Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 722

May 5, 2012Banner County, Cheyenne County, Kimball County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 5, 2012, 5:44 PM MDT for Banner County, Cheyenne County, Kimball County, Nebraska. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: May 5, 2012, 5:44 PM MDT (23:44 UTC)
Expired: May 5, 2012, 6:45 PM MDT
In force: 61 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Banner County, NE, Cheyenne County, NE, Kimball County, NE

The radar

The Cheyenne radar (KCYS), 107 km from the middle of the area, began a volume at 23:44 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 nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.7 hours before the alert went out and 166 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2826 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: -33 m²/s²
0-3 km storm-relative helicity: 33 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.

580 
ACUS11 KWNS 052344
SWOMCD
SPC MCD 052344 
NEZ000-COZ000-WYZ000-060045-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
0644 PM CDT SAT MAY 05 2012

AREAS AFFECTED...SE WY...SWRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 052344Z - 060045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED SUPERCELLS MAY CONTINUE TO POSE A RISK FOR SEVERE
WEATHER ...BUT IT IS NOT CLEAR THE THREAT WILL PERSIST MUCH BEYOND
01-02Z.

DISCUSSION...ISOLATED SUPERCELL DEVELOPMENT HAS BEEN ONGOING THE
PAST COUPLE OF HOURS...IN THE PRESENCE OF MODERATELY LARGE CAPE AND
STRONG SHEAR ...WITHIN A MOIST UPSLOPE REGIME ACROSS THE REGION.  IT
IS UNCLEAR HOW MUCH LONGER THIS ACTIVITY WILL PERSIST...AS LATEST
MODEL GUIDANCE SUGGESTS A SOUTHWARD COLD FRONTAL SURGE THROUGH MUCH
OF THE NORTH CENTRAL HIGH PLAINS BY 01-02Z.  ONCE THIS
OCCURS...UPSLOPE ACROSS SOUTHEASTERN WYOMING AND SOUTHWESTERN
NEBRASKA WILL CEASE...WITH MORE PROMINENT CONVECTIVE DEVELOPMENT
EXPECTED TO OCCUR IN THE PRIMARY WARM ADVECTION REGIME TO THE EAST
NORTHEAST...ACROSS PARTS OF NORTHERN NEBRASKA/SOUTHEASTERN SOUTH
DAKOTA.

..KERR.. 05/05/2012

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

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

LAT...LON   41290431 41620406 41760339 41520245 41050262 40870369
            41290431

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 8:54 PM MDT	Mesoscale Discussion	SPC	Adams, Antelope, Boone, Buffalo, Burt, Butler and 42 more	96 min
May 4, 9:55 PM MDT	Mesoscale Discussion	SPC	Adams, Antelope, Boone, Buffalo, Burt, Butler and 34 more	35 min
May 4, 10:00 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Boone, Buffalo, Burt, Butler, Cass and 34 more	3 hr
May 5, 1:09 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Butler, Cedar, Colfax and 22 more	96 min
May 5, 2:52 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Cedar, Cuming, Dakota, Dixon and 11 more	83 min
May 5, 4:31 PM MDT	Tornado Watch	SPC	Antelope, Boone, Cedar, Custer, Dakota, Dawson and 15 more	5 hr
May 5, 5:21 PM MDT	Mesoscale Discussion	SPC	Boyd, Brown, Keya Paha, Rock, Thomas	84 min
May 5, 5:46 PM MDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Boyd, Brown, Cherry, Deuel and 10 more	6 hr

Nearby

Mesoscale Discussions in Nebraska, 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.