Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 2176

December 19, 20129 counties in Colorado; 27 counties in Kansas; 33 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Dec 19, 2012, 9:47 AM MST for 9 counties in Colorado; 27 counties in Kansas; 33 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Dec 19, 2012, 9:47 AM MST (16:47 UTC)
Expired
Dec 19, 2012, 3:45 PM MST
In force
6 hr
Issued by
the Storm Prediction Center
All 69 counties

Cheyenne County, CO, Kiowa County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Ellis County, KS, Finney County, KS, Gove County, KS, Graham County, KS, Greeley County, KS, Hodgeman County, KS, Jewell County, KS, Kearny County, KS, Lane County, KS, Logan County, KS, Ness County, KS, Norton County, KS, Osborne County, KS, Phillips County, KS, Rawlins County, KS, Rooks County, KS, Rush County, KS, Scott County, KS, Sheridan County, KS, Sherman County, KS, Smith County, KS, Thomas County, KS, Trego County, KS, Wallace County, KS, Wichita County, KS, Adams County, NE, Buffalo County, NE, Chase County, NE, Clay County, NE, Custer County, NE, Dawson County, NE, Deuel County, NE, Dundy County, NE, Fillmore County, NE, Franklin County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Hayes County, NE, Hitchcock County, NE, Howard County, NE, Kearney County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, Merrick County, NE, Nuckolls County, NE, Perkins County, NE, Phelps County, NE, Red Willow County, NE, Sherman County, NE, Valley County, NE, Webster County, NE, York County, NE

The radar

The Goodland radar (KGLD), 112 km from the middle of the area, began a volume at 16:48 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, 4.8 hours before the alert went out and 120 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 2012-12-19Temperature 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 2012-12-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 square meters per square second.1939587897117136Sfc1 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
1821 m above ground
0-6 km bulk shear
81 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
297 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.

555 
ACUS11 KWNS 191648
SWOMCD
SPC MCD 191647
KSZ000-NEZ000-COZ000-192245-

MESOSCALE DISCUSSION 2176
NWS STORM PREDICTION CENTER NORMAN OK
1047 AM CST WED DEC 19 2012

AREAS AFFECTED...NERN/E-CNTRL CO...NWRN/W-CNTRL/N-CNTRL
KS...SWRN/S-CNTRL/CNTRL NEB

CONCERNING...BLIZZARD

VALID 191647Z - 192245Z

SUMMARY...BLIZZARD CONDITIONS WILL DEVELOP AFTER 19Z ACROSS PARTS OF
CO/NEB/KS...AND SPREAD EWD/ENEWD INTO THE EVENING.

DISCUSSION...DURING THE NEXT FEW HOURS...STRONG SFC CYCLOGENESIS
WILL OCCUR OVER SWRN KS AND THE OK PANHANDLE AS STRONG DCVA LEADING
AN APPROACHING PV MAX OVERTAKES A BROAD AREA OF LOW-LEVEL
BAROCLINICITY. THE DEVELOPING SFC LOW WILL TRACK EWD NEAR OR JUST
NORTH OF THE KS/OK BORDER THROUGH THIS EVENING...WHILE A VERY TIGHT
SFC PRESSURE GRADIENT W/NW OF THE CENTER OF THE LOW SUPPORTS
NNWLY/NLY WINDS OF 25 TO 40 MPH WITH GUSTS OF 45 TO 60 MPH. THESE
WINDS WILL SPREAD EWD/ENEWD ACROSS THE DISCUSSION AREA AFTER 19Z.
THE STRONGEST WINDS ARE FORECAST TO EXTEND FROM E-CNTRL/NERN CO EWD
ACROSS NWRN/W-CNTRL/N-CNTRL KS AND SWRN/S-CNTRL NEB. SUPPORT FOR
THESE WINDS WILL EMANATE FROM 40-50 KT OF 0-1-KM MEAN FLOW PER
FORECAST SOUNDINGS AMIDST STEEP SFC-1-KM-AGL LAPSE RATES DRIVEN BY
INCREASING COLD ADVECTION WITH HEIGHT JUST ABOVE THE SFC.

STRONG 850-500-MB FRONTOGENESIS OCCURRING WITHIN THE DEFORMATION
ZONE OF THE CYCLONE WILL SUPPORT ASCENT OVERLAPPING WITH THE
DENDRITIC GROWTH ZONE TO YIELD AN EWD/ENEWD-DEVELOPING BAND OF HEAVY
SNOW WITH RATES OF 1-1.5 IN/HR. THE LATEST SHORT-RANGE GUIDANCE
SUGGESTS THAT THIS BAND WILL DEVELOP EWD/ENEWD FROM PARTS OF NERN CO
INTO NWRN/N-CNTRL KS AND ACROSS SWRN/S-CNTRL NEB. WEAK ELEVATED
BUOYANCY MAY SUPPORT AN ISOLATED LIGHTNING STRIKE OR TWO WITHIN THE
HEAVIEST SNOW BURSTS.

THE AFOREMENTIONED FACTORS WILL SUPPORT BLIZZARD CONDITIONS
ASSOCIATED WITH VISIBILITIES BELOW ONE-QUARTER MILE AND BLOWING SNOW
ACROSS THE DISCUSSION AREA. THE AREA OF GREATEST CONCERN FOR
BLIZZARD CONDITIONS LIES WITHIN THE OVERLAPPING AREAS OF HIGHEST
CONFIDENCE FOR 1-1.5-IN/HR SNOW RATES AND STRONGEST WINDS -- I.E.
FROM NERN CO ENEWD INTO S-CNTRL NEB.

..COHEN.. 12/19/2012

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

ATTN...WFO...TOP...ICT...GID...LBF...DDC...GLD...PUB...BOU...
CYS...

LAT...LON   41680035 41779892 41079755 40199759 39289848 38169939
            37860071 38310278 38880399 39760421 40620353 41450174
            41680035

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 19, 1:08 PM MSTMesoscale DiscussionSPCBarton, Clay, Cloud, Dickinson, Ellsworth, Lincoln and 10 more6 hr

Nearby

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