Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 506

April 12, 20127 counties in Kansas; 11 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2012, 11:24 PM CDT for 7 counties in Kansas; 11 counties in Nebraska. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Apr 12, 2012, 11:24 PM CDT (04:24 UTC)
Expired: Apr 13, 2012, 1:00 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center

Counties Decatur County, KS, Gove County, KS, Graham County, KS, Norton County, KS, Phillips County, KS, Sheridan County, KS, Thomas County, KS, Buffalo County, NE, Dawson County, NE, Franklin County, NE, Furnas County, NE, Gosper County, NE, Harlan County, NE, Kearney County, NE, Phelps County, NE, Red Willow County, NE, Sherman County, NE, Valley County, NE

The radar

The Grand Island radar (KUEX), 146 km from the middle of the area, began a volume at 04:26 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, 4.4 hours before the alert went out and 109 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: 188 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 487 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 458 m²/s²
0-3 km storm-relative helicity: 490 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.5

Open this sounding in Storm Lab

The text

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

964 
ACUS11 KWNS 130424
SWOMCD
SPC MCD 130424 
NEZ000-KSZ000-130600-

MESOSCALE DISCUSSION 0506
NWS STORM PREDICTION CENTER NORMAN OK
1124 PM CDT THU APR 12 2012

AREAS AFFECTED...CENTRAL NEB/NORTHWEST KS

CONCERNING...SEVERE THUNDERSTORM WATCH 158...159...

VALID 130424Z - 130600Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
158...159...CONTINUES.

SEVERE TSTM WATCHES 158/159 CONTINUE UNTIL 07Z/09Z
RESPECTIVELY...WITH SEVERE HAIL/WIND REMAINING POSSIBLE ON AN
ISOLATED BASIS.

A NNE-SSW ORIENTED LINEAR BAND CONTINUES TO MAKE A SLOW BUT STEADY
EASTWARD PROGRESSION ACROSS CENTRAL NEB/NORTHWEST KS LATE THIS
EVENING. THE MOST UNSTABLE INFLOW /ALBEIT ONLY MODESTLY UNSTABLE AND
INCREASINGLY ELEVATED/ WILL CONTINUE TO OCCUR IN PROXIMITY TO THE
PORTION OF THE LINE EITHER SIDE OF THE KS-NEB BORDER
VICINITY...NEAR/NORTHEAST OF A WARM FRONT ACROSS THE REGION.
ADDITIONAL CELL MERGERS/UPSCALE EXPANSION MAY SLOWLY OCCUR OVER TIME
AS WARM ADVECTION INCREASES/FOCUSES PROGRESSIVELY NORTHEASTWARD.
SUCH A SCENARIO COULD CONTRIBUTE TO SOME ADDITIONAL COLD POOL
EXPANSION/MODEST ACCELERATION OF THE LINE OVERNIGHT...BUT EVEN
SO...A RELATIVELY STABLE BOUNDARY LAYER/MODESTLY UNSTABLE ELEVATED
INFLOW SUGGEST ANY SEVERE HAIL/WIND POTENTIAL WILL REMAIN QUITE
LIMITED/ISOLATED...ESPECIALLY WITH NORTHEASTWARD EXTENT INTO CENTRAL
NEB.

..GUYER.. 04/13/2012

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

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

LAT...LON   39980079 40920006 42199912 40559857 38520031 39350146
            39980079

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 12, 7:53 PM CDT	Mesoscale Discussion	SPC	Cheyenne, Decatur, Gove, Lane, Logan, Rawlins and 6 more	97 min
Apr 12, 8:38 PM CDT	Severe Thunderstorm Watch	SPC	Cheyenne, Decatur, Gove, Graham, Greeley, Lane and 9 more	4 hr
Apr 13, 2:37 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 9 more	113 min
Apr 13, 3:40 PM CDT	Severe Thunderstorm Watch	SPC	Allen, Anderson, Bourbon, Butler, Chase, Chautauqua and 19 more	6 hr
Apr 13, 5:40 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 14 more	65 min
Apr 12, 8:57 PM CDT	Mesoscale Discussion	SPC	Blaine, Buffalo, Custer, Dawson, Franklin, Furnas and 7 more	93 min

Nearby

Mesoscale Discussions in Nebraska, 2012 Mesoscale Discussions in Kansas, 2012 Every 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.