U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 310101 
Storm Prediction Center ac 310100 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0800 PM CDT Wednesday Jul 30 2014 

Valid 310100z - 311200z 

..no severe thunderstorm areas forecast... 

a few strong to severe storms are possible across portions of 
southern Oklahoma and North Texas and across eastern New Mexico 
until around middle evening. A few strong to severe storms are also 
possible over a part of western and southwestern Oregon this 

..cntrl OK through north central Texas... 

Cluster of storms continue through central and scntrl OK in 
association with a southeastward moving vorticity maximum and attendant NE-SW 
oriented frontal boundary. This activity is occurring north of a 
stationary front located across north central Texas where the atmosphere is 
very moist through a deep layer...but where clouds and weak lapse 
rates have resulted in limited instability with MUCAPE generally 
between 400-800 j/kg. Storms are embedded within 35-45 knots effective 
shear with veering low-level wind profiles...and a couple of storms 
have exhibited marginal supercell structures. Threat for a brief 
tornado and locally strong wind gusts will persist through middle 
evening as activity develops southeastward into southern OK and nctnrl Texas...but 
overall threat will remain limited due to the marginal thermodynamic 

..nwrn through southwestern Texas... 

Other storms have developed along southwestern extension of the front across 
northwestern through southwestern Texas where more substantial diabatic warming and 
deeper mixing within the boundary layer have resulted in an axis of 
1000-1500 j/kg MLCAPE. These storms are high based and exist within 
a weaker shear environment...but will pose a modest threat for 
isolated large hail and downburst winds through middle evening. 

..ern nm... 

Mostly high based storms spreading off the higher terrain into the 
moderately unstable environment across eastern nm will continue to pose 
a threat for isolated downburst winds and hail through mid-evening. 

..wrn or... 

A few high based storms have developed within the deeply mixed but 
marginally unstable boundary layer across western Oregon ahead of a northward 
moving shortwave trough. Downburst winds and small hail could 
accompany the stronger storms next 2-3 hours...but coverage of any 
such events will likely remain sparse. 

.Dial.. 07/31/2014 

Mesoscale Discussion

acus11 kwns 302348 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 302348 

Mesoscale discussion 1503 
National Weather Service Storm Prediction Center Norman OK 
0648 PM CDT Wednesday Jul 30 2014 

Areas affected...far southeast nm...far West Texas...west-central Texas 

Concerning...severe potential...watch unlikely 

Valid 302348z - 310115z 

Probability of watch issuance...20 percent 

Summary...marginally severe wind gusts may occur over the next few 
hours from West Texas and far southeast nm east-northeastward across west-central Texas. The severe 
threat may increase some over the next hour but should remain too 
marginal for ww issuance. 

Discussion...the latest surface analysis shows a pre-frontal trough 
located from near Midland-Odessa northeastward to just east of Wichita Falls 
with a well-defined wind shift on the northwestern edge of the trough where 
surface dewpoints are mainly in the 60s f. This has resulted in a 
corridor of moderate instability across west-central Texas where scattered 
thunderstorms are developing at this time. To the south of the instability 
axis...rap data suggests that low-level lapse rates have become very 
steep with 0-3 km values approaching dry-adiabatic. Short-term model 
forecasts move this convection southeastward into a slightly drier airmass 
where surface dewpoints drop into the 50s f. This dryer airmass combined 
with large surface temperature-dewpoint spreads and steep low-level lapse rates 
should help enhance downdraft accelerations resulting in a marginal 
wind damage threat. The threat may persist for few hours before the 
airmass becomes more stable later this evening. 

.Broyles/Mead.. 07/30/2014 

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


Latitude...Lon 31450152 31130341 31570413 32040428 32410393 32630347 
32820227 33140108 33310020 33019960 32489939 32189940 
31929982 31760022 31450152