U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 161247 
Storm Prediction Center ac 161246 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0746 am CDT Mon Sep 16 2019 

Valid 161300z - 171200z 

..no severe thunderstorm areas forecast... 

severe storms are unlikely today and tonight. 

A deep midlevel trough, with associated cool midlevel temperatures 
and steep lapse rates, will continue to progress inland over the 
Pacific coast today and the Great Basin tonight. A few low-topped 
thunderstorms will be possible the first part of the day along the 
cold front in northeast CA, while occasional storms will spread 
inland across or to northwest Nevada by this evening. Farther south and 
east, the cold front will cross Nevada this evening and reach Utah 
tonight. The monsoonal moisture plume will likely remain east of 
the front and associated ascent, which casts substantial doubt on 
the potential for thunderstorms along the front tonight. 

In response to the Pacific coast trough, a weakening subtropical 
shortwave trough over nm/Colorado will eject northeastward toward the 
eastern Dakotas/Minnesota and could support some elevated convection near 
the end of the forecast period. Scattered thunderstorms are likely 
through tonight near the northwest Gulf Coast with a weak tropical 
disturbance. The convection should spread inland this afternoon 
with outflows, and then consolidate tonight near the middle and 
Upper Texas coast. 

.Thompson/Gleason.. 09/16/2019 


Mesoscale Discussion

acus11 kwns 150240 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 150240 

Mesoscale discussion 1979 
National Weather Service Storm Prediction Center Norman OK 
0940 PM CDT Sat Sep 14 2019 

Areas affected...Arizona 

Concerning...Severe Thunderstorm Watch 653... 

Valid 150240z - 150415z 

The severe weather threat for Severe Thunderstorm Watch 653 

Summary...severe threat is decreasing across ww653. 

Discussion...earlier convection that developed over the higher 
terrain of central Arizona has propagated southwest across the lower 
deserts. This activity has struggled to organize, though gusty winds 
have likely been noted with the strongest storms. Even so, overall 
severe threat appears to be waning as diurnal cooling and 
boundary-layer stabilization appears to be negatively influencing 

.Darrow.. 09/15/2019 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 31931330 33451331 33621227 32461180 31931330