Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 534

April 14, 201229 counties in Iowa; 15 counties in Missouri; 32 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2012, 6:57 PM CDT for 29 counties in Iowa; 15 counties in Missouri; 32 counties in Nebraska. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Apr 14, 2012, 6:57 PM CDT (23:57 UTC)
Expired
Apr 14, 2012, 8:00 PM CDT
In force
63 min
Issued by
the Storm Prediction Center
All 76 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Fremont County, IA, Guthrie County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Adair County, MO, Andrew County, MO, Atchison County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Sullivan County, MO, Worth County, MO, Adams County, NE, Buffalo County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Phelps County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Thayer County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 92 km from the middle of the area, began a volume at 23:57 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, 12.0 hours before the alert went out and 93 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.

858 
ACUS11 KWNS 142358
SWOMCD
SPC MCD 142357
IAZ000-MOZ000-KSZ000-NEZ000-150100-

MESOSCALE DISCUSSION 0534
NWS STORM PREDICTION CENTER NORMAN OK
0657 PM CDT SAT APR 14 2012

AREAS AFFECTED...SERN NEB...SRN IA...NRN MO...NERN KS

CONCERNING...TORNADO WATCH 167...169...171...

VALID 142357Z - 150100Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH
167...169...171...CONTINUES.

A NEW WW HAS BEEN ISSUED FOR PORTIONS OF SERN NEB FOR POTENTIAL NEW
DEVELOPMENT AND ONGOING CONVECTION TO THE WEST OF AN EXITING MCS.
INTENSIFICATION OF STORMS REMAINS POSSIBLE ACROSS SRN IA...AND NRN
MO...ESPECIALLY IN ADVANCE OF A BOWING SEGMENT OVER SWRN IA.

23Z SURFACE ANALYSIS REFLECTS A DEEPENING SURFACE LOW OVER NWRN
KS/SWRN NEB...WITH SURFACE PRESSURE FALLS NOTED OVER NERN NEB/NWRN
IA IN RESPONSE TO HEIGHT FALLS ALOFT / A VORT MAX NOTED ON WV
IMAGERY OVER SERN WY/NERN CO. WITH A SURFACE LOW DEVELOPING INTO
NERN NEB...NOTABLE BACKING IS PROJECTED ACROSS FAR ERN NEB AND IA.
AREA VAD WIND PROFILE DATA IS ALREADY SHOWING SIGNIFICANT
STRENGTHENING OF LOW LEVEL WINDS.../50 KT AT 1000 FT ACROSS NERN
KS/NWRN MO...WITH HODOGRAPHS LARGELY BECOMING FAVORABLE FOR
SUPERCELLS CAPABLE OF DMGG WINDS...LARGE HAIL...AND POTENTIALLY
SIGNIFICANT TORNADOES. WARM ADVECTION REGIME WILL CONTINUE TO
SUPPORT A DESTABILIZING/RECOVERING AIR MASS...WITH NEW DEVELOPMENT
OF STORMS POSSIBLE.

..HURLBUT.. 04/14/2012

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

ATTN...WFO...DVN...DMX...EAX...OAX...TOP...GID...LBF...

LAT...LON   41909263 40839201 40019264 39869433 39799516 40039728
            40289884 40609973 41289942 41559649 41749474 41909263

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, 4:47 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Cass, Clarke, Dallas and 17 more58 min
Apr 14, 5:00 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 18 more7 hr
Apr 13, 7:34 PM CDTMesoscale DiscussionSPCBarry, Benton, Camden, Cedar, Christian, Cole and 29 more116 min
Apr 13, 9:14 PM CDTMesoscale DiscussionSPCBates, Vernon61 min
Apr 14, 10:43 AM CDTTornado Watch PDSSPCHitchcock, Red Willow7 hr
Apr 14, 11:27 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Fillmore, Franklin, Furnas and 19 more2 hr
Apr 14, 1:41 PM CDTMesoscale DiscussionSPCArthur, Custer, Dawson, Frontier, Garden, Grant and 9 more2 hr
Apr 14, 2:33 PM CDTTornado WatchSPCBlaine, Custer, Frontier, Garfield, Hayes, Holt and 7 more8 hr
Apr 14, 5:24 PM CDTTornado Watch PDSSPCHitchcock, Red Willow9 hr
Apr 14, 6:27 PM CDTTornado Watch PDSSPCAdams, Buffalo, Cass, Clay, Dawson, Fillmore and 30 more9 hr

Nearby

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