U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 181656 
Storm Prediction Center ac 181655 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1055 am CST sun Feb 18 2018 

Valid 191200z - 201200z 

..no severe thunderstorm areas forecast... 

organized severe thunderstorms are not forecast across the lower 48 
states on Monday. 

An amplified pattern featuring a large-scale mid-level trough over 
Idaho through California will pivot eastward to Wyoming/Montana and into The Four Corners 
by early Tuesday. A lower-latitude trough over northern Baja 
California on Sunday will eject eastward and weaken by early Monday 
over nm. This disturbance will weaken while its southern portion 
moves into the southern High Plains late Monday night ahead of the 
main trough. A broad, moist conveyer will extend from the Texas Gulf 
Coast north and northeastward into the southern Great Lakes. 
Episodic bouts of showers/thunderstorms are forecast to develop 
within this elongated corridor with considerable cloudiness expected 
to stifle stronger surface heating. Instability is forecast to be 
greatest across the southern Great Plains to the east of a dryline 
where upwards of 500+ j/kg MLCAPE may develop in a narrow plume from 
western north-central Texas into west-central OK. Yet, forecast model 
guidance --including both parameterized and explicit-- do not 
develop storms during the afternoon/early evening. As the main 
mid-level wave encroaches upon the region late Monday night, 
isolated to widely scattered showers and thunderstorms are forecast 
from the Edwards Plateau in west-central Texas north into central Kansas 
and farther northeast into the southwest Great Lakes. 

.Smith.. 02/18/2018