Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 842

May 19, 2012Harper County, Sumner County, Kansas; Alfalfa County, Grant County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 19, 2012, 7:03 PM CDT for Harper County, Sumner County, Kansas; Alfalfa County, Grant County, Oklahoma. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
May 19, 2012, 7:03 PM CDT (00:03 UTC)
Expired
May 19, 2012, 8:00 PM CDT
In force
57 min
Issued by
the Storm Prediction Center

Counties Harper County, KS, Sumner County, KS, Alfalfa County, OK, Grant County, OK

The radar

The Vance AFB radar (KVNX), 40 km from the middle of the area, began a volume at 00:04 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

Lamont, OK (KLMN), launched 00:00Z, 0.1 hours before the alert went out and 68 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, Lamont, OK at 00:00Z on 2012-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1730 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, Lamont, OK at 00:00Z on 2012-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 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
1730 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
1706 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

674 
ACUS11 KWNS 200003
SWOMCD
SPC MCD 200003 
KSZ000-OKZ000-200100-

MESOSCALE DISCUSSION 0842
NWS STORM PREDICTION CENTER NORMAN OK
0703 PM CDT SAT MAY 19 2012

AREAS AFFECTED...S-CNTRL KS...N-CNTRL OK

CONCERNING...SEVERE THUNDERSTORM WATCH 281...282...

VALID 200003Z - 200100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
281...282...CONTINUES.

SUMMARY...TORNADO THREAT WILL LIKELY WANE IN THE NEXT HOUR WITH
TSTMS DEVELOPING SWWD ALONG THE COLD FRONT ALONG THE KS/OK BORDER.

DISCUSSION...NUMEROUS TORNADO REPORTS HAVE OCCURRED IN THE PAST HOUR
WITH A TSTM CLUSTER JUST AHEAD OF AND ALONG A COLD FRONT ANALYZED
FROM AROUND 20 W CNK TO 20 SE P28. THIS THREAT HAS BEEN MAXIMIZED
ALONG THE N/S TO NE/SW INFLECTION POINT OF THE FRONT WITH THE
ORIENTATION OF THE CLUSTER...INTERCEPTING THE LOW-LEVEL MOIST AXIS
CHARACTERIZED BY LOWER 60S SURFACE DEW POINTS. THIS THREAT WILL WANE
AS LOW-LEVEL FLOW HAS COMMENCED WEAKENING PER TIME-SERIES OF ICT VWP
DATA. THIS WEAKENING SHOULD PERSIST WITH FLOW BECOMING INCREASINGLY
DIVERGENT AS WELL WITH NEB SHORT WAVE IMPULSE PROGRESSING AWAY FROM
THE REGION.

..GRAMS.. 05/20/2012

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

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

LAT...LON   37199837 37569790 37709762 37649742 37359733 36979750
            36719777 36589807 36589835 36709854 36789858 37199837

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 9:03 PM CDTSevere Thunderstorm WatchSPCButler, Chautauqua, Cowley, Elk, Greenwood, Montgomery and 3 more7 hr
May 19, 11:09 PM CDTMesoscale DiscussionSPCChautauqua, Cowley, Elk, Labette, Montgomery, Wilson66 min
May 20, 1:30 AM CDTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Creek, Garvin and 14 more90 min
May 20, 3:00 AM CDTMesoscale DiscussionSPCCaddo, Cleveland, Grady, Kiowa, McClain, Okfuskee and 2 more90 min

Nearby

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