Alert archive / Iowa / Mesoscale Discussions in 2012
Mesoscale Discussion 2087
The Storm Prediction Center issued this mesoscale discussion at Oct 24, 2012, 6:38 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 24, 2012, 6:38 PM CDT (23:38 UTC)
- Expired
- Oct 24, 2012, 8:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 62 counties
Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Fayette County, IA, Floyd County, IA, Grundy County, IA, Hardin County, IA, Howard County, IA, Iowa County, IA, Jasper County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Warren County, IA, Winneshiek County, IA, Baraga County, MI, Gogebic County, MI, Houghton County, MI, Iron County, MI, Keweenaw County, MI, Ontonagon County, MI, Fillmore County, MN, Houston County, MN, Winona County, MN, Ashland County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Crawford County, WI, Dunn County, WI, Eau Claire County, WI, Forest County, WI, Iron County, WI, Jackson County, WI, La Crosse County, WI, Lincoln County, WI, Marathon County, WI, Monroe County, WI, Oneida County, WI, Pepin County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Vilas County, WI, Wood County, WI
The radar
The La Crosse radar (KARX), 49 km from the middle of the area, began a volume at 23:41 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
Minneapolis, MN (KMPX), launched 12:00Z, 11.6 hours before the alert went out and 204 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 651 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 131 m²/s²
- 0-3 km storm-relative helicity
- 181 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
511
ACUS11 KWNS 242339
SWOMCD
SPC MCD 242338
MIZ000-WIZ000-IAZ000-MNZ000-250145-
MESOSCALE DISCUSSION 2087
NWS STORM PREDICTION CENTER NORMAN OK
0638 PM CDT WED OCT 24 2012
AREAS AFFECTED...WRN UPPER MI...NRN AND WRN WI...SERN MN AND ERN
IA...
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 242338Z - 250145Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...A GRADUAL INCREASE IN STORM COVERAGE AND INTENSITY IS
EXPECTED...WITH MAINLY A HAIL THREAT ALONG WITH A FEW STRONG WIND
GUSTS.
DISCUSSION...A FEW THUNDERSTORMS HAVE FORMED FROM NWRN WI NEWD OVER
LAKE SUPERIOR ALONG AND N OF THE SYNOPTIC FRONT. HERE...LIFT FROM
WARM ADVECTION IS BEING MAXIMIZED WHICH IS BEING REFLECTED BY 1-1.5
MB/HR PRESSURE FALLS. SOME OF THE SRN CELLS MAY TREK ENEWD ALONG THE
WARM FRONT WITH ACCESS TO A MORE UNSTABLE AIR MASS CHARACTERIZED BY
63-64 F DEWPOINTS. STRONG DEEP LAYER SHEAR WILL REMAIN IN PLACE
WHICH WILL BE FAVORABLE FOR SUPERCELLS. THUS...STORMS MAY PRODUCE
BOTH LARGE HAIL AND PERHAPS DAMAGING WIND GUSTS. THE COOL BOUNDARY
LAYER MAY PRECLUDE MUCH OF A TORNADO THREAT...ALTHOUGH LOW LEVEL
HODOGRAPH STRUCTURES WILL BE FAVORABLE FOR ROTATION.
ADDITIONAL STORMS ARE EXPECTED TO FORM SWWD INTO IA AS THE LOW LEVEL
JET INCREASES AND COOLING ALOFT OCCURS. HAIL AND WIND WILL BE
POSSIBLE HERE AS WELL.
..JEWELL/THOMPSON.. 10/24/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MQT...GRB...DVN...DLH...ARX...MPX...DMX...
LAT...LON 42499122 41119219 40929315 41139388 41619396 42889290
44019223 45079197 46329144 46689096 46949034 47558823
47478763 46698786 44898944 42499122Nearby
Mesoscale Discussions in Iowa, 2012Mesoscale 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.