Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 105

February 3, 201210 counties in Kansas; 60 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Feb 3, 2012, 6:36 PM CST for 10 counties in Kansas; 60 counties in Nebraska. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 3, 2012, 6:36 PM CST (00:36 UTC)
Expired
Feb 3, 2012, 10:30 PM CST
In force
4 hr
Issued by
the Storm Prediction Center
All 70 counties

Decatur County, KS, Graham County, KS, Jewell County, KS, Mitchell County, KS, Norton County, KS, Osborne County, KS, Phillips County, KS, Republic County, KS, Rooks County, KS, Smith County, KS, Adams County, NE, Antelope County, NE, Blaine County, NE, Boone County, NE, Buffalo County, NE, Burt County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dawson County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Frontier County, NE, Furnas County, NE, Gage County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Hayes County, NE, Hitchcock County, NE, Holt County, NE, Howard County, NE, Jefferson County, NE, Kearney County, NE, Lancaster County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, Madison County, NE, McPherson County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Red Willow County, NE, Rock County, NE, Saline County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thayer County, NE, Thomas County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Webster County, NE, Wheeler County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 61 km from the middle of the area, began a volume at 00:33 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

Omaha, NE (KOAX), launched 00:00Z, 0.6 hours before the alert went out and 175 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, Omaha, NE at 00:00Z on 2012-02-04Temperature 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, Omaha, NE at 00:00Z on 2012-02-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 281 square meters per square second.1939587897117Sfc1 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
598 m above ground
0-6 km bulk shear
83 kt
0-1 km storm-relative helicity
281 m²/s²
0-3 km storm-relative helicity
448 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.

311 
ACUS11 KWNS 040037
SWOMCD
SPC MCD 040036
NEZ000-KSZ000-040430-

MESOSCALE DISCUSSION 0105
NWS STORM PREDICTION CENTER NORMAN OK
0636 PM CST FRI FEB 03 2012

AREAS AFFECTED...CNTRL/ERN NEB...N-CNTRL KS

CONCERNING...HEAVY SNOW

VALID 040036Z - 040430Z

SNOWFALL RATES OF 1 INCH PER HOUR /LOCALLY HIGHER/ ARE ANTICIPATED
ACROSS A LARGE PART OF CNTRL/ERN NEB AND N-CNTRL KS DURING THE
EVENING AND OVERNIGHT HOURS.

ONGOING MODERATE TO LOCALLY HEAVY SNOW WILL CONTINUE INTO
MID-EVENING ALONG AND NORTH OF A LINE FROM NORTH PLATTE TO NORFOLK.
THIS SNOW WILL BE MAINTAINED WITH THE PLUME OF MOIST ASCENT OWING TO
WAA EMBEDDED WITHIN A BRANCH OF THE WARM CONVEYOR BELT WRAPPING
AROUND A MID-LEVEL VORT MAX POSITIONED OVER NWRN KS. SNOWFALL RATES
MAY LOCALLY REACH 1 IN/HR IN A FEW LOCATIONS...MAINLY FROM LOGAN
COUNTY ENEWD INTO LOUP COUNTY...WHERE REGIONAL RADAR IMAGERY DEPICTS
A BAND OF PERSISTENTLY ENHANCED REFLECTIVITY. ALSO...NNELY WINDS OF
15-25 MPH MAY RESULT IN BLOWING/DRIFTING SNOW.

AFTER 03Z...THE THREAT FOR HEAVY SNOW...WITH RATES LIKELY REACHING
/AND LOCALLY EXCEEDING/ 1 IN/HR...WILL REFOCUS TO THE SOUTH...WHILE
DEVELOPING NWD FROM N-CNTRL KS INTO CNTRL AND ERN NEB. THESE RATES
WILL CONTINUE INTO THE OVERNIGHT HOURS. ASCENT FOR THIS LATTER
ACTIVITY WILL EMANATE FROM A ZONE OF INCREASING DCVA LEADING THE
AFOREMENTIONED VORT MAX...ENHANCED BY THE ASCENDING BRANCH OF THE
AGEOSTROPHIC CIRCULATION WITHIN LEFT-EXIT REGION OF AN UPPER-LEVEL
JET STREAK CROSSING THE AREA.

WHILE INITIALLY SOMEWHAT WARM...THERMODYNAMIC PROFILES WILL BECOME
INCREASINGLY CONDUCIVE FOR A PHASE CHANGE FROM RAIN TO SNOW DURING
THE EVENING HOURS IN RESPONSE TO /1/ STRONG ADIABATIC COOLING OWING
TO THE FORCED ASCENT.../2/ NOCTURNAL DIABATIC COOLING...AND /3/
LOW-LEVEL COLD ADVECTION ON THE BACKSIDE OF A NEWD-MIGRATING SFC LOW
ACROSS OK/KS. ACROSS S-CNTRL NEB INTO N-CNTRL KS...RUC/NAM FORECAST
SOUNDINGS INDICATE THE DEVELOPMENT OF A SHALLOW LAYER OF VERY
MARGINAL BUOYANCY ROOTED BETWEEN 550 AND 600 MB /MUCAPE VALUES
GENERALLY AOB 100 J PER KG/ ATOP A NEARLY ISOTHERMAL LAYER JUST
BELOW FREEZING WITHIN THE LOW/MID LEVELS. IN ADDITION TO FAVORING
SNOW AGGREGATION PROCESSES...THIS PROFILE MAY SUPPORT A LIGHTNING
STRIKE OR TWO ALONG WITH LOCALLY HIGHER SNOWFALL RATES AROUND 1.5
IN/HR.

..COHEN.. 02/04/2012

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

ATTN...WFO...FSD...OAX...TOP...GID...LBF...GLD...

LAT...LON   41459607 40809619 40109680 39399815 39189973 39620081
            40720147 41760116 42659895 42369662 41459607

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 4, 3:27 AM CSTMesoscale DiscussionSPCRepublic4 hr

Nearby

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