Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 605

April 27, 201240 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2012, 1:29 PM CDT for 40 counties in Kansas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2012, 1:29 PM CDT (18:29 UTC)
Expired
Apr 27, 2012, 3:00 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 40 counties

Allen County, KS, Anderson County, KS, Bourbon County, KS, Butler County, KS, Chase County, KS, Chautauqua County, KS, Clay County, KS, Cloud County, KS, Coffey County, KS, Cowley County, KS, Crawford County, KS, Dickinson County, KS, Douglas County, KS, Elk County, KS, Ellsworth County, KS, Franklin County, KS, Geary County, KS, Greenwood County, KS, Harvey County, KS, Jewell County, KS, Lincoln County, KS, Linn County, KS, Lyon County, KS, Marion County, KS, McPherson County, KS, Mitchell County, KS, Montgomery County, KS, Morris County, KS, Neosho County, KS, Osage County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Saline County, KS, Sedgwick County, KS, Shawnee County, KS, Wabaunsee County, KS, Wilson County, KS, Woodson County, KS

The radar

The Topeka radar (KTWX), 78 km from the middle of the area, began a volume at 18:32 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, 6.5 hours before the alert went out and 126 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 2012-04-27Temperature 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 2012-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 272 square meters per square second.193958Sfc1 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
1420 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
272 m²/s²
0-3 km storm-relative helicity
417 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.

490 
ACUS11 KWNS 271829
SWOMCD
SPC MCD 271829 
MOZ000-KSZ000-272000-

MESOSCALE DISCUSSION 0605
NWS STORM PREDICTION CENTER NORMAN OK
0129 PM CDT FRI APR 27 2012

AREAS AFFECTED...N-CNTRL TO SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 271829Z - 272000Z

SEVERE THREAT IS STILL EXPECTED TO INCREASE THIS AFTERNOON...BUT
APPEARS TO BE DELAYED IN TIMING AS TSTM INITIATION IN S-CNTRL KS HAS
BEEN CURTAILED BY STRONG SUBSIDENCE. WITH STRONGER HEATING NOW
OCCURRING AHEAD OF THE DRYLINE...CONVECTION WILL GROW ACROSS N-CNTRL
KS AND EVENTUALLY DEVELOP S/SEWD TOWARDS SERN KS. A TORNADO WATCH
WILL LIKELY BE ISSUED BETWEEN 19-21Z.

SUBSTANTIAL DRYING NOTED IN WATER VAPOR IMAGERY HAS SPREAD ACROSS
S-CNTRL KS WITH LARGE-SCALE SUBSIDENCE S OF THE COMPACT SHORT WAVE
IMPULSE OVER NWRN KS. THIS APPEARS TO BE THE PRIMARY LIMITING FACTOR
SUPPRESSING TSTM DEVELOPMENT THUS FAR S OF THE IMMEDIATE VICINITY OF
THE TRIPLE POINT /LOCATED AROUND 30 S HLC AT 18Z/. WITH INDIVIDUAL
CELL MOTIONS SHIFTING N/NEWD OF THE SURFACE WARM FRONT THAT ARCED
SEWD INTO SERN KS...CONVECTION THUS FAR HAS STRUGGLED TO REACH
SEVERE INTENSITY. 12Z CONVECTION-ALLOWING WRF AND RECENT HRRR RUNS
SUGGEST THAT CONVECTION MAY REMAIN TIED ALONG AND JUST N OF THE WARM
FRONT IN THE LOBE OF ASCENT ASSOCIATED WITH THE SHORT WAVE IMPULSE.
STILL...WITH A 50 MILE WIDE AREA OF STRONGER HEATING OCCURRING
BETWEEN THE DRYLINE AND REMNANT STRATUS DECK IN CNTRL KS...THIS
SHOULD PROVE FAVORABLE FOR SUSTAINING DEVELOPMENT OF A FEW
SUPERCELLS WITH ATTENDANT LARGE HAIL/TORNADO THREATS.

..GRAMS.. 04/27/2012

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

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

LAT...LON   39669891 39929829 39969775 39579642 38929516 38179450
            37299487 37119634 37279718 37659765 38699829 39669891

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 26, 9:41 PM CDTMesoscale DiscussionSPCCheyenne, Grant, Greeley, Hamilton, Kearny, Logan and 7 more2 hr
Apr 26, 10:00 PM CDTSevere Thunderstorm WatchSPCCheyenne, Grant, Greeley, Hamilton, Kearny, Logan and 8 more7 hr
Apr 27, 2:24 AM CDTMesoscale DiscussionSPCCheyenne, Grant, Greeley, Hamilton, Kearny, Morton and 5 more2 hr
Apr 27, 4:43 AM CDTMesoscale DiscussionSPCCheyenne, Grant, Greeley, Hamilton, Haskell, Kearny and 8 more32 min
Apr 27, 6:16 AM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Butler, Chase, Coffey and 22 more59 min
Apr 27, 10:15 AM CDTMesoscale DiscussionSPCBarber, Barton, Butler, Cowley, Dickinson, Ellis and 21 more2 hr
Apr 27, 2:11 PM CDTTornado WatchSPCAllen, Anderson, Bourbon, Butler, Chase, Chautauqua and 46 more7 hr
Apr 27, 3:44 PM CDTMesoscale DiscussionSPCAllen, Anderson, Butler, Chase, Chautauqua, Clay and 22 more61 min
Apr 27, 6:07 PM CDTMesoscale DiscussionSPCAllen, Anderson, Atchison, Bourbon, Brown, Cherokee and 32 more113 min

Nearby

Mesoscale 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.