONVECTIVE DEVELOPMENT ALONG AND
AHEAD OF A COLD FRONT CURRENTLY SITUATED FROM WRN WI SWWD INTO NERN
IA. AIRMASS AHEAD OF THE FRONT CONTINUES TO DESTABILIZE WITH HEATING
OF THE DAY AND SURFACE-BASED CAPE IS CURRENTLY NEARING 1000 J/KG IN
SOME LOCATIONS. A WIDE ARRAY OF MODEL GUIDANCE INDICATES A
REMARKABLY CONSISTENT SIGNAL FOR THE DEVELOPMENT AND INCREASING
COVERAGE OF DEEP CONVECTION...ESPECIALLY ACROSS NRN AND ERN
WI...THROUGH THIS AFTERNOON. THIS MODEL SIGNAL IS LIKELY A RESULT OF
FAVORABLE LARGE SCALE FORCING FOR ASCENT MOVING INTO THE REGION AND
A LACK OF STRONGER INHIBITION THAN WHAT HAS BEEN IN PLACE IN RECENT
DAYS.
AMBIENT DEEP-LAYER SHEAR OF 40KT WITHIN THE SERN FLANK OF THE LARGE
UPPER LOW TO THE WEST WILL SUPPORT INCREASING STORM ORGANIZATION
WITH SUPERCELLS AND BOWING LINE SEGMENTS POTENTIALLY EVOLVING WITH
TIME. LARGE HAIL AND LOCALLY DAMAGING WINDS MAY ACCOMPANY THE
STRONGER STORMS LATER TODAY.
..CARBIN.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GRB...LOT...MKX...DVN...DLH...ARX...
LAT...LON 44159089 44949062 45459001 45808920 45568804 44598754
43768771 42898837 42078983 42279097 43049146 44159089SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 28, 4:59 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, DeKalb, Henderson, Henry and 15 more | 91 min |
| May 28, 6:02 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Grundy and 10 more | 3 hr |
| May 27, 9:51 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Cherokee, Clay, Dickinson, Emmet, Ida and 5 more | 84 min |
| May 28, 12:54 PM CDT | Severe Thunderstorm Watch | SPC | Clayton | 7 hr |
| May 27, 7:47 PM CDT | Mesoscale Discussion | SPC | Burnett, Douglas, Pierce, Polk, Saint Croix | 88 min |
| May 27, 10:11 PM CDT | Mesoscale Discussion | SPC | Burnett, Douglas, Pierce, Polk, Saint Croix | 94 min |
| May 28, 1:48 PM CDT | Mesoscale Discussion | SPC | Ashland, Barron, Bayfield, Burnett, Chippewa, Douglas and 8 more | 57 min |
| May 28, 2:07 PM CDT | Severe Thunderstorm Watch | SPC | Ashland, Barron, Bayfield, Burnett, Chippewa, Douglas and 10 more | 6 hr |
| May 28, 3:58 PM CDT | Mesoscale Discussion | SPC | Adams, Ashland, Barron, Bayfield, Brown, Burnett and 59 more | 92 min |
| May 28, 6:28 PM CDT | Mesoscale Discussion | SPC | Barron, Chippewa, Dunn, Rusk, Sawyer, Washburn | 62 min |
Nearby
Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Iowa, 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.