MD 1067 CONCERNING SEVERE THUNDERSTORM WATCH 341…343…344… FOR EASTERN KS/WESTERN…CENTRAL…AND NORTHEAST MISSOURI
Mesoscale Discussion 1067 NWS Storm Prediction Center Norman OK 0258 AM CDT Sat Jun 17 2017 Areas affected...Eastern KS/western...central...and northeast Missouri Concerning...Severe Thunderstorm Watch 341...343...344... Valid 170758Z - 171000Z The severe weather threat for Severe Thunderstorm Watch 341, 343, 344 continues. SUMMARY...The greatest severe-weather threat (damaging winds and hail) is expected to be across eastern KS and west-central to southwest MO through early this morning. KS counties located along the western part of WW 344 may need to be added, while parts of WW 341 is extended in time, as new storms continue to form across the west/northwest periphery of the ongoing convective complex and spread to the southeast. Meanwhile, the severe-weather threat should continue to weaken across WW 343. DISCUSSION......WW 341 and WW 344... Trends in IR satellite and radar imagery indicated the western and southwest portions of the large KS/MO/IA/IL mesoscale-convective complex across eastern KS and western and southwest portions of MO should pose the greatest severe-weather threat through early this morning. Coldest cloud tops and the most persistent, intense storms per MRMS data extended from southeast Marshall/northern Pottawatomie Counties KS to Franklin/northern Anderson and Miami Counties KS to Henry/northwest Benton/southwest Pettis Counties MO. A southwest 40-kt low-level jet extending into the southwest portion of the MCC from OK will sustain an inflow of very strong instability (2500-4000 J/kg of most-unstable CAPE per objective analyses and 06Z Lamont, OK sounding). This combined with vertically veering wind profile (per 06Z LMN sounding), with effective bulk shear exceeding 45-50 kt, will maintain strong updrafts. In addition to locally damaging winds remaining possible, a plume of steep midlevel lapse rates (7-8 C/km per 06Z LMN sounding) extending from southern KS to southern MO will favor a large-hail threat along the west/southwest part of the MCC. This latter threat could result in additional counties in east-central/southeast KS being added to WW 344. ...WW 343... Weakening trends in MRMS CAPPI (5-9 km) and MESH data combined with a great reduction in lightning data across northeast MO suggest the overall severe-weather threat should continue wane across WW 343 during the overnight. Veering 850-mb winds further weakening low-level convergence across this region support this scenario, and this watch could be canceled prior to 10Z (5 AM). ..Peters.. 06/17/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT... LAT...LON 39719648 39549593 39309571 38929507 38759467 38639440 38639376 38679331 38529254 38439201 38579164 39519130 39059065 38609101 37839157 37099236 36739419 37019543 38549618 39719648
from SPC Mesoscale Discussions http://bit.ly/2sDMybM
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