Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1939

August 10, 2011Phillips County, Sedgwick County, Colorado; 7 counties in Kansas; 13 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 10, 2011, 9:10 PM MDT for Phillips County, Sedgwick County, Colorado; 7 counties in Kansas; 13 counties in Nebraska. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Aug 10, 2011, 9:10 PM MDT (03:10 UTC)
Expired: Aug 10, 2011, 10:45 PM MDT
In force: 95 min
Issued by: the Storm Prediction Center

All 22 counties

Phillips County, CO, Sedgwick County, CO, Cheyenne County, KS, Decatur County, KS, Logan County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Arthur County, NE, Chase County, NE, Deuel County, NE, Dundy County, NE, Frontier County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Perkins County, NE, Red Willow County, NE

The radar

The Goodland radar (KGLD), 115 km from the middle of the area, began a volume at 03:10 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, 3.2 hours before the alert went out and 103 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: 765 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1073 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 271 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 11.0

Open this sounding in Storm Lab

The text

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

172 
ACUS11 KWNS 110310
SWOMCD
SPC MCD 110310 
NEZ000-KSZ000-COZ000-110445-

MESOSCALE DISCUSSION 1939
NWS STORM PREDICTION CENTER NORMAN OK
1010 PM CDT WED AUG 10 2011

AREAS AFFECTED...CO...NE...KS

CONCERNING...SEVERE THUNDERSTORM WATCH 764...765...

VALID 110310Z - 110445Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
764...765...CONTINUES.

TWO STORMS PERSIST WITHIN WATCHES 764 AND 765 THIS EVENING. STORM
NUMBER ONE...IN WATCH 764...WAS MOVING SSE AROUND 18KT FROM HOOKER
COUNTY INTO MCPHERSON COUNTY IN CNTRL NEB. THIS LONG-LIVED CELL MAY
BE ACCOMPANIED BY HIGH WINDS ASSOCIATED WITH THE REAR-FLANK
DOWNDRAFT...AS WELL AS LARGE HAIL. THIS SUPERCELL WILL CONTINUE TO
BE CONTAINED WELL WITHIN WATCH 764 OVER THE NEXT HOUR. IF THIS STORM
MAINTAINS ITS CURRENT STRUCTURE AND INTENSITY OVER THE NEXT HOUR...A
LOCAL EXTENSION IN TIME TO WATCH 764 MAY BE NEEDED SINCE THE STORM
COULD MOVE INTO THE NORTH PLATTE AREA SOMETIME AFTER 05 UTC/MIDNIGHT
CDT.

STORM NUMBER TWO IS A PERSISTENT SUPERCELL THAT IS NOW MOVING INTO
WATCH 765 IN NORTHWEST YUMA COUNTY COLORADO. THIS CELL IS TRACKING
SEWD AROUND 25KT AND MAY MAKE IT INTO EXTREME NWRN KS IN ABOUT AN
HOUR.

..CARBIN.. 08/11/2011

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

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

LAT...LON   39030023 38720120 40240257 41700221 41750076 41480029
            39030023

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 10, 6:50 PM MDT	Severe Thunderstorm Watch	SPC	Cheyenne, Kit Carson, Yuma	3 hr
Aug 11, 2:15 AM MDT	Mesoscale Discussion	SPC	Harper	90 min
Aug 11, 3:15 PM MDT	Mesoscale Discussion	SPC	Arthur, Cherry, Garden, Grant, Hooker, Logan and 3 more	60 min
Aug 11, 3:38 PM MDT	Tornado Watch	SPC	Blaine, Boyd, Brown, Cherry, Custer, Garfield and 9 more	9 hr
Aug 11, 5:38 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Cedar, Colfax, Cuming and 13 more	97 min

Nearby

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