Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 983

May 30, 20129 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 30, 2012, 4:41 PM CDT for 9 counties in Nebraska. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 30, 2012, 4:41 PM CDT (21:41 UTC)
Expired
May 30, 2012, 6:15 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Buffalo County, NE, Custer County, NE, Dawson County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Hitchcock County, NE, Phelps County, NE, Red Willow County, NE

The radar

The Grand Island radar (KUEX), 141 km from the middle of the area, began a volume at 21:44 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 9.7 hours before the alert went out and 81 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2012-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2012-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 343 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1457 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
343 m²/s²
0-3 km storm-relative helicity
487 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.

964 
ACUS11 KWNS 302141
SWOMCD
SPC MCD 302141 
NEZ000-KSZ000-302315-

MESOSCALE DISCUSSION 0983
NWS STORM PREDICTION CENTER NORMAN OK
0441 PM CDT WED MAY 30 2012

AREAS AFFECTED...SWRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 302141Z - 302315Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...AT LEAST ISOLATED LARGE HAIL AND WIND ARE LIKELY OVER SWRN
NEB BEFORE STORMS GET INTO WW 323.

DISCUSSION...STORMS ARE ERUPTING ALONG THE COLD FRONT OVER SWRN
NEB...WITH STEEP LAPSE RATE PROFILES IN PLACE. SURFACE ANALYSIS
SHOWS A NARROW AREA OF INSTABILITY AHEAD OF THIS FRONT...AND W OF
SOME COOLER OUTFLOW FROM EARLIER STORMS. WITH INCREASING FORCING
WITH THE UPPER TROUGH DIVING SEWD...THE  SWRN NEB STORMS SHOULD
CONTINUE TO INTENSIFY...ALBEIT IN A RELATIVELY SMALL AREA BEFORE
THEY ENTER WW 323.

..JEWELL/CORFIDI.. 05/30/2012

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

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

LAT...LON   39920145 40760082 41340029 41499965 41269911 40699901
            40389931 40019972 39969996 39940026 39920145

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 30, 10:50 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Custer, Dawson, Fillmore and 20 more85 min
May 30, 3:57 PM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Clay, Dawson, Dundy, Fillmore and 11 more7 hr
May 30, 6:57 PM CDTMesoscale DiscussionSPCFranklin, Furnas, Harlan, Nuckolls, Thayer, Webster2 hr

Nearby

Mesoscale Discussions in Nebraska, 2012Every 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.