Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 289

March 19, 201236 counties in Iowa; 24 counties in Minnesota; 7 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2012, 1:34 PM CDT for 36 counties in Iowa; 24 counties in Minnesota; 7 counties in South Dakota. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Mar 19, 2012, 1:34 PM CDT (18:34 UTC)
Expired: Mar 19, 2012, 3:30 PM CDT
In force: 116 min
Issued by: the Storm Prediction Center

All 67 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lyon County, IA, Madison County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Union County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Wright County, IA, Big Stone County, MN, Blue Earth County, MN, Brown County, MN, Chippewa County, MN, Cottonwood County, MN, Faribault County, MN, Jackson County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, McLeod County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Renville County, MN, Rock County, MN, Sibley County, MN, Swift County, MN, Watonwan County, MN, Yellow Medicine County, MN, Brookings County, SD, Codington County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Minnehaha County, SD, Moody County, SD

The radar

The Sioux Falls radar (KFSD), 129 km from the middle of the area, began a volume at 18:35 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, 6.6 hours before the alert went out and 222 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 344 J/kg
Mixed-layer CIN: -272 J/kg
Mixed-layer LCL: 709 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 91 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.

962 
ACUS11 KWNS 191834
SWOMCD
SPC MCD 191834 
IAZ000-MNZ000-SDZ000-192030-

MESOSCALE DISCUSSION 0289
NWS STORM PREDICTION CENTER NORMAN OK
0134 PM CDT MON MAR 19 2012

AREAS AFFECTED...FAR ERN SD...SWRN MN...WRN IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 191834Z - 192030Z

THUNDERSTORMS WILL CONTINUE TO INCREASE THE NEXT FEW HOURS. THE MAIN
THREAT WILL BE LARGE HAIL WITH SOME POTENTIAL FOR LOCALLY GUSTY
WINDS THE NEXT SEVERAL HOURS.

A LINE OF STORMS HAD DEVELOPED AHEAD OF A COLD FRONT AND ALONG A
WEAK OUTFLOW BOUNDARY JUST EAST OF THE MISSOURI RIVER FROM NWRN IA
NWD TO JUST N OF FSD. SLOW INTENSIFICATION OF THESE STORMS HAS
OCCURRED OVER THE LAST COUPLE OF HOURS AS THE AIR MASS HAS
DESTABILIZED WITH TEMPERATURES WARMING INTO THE LOW 70S. MLCAPE
VALUES AROUND 500-1000 J/KG WERE NOTED VIA 17Z MESOANALYSIS AND WITH
ADDITIONAL DAYTIME HEATING...WHAT LITTLE MLCIN REMAINS WILL QUICKLY
ERODE. PER 12Z RAOBS...STEEP MIDLEVEL LAPSE RATES NEAR 7-7.5 DEG
C/KM COMBINED WITH THIS MARGINAL INSTABILITY WILL LEAD TO STRONG
UPDRAFTS AND AT LEAST ISOLATED INSTANCES OF SEVERE HAIL ARE
POSSIBLE. WHILE BULK SHEAR VALUES WILL FAVOR SUPERCELL AND BOWING
SEGMENTS...GIVEN THE LACK OF STRONGER UPPER LEVEL FORCING TO FOCUS
SEVERE THREAT...A WW MAY NOT BE IMMEDIATELY NEEDED AS STORMS MAY
STAY RATHER UNORGANIZED.

..LEITMAN.. 03/19/2012

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

ATTN...WFO...MPX...DMX...FSD...OAX...ABR...

LAT...LON   43349667 44779731 45249736 45499698 45569575 45369494
            44959433 44129382 43249340 42229351 41339361 40969391
            40899442 41009489 41139521 41949587 43349667

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 19, 3:40 PM CDT	Mesoscale Discussion	SPC	Appanoose, Boone, Clarke, Dallas, Davis, Decatur and 13 more	95 min
Mar 19, 6:43 PM CDT	Mesoscale Discussion	SPC	Benton, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 11 more	62 min
Mar 19, 3:29 PM CDT	Mesoscale Discussion	SPC	Becker, Benton, Big Stone, Clay, Clearwater, Douglas and 18 more	2 hr

Nearby

Mesoscale Discussions in Iowa, 2012 Mesoscale Discussions in Minnesota, 2012 Mesoscale Discussions in South Dakota, 2012 Every 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.