U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 260552 
Storm Prediction Center ac 260551 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1251 am CDT Tuesday Jul 26 2016 

Valid 271200z - 281200z 

..there is a marginal risk of severe thunderstorms from the middle-MO valley into 
parts of the central and northern plains... 

..there is a marginal risk of severe thunderstorms for parts of southern Virginia and northern 

Isolated severe thunderstorms are possible across parts of the Great 
Plains and the middle-Atlantic region Wednesday afternoon and evening. 

A shortwave trough will gradually amplify across the middle-MS valley 
into the upper Great Lakes...loosely associated with a deep-layer 
low over eastern Canada. A separate midlevel speed maximum will move 
across the Central High plains during the afternoon...along the northestern 
periphery of anticyclonic flow aloft centered over the western Great 
Basin. A surface cold front will slowly spread southward across the 
Dakotas and northern Minnesota...while a weak nearly stationary 
front extends from the middle-Atlantic region westward into the Central 

..mid-MO valley into parts of the central/northern plains... 
Early morning convection is forecast to weaken by the early portion 
of the Wednesday/d2 period...and a boundary /potentially modified by 
convection/ should extend from southeastern South Dakota southwestward into northestern Colorado by late 
morning. Reservoir of low 60s f dewpoints will exist across the 
middle-MO valley into eastern portions of neb/KS...with drier low-level air 
/50s f dewpoints/ extending to the west and north into the northern High Plains. 
Timing of individual impulses remains somewhat uncertain...but 
general consensus is a midlevel speed maximum will move into the Central 
High plains during the afternoon...and encourage thunderstorm development 
along the boundary across parts of central Nebraska. Despite weak low-level 
winds...northwesterly midlevel flow should be sufficient /20-30 knots/ to 
support evolution of a couple clusters propagating generally southeastward 
into eastern Nebraska and northern Kansas during the evening. Given uncertainty 
related to the timing of impulses...and somewhat marginal 
boundary-layer moisture...confidence remains too low for slight risk 
delineation at this time. 

Additional thunderstorms are possible within an upslope regime along the 
Front Range into the parts of southeastern Montana. A few strong wind gusts 
and/or small hail will be possible with convection across the 
central/northern High Plains. 

..srn Virginia and northern NC... 
A band of moderate westerlies aloft /20-25 knots at 500 mb/ will persist 
along the southern periphery of an eastern Canada trough across the central 
Appalachians to the middle-Atlantic region. Rich moisture will be in 
place to the S of a stalled boundary across southern Virginia...and strong 
diurnal heating should yield MLCAPE values approaching 2000 
j/kg...despite relatively warm middle-tropospheric temperature 
profiles. Deep-layer shear may be sufficient to sustain a few 
multicell clusters capable of damaging wind gusts from the higher 
terrain eastward to the coast. 

.Rogers.. 07/26/2016