Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 509

April 13, 201215 counties in Kansas; Barton County, Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2012, 2:37 PM CDT for 15 counties in Kansas; Barton County, Missouri. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2012, 2:37 PM CDT (19:37 UTC)
Expired
Apr 13, 2012, 4:30 PM CDT
In force
113 min
Issued by
the Storm Prediction Center

Counties Allen County, KS, Anderson County, KS, Bourbon County, KS, Chautauqua County, KS, Cherokee County, KS, Coffey County, KS, Crawford County, KS, Elk County, KS, Franklin County, KS, Labette County, KS, Linn County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Barton County, MO

The radar

The Tulsa radar (KINX), 158 km from the middle of the area, began a volume at 19:35 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 7.6 hours before the alert went out and 157 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, Topeka, KS at 12:00Z on 2012-04-13Temperature 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, Topeka, KS at 12:00Z on 2012-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 525 square meters per square second.19395878Sfc1 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
602 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
525 m²/s²
0-3 km storm-relative helicity
689 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

517 
ACUS11 KWNS 131938
SWOMCD
SPC MCD 131937
MOZ000-KSZ000-132130-

MESOSCALE DISCUSSION 0509
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT FRI APR 13 2012

AREAS AFFECTED...SERN KS THROUGH A PORTION OF EXTREME SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 131937Z - 132130Z

A FEW STORMS MAY DEVELOP OVER SERN KS BY 21Z. SUPERCELLS WITH
ISOLATED LARGE HAIL WILL BE THE PRIMARY THREAT...BUT AN ISOLATED
TORNADO OR TWO CANNOT BE RULED OUT...MAINLY DURING THE EARLY
EVENING.

EARLY THIS AFTERNOON A WEAK FRONTAL BOUNDARY EXTENDS FROM NERN KS
SWWD THROUGH S-CNTRL KS AND WRN OK. THE ATMOSPHERE HAS DESTABILIZED
IN MOIST WARM SECTOR WHERE DIABATIC WARMING AND LOW 60S DEWPOINTS
BENEATH STEEP LAPSE RATES HAVE CONTRIBUTED TO 1500-2000 J/KG MLCAPE.
CUMULUS IS INCREASING ALONG THE BOUNDARY AS WELL AS IN WARM SECTOR
AND LATEST OBJECTIVE ANALYSIS SHOWS ONLY A WEAK CAP REMAINING.
THEREFORE A FEW STORMS WILL LIKELY DEVELOP WITHIN THE NEXT HOUR OR
SO. LOW LEVEL SHEAR HAS DECREASED IN WAKE OF PRIMARY LLJ THAT HAS
SHIFTED NEWD INTO THE MID MS VALLEY AREA. HOWEVER...DEEP SHEAR OF
35-40 KT WILL SUPPORT SUPERCELLS CAPABLE OF MAINLY ISOLATED LARGE
HAIL. SOME THREAT FOR AN ISOLATED TORNADO OR TWO MAY INCREASE TOWARD
EVENING AS THE LLJ STRENGTHENS.

..DIAL.. 04/13/2012

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   37059501 37059604 37049694 37499635 38339583 38829520
            38059466 37509430 37059501

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 7:53 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Gove, Lane, Logan, Rawlins and 6 more97 min
Apr 12, 8:38 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Gove, Graham, Greeley, Lane and 9 more4 hr
Apr 12, 11:24 PM CDTMesoscale DiscussionSPCDecatur, Gove, Graham, Norton, Phillips, Sheridan and 1 more96 min
Apr 13, 3:40 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Bourbon, Butler, Chase, Chautauqua and 19 more6 hr
Apr 13, 5:40 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 14 more65 min

Nearby

Mesoscale Discussions in Kansas, 2012Mesoscale Discussions in Missouri, 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.