U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 230554 
Storm Prediction Center ac 230553 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1253 am CDT Mon Apr 23 2018 

Valid 241200z - 251200z 

..there is a marginal risk of severe thunderstorms from southwest 
Texas into far southwest OK... 

Isolated severe thunderstorms are possible from southwest Texas 
northeastward into far southwest Oklahoma. 

Mature cyclone centered over middle Tennessee/central Kentucky at the beginning 
of the period is expected to move northeastward across the central 
Appalachians. Surface low beneath the mid/upper cyclone will 
continue to fill while a secondary low develops farther east and 
moves northeastward across the Carolinas. Some thunderstorms are 
possible in the vicinity of the secondary low as well as across Florida 
as the surface trough moves through. 

Farther west, a shortwave trough will move southeastward into the 
Central Plains, encouraging a southward surge of a cold Continental 
airmass into the Southern Plains. A warm and deeply mixed airmass 
ahead of the cold front over the southern High Plains will likely 
support isolated to widely scattered thunderstorms. 

..southern High Plains... 
Southerly winds are anticipated across the region ahead of the 
approaching cold front but only modest low-level moisture (i.E. 
Dewpoints in the low 50s) is expected to reach the area. Even with 
this meager low-level moisture, destabilization is still expected as 
the boundary layer mixes to near 700 mb and surface temperatures 
climb into the low to mid 80s. This destabilization will support 
isolated thunderstorms along the front. Thunderstorms are also 
possible ahead of front as forcing for ascent from the shortwave 
trough moving through the Central Plains reaches the region. 
Low-level flow is not expected to be particularly strong but 
mid-level flow will gradually increase during the late afternoon and 
evening, supporting the potential for updraft organization and an 
isolated severe storm or two. 

Predominantly elevated thunderstorms will likely be ongoing at the 
beginning of the period across the region. A few surface-based 
storms are possible within the warm sector confined to the coastal 
regions. Limited spatial extent for strong thunderstorms as well as 
the displacement of the stronger flow northward suggest any severe 
threat will be too isolated to merit any severe probabilities with 
this outlook. 

..central/southern Florida Peninsula... 
Scattered thunderstorms are possible on both sides of a weakening 
frontal zone moving slowly southward across the region. Generally 
weak flow and poor lapse rates should keep the severe probabilities 
below 5%. 

.Mosier.. 04/23/2018