Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 846

May 19, 20126 counties in Kansas; 22 counties in Oklahoma; Hardeman County, Wilbarger County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 19, 2012, 11:09 PM CDT for 6 counties in Kansas; 22 counties in Oklahoma; Hardeman County, Wilbarger County, Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: May 19, 2012, 11:09 PM CDT (04:09 UTC)
Expired: May 20, 2012, 12:15 AM CDT
In force: 66 min
Issued by: the Storm Prediction Center

All 30 counties

Chautauqua County, KS, Cowley County, KS, Elk County, KS, Labette County, KS, Montgomery County, KS, Wilson County, KS, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Garfield County, OK, Grady County, OK, Greer County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Noble County, OK, Nowata County, OK, Oklahoma County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Tillman County, OK, Washington County, OK, Washita County, OK, Hardeman County, TX, Wilbarger County, TX

The radar

The Norman radar (KTLX), 65 km from the middle of the area, began a volume at 04:13 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

Norman, OK (KOUN), launched 00:00Z, 4.2 hours before the alert went out and 71 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: 539 J/kg
Mixed-layer CIN: -464 J/kg
Mixed-layer LCL: 1944 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 337 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.

897 
ACUS11 KWNS 200410
SWOMCD
SPC MCD 200409
KSZ000-OKZ000-TXZ000-200515-

MESOSCALE DISCUSSION 0846
NWS STORM PREDICTION CENTER NORMAN OK
1109 PM CDT SAT MAY 19 2012

AREAS AFFECTED...NWRN TX...SERN TO N-CNTRL OK...SERN KS

CONCERNING...SEVERE THUNDERSTORM WATCH 284...

VALID 200409Z - 200515Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 284
CONTINUES.

SUMMARY...PRIMARY THREAT FOR LARGE HAIL AND SEVERE WIND APPEARS TO
BE CONFINED TO THE SRN PORTION OF WW 284 ACROSS SWRN OK. BUT THIS
ACTIVITY SHOULD BECOME INCREASINGLY MARGINAL OVERNIGHT.

DISCUSSION...MID-LEVEL REFLECTIVITY HAS SUBSTANTIALLY WEAKENED
DURING THE PAST HOUR IN MOST OF SERN KS TO N-CNTRL OK. HERE...IT
APPEARS THAT INCREASING MLCIN HAS OVERCOME MARGINAL WARM SECTOR
SURFACE DEW POINTS FROM THE MIDDLE TO UPPER 50S. SEVERE TSTMS HAVE
REMAINED OVER SWRN OK WITH SEVERAL REPORTS OF LARGE HAIL /A FEW
SIGNIFICANT/...WITH MORE PRONOUNCED INFLOW AMIDST HIGHER SURFACE DEW
POINTS IN THE LOWER 60S. THESE CELLS HAVE BEGUN TO PROPAGATE MORE
E/SEWD RATHER THAN S/SEWD. THIS TYPE OF MOVEMENT SHOULD BE CONDUCIVE
FOR A TRANSITION TO SEVERE WINDS...NOTED BY A RECENT 50 KT GUST AT
THE HOBART OK-MESONET SITE. BUT WITH INCREASING MLCIN AND DECREASING
DEEP-LAYER FLOW AS THE MID-MO VALLEY SHORT WAVE IMPULSE CONTINUES TO
PROGRESS NEWD...THE SEVERE THREAT HERE SHOULD BECOME INCREASINGLY
MARGINAL/LOCALIZED OVERNIGHT.

..GRAMS.. 05/20/2012

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   34909963 35479893 36639771 37289681 37579596 37649544
            37379502 37119514 35349720 34589803 34039891 34059961
            34439988 34909963

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 19, 7:03 PM CDT	Mesoscale Discussion	SPC	Harper, Sumner	57 min
May 19, 9:03 PM CDT	Severe Thunderstorm Watch	SPC	Butler, Chautauqua, Cowley, Elk, Greenwood, Montgomery and 3 more	7 hr
May 20, 1:30 AM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Cleveland, Comanche, Creek, Garvin and 14 more	90 min
May 20, 3:00 AM CDT	Mesoscale Discussion	SPC	Caddo, Cleveland, Grady, Kiowa, McClain, Okfuskee and 2 more	90 min
May 20, 3:51 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Foard, Knox, Wichita, Wilbarger	84 min
May 20, 5:30 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Dickens, Fisher, Foard and 13 more	3 hr

Nearby

Mesoscale Discussions in Oklahoma, 2012 Mesoscale Discussions in Kansas, 2012 Mesoscale Discussions in Texas, 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.