Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 532

April 14, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2012, 4:47 PM CDT for 4 states. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Apr 14, 2012, 4:47 PM CDT (21:47 UTC)
Expired
Apr 14, 2012, 5:45 PM CDT
In force
58 min
Issued by
the Storm Prediction Center
All 50 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Fremont County, IA, Guthrie County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Wayne County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Nemaha County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Worth County, MO, Cass County, NE, Douglas County, NE, Gage County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE, Saunders County, NE

The radar

The Omaha radar (KOAX), 137 km from the middle of the area, began a volume at 21:49 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.8 hours before the alert went out and 138 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 12:00Z on 2012-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2012-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1847 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
89 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.

591 
ACUS11 KWNS 142147
SWOMCD
SPC MCD 142147 
IAZ000-MOZ000-KSZ000-NEZ000-142245-

MESOSCALE DISCUSSION 0532
NWS STORM PREDICTION CENTER NORMAN OK
0447 PM CDT SAT APR 14 2012

AREAS AFFECTED...ERN NEB...NERN KS...SRN IA...NWRN MO

CONCERNING...TORNADO WATCH 166...168...

VALID 142147Z - 142245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 166...168...CONTINUES.

THREAT OF TORNADOES...DMGG WINDS...AND LARGE HAIL CONTINUES...AND
WILL SPREAD INTO NRN MO THIS EVENING. WW 168 WILL LIKELY BE REPLACED
WITH A NEW TORNADO WW WITHIN THE NEXT HOUR. WW 166 CONTINUES.

21Z SURFACE ANALYSIS SUPPORTED BY RECENT RADAR IMAGERY INDICATES AN
MCV FEATURE DEVELOPING ACROSS ERN NEB. ALTHOUGH THE THREAT IS
PREDOMINANTLY HEAVY RAINFALL AND HAIL ACROSS ERN NEB ATTM...THE
STRENGTHENING WARM ADVECTION REGIME INTO THIS EVENING SHOULD ALLOW
FOR SUFFICIENT SURFACE-BASED DESTABILIZATION DOWNSTREAM OF THE
ONGOING CONVECTION. OCCURRING IN CONJUNCTION WITH STRENGTHENING DEEP
LAYER WIND FIELDS...AN INCREASING THREAT OF TORNADOES...DMGG
WINDS...AND LARGE HAIL IS EXPECTED...WITH THE POTENTIAL OF DISCRETE
SUPERCELLS ALONG THE NWD PROGRESSING WARM FRONT /CURRENTLY ANALYZED
NEAR THE NEB/KS AND IA/MO BORDER/...AND A MORE ORGANIZED MCS AHEAD
OF THE AFOREMENTIONED MCV. A REPLACEMENT WW WILL THEREFORE NEED TO
BE COORDINATED WITHIN THE NEXT HOUR.

..HURLBUT.. 04/14/2012

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

ATTN...WFO...DMX...EAX...OAX...TOP...

LAT...LON   41659506 41779399 41649311 41109249 40649257 40189345
            39559484 39509562 39889659 40319706 41179701 41439654
            41659506

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 12:00 PM CDTTornado Watch PDSSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more7 hr
Apr 14, 2:15 PM CDTMesoscale DiscussionSPCAdams, Audubon, Cass, Fremont, Harrison, Mills and 5 more90 min
Apr 14, 2:56 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 14 more2 hr
Apr 14, 5:00 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 18 more7 hr
Apr 14, 6:57 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 23 more63 min
Apr 13, 9:14 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Butler, Chase, Chautauqua and 17 more61 min
Apr 14, 3:42 AM CDTTornado WatchSPCChautauqua, Labette, Montgomery5 hr
Apr 14, 7:11 AM CDTMesoscale DiscussionSPCCherokee, Labette64 min
Apr 14, 9:42 AM CDTMesoscale DiscussionSPCClark, Finney, Ford, Gove, Grant, Gray and 10 more93 min
Apr 14, 10:43 AM CDTTornado Watch PDSSPCBarber, Barton, Clark, Clay, Cloud, Comanche and 42 more7 hr
Apr 14, 11:44 AM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Clay, Cloud, Comanche and 40 more61 min
Apr 14, 12:11 PM CDTMesoscale DiscussionSPCButler, Chase, Chautauqua, Coffey, Cowley, Dickinson and 19 more64 min
Apr 14, 1:41 PM CDTMesoscale DiscussionSPCDecatur, Rawlins2 hr
Apr 14, 1:44 PM CDTMesoscale DiscussionSPCBarton, Clark, Cloud, Edwards, Ellis, Ellsworth and 20 more61 min
Apr 14, 2:28 PM CDTMesoscale DiscussionSPCClay, Cloud, Jewell, Lincoln, Mitchell, Ottawa and 2 more32 min
Apr 14, 3:01 PM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Comanche, Edwards, Ellsworth and 10 more29 min
Apr 14, 3:48 PM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Clay, Cloud, Comanche and 33 more57 min
Apr 14, 4:54 PM CDTMesoscale DiscussionSPCBarber, Barton, Clay, Cloud, Comanche, Dickinson and 32 more66 min
Apr 14, 5:24 PM CDTTornado Watch PDSSPCBarber, Barton, Brown, Butler, Chase, Chautauqua and 57 more9 hr
Apr 13, 7:34 PM CDTMesoscale DiscussionSPCBarry, Benton, Camden, Cedar, Christian, Cole and 29 more116 min
Apr 14, 11:27 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Fillmore, Franklin, Furnas and 19 more2 hr
Apr 14, 2:33 PM CDTTornado WatchSPCBlaine, Custer, Frontier, Garfield, Hayes, Holt and 7 more8 hr
Apr 14, 6:27 PM CDTTornado Watch PDSSPCAdams, Buffalo, Cass, Clay, Dawson, Fillmore and 30 more9 hr

Nearby

Mesoscale Discussions in Iowa, 2012Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Nebraska, 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.