Valid 290100Z – 291200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS AND THE MIDDLE ATLANTIC…
…SUMMARY…
Scattered thunderstorms, a few severe, will continue across portions
of the southern High Plains into southwestern Missouri. A few strong
storms will also linger across southern Pennsylvania into northern
Maryland.
…01z Update…
Early-evening water-vapor imagery depicts a well-defined short-wave
trough ejecting northeast across the lower MO Valley region.
Organized convection continues ahead of this feature but the
greatest risk for robust updrafts is along the southern flank of
this system across southeastern KS into southwestern MO over the
next few hours. Some hail/wind threat will persist with this
activity.
Farther west, steeper lapse rate-regime across the southern High
Plains has contributed to gusty winds/hail with strongest storms
from southeast NM into western OK. 00z sounding from OUN exhibited
substantial SBCAPE (~4000 J/kg) with sfc-6km bulk shear approaching
40kt. However, short-wave ridging and loss of daytime heating should
render this activity more isolated and less organized than
downstream convection.
Convection that developed along southern fringe of Canadian
short-wave trough has propagated southeast across the OH Valley and
is approaching the PA/MD border. This activity should gradually
weaken with loss of daytime heating in the absence of large-scale
support.
..Darrow.. 09/29/2019
$$