ACUS02 KWNS 011724
SPC AC 011724
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1124 AM CST Wed Mar 01 2017
Valid 021200Z - 031200Z
...NO THUNDERSTORM AREAS FORECAST...
Severe weather is not forecast over the Lower 48 states on Thursday.
A vigorous shortwave trough located over the Northeast will quickly
move to Nova Scotia and the western Atlantic on Thursday. A cold
front attendant to this trough will move south across the FL
Peninsula this forecast period. Warm midlevel temperatures across
north FL should inhibit the development of thunderstorms.
Meanwhile, isolated thunderstorms cannot be ruled out farther south
as the cold front reaches south FL and in vicinity of a sea breeze
front. However, weak forcing aloft and weak lapse rates should
limit the probability for thunderstorms.
A fast-moving shortwave trough will track from the upper Midwest and
amplify across the OH Valley this forecast period, approaching the
central Appalachians by 12Z Friday. A concurrent surface low/cold
front will move quickly to the east-southeast across IA and into IL
by Thursday afternoon, and advance through the OH/TN Valleys
Thursday night, with the low reaching southern PA/northern VA region
late in the period. Cooler surface temperatures and a lack of
higher surface dew points would suggest a limited potential for
convective development. However, forecast soundings suggest
sufficient destabilization should occur along the track of the
surface low/cold front from southeast IA through central IL into
west/southwest IN. Steepening lower tropospheric lapse rates
(surface-3 km exceeding 8 C/km in the afternoon) while relatively
rapid cooling occurs in the 600-750-mb layer may prove favorable for
weak buoyancy to reach temperatures cold enough for charge
separation within shallow convection. This convection should be
located along the fast-moving cold front, enhancing the transfer of
higher momentum air to the surface. The potential for lightning
production is expected to remain less than 10%, precluding the
inclusion of a general thunderstorm area, though locally enhanced
convective gusts cannot be ruled out.