043
ACUS01 KWNS 061246
SWODY1
SPC AC 061245

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0745 AM CDT Sun Oct 06 2024

Valid 061300Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN OHIO...WESTERN NEW YORK/PENNSYLVANIA...AND THE NORTHERN WEST
VIRGINIA PANHANDLE...

...SUMMARY...
Isolated to scattered severe thunderstorms should occur this
afternoon and evening from parts of eastern Ohio into western New
York/Pennsylvania, West Virginia, and western Maryland. Damaging
winds and hail should be the main threats.

...Upper Ohio Valley into the Lower Great Lakes and Central
Appalachians...
A vigorous upper trough over Ontario and the Great Lakes will
continue advancing eastward across parts of Quebec and the Northeast
today. A related surface low over northern Ontario this morning will
slowly occlude through the day, while a cold front extending across
the upper Great Lakes and Midwest advances southeastward over the OH
Valley and western Mid-Atlantic by this evening. A narrow corridor
of modest low-level moisture will return northward ahead of this
cold front, with surface dewpoints generally in the 50s to perhaps
low 60s. Modestly steepened mid-level lapse rates overspreading the
warm sector through the day, in tandem with diurnal heating, should
support around 500-1500 J/kg of MLCAPE by mid afternoon. A belt of
enhanced (50-60 kt) mid-level flow attendant to the upper trough
will move over parts of the upper OH Valley, lower Great Lakes, and
western Mid-Atlantic this afternoon and evening. This strong flow
aloft will contribute to substantial deep-layer shear (around 35-50
kt) and organized severe convection.

Current expectations are for robust thunderstorms to develop along
the cold front in eastern OH/western NY and northwest PA around
20-22Z. This initial development may be supercellular given the
strong deep-layer shear, with an associated threat for severe hail
given favorable lapse rates aloft. A brief tornado or two may also
occur. But, a fairly quick transition to a line is anticipated given
the linear forcing of the cold front. As this occurs, the threat for
scattered damaging winds should quickly increase as convection moves
east-southeastward from eastern OH across western NY/PA and into
WV/western MD. Given the fairly narrow warm sector, this activity
should weaken by mid evening with the loss of daytime heating, and
as it encounters a much less unstable airmass in the central
Appalachians.

..Gleason/Dean.. 10/06/2024

$$