U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 170636 
Storm Prediction Center ac 170635 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1235 am CST Wed Jan 17 2018 

Valid 181200z - 191200z 

..no severe thunderstorm areas forecast... 

isolated thunderstorms are possible along the Pacific northwest 
coast Thursday into Thursday night. 

A powerful southwesterly mid/upper jet will sink southward along the 
Pacific northwest coastline Thursday. Concurrently, strong 
southwesterlies will also spread farther inland towards the northern 
High Plains through the period. Downstream ridging will gradually 
flatten in response, while slowly shifting southeast across the 
Desert Southwest and Central Plains. To its southeast, a weak 
impulse will cross from northern Mexico into far southern Texas 
Thursday night. 

..Pacific northwest... 
Behind the aforementioned southwesterly jet, cold mid-level temps 
(around -30 to -34 c at 500mb) will overspread parts of the Pacific 
northwest. Increasing low/mid-level instability, combined with 
adequate boundary-layer moisture near the coast, will promote 
scattered convection through the period. Forecast soundings indicate 
that a few updrafts should deepen enough for isolated lightning 
strikes along the Washington, Oregon, and northern California 

..south Texas... 
As a weak impulse crosses the Rio Grande late in the period, 
cooling/moistening mid levels over south Texas will generate weak 
elevated buoyancy. While a thunderstorm cannot be ruled out, 
forecast soundings indicate nascent updrafts will struggle with 
dry-air entrainment near 700-600mb, likely precluding deep 

.Picca.. 01/17/2018