Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1982

August 14, 20117 counties in Colorado; 6 counties in Kansas; 24 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 14, 2011, 6:44 PM MDT for 7 counties in Colorado; 6 counties in Kansas; 24 counties in Nebraska. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Aug 14, 2011, 6:44 PM MDT (00:44 UTC)
Expired: Aug 14, 2011, 8:15 PM MDT
In force: 91 min
Issued by: the Storm Prediction Center

All 37 counties

Kit Carson County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Arthur County, NE, Banner County, NE, Box Butte County, NE, Chase County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hayes County, NE, Hitchcock County, NE, Hooker County, NE, Keith County, NE, Kimball County, NE, Lincoln County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Red Willow County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE

The radar

The North Platte radar (KLNX), 182 km from the middle of the area, began a volume at 00:45 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

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.7 hours before the alert went out and 168 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: 1461 J/kg
Mixed-layer CIN: -93 J/kg
Mixed-layer LCL: 1398 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 125 m²/s²
0-3 km storm-relative helicity: 416 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 21.7

Open this sounding in Storm Lab

The text

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

010 
ACUS11 KWNS 150044
SWOMCD
SPC MCD 150044 
NEZ000-KSZ000-COZ000-WYZ000-150215-

MESOSCALE DISCUSSION 1982
NWS STORM PREDICTION CENTER NORMAN OK
0744 PM CDT SUN AUG 14 2011

AREAS AFFECTED...WRN NEB...NERN CO...NWRN KS

CONCERNING...SEVERE THUNDERSTORM WATCH 781...

VALID 150044Z - 150215Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 781
CONTINUES.

STORMS HAVE BEEN STRUGGLING TO BECOME ORGANIZED ACROSS WW 781 THIS
AFTERNOON. THE MOST LIKELY AREA TO STILL EXPERIENCE STRONG WINDS AND
SEVERE HAIL WILL BE ACROSS NWRN KS INTO ADJACENT PARTS OF SWRN NEB. 


THE MAIN LIMITING FACTOR HAS BEEN A STRONG CAP AND ABUNDANT CLOUD
COVER PREVENTING MORE WIDESPREAD ROBUST CONVECTION. HOWEVER...THE
AREA NEAR AND E OF GLD NWD INTO ADJACENT SWRN NEB MAY STILL SUPPORT
SEVERE CONVECTION. THIS AREA IS WITHIN THE AXIS OF STRONG
INSTABILITY WITH MLCAPE VALUES APPROACHING 3000 J/KG AND EFFECTIVE
SHEAR VALUES NEAR 35 KT. THIS MAY ALLOW EXISTING CONVECTIVE NEAR THE
CO/KS AND CO/NEB BORDER TO BECOME BETTER ORGANIZED AS IT MOVES INTO
A BETTER DOWNSTREAM ENVIRONMENT. THEREFORE...THE DOWNSTREAM
ENVIRONMENT WITHIN THE WATCH COULD STILL SUPPORT STRONG WIND GUSTS
AND SEVERE HAIL FOR A FEW MORE HOURS BEFORE STORMS BECOME
INCREASINGLY ELEVATED WITH NIGHTFALL AND MOVE AWAY FROM AREA OF BEST
FORCING/INSTABILITY.

..LEITMAN.. 08/15/2011

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

ATTN...WFO...LBF...GLD...BOU...CYS...

LAT...LON   42830410 42810058 39050039 39080377 42830410

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 15, 12:26 AM MDT	Mesoscale Discussion	SPC	Cloud, Jewell, Mitchell, Osborne, Republic, Smith and 1 more	3 hr

Nearby

Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in Colorado, 2011 Mesoscale Discussions in Kansas, 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.