Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 902

May 25, 20124 states

The Storm Prediction Center issued this mesoscale discussion at May 25, 2012, 9:17 PM CDT for 4 states. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
May 25, 2012, 9:17 PM CDT (02:17 UTC)
Expired
May 25, 2012, 10:45 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 90 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone 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, Harrison County, IA, Humboldt County, IA, Ida County, IA, Lucas County, IA, Madison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page 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, Phillips County, KS, Smith County, KS, Atchison County, MO, Nodaway County, MO, Worth County, MO, Adams County, NE, Boone County, NE, Buffalo County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dawson County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Gage County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Phelps County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thayer County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Webster County, NE, York County, NE

The radar

The Omaha radar (KOAX), 47 km from the middle of the area, began a volume at 02:19 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, 2.3 hours before the alert went out and 47 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 2012-05-26Temperature 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 00:00Z on 2012-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 328 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
1031 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
328 m²/s²
0-3 km storm-relative helicity
876 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.1

Open this sounding in Storm Lab

The text

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

421 
ACUS11 KWNS 260217
SWOMCD
SPC MCD 260217 
IAZ000-MOZ000-NEZ000-KSZ000-260345-

MESOSCALE DISCUSSION 0902
NWS STORM PREDICTION CENTER NORMAN OK
0917 PM CDT FRI MAY 25 2012

AREAS AFFECTED...FAR NRN KS/S CENTRAL AND ERN NEB INTO WRN IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 260217Z - 260345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...INCREASING CONVECTION OVER THE NEXT FEW HOURS ATOP A COOL
BOUNDARY LAYER SUGGESTS HAIL THREAT MAY BECOME GREAT ENOUGH TO
WARRANT WW ISSUANCE.

DISCUSSION...LATEST RADAR LOOP SHOWS CONVECTION BEGINNING TO DEVELOP
ACROSS FAR NRN KS -- N OF THE ONGOING CENTRAL KS SUPERCELL STORMS --
AND INTO PARTS OF CENTRAL NEB.  THESE STORMS ARE DEVELOPING IN
RESPONSE TO AN INCREASING LOW-LEVEL JET...ATOP A COOL/STABLE
BOUNDARY LAYER ABOVE WHICH CAPE VALUES OF AROUND 1000 J/KG ARE
SUGGESTED /PER THE EVENING OMAHA NEB RAOB/.  WITH SHEAR THROUGH THE
CLOUD-BEARING LAYER SUPPORTIVE OF ORGANIZED STORMS...THIS SETUP
APPEARS TO SUPPORT POTENTIAL FOR MARGINALLY SEVERE HAIL.  WE WILL
CONTINUE TO MONITOR EVOLUTION OF THE CONVECTION -- AS INDICATIONS OF
POTENTIAL FOR SUBSTANTIAL COVERAGE OF STRONGER CELLS COULD WARRANT
WW ISSUANCE.

..GOSS/HART.. 05/26/2012

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

ATTN...WFO...DMX...EAX...FSD...OAX...TOP...GID...LBF...GLD...

LAT...LON   39959749 39509960 40230029 41000002 42039796 42649575
            42909392 42109344 40809323 40209525 39959749

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 12:46 AM CDTMesoscale DiscussionSPCAllamakee, Benton, Black Hawk, Boone, Bremer, Buchanan and 44 more89 min
May 25, 8:29 PM CDTMesoscale DiscussionSPCBarton, Ellis, Ellsworth, Lincoln, Mitchell, Ness and 5 more2 hr
May 25, 8:43 PM CDTMesoscale DiscussionSPCBarber, Clark, Comanche, Edwards, Ford, Kingman and 4 more62 min
May 25, 10:44 PM CDTMesoscale DiscussionSPCBarton, Ellsworth, Lincoln, Pawnee, Rush, Russell61 min
May 26, 2:46 PM CDTMesoscale DiscussionSPCFinney, Grant, Gray, Hamilton, Haskell, Kearny and 5 more119 min
May 26, 1:58 AM CDTMesoscale DiscussionSPCBoyd, Holt, Keya Paha, Knox, Rock92 min
May 26, 3:48 PM CDTMesoscale DiscussionSPCAdams, Antelope, Boone, Buffalo, Burt, Butler and 50 more87 min
May 26, 3:55 PM CDTMesoscale DiscussionSPCArthur, Banner, Box Butte, Cheyenne, Deuel, Garden and 7 more2 hr
May 26, 4:48 PM CDTSevere Thunderstorm WatchSPCArthur, Blaine, Boyd, Brown, Cherry, Custer and 15 more5 hr
May 26, 6:44 PM CDTMesoscale DiscussionSPCArthur, Blaine, Brown, Cherry, Garden, Garfield and 9 more91 min

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.