ZCZC SPCSWOMCD ALL ACUS11 KWNS 300430 SPC MCD 300430 MOZ000-ARZ000-OKZ000-KSZ000-300700- Mesoscale Discussion 0248 NWS Storm Prediction Center Norman OK 1130 PM CDT Fri Mar 29 2019 Areas affected...Parts of OK into far southeastern KS...southwestern MO...and northwestern AR Concerning...Severe potential...Watch possible Valid 300430Z - 300700Z Probability of Watch Issuance...40 percent SUMMARY...Isolated large hail may occur overnight as thunderstorms increase in coverage and intensity. While not immediately likely, severe thunderstorm watch issuance may be needed by 1-2 AM CDT. DISCUSSION...04Z surface analysis shows a 1008 mb low centered along the KS/MO border near Pittsburg, KS. A cold front extends southwestward from this low across central/western OK into the TX Panhandle, while a warm front is located over parts of southwestern MO. A shortwave trough over the central High Plains will shift eastward overnight. At least scattered thunderstorms appear likely to develop by 06-07Z (1-2 AM CDT) as large-scale ascent associated with the shortwave trough overspreads much of OK and vicinity. Initial convective development appears to be underway across the eastern TX Panhandle and northwestern OK at 0420Z with cooling of cloud tops noted on infrared satellite imagery. These thunderstorms will likely remain elevated above a stable near-surface layer as they move eastward across OK and eventually southwestern MO/northwestern AR overnight. Steep mid-level lapse rates of 7.5 to 8.5 C/km present on 00Z area soundings are supporting MUCAPE of 1000-2000 J/kg across much of OK. Around 40-50 kt of effective bulk shear in the cloud-bearing layer should initially support supercells with an isolated large hail threat. Convective mode becomes less clear with eastward extent across OK, as storms may have a tendency to organize into one or more line segments as they interact with the cold front. Gusty winds may also occur, but downdrafts will probably struggle to reach the surface given the strong low-level inversion. Convective trends will be monitored over the next several hours for possible watch issuance. ..Gleason/Guyer.. 03/30/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...ICT...OUN... LAT...LON 34629951 34859985 35279994 36949645 37189543 37469415 37279334 36479335 36079357 35459445 35099541 34889619 34699701 34559808 34509881 34629951 NNNN