Alert archive / Nebraska / Mesoscale Discussions in 2016

Mesoscale Discussion 558

May 8, 201628 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 8, 2016, 4:45 PM CDT for 28 counties in Nebraska. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: May 8, 2016, 4:45 PM CDT (21:45 UTC)
Expired: May 8, 2016, 6:15 PM CDT
In force: 90 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 28 counties

Adams County, NE, Blaine County, NE, Boone County, NE, Buffalo County, NE, Butler County, NE, Clay County, NE, Custer County, NE, Dawson County, NE, Fillmore County, NE, Frontier County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Kearney County, NE, Loup County, NE, Merrick County, NE, Nance County, NE, Phelps County, NE, Polk County, NE, Saline County, NE, Seward County, NE, Sherman County, NE, Valley County, NE, Wheeler County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 92 km from the middle of the area, began a volume at 21:47 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 151May 8, 5:10 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 9.8 hours before the alert went out and 145 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: 921 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 299 m²/s²
0-3 km storm-relative helicity: 343 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

367 
ACUS11 KWNS 082145
SWOMCD
SPC MCD 082145 
NEZ000-082315-

MESOSCALE DISCUSSION 0558
NWS STORM PREDICTION CENTER NORMAN OK
0445 PM CDT SUN MAY 08 2016

AREAS AFFECTED...PORTIONS OF CENTRAL/EASTERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 082145Z - 082315Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...AT LEAST AN ISOLATED SEVERE RISK MAY INCREASE THROUGH LATE
AFTERNOON/EARLY EVENING ACROSS CENTRAL NEB AND EVENTUALLY PORTIONS
OF EASTERN NEB. MONITORING DEVELOPMENTAL TRENDS FOR A POSSIBLE
WATCH.

DISCUSSION...WHILE CLOUD COVER PERSISTS ALONG/NORTH OF A
SLOW-NORTHWARD-SHIFTING WARM FRONT...THE BOUNDARY LAYER HAS
GRADUALLY DESTABILIZED SINCE MID-AFTERNOON ACROSS CENTRAL NEB...WITH
MIDDLE 50S F SURFACE DEWPOINTS APPEARING TO CONTRIBUTE TO AS MUCH AS
1500 J/KG MLCAPE ACROSS CENTRAL NEB. ONE STORM HAS RECENTLY
INTENSIFIED NEAR THE LEXINGTON NEB VICINITY AS OF 2120Z. AS FURTHER
DESTABILIZATION OCCURS /ALBEIT MODEST IN MANY RESPECTS/...ADDITIONAL
STORM DEVELOPMENT WILL LIKELY BE AIDED BY A NORTHEASTWARD-SPREADING
MID-LEVEL IMPULSE OVER NORTHWEST/WEST-CENTRAL KS. AT THE VERY
LEAST...WITH SUPERCELL-SUPPORTIVE VERTICAL SHEAR...ISOLATED/EPISODIC
SEVERE HAIL APPEARS LIKELY ESPECIALLY ACROSS CENTRAL NEB...AND
ISOLATED DAMAGING WINDS AND/OR A TORNADO COULD OCCUR ACROSS
SOUTH-CENTRAL NEB.

..GUYER/CORFIDI.. 05/08/2016

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

ATTN...WFO...OAX...GID...LBF...

LAT...LON   40440063 41690035 42339943 42109876 41299701 40049680
            40319734 40440063

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 7, 9:04 PM CDT	Mesoscale Discussion	SPC	Chase, Dundy, Frontier, Hayes, Hitchcock, Keith and 3 more	86 min
May 8, 3:44 PM CDT	Tornado Watch	SPC	Franklin, Furnas, Harlan, Nuckolls, Red Willow, Webster	8 hr
May 8, 5:09 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Blaine, Brown, Buffalo, Cherry, Clay and 26 more	7 hr
May 8, 6:33 PM CDT	Mesoscale Discussion	SPC	Franklin, Furnas, Harlan, Webster	87 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.