Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1221

June 14, 201128 counties in Nebraska; 9 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2011, 4:46 PM CDT for 28 counties in Nebraska; 9 counties in South Dakota. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Jun 14, 2011, 4:46 PM CDT (21:46 UTC)
Expired: Jun 14, 2011, 5:45 PM CDT
In force: 59 min
Issued by: the Storm Prediction Center

All 37 counties

Antelope County, NE, Blaine County, NE, Boone County, NE, Boyd County, NE, Brown County, NE, Buffalo County, NE, Cherry County, NE, Custer County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Holt County, NE, Hooker County, NE, Howard County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Platte County, NE, Polk County, NE, Rock County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Aurora County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Douglas County, SD, Gregory County, SD, Hand County, SD, Jerauld County, SD, Spink County, SD

The radar

The North Platte radar (KLNX), 163 km from the middle of the area, began a volume at 21:48 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

Aberdeen, SD (KABR), launched 12:00Z, 9.8 hours before the alert went out and 223 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1348 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 527 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 88 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.

364 
ACUS11 KWNS 142146
SWOMCD
SPC MCD 142146 
NEZ000-SDZ000-142245-

MESOSCALE DISCUSSION 1221
NWS STORM PREDICTION CENTER NORMAN OK
0446 PM CDT TUE JUN 14 2011

AREAS AFFECTED...CENTRAL SD SWD INTO NRN/CENTRAL NEB

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 142146Z - 142245Z

THUNDERSTORMS....WITH SEVERE HAIL...WILL BE POSSIBLE THE NEXT FEW
HOURS FROM CENTRAL SD SWD INTO NRN/CENTRAL NEB. THE THREAT IS
CURRENTLY EXPECTED TO BE TOO ISOLATED FOR A WW.

THUNDERSTORMS WERE LOCATED ALONG AN INVERTED TROUGH AND AHEAD OF A
SHORTWAVE TROUGH MOVING EWD THROUGH WRN NEB/SD. ALTHOUGH A NARROW
WEDGE OF MODERATELY INSTABILITY EXISTS AHEAD OF THE TROUGH IN
SD...THESE STORMS SHOULD SLOWLY WEAKEN AS THEY SHIFT EWD
INTO A CLOUDIER AND MORE STABLE AIR MASS LOCATED ACROSS ERN SD.

STRONGER HEATING HAS RESULTED IN GREATER INSTABILITY IN NRN NEB AND
STORMS MOVING INTO THIS REGION WILL HAVE A GREATER POTENTIAL FOR
HAIL...SOME GREATER THAN 1 INCH IN DIAMETER. HOWEVER...THE 
RELATIVELY WEAK SHEAR IN THE 20-30 KT RANGE AND EXPECTED SMALL AREA
OF STORMS PROBABLY PRECLUDES A WATCH ISSUANCE.

..IMY.. 06/14/2011

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

ATTN...WFO...FSD...OAX...ABR...GID...LBF...

LAT...LON   44379926 45089911 45549863 45379809 44769830 43729831
            42669799 41699726 41189725 40819784 40839895 40939976
            41550084 41960129 42570143 42900114 42959940 44379926

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 13, 9:44 PM CDT	Mesoscale Discussion	SPC	Arthur, Chase, Cherry, Cheyenne, Deuel, Dundy and 7 more	91 min
Jun 14, 1:50 AM CDT	Mesoscale Discussion	SPC	Chase, Dawson, Dundy, Frontier, Furnas, Gosper and 7 more	115 min

Nearby

Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in South Dakota, 2011 Every 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.