Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 1041

June 3, 201244 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2012, 8:04 PM CDT for 44 counties in Iowa. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
Jun 3, 2012, 8:04 PM CDT (01:04 UTC)
Expired
Jun 3, 2012, 9:30 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 44 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, Clarke County, IA, Crawford County, IA, Dallas County, IA, Decatur County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Kossuth County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Woodbury County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 72 km from the middle of the area, began a volume at 01:07 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, 1.1 hours before the alert went out and 163 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-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2012-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1397 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2012-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1397 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1952 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.0

Open this sounding in Storm Lab

The text

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

751 
ACUS11 KWNS 040105
SWOMCD
SPC MCD 040104
IAZ000-NEZ000-040230-

MESOSCALE DISCUSSION 1041
NWS STORM PREDICTION CENTER NORMAN OK
0804 PM CDT SUN JUN 03 2012

AREAS AFFECTED...PORTIONS OF SWRN INTO CNTRL IA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 040104Z - 040230Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...MARGINAL WIND AND HAIL THREAT WILL EXIST INTO THE EVENING
HOURS. WEAK INSTABILITY/UPPER FORCING WILL LIMIT UPDRAFT STRENGTH
AND THEREFORE SEVERE POTENTIAL. A WW IS NOT ANTICIPATED AT THIS
TIME.

DISCUSSION...THUNDERSTORMS WERE DEVELOPING ALONG A WEAK SFC
TROUGH/CONFLUENCE BOUNDARY ACROSS NWRN IA. WEAK INSTABILITY ON THE
BACKSIDE OF A SLIGHTLY DEEPENING SHORTWAVE TROUGH ACROSS THE MIDWEST
COUPLED WITH 30-40 KT DEEP LAYER SHEAR WILL SUPPORT SEMI-ORGANIZED
CLUSTER OF STORMS ALONG THIS BOUNDARY. 00Z OAX RAOB SHOWED STEEP
LAPSE RATES AND COOL TEMPERATURES ALOFT WHICH WOULD SUPPORT AT LEAST
SMALL TO MARGINALLY SEVERE HAIL IN THE STRONGER CELLS GIVEN DEEP
LAYER SHEAR PROFILES. HOWEVER...THIS RAOB IS PROBABLY NOT AS
REPRESENTATIVE OF THE ENVIRONMENT FURTHER E TOWARD CNTRL IA WHERE
TEMPERATURES ARE COOLER AND SFC DEWPOINTS SOMEWHAT LOWER. BUT LOW
LEVEL LAPSE RATES OF 7.5-8.5 DEG C/KM WILL ALSO SUPPORT GUSTY WIND
POTENTIAL IN ADDITION TO THE MARGINAL HAIL THREAT AS STORMS
GENERALLY TRACK TOWARD THE S/SE.

..LEITMAN/CORFIDI.. 06/04/2012

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

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

LAT...LON   42419611 43259442 43289400 42209295 41669279 40869310
            40579434 40689560 41629618 42419611

Nearby

Mesoscale Discussions in Iowa, 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.