Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 296

March 19, 201217 counties in Iowa; 17 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2012, 6:43 PM CDT for 17 counties in Iowa; 17 counties in Minnesota. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Mar 19, 2012, 6:43 PM CDT (23:43 UTC)
Expired: Mar 19, 2012, 7:45 PM CDT
In force: 62 min
Issued by: the Storm Prediction Center

All 34 counties

Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Howard County, IA, Linn County, IA, Mitchell County, IA, Tama County, IA, Winneshiek County, IA, Worth County, IA, Benton County, MN, Carver County, MN, Dakota County, MN, Dodge County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Hennepin County, MN, Le Sueur County, MN, Mower County, MN, Olmsted County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Steele County, MN, Waseca County, MN, Wright County, MN

The radar

The Minneapolis radar (KMPX), 111 km from the middle of the area, began a volume at 23:47 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, 11.7 hours before the alert went out and 112 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.

384 
ACUS11 KWNS 192343
SWOMCD
SPC MCD 192343 
IAZ000-MNZ000-200045-

MESOSCALE DISCUSSION 0296
NWS STORM PREDICTION CENTER NORMAN OK
0643 PM CDT MON MAR 19 2012

AREAS AFFECTED...ERN IA/MN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 192343Z - 200045Z

ISOLATED SEVERE STORMS CAPABLE OF PRIMARILY DMGG WIND MAY BE
POSSIBLE OVER THE NEXT FEW HOURS. HOWEVER...GIVEN THE ISOLATED
NATURE...A WW IS NOT ANTICIPATED. 

CONVECTIVE COVERAGE HAS BEEN GRADUALLY INCREASING...PRIMARILY IN
RESPONSE TO STRENGTHENING SURFACE CONVERGENCE FROM CNTRL MO NWD
THROUGH CNTRL IA/MN...AND INCREASING UPPER DIVERGENCE AS A BROAD
TROUGH SHIFTS EWD. CURRENT DETERMINISTIC MODELS /SUPPORTED BY AREA
PROFILER NETWORK/ SHOW A PRIMARY JET AXIS JUST BEGINNING TO IMPINGE
UPON THE MCD AREA...WHICH MAY BE CONTRIBUTING TO SUSTAINED
UPDRAFTS/VERTICAL MOTION. GIVEN THE STRENGTH OF THE DEEP LAYER WIND
FIELDS /I.E. 50 KTS AT 1 KFT PER AREA VAD WIND PROFILE
DATA/...SEVERE CONVECTIVE GUSTS CANNOT BE RULED OUT IN ASSOCIATION
WITH THE ONGOING STORMS. HOWEVER...DIURNAL COOLING WILL GRADUALLY
STABILIZE THE BOUNDARY LAYER...LIMITING DMGG WIND POTENTIAL AT THE
SURFACE...DESPITE STRONG DEEP LAYER WIND FIELDS. MARGINAL
INSTABILITY ATTM SUGGESTS A LIMITED SEVERE POTENTIAL AS WELL...AND
THEREFORE A WW WILL LIKELY NOT BE NEEDED.

..HURLBUT.. 03/19/2012

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

ATTN...WFO...DVN...ARX...MPX...DMX...

LAT...LON   45849465 45799362 44519278 43129151 41959131 41739226
            42359315 44049389 45849465

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 19, 1:34 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 30 more	116 min
Mar 19, 3:40 PM CDT	Mesoscale Discussion	SPC	Appanoose, Boone, Clarke, Dallas, Davis, Decatur and 13 more	95 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 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.