Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 419

April 2, 201212 counties in Kansas; 4 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2012, 5:46 PM CDT for 12 counties in Kansas; 4 counties in Nebraska. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Apr 2, 2012, 5:46 PM CDT (22:46 UTC)
Expired: Apr 2, 2012, 6:45 PM CDT
In force: 59 min
Issued by: the Storm Prediction Center

Counties Barton County, KS, Cloud County, KS, Ellis County, KS, Jewell County, KS, Lincoln County, KS, Mitchell County, KS, Ness County, KS, Osborne County, KS, Republic County, KS, Rush County, KS, Russell County, KS, Smith County, KS, Fillmore County, NE, Nuckolls County, NE, Saline County, NE, Thayer County, NE

The radar

The Grand Island radar (KUEX), 93 km from the middle of the area, began a volume at 22:49 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

Dodge City, (KDDC), launched 12:00Z, 10.8 hours before the alert went out and 236 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: 4253 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -52 m²/s²
0-3 km storm-relative helicity: -24 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.

408 
ACUS11 KWNS 022246
SWOMCD
SPC MCD 022246 
KSZ000-NEZ000-022345-

MESOSCALE DISCUSSION 0419
NWS STORM PREDICTION CENTER NORMAN OK
0546 PM CDT MON APR 02 2012

AREAS AFFECTED...CNTRL/NERN KS...SERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 022246Z - 022345Z

TSTM DEVELOPMENT IS POSSIBLE ALONG A STATIONARY FRONT...WITH PRIMARY
THREATS OF LARGE HAIL AND DMGG WIND GUSTS.  PROBABILITY OF WW
ISSUANCE IS 40 PERCENT.

SFC ANALYSIS FROM 22Z SHOWS A STALLED FRONT FROM 40 NE DDC TO 20 W
BIE...WITH TOWERING CU FIELD SPREADING NEWD INTO PORTIONS OF N-CNTRL
KS. POINT FORECAST SOUNDINGS AND RUC OBJECTIVE ANALYSIS FIELDS
INDICATE A WEAK CAPPING INVERSION IS LIKELY PRESENT...AND WITH
LARGE-SCALE ASCENT ACCOMPANYING A SWRN CONUS UPPER TROUGH STILL
POSITIONED TO THE S/W OF THE AREA...CONVECTION HAS BEEN SLOWER TO
DEVELOP HERE. HOWEVER...WARM SFC TEMPERATURES AND PERSISTENT
LOW-LEVEL FRONTAL CONVERGENCE MAY BE SUFFICIENT TO INITIATE AT LEAST
ISOLATED TSTMS THIS AFTERNOON NE OF ONGOING ACTIVITY. MLCAPE VALUES
RANGING FROM 2000-3000 J/KG ALONG WITH MIDLEVEL LAPSE RATES
EXCEEDING 8 C/KM WILL SUPPORT THE POTENTIAL FOR LARGE HAIL. STEEP
LOW-LEVEL LAPSE RATES WITHIN A WELL-MIXED BOUNDARY LAYER MAY ALSO
SUPPORT A DMGG WIND THREAT...PARTICULARLY ACROSS NERN KS/SERN NEB
WHERE STRONG DAYTIME HEATING HAS ALLOWED TEMPERATURES TO APPROACH 90
F.

ONE LIMITING FACTOR IS NEARLY UNIDIRECTIONAL/MERIDIONAL DEEP-LAYER
FLOW OVER THE AREA...WITH ANAFRONTAL CHARACTERISTICS LEADING TO
STORM MOTIONS TOWARDS COOLER/MORE STABLE AIR N OF THE FRONT.
HOWEVER...REGENERATION OF UPDRAFTS ALONG THE FRONT IS POSSIBLE...AS
MODERATE FRONTAL CONVERGENCE AND ISENTROPIC ASCENT PERSIST.
ADDITIONALLY...A HAIL THREAT MAY STILL EXIST ON THE IMMEDIATE COOL
SIDE OF THE FRONT AS STORMS BECOME ROOTED ABOVE THE BOUNDARY LAYER
BUT MIDLEVEL LAPSE RATES REMAIN SUFFICIENTLY STEEP. CONVECTIVE
TRENDS WILL BE MONITORED FOR POSSIBLE WW ISSUANCE.

..ROGERS.. 04/02/2012

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

ATTN...WFO...OAX...TOP...ICT...GID...DDC...

LAT...LON   39769728 38929795 38309877 38279962 38419999 39029962
            40009858 40579785 40779749 40639703 39769728

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 2, 3:00 PM CDT	Mesoscale Discussion	SPC	Barber, Barton, Clark, Comanche, Edwards, Ford and 14 more	2 hr
Apr 2, 3:37 PM CDT	Severe Thunderstorm Watch	SPC	Barber, Clark, Comanche, Edwards, Ford, Gray and 8 more	7 hr

Nearby

Mesoscale Discussions in Kansas, 2012 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.