Alert archive / Wisconsin / Mesoscale Discussions in 2012
Mesoscale Discussion 852
The Storm Prediction Center issued this mesoscale discussion at May 20, 2012, 3:57 PM EDT for 6 counties in Michigan; 18 counties in Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 20, 2012, 3:57 PM EDT (19:57 UTC)
- Expired
- May 20, 2012, 6:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 24 counties
Baraga County, MI, Dickinson County, MI, Houghton County, MI, Iron County, MI, Marquette County, MI, Menominee County, MI, Adams County, WI, Brown County, WI, Calumet County, WI, Florence County, WI, Forest County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI
The radar
The Green Bay radar (KGRB), 113 km from the middle of the area, began a volume at 19:58 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, 8.0 hours before the alert went out and 115 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
- 752 J/kg
- Mixed-layer CIN
- -121 J/kg
- Mixed-layer LCL
- 1614 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
936
ACUS11 KWNS 201958
SWOMCD
SPC MCD 201957
MIZ000-WIZ000-202200-
MESOSCALE DISCUSSION 0852
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT SUN MAY 20 2012
AREAS AFFECTED...CNTRL AND NRN WI THROUGH THE WRN UPPER PENINSULA OF
MI
CONCERNING...SEVERE THUNDERSTORM WATCH 285...
VALID 201957Z - 202200Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 285
CONTINUES.
SUMMARY...ISOLATED DAMAGING WIND AND LARGE HAIL WILL REMAIN A THREAT
WITH THE STRONGER STORMS MOVING THROUGH NERN WI AND THE WRN PORTIONS
OF THE UPPER MI PENINSULA INTO THE EARLY EVENING.
DISCUSSION...A COUPLE OF LINES OF STORMS CONTINUE DEVELOPING FROM
NRN WI INTO THE UPPER MI PENINSULA ALONG AND AHEAD OF A COLD FRONT
AND WITHIN ZONE OF DEEPER ASCENT ASSOCIATED EJECTING SHORTWAVE
TROUGH. THE DOWNSTREAM ATMOSPHERE REMAINS MODESTLY UNSTABLE WITH
1000 J/KG MLCAPE...25-30F NEAR SFC TEMPERATURE-DEWPOINT SPREADS AND
SUFFICIENT /35-40 KT/ VERTICAL SHEAR FOR SOME OF THE UPDRAFTS TO
DEVELOP MID LEVEL ROTATION. THIS ENVIRONMENT WILL PROMOTE A THREAT
OF ISOLATED DAMAGING WIND AND HAIL INTO THE EARLY EVENING.
..DIAL.. 05/20/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MQT...GRB...MKX...ARX...
LAT...LON 46638726 44868737 43838808 43878992 45668973 47028868
46638726SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 11:52 AM EDT | Mesoscale Discussion | SPC | Baraga, Dickinson, Iron | 113 min |
| May 20, 1:24 PM EDT | Severe Thunderstorm Watch | SPC | Baraga, Dickinson, Gogebic, Houghton, Iron, Marquette and 2 more | 7 hr |
| May 20, 2:17 PM EDT | Mesoscale Discussion | SPC | Columbia, Dane, Dodge, Green, Jefferson, Kenosha and 4 more | 118 min |
| May 20, 4:50 PM EDT | Mesoscale Discussion | SPC | Walworth, Waukesha | 85 min |
Nearby
Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Michigan, 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.