MD 0554 CONCERNING SEVERE THUNDERSTORM WATCH 159… FOR PORTIONS OF CENTRAL/NORTHEASTERN OKLAHOMA…SOUTHEASTERN KANSAS…AND FAR WESTERN MISSOURI
Mesoscale Discussion 0554 NWS Storm Prediction Center Norman OK 0714 PM CDT Tue Apr 25 2017 Areas affected...Portions of central/northeastern Oklahoma...southeastern Kansas...and far western Missouri Concerning...Severe Thunderstorm Watch 159... Valid 260014Z - 260145Z The severe weather threat for Severe Thunderstorm Watch 159 continues. SUMMARY...Severe thunderstorms will continue to develop across western portions of Watch 159 this evening, with activity gradually spreading east. Large hail and damaging winds will be the primary threats, but a tornado or two will also be possible across primarily southeastern portions of the watch. DISCUSSION...More vigorous convection has developed this evening from Chautauqua Co, KS south/southwestward to northern portions of the OKC Metro, in response to low-level convergence along a cold front. Despite considerable residual dry air near the LFC (noted in the 00Z OUN sounding), low-level ascent has been strong enough to sustain a few strong/severe thunderstorms. In conjunction with MLCAPE values around 1500-2500 J/kg, ample effective shear (noted in KTLX VWP data) will continue to support mid-level updraft rotation, enhancing hail growth as these cells spread northeast. In addition to these storms, cells are expected to develop farther south along/west of the boundary. Visible satellite and radar data depict mid-level precipitation to the west/southwest of OKC, suggesting improved large-scale ascent associated with an approaching impulse. This ascent will further reduce convective inhibition across southern portions of the watch this evening. In turn, sustained surface-based updrafts are expected to develop over the next hour or so. As these cells encounter richer moisture to the east (e.g., surface dew points in the mid 60s), they will likely intensify, with an attendant threat for large hail and damaging winds. The damaging wind threat may be bolstered if cells congeal into small bowing segments that propagate into the instability axis over eastern Oklahoma. Additionally, as low-level moisture continues to stream north, a strengthening low-level jet (and resultant uptick in low-level shear) may support a tornado or two across southern/southeastern portions of the watch over the next several hours. ..Picca.. 04/26/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN... LAT...LON 35119810 36509718 37849630 38119525 37979442 36599431 35399556 34659676 34649767 34909810 35119810
from SPC Mesoscale Discussions http://bit.ly/2qcdD0w
Be First to Comment