Mesoscale Discussion 337

Issued

Mar 26, 2017, 6:33 PM CDT (23:33 UTC)

Expired

Mar 26, 2017, 8:00 PM CDT

In force

87 min

Issued by

the Storm Prediction Center

Counties Barber County, KS, Chautauqua County, KS, Cowley County, KS, Elk County, KS, Harper County, KS, Montgomery County, KS, Sumner County, KS, Alfalfa County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Major County, OK, Noble County, OK, Nowata County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Washington County, OK, Woods County, OK

The Vance AFB radar (KVNX), 68 km from the middle of the area, began a volume at 23:33 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.

224 
ACUS11 KWNS 262333
SWOMCD
SPC MCD 262333 
OKZ000-KSZ000-270100-

Mesoscale Discussion 0337
NWS Storm Prediction Center Norman OK
0633 PM CDT Sun Mar 26 2017

Areas affected...Northwest Oklahoma and South-central Kansas

Concerning...Tornado Watch 85...86...

Valid 262333Z - 270100Z

The severe weather threat for Tornado Watch 85, 86 continues.

SUMMARY...Thunderstorms will continue to develop and intensify this
evening. These thunderstorms will move east with large hail,
damaging winds, and a tornado or two possible.

DISCUSSION...23Z surface analysis has a surface low taking shape
across northwest Oklahoma with a dryline extending south from the
low and a warm front extending east-northeast. Thunderstorms
developed on the cool side of the warm front across south-central
Kansas and this complex should continue east along/near the front
for the next several hours. Given steep mid-level lapse rates and
most-unstable CAPE values on the order of 500-1000 J/kg ahead of
these thunderstorms, large hail and isolated damaging thunderstorm
wind gusts should be the primary threat.

Farther south, in Oklahoma, recent satellite imagery suggests a zone
of stronger ascent is approaching the triple point from the west. An
isolated thunderstorm has managed to develop back in the drier
airmass. As this zone of stronger ascent begins to overspread the
triple point and tap into a more unstable airmass, surface-based or
near-surface-based thunderstorms should develop and move east during
the evening hours. Given most-unstable CAPE values around 1000 J/kg
and deep-layer shear on the order of 50 knots, large hail and
damaging thunderstorm winds will be the primary threats across
northern Oklahoma. Although surface-based CAPE is limited (~500
J/kg), if a thunderstorm can become established and tap into the
vorticity reservoir along the surface warm front, a tornado would be
possible.

..Marsh.. 03/26/2017

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   36319890 36859896 37449856 37609753 37639620 37479534
            36799535 36319593 36059682 36069852 36319890

Mesoscale Discussions in Oklahoma, 2017Mesoscale Discussions in Kansas, 2017Every mesoscale discussion in 2017

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.