U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 190727 
Storm Prediction Center ac 190725 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0225 am CDT sun Apr 19 2015 

Valid 211200z - 221200z 

..there is a slight risk of severe thunderstorms across parts of the southern High 

..there is a marginal risk of severe thunderstorms across parts of the Southern 

Thunderstorm development is expected to take place late Tuesday 
afternoon across the Southern Plains where large hail and wind 
damage will be possible. Thunderstorms may also form over parts of 
the southern and central rockies...southern Great 
Lakes...south-central Florida Peninsula and in the Sierra Nevada. 

..srn plains... 
A broad cyclonic flow pattern is forecast across the eastern half of the 
nation on Tuesday as an upper-level ridge moves slowly across the 
southern rockies and Great Basin. At the surface...a low is forecast to move 
eastward into the southern High Plains with a dryline setting up across West 
Texas. Southerly low-level winds to the east of the dryline should result in 
moisture advection throughout the period. Model solutions vary on 
how much moisture will return northward. The NAM and GFS solutions suggest 
that surface dewpoints will reach the lower 60s f in the Texas Hill country 
and West Texas with middle to upper 50s f possibly in the Low Rolling 
Plains and on The Caprock. Both the NAM and GFS solutions develop 
convection along an axis of instability from the eastern Texas Panhandle 
southeastward into northwest Texas late Tuesday afternoon. GFS forecast soundings at 
00z/Wednesday show pockets of moderate instability in place with 
about 40 knots of deep-layer shear owing to directional shear below 700 
mb and 50 knots of flow aloft. This combined with steep lapse rates 
would support supercells with large hail. Isolated wind damage would 
also be possible. Although the models are somewhat in agreement 
concerning convective initiation on The Caprock and over the Low 
Rolling Plains...the extended forecast range introduces much 
uncertainty. The upper-level ridge could help to inhibit storm 
development keeping convective coverage isolated across the region. 
At this time...will introduce a small slight risk area across parts of northwest 
Texas...the southeast Texas Panhandle and SW OK where the potential for severe 
storms appears the greatest. 

.Broyles.. 04/19/2015