Mesoscale Discussion 1068
NWS Storm Prediction Center Norman OK
0531 AM CDT Sat Jun 17 2017
Areas affected...Southeast KS and southwest MO into far northeast OK
and northwest AR
Concerning...Severe Thunderstorm Watch 344...
Valid 171031Z - 171200Z
The severe weather threat for Severe Thunderstorm Watch 344
SUMMARY...Severe-weather threat will be the greatest across the
western portion of WW 344 (in southeast KS and southwest MO) through
early this morning. Large hail and locally damaging wind gusts will
be the primary severe risks. Although some severe hail and/or
stronger/damaging wind gusts could affect part of far northeast OK
and northwest AR, the expected spatial coverage is expected to
remain too small to warrant a new WW issuance, at this time.
DISCUSSION...The leading band of storms in southwest MO exited the
southern extent of WW 344 just before 10Z and is moving to the
south-southeast at close to 40 kt. Although this forward speed
would tend to support locally strong/damaging wind gusts, the
strength of surface-based inhibition and weak surface-3-km lapse
rates should continue to limit most stronger/damaging wind gusts
from reaching the surface as activity moves into northwest AR.
Meanwhile, a threat remains for mainly large hail, some exceeding 2
inches in diameter, across southeast KS into far southwest MO
through early this morning. Trends in MRMS MESH data and CAPPI (5-9
km) through 1005Z indicated strong, sustained updrafts in southeast
KS (Allen and Crawford Counties), while upstream storms moving
southeast into and through Douglas County KS were restrengthening.
Trends in IR satellite imagery indicated an overall shrinking in
size of the larger thunderstorm complex in eastern KS and MO.
However, a 35-40-kt west-southwesterly low-level jet extending from
OK into the southwest periphery of this convection is expected to
sustain thunderstorm development through early this morning, with an
influx of strong instability. This combined with effective bulk
shear around 50 kt and steep midlevel lapse rates will support
strong, sustained updrafts with large hail the primary threat.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 36719281 36369313 36269379 36259439 36369473 37199536
37489545 38039550 38039428 37279306 36719281