U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 190730 
Storm Prediction Center ac 190729 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0229 am CDT sun Aug 19 2018 

Valid 211200z - 221200z 

..there is a slight risk of severe thunderstorms across the upper 
Ohio River valley and north-central Appalachians... 

Severe thunderstorms will be possible on Tuesday especially across 
portions of the Appalachians and mid-Atlantic states. 

..Appalachians/upper Ohio River valley and mid-Atlantic/northeast 
although the primary surface cyclogenesis will be focused north of 
the international border, a semi-amplified belt of seasonally strong 
westerlies will overspread much of the region on Tuesday coincident 
with an eastward-moving cold front. While the possibility of 
relatively widespread early-day convection and cloud cover limits 
confidence in appreciable destabilization, relatively strong 
low-level shear and upwards of 35-40 kt effective shear suggests the 
potential for sustained multicells and some supercells where 
adequate diurnally enhanced destabilization occurs. This currently 
appears most probable across the north-central Appalachians and 
upper Ohio River valley vicinity. That said, at least isolated 
severe storms may occur as far south as the Carolinas under a more 
modestly strong flow regime. 

..Central High plains... 
At least a few severe thunderstorms may occur across the region 
Tuesday afternoon into evening. This will be in association with 
enhanced moist low-level upslope flow to the north of a southern 
High Plains surface low and in conjunction with a moderately strong 
belt of westerlies to the north of the southern High Plains-centered 
upper-level ridge. 

.Guyer.. 08/19/2018