Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 690

May 4, 201212 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at May 4, 2012, 12:20 AM CDT for 12 counties in Kansas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 4, 2012, 12:20 AM CDT (05:20 UTC)
Expired
May 4, 2012, 1:15 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Barber County, KS, Clark County, KS, Comanche County, KS, Edwards County, KS, Harper County, KS, Harvey County, KS, Kingman County, KS, Kiowa County, KS, Pratt County, KS, Reno County, KS, Sedgwick County, KS, Stafford County, KS

The radar

The Wichita radar (KICT), 97 km from the middle of the area, began a volume at 05:20 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

Dodge City, (KDDC), launched 00:00Z, 5.3 hours before the alert went out and 121 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, Dodge City, at 00:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2761 joules per kilogram.LCLLFCEL10008507005003002001001 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, Dodge City, at 00:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
2761 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
1630 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

791 
ACUS11 KWNS 040521
SWOMCD
SPC MCD 040520
KSZ000-040615-

MESOSCALE DISCUSSION 0690
NWS STORM PREDICTION CENTER NORMAN OK
1220 AM CDT FRI MAY 04 2012

AREAS AFFECTED...SOUTH CENTRAL KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 040520Z - 040615Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A WW MAY BE NEEDED FOR PARTS OF SOUTH CENTRAL KS.
SPATIOTEMPORAL UNCERTAINTIES MAY PRECLUDE WW ISSUANCE...THOUGH
CONVECTIVE TRENDS WILL BE MONITORED.

STRONG-SVR STORMS DEVELOPING ACROSS A SMALL PART OF SOUTH CENTRAL
KS...SINCE 0415-0420Z PER REGIONAL RADAR IMAGERY...WILL CONTINUE TO
POSE A THREAT FOR AT LEAST ISOLATED SVR WEATHER AS ACTIVITY MOVES
ENEWD.

DISCUSSION...OBJECTIVE ANALYSES INDICATED THE STRONG-SVR STORMS THAT
DEVELOPED QUICKLY OVER SOUTH CENTRAL KS /NRN COMANCHE AND SRN KIOWA
COUNTIES EWD TO PRATT AND NRN BARBER COUNTIES/ FORMED ALONG THE W/NW
EXTENT OF MOISTURE RETURN INTO A VERY UNSTABLE AIR MASS /MUCAPE
3000-4000 J PER KG/.  IN ADDITION...A WEAK MIDLEVEL TROUGH ANALYZED
OVER NERN NM PER 00Z UPPER AIR DATA MAY BE PROVIDING SUFFICIENT DPVA
FOR THIS TSTM DEVELOPMENT.  THUS...GIVEN THIS PROGRESSIVE MIDLEVEL
FEATURE AND CONTINUED MOISTURE AND WARM AIR ADVECTION WITHIN THE
NOSE OF A 50 KT SLY LLJ PER AREA WIND PROFILERS AND WSR-88D VWP
DATA...ADDITIONAL TSTMS APPEAR PROBABLE OVERNIGHT ACROSS SRN KS.
18Z/00Z GFS INDICATED CONVECTIVE QPF OVER PARTS OF SRN KS THROUGH
THE OVERNIGHT PERIOD.  THE DEGREE OF INSTABILITY COMBINED WITH
EFFECTIVE BULK SHEAR OF 30-40 KT SUGGESTS ORGANIZED STORMS PRODUCING
LARGE HAIL AND STRONG WIND GUSTS WILL BE POSSIBLE.

..PETERS/CORFIDI.. 05/04/2012

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

ATTN...WFO...ICT...DDC...

LAT...LON   38209872 38259738 37859691 37379709 37139805 37079907
            37099979 37329995 37689970 38209872

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 3, 7:09 PM CDTTornado WatchSPCDoniphan6 hr
May 3, 11:18 PM CDTMesoscale DiscussionSPCDoniphan27 min
May 4, 12:53 AM CDTSevere Thunderstorm WatchSPCDoniphan4 hr
May 4, 1:43 AM CDTSevere Thunderstorm WatchSPCButler, Chase, Chautauqua, Cowley, Elk, Greenwood and 7 more2 hr

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.