Alert archive / Nebraska / Mesoscale Discussions in 2016

Mesoscale Discussion 720

May 24, 201621 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 24, 2016, 10:43 PM CDT for 21 counties in Nebraska. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: May 24, 2016, 10:43 PM CDT (03:43 UTC)
Expired: May 25, 2016, 12:15 AM CDT
In force: 92 min
Issued by: the Storm Prediction Center

All 21 counties

Adams County, NE, Buffalo County, NE, Custer County, NE, Dawson County, NE, Franklin County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Hall County, NE, Harlan County, NE, Hayes County, NE, Hitchcock County, NE, Howard County, NE, Kearney County, NE, Lincoln County, NE, Logan County, NE, Phelps County, NE, Red Willow County, NE, Sherman County, NE, Valley County, NE, Webster County, NE

The radar

The Grand Island radar (KUEX), 141 km from the middle of the area, began a volume at 03:44 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 209May 24, 11:05 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 3.7 hours before the alert went out and 83 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: 1159 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1520 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

158 
ACUS11 KWNS 250343
SWOMCD
SPC MCD 250343 
NEZ000-KSZ000-250515-

MESOSCALE DISCUSSION 0720
NWS STORM PREDICTION CENTER NORMAN OK
1043 PM CDT TUE MAY 24 2016

AREAS AFFECTED...SOUTHWEST TO SOUTH-CENTRAL NEBRASKA

CONCERNING...TORNADO WATCH 206...

VALID 250343Z - 250515Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 206 CONTINUES.

SUMMARY...A NEW SEVERE THUNDERSTORM WATCH WILL LIKELY BE NEEDED TO
THE EAST OF TORNADO WATCH 206...AS A BROKEN BAND OF STRONG TO SEVERE
STORMS MOVES TO THE EAST INTO A MODERATELY UNSTABLE AIR MASS.

DISCUSSION...TRENDS MOSAIC RADAR IMAGERY SHOWED A LONG-LIVED
SUPERCELL BEING SUSTAINED LATE THIS EVENING AS IT MOVES OUT OF
NORTHEAST CO INTO SOUTHWEST NEB WITH A HISTORY OF PRODUCING A COUPLE
OF TORNADOES AND VERY LARGE HAIL /3.5 INCHES IN DIAMETER IN
NORTHEAST YUMA COUNTY/.  MEANWHILE...THE POLEWARD-EXTENDING BAND OF
STORMS HAS INCREASED IN INTENSITY AS IT MOVED AWAY FROM FAR
NORTHEAST CO AND ADJACENT SOUTHERN NEB PANHANDLE.  THE AIR MASS EAST
OF THESE STORMS THROUGH EAST OF WW 206 /TOWARD GREELEY COUNTY NEB
AND WEBSTER COUNTY KS/ REMAINS MODERATELY UNSTABLE...WITH A SLY LLJ
EXTENDING FROM WEST TX THROUGH WESTERN KS INTO WESTERN NEB. 
INCREASING LOW-LEVEL WARM ADVECTION AND FORCING FOR ASCENT INTO
SOUTHWEST NEB ATTENDANT TO THE LLJ WILL SUPPORT EASTWARD MOVEMENT OF
THE ONGOING BROKEN BAND OF STORMS.  THE MIDDLE PORTION OF THESE
STORMS IN THE EASTERN PART OF WW 206 /APPROACHING WESTERN LINCOLN
COUNTY NEB/ WAS TRACKING EAST AT 35 KT WHICH IS SUFFICIENT TO
SUPPORT A DAMAGING-WIND THREAT.

THE WESTERN KS LLJ IS EXPECTED TO VEER TO SOUTHWESTERLY OVERNIGHT...
SUSTAINING AN EASTWARD MOVEMENT INTO SOUTH-CENTRAL NEB THROUGH
06-08Z.  FARTHER EAST...THIS BAND OF STORMS MAY STRUGGLE TO BE
MAINTAINED AS COOLER...MORE STABLE AIR SPREADS TO THE NORTH INTO THE
KEARNEY...HASTINGS AND GRAND ISLAND PORTIONS OF SOUTH-CENTRAL NEB
FROM THE LARGE KS MCS.

..PETERS/EDWARDS.. 05/25/2016

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

ATTN...WFO...GID...LBF...GLD...

LAT...LON   40140147 40850106 41680093 41539841 40049824 40039866
            39949983 40010081 40140147

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 24, 7:09 PM CDT	Tornado Watch	SPC	Chase, Deuel, Dundy, Hayes, Hitchcock, Keith and 3 more	6 hr
May 24, 9:02 PM CDT	Mesoscale Discussion	SPC	Cherry, Sheridan	58 min
May 24, 9:49 PM CDT	Mesoscale Discussion	SPC	Gage, Jefferson, Nuckolls, Pawnee, Richardson, Thayer	86 min
May 24, 10:09 PM CDT	Severe Thunderstorm Watch	SPC	Gage, Johnson, Nemaha, Pawnee, Richardson	6 hr
May 24, 11:07 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Blaine, Buffalo, Custer, Dawson, Franklin and 17 more	6 hr
May 24, 11:56 PM CDT	Mesoscale Discussion	SPC	Chase, Dundy, Hayes, Hitchcock, Lincoln	64 min
May 25, 3:33 AM CDT	Mesoscale Discussion	SPC	Adams, Buffalo, Chase, Dawson, Franklin, Frontier and 8 more	57 min
May 25, 2:52 PM CDT	Mesoscale Discussion	SPC	Arthur, Blaine, Boyd, Brown, Chase, Cherry and 16 more	53 min

Nearby

Mesoscale Discussions in Nebraska, 2016 Every mesoscale discussion in 2016

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.