Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1024

May 29, 20114 states

The Storm Prediction Center issued this mesoscale discussion at May 29, 2011, 9:24 PM CDT for 4 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
May 29, 2011, 9:24 PM CDT (02:24 UTC)
Expired
May 29, 2011, 11:00 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 51 counties

Audubon County, IA, Crawford County, IA, Harrison County, IA, Ida County, IA, Mills County, IA, Monona County, IA, Plymouth County, IA, Pottawattamie County, IA, Shelby County, IA, Sioux County, IA, Woodbury County, IA, Republic County, KS, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Otoe County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thayer County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, York County, NE, Clay County, SD, Union County, SD

The radar

The Omaha radar (KOAX), 40 km from the middle of the area, began a volume at 02:28 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, 2.4 hours before the alert went out and 40 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 2011-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3559 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 2011-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 440 square meters per square second.19395878Sfc1 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
3559 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
597 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
440 m²/s²
0-3 km storm-relative helicity
720 m²/s²
Significant tornado parameter
0.0
Supercell composite
59.8

Open this sounding in Storm Lab

The text

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

084 
ACUS11 KWNS 300225
SWOMCD
SPC MCD 300224
IAZ000-NEZ000-KSZ000-SDZ000-300400-

MESOSCALE DISCUSSION 1024
NWS STORM PREDICTION CENTER NORMAN OK
0924 PM CDT SUN MAY 29 2011

AREAS AFFECTED...PORTIONS EXTREME N-CENTRAL KS...ERN NEB...WRN
IA...EXTREME SERN SD.

CONCERNING...TORNADO WATCH 398...

VALID 300224Z - 300400Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 398 CONTINUES.

QUASISTATIONARY FRONT WAS ANALYZED NEAR GLD-LNK-ALO LINE...AS
EARLIER TWO-TIERED BAROCLINIC ZONE APPEARS TO BE CONSOLIDATING.
ISOLATED CELL THAT HAD GONE UP NEAR LNK BEFORE 00Z HAS DISSIPATED.
CHANCES OF ADDITIONAL SFC-BASED CONVECTIVE INITIATION NEAR FRONTAL
SEGMENT...AND THEREFORE DEVELOPMENT OF POTENTIALLY TORNADIC
SUPERCELLS...APPEAR TO BE DIMINISHING STEADILY WITH TIME AS DIABATIC
COOLING GRADUALLY STRENGTHENS MLCINH.  ACTIVITY MOVING NEWD FROM KS
STILL MAY PRODUCE LARGE HAIL AND SVR GUSTS ACROSS AREAS BETWEEN
HSI-BIE.  DAMAGING GUST WAS REPORTED IN THAYER COUNTY AT 150Z.  THIS
ACTIVITY MAY REMAIN  SFC-BASED ANOTHER HOUR OR TWO IF INTERNAL STORM
DYNAMICS ARE FORCING ASCENT THROUGH AMBIENT CINH LAYER.
HOWEVER...THAT CINH WILL INCREASE WITH TIME....CAUSING EFFECTIVE
INFLOW PARCELS TO BE EITHER CAPPED STRONGLY OR ROOTED ABOVE BOUNDARY
LAYER.

MEANWHILE...CONVECTION IS DEVELOPING N OF NRN SFC FRONTAL
SEGMENT...BETWEEN BVN-OFK AND NW OF WW.  THIS ACTIVITY...NEAR ERN
BRANCH OF 45-50 KT LLJ...MAY BE START OF BROADER PLUME OF CONVECTION
THAT IS PROGGED TO DEVELOP OVER NERN NEB AND MOVE NEWD ACROSS
PORTIONS SERN SD/NWRN IA/SRN MN OVERNIGHT.  ACTIVITY WILL HAVE
POTENTIAL FOR LARGE HAIL...IN ENVIRONMENT CHARACTERIZED BY
INCREASING LOW-LEVEL THETAE ABOVE SFC..STEEP MIDLEVEL LAPSE RATES
PER OAX SOUNDING...FAVORABLE EFFECTIVE SHEAR...AND ISENTROPIC ASCENT
TO LFC.  THOSE AREAS WILL BE MONITORED FOR POSSIBLE WW.

..EDWARDS.. 05/30/2011

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

ATTN...WFO...DMX...FSD...OAX...TOP...GID...

LAT...LON   41589477 39829671 39839833 40539839 42229816 43029719
            43269605 41589477

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 7:16 PM CDTTornado WatchSPCFremont, Harrison, Mills, Montgomery, Pottawattamie, Shelby4 hr
May 29, 10:58 PM CDTSevere Thunderstorm WatchSPCDickinson, Lyon, O'Brien, Osceola, Plymouth, Sioux6 hr
May 30, 3:33 PM CDTMesoscale DiscussionSPCClark, Edwards, Ellis, Ford, Gove, Graham and 12 more87 min
May 30, 1:40 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boone, Boyd, Buffalo, Cedar and 16 more95 min
May 30, 2:08 PM CDTTornado WatchSPCAdams, Antelope, Blaine, Boone, Boyd, Brown and 29 more7 hr
May 30, 2:19 PM CDTMesoscale DiscussionSPCArthur, Cheyenne, Deuel, Garden, Keith, Kimball and 1 more56 min
May 30, 4:45 PM CDTSevere Thunderstorm WatchSPCArthur, Chase, Cherry, Deuel, Dundy, Garden and 9 more3 hr
May 30, 5:47 PM CDTMesoscale DiscussionSPCArthur, Brown, Chase, Cherry, Deuel, Dundy and 9 more58 min
May 30, 6:17 PM CDTMesoscale DiscussionSPCAdams, Antelope, Blaine, Boone, Boyd, Brown and 25 more118 min
May 30, 2:52 AM CDTMesoscale DiscussionSPCBeadle, Brookings, Clark, Codington, Deuel, Grant and 4 more113 min
May 30, 4:05 AM CDTSevere Thunderstorm WatchSPCDay, Grant, Marshall, Roberts5 hr
May 30, 3:52 PM CDTTornado WatchSPCClark, Codington, Day, Deuel, Grant, Hamlin and 2 more7 hr

Nearby

Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in South Dakota, 2011Every mesoscale discussion in 2011

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.