U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 030600 
Storm Prediction Center ac 030559 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1259 am CDT Monday Aug 03 2015 

Valid 041200z - 051200z 

..there is a marginal risk of severe thunderstorms from portions of the plains 
through the middle MS valley...Tennessee Valley and southern portion of the Ohio 

..there is a marginal risk of severe thunderstorms from portions of the middle 
Atlantic into New England... 

A few strong to severe storms will be possible from the Central High 
plains through the middle Mississippi Valley and Tennessee Valley 
areas. Other strong storms may occur from a portion of New England 
into the middle Atlantic region. 


Blocking pattern will persist through Tuesday with upper low 
remaining in place from the Ohio Valley into the northestern states. A series 
of impulses will rotate through this feature. At least a couple of 
vorticity maxima will undercut western U.S. Upper ridge and continue 
through the central and northern plains and middle MS valley areas. At the surface 
a cold front will move through remainder of New England with 
trailing portions of this boundary extending southwestward through the middle 
Atlantic and then westward into the Central Plains. 

..cntrl/Southern Plains through middle MS valley and Tennessee/Ohio Valley areas... 

Areas of thunderstorms should be ongoing 12z Tuesday within zone of 
ascent north of the quasi-stationary front from the middle MS valley 
westward into the Central Plains. Other thunderstorms should be in progress 
from western Kansas nwwd into the central/northern rockies in association with 
ascent attending a couple of slow moving shortwave troughs that will 
undercut upper ridge. Potential exists for the atmosphere to become 
moderately unstable within portions of the moist warm sector...but 
areas of widespread clouds and ongoing thunderstorms lower 
confidence in where the best destabilization will occur. Most of 
this region will remain SW of stronger winds aloft with vertical 
shear supportive of multicells. An exception will be possibly over 
western Kansas where models indicate east-southeasterly winds will develop north of weak 
surface low and beneath slightly stronger westerly winds aloft within base of 
a low-amplitude shortwave trough. Where sufficient boundary layer 
warming occurs...storms should undergo some intensification during 
the afternoon and pose a threat for mainly a few instances of 
damaging wind. Due to the potential mitigating influence of ongoing 
storms on the thermodynamic environment...will maintain the marginal 
risk category this update. 

Farther east into the middle MS and Tennessee/Ohio valleys additional storms 
should develop in vicinity of the stalled front as the atmosphere 
destabilizes. The strongest diabatic warming and destabilization are 
expected from portions of Tennessee and southern Kentucky. This region will also 
reside south of the stronger winds aloft...but the thermodynamic 
environment may support a few instances of mainly damaging wind 
during the afternoon. 

..New England through the middle Atlantic area... 

Moderate instability is possible ahead of cold front Tuesday over 
portions of New England and southward into the middle Atlantic. Storms are 
expected to redevelop as surface layer destabilizes. Some risk will 
exist for a few strong to severe storms from late morning through 
middle afternoon...especially given favorable wind profiles in this 
region. However...overall magnitude of threat will depend on frontal 
timing and extent of clouds and early convection which remains 
uncertain at this time. 

.Dial.. 08/03/2015