Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 883

May 23, 201217 counties in Iowa; 18 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 23, 2012, 6:49 PM CDT for 17 counties in Iowa; 18 counties in Nebraska. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 23, 2012, 6:49 PM CDT (23:49 UTC)
Expired
May 23, 2012, 8:15 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
All 35 counties

Buena Vista County, IA, Calhoun County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dickinson County, IA, Emmet County, IA, Harrison County, IA, Ida County, IA, Kossuth County, IA, Monona County, IA, Palo Alto County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Woodbury County, IA, Burt County, NE, Butler County, NE, Cass County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nuckolls County, NE, Otoe County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 94 km from the middle of the area, began a volume at 23:50 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 12:00Z, 11.8 hours before the alert went out and 94 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 2012-05-23Temperature 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 2012-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 271 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1627 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
271 m²/s²
0-3 km storm-relative helicity
363 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

025 
ACUS11 KWNS 232350
SWOMCD
SPC MCD 232349
MNZ000-IAZ000-NEZ000-KSZ000-240115-

MESOSCALE DISCUSSION 0883
NWS STORM PREDICTION CENTER NORMAN OK
0649 PM CDT WED MAY 23 2012

AREAS AFFECTED...ERN NEB/WRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 293...

VALID 232349Z - 240115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 293
CONTINUES.

SUMMARY...SEVERE THREAT CONTINUES WITHIN WW 293.

DISCUSSION...RADAR LOOP SHOWS SCATTERED STRONG/ISOLATED SEVERE
STORMS ONGOING WITHIN A BAND CENTERED ON THE MO VALLEY OF ERN
NEB/WRN IA...JUST AHEAD OF THE SURFACE FRONT.  WITH THE AIRMASS
ACROSS THIS REGION STILL AMPLY UNSTABLE /MIXED-LAYER CAPE 500 TO
1500 J/KG/ AHEAD OF THE FRONT AND SHEAR FAVORABLE FOR
ORGANIZED/ROTATING STORMS...THREAT FOR ISOLATED LARGE HAIL/DAMAGING
WINDS WILL CONTINUE FOR THE NEXT COUPLE OF HOURS.  SOME DECREASE IN
THREAT SHOULD BEGIN THEREAFTER...AS DIURNAL BOUNDARY-LAYER
STABILIZATION BEGINS.

..GOSS.. 05/23/2012

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

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

LAT...LON   43519412 42779429 40179638 39939781 40109831 42769572
            43479518 43519412

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 23, 2:56 PM CDTMesoscale DiscussionSPCBuena Vista, Carroll, Cherokee, Clay, Crawford, Harrison and 11 more94 min
May 23, 4:07 PM CDTSevere Thunderstorm WatchSPCAudubon, Buena Vista, Calhoun, Carroll, Cherokee, Clay and 23 more7 hr

Nearby

Mesoscale Discussions in Nebraska, 2012Mesoscale 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.