Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 2114

November 10, 201218 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Nov 10, 2012, 7:56 PM CST for 18 counties in Iowa. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Nov 10, 2012, 7:56 PM CST (01:56 UTC)
Expired: Nov 10, 2012, 9:30 PM CST
In force: 94 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dickinson County, IA, Emmet County, IA, Harrison County, IA, Ida County, IA, Monona County, IA, O'Brien County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Shelby County, IA, Woodbury County, IA

The radar

The Sioux Falls radar (KFSD), 150 km from the middle of the area, began a volume at 02:00 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.9 hours before the alert went out and 162 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: 567 J/kg
Mixed-layer CIN: -105 J/kg
Mixed-layer LCL: 1120 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 245 m²/s²
0-3 km storm-relative helicity: 228 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

060 
ACUS11 KWNS 110157
SWOMCD
SPC MCD 110156
IAZ000-NEZ000-SDZ000-110330-

MESOSCALE DISCUSSION 2114
NWS STORM PREDICTION CENTER NORMAN OK
0756 PM CST SAT NOV 10 2012

AREAS AFFECTED...PORTIONS OF NW IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 110156Z - 110330Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED STG/SVR TSTMS WILL BE POSSIBLE OVER PORTIONS OF
NWRN IA BETWEEN 02Z AND 05Z. THE NEED FOR A WW IS NOT CLEAR ALTHOUGH
CONVECTIVE TRENDS WILL BE MONITORED.

DISCUSSION...SVR TSTMS OVER ERN NEB...35 NW KOMA...CONTINUE TO MOVE
RAPIDLY NE AND EXTRAPOLATION PLACES THESE STORMS ALONG THE MO RIVER
AND THE NRN EDGE OF WW 675 BY 0215Z. MODEST MUCAPE VALUES OF 250-500
J/KG EXIST ACROSS A SMALL PORTION OF NWRN IA AND WITH ADDITIONAL
DIURNAL COOLING THESE VALUES SHOULD DECREASE OVER THE NEXT FEW
HOURS. NEVERTHELESS...THERE MAY BE A SUFFICIENT COLD POOL WITH THE
ERN NEB CONVECTION FOR AN ISOLATED SVR WIND/HAIL THREAT TO EXIST
ACROSS NWRN IA AS THESE STORMS CONTINUE TO MOVE NEWD ALONG AND JUST
IN ADVANCE OF A COLD FRONT. HOWEVER...UNCERTAINTY EXISTS WHETHER THE
COVERAGE WILL WARRANT A WW.

..BUNTING/MEAD.. 11/11/2012

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

ATTN...WFO...DMX...FSD...OAX...

LAT...LON   42089628 42329637 42589662 43199581 43459517 43479485
            43439450 43309441 42559437 41649501 41189587 42089628

Nearby

Mesoscale Discussions in Iowa, 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.