Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 1695

August 3, 201216 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 3, 2012, 11:19 PM CDT for 16 counties in Nebraska. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Aug 3, 2012, 11:19 PM CDT (04:19 UTC)
Expired: Aug 4, 2012, 12:45 AM CDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Antelope County, NE, Blaine County, NE, Boone County, NE, Cedar County, NE, Custer County, NE, Garfield County, NE, Greeley County, NE, Knox County, NE, Logan County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Thomas County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 119 km from the middle of the area, began a volume at 04:21 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, 4.3 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: 1191 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 2741 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

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

905 
ACUS11 KWNS 040419
SWOMCD
SPC MCD 040419 
NEZ000-SDZ000-040545-

MESOSCALE DISCUSSION 1695
NWS STORM PREDICTION CENTER NORMAN OK
1119 PM CDT FRI AUG 03 2012

AREAS AFFECTED...PARTS OF CENTRAL AND NERN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 554...

VALID 040419Z - 040545Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 554
CONTINUES.

SUMMARY...ISOLATED THREAT FOR HAIL AND/OR A DAMAGING WIND GUST
CONTINUES ACROSS PARTS OF WW 554.

DISCUSSION...LATEST RADAR LOOP CONTINUES TO SHOW A CLUSTER OF
SLIGHTLY ELEVATED THUNDERSTORMS ONGOING ACROSS CENTRAL AND NERN
NEB...WITH OTHER/MORE SUBSTANTIALLY ELEVATED CONVECTION DEVELOPING
FARTHER N INVOF THE NEB/SD BORDER.  THE STORMS ARE OCCURRING TO THE
COOL SIDE OF A FRONT/OUTFLOW COMBINATION MOVING SSEWD ACROSS
NEB...THOUGH ONE STORM -- NOW OVER FAR SWRN CUSTER CO -- APPEARS TO
BE A MORE NEARLY SURFACE-BASED STORM IMMEDIATELY N OF THE SURFACE
BOUNDARY.  ALONG WITH A THREAT FOR A DAMAGING GUST WITH THIS
CELL...POTENTIAL FOR MARGINAL HAIL CONTINUES WITH A FEW OF THE
STRONGER/MORE-ELEVATED CELLS.

..GOSS.. 08/04/2012

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

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

LAT...LON   41059965 40880051 41640101 42130051 42239892 42959804
            42749682 41989721 41059965

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 3, 7:11 PM CDT	Severe Thunderstorm Watch	SPC	Antelope, Blaine, Boyd, Brown, Cedar, Custer and 14 more	7 hr
Aug 3, 7:33 PM CDT	Severe Thunderstorm Watch	SPC	Dakota, Dixon	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.