Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 168

February 28, 201232 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2012, 5:15 PM CST for 32 counties in Kansas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 28, 2012, 5:15 PM CST (23:15 UTC)
Expired: Feb 28, 2012, 7:15 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

All 32 counties

Barton County, KS, Brown County, KS, Butler County, KS, Chase County, KS, Clay County, KS, Dickinson County, KS, Ellsworth County, KS, Geary County, KS, Greenwood County, KS, Harvey County, KS, Jackson County, KS, Jefferson County, KS, Kingman County, KS, Lincoln County, KS, Lyon County, KS, Marion County, KS, Marshall County, KS, McPherson County, KS, Morris County, KS, Nemaha County, KS, Osage County, KS, Ottawa County, KS, Pottawatomie County, KS, Pratt County, KS, Reno County, KS, Rice County, KS, Riley County, KS, Saline County, KS, Sedgwick County, KS, Shawnee County, KS, Stafford County, KS, Wabaunsee County, KS

The radar

The Topeka radar (KTWX), 99 km from the middle of the area, began a volume at 23:15 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, 11.3 hours before the alert went out and 147 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: 1369 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 396 m²/s²
0-3 km storm-relative helicity: 319 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.

223 
ACUS11 KWNS 282316
SWOMCD
SPC MCD 282315
KSZ000-NEZ000-290115-

MESOSCALE DISCUSSION 0168
NWS STORM PREDICTION CENTER NORMAN OK
0515 PM CST TUE FEB 28 2012

AREAS AFFECTED...CNTRL/ERN KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 282315Z - 290115Z

ISOLATED DISCRETE CELLS ARE ATTEMPTING TO FORM S OF WW 39 ALONG THE
DRYLINE IN S-CNTRL KS. GIVEN PRESENCE OF VERY STRONG AND DRY
MID-LEVEL SWLYS AMIDST MODEST INSTABILITY...UNCERTAINTY EXISTS IN
THE SUSTAINABILITY OF TSTM DEVELOPMENT IN THE NEAR-TERM. LATER THIS
EVENING...AS THE PACIFIC COLD FRONT OVERTAKES THE DRYLINE...TSTMS
APPEAR MORE LIKELY INTO ERN KS WITH ALL MODES OF SEVERE THREATS
POSSIBLE. THE PROBABILITY OF A WW ISSUANCE BY 01Z IS 60 PERCENT.

23Z SURFACE ANALYSIS PLACED A 993 MB CYCLONE NEAR LBF WITH AN
ATTENDANT DRYLINE DRAPED SWD THROUGH CNTRL KS...AND A PACIFIC COLD
FRONT ARCING SWWD FROM THE LOW ACROSS NWRN KS. TCU/SMALL CBS ARE
APPARENT IN VISIBLE IMAGERY INTO S-CNTRL KS...WITH CU FIELD HAVING
DIMINISHED FARTHER S IN WRN OK. SURFACE DEW POINTS SHOULD CONTINUE
TO RISE AHEAD OF THE DRYLINE...WITH MIDDLE TO UPPER 50S BECOMING
COMMON THIS EVENING. STILL...GIVEN THE PRESENCE OF A MID-LEVEL DRY
SLOT EVIDENT IN WATER VAPOR IMAGERY AND 100 KT JET STREAK AT 500
MB...BUOYANCY WILL LIKELY REMAIN MODEST WITH MLCAPE OF 500 TO 1000
J/KG. ENTRAINMENT OF DRY AIR ALONG WITH THE INTENSE MID-LEVEL WINDS
MAY CURTAIL SUSTAINED TSTM DEVELOPMENT S/SE OF WW 39 UNTIL THE COLD
FRONT OVERTAKES THE DRYLINE /AS INFERRED FROM MOST
CONVECTION-ALLOWING MODEL GUIDANCE/.

..GRAMS.. 02/28/2012

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

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

LAT...LON   37589879 38219914 38809891 39219791 40009639 40149576
            39879545 39349531 38059582 37379685 37259811 37589879

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 28, 2:25 PM CST	Mesoscale Discussion	SPC	Cloud, Ellis, Graham, Jewell, Marshall, Mitchell and 7 more	3 hr
Feb 28, 3:53 PM CST	Tornado Watch	SPC	Clay, Cloud, Dickinson, Geary, Jewell, Mitchell and 8 more	5 hr
Feb 28, 5:41 PM CST	Tornado Watch	SPC	Barton, Butler, Chase, Cowley, Ellsworth, Harper and 11 more	3 hr

Nearby

Mesoscale Discussions in Kansas, 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.