U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 251632 
Storm Prediction Center ac 251630 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1130 am CDT Sat Mar 25 2017 

Valid 251630z - 261200z 

..there is a slight risk of severe thunderstorms across the central 
Gulf Coast states... 

..there is a marginal risk of severe thunderstorms from the Gulf 
Coast to the middle MS River Valley... 

Isolated strong to locally severe thunderstorms may occur through 
the afternoon and early evening hours across the central Gulf Coast 
states northward into the middle Mississippi River valley. 

..Gulf Coast/lower MS River Valley/mid-south... 
Well ahead of the synoptic cold front, the outflow-focused remnants 
of last night's convection continue to decelerate while slowly 
progressing into western al, while otherwise stalling along coastal 
la. It appears the strongest/most organized convection will remain 
semi-focused this afternoon across southeast la and possibly 
near-coastal portions of MS/Alabama into the Florida Panhandle. 
Low/mid-tropospheric winds should continue to gradually weaken 
during the day, but some additional heating/destabilization will 
nonetheless support some stronger mostly linear storms capable of 
locally damaging winds and possibly a tornado. 

Otherwise, a few stronger storms could redevelop this afternoon 
across the mid-south/lower MS River Valley vicinity near/just ahead 
of the synoptic front within a modestly unstable environment. 
However, semi-prevalent cloud cover and weakening mass convergence 
should limit any such risk. 

..middle MS River Valley... 
The slow-moving closed/cold cyclone will continue to drift 
east-northeastward today from the Ozarks toward central/southern Illinois 
by tonight. Immediately ahead of this nearly stacked low, locally 
stronger heating (60s f surface temperatures) and moderately steep 
lapse rates, as noted between 850mb-650mb in the 12z observed 
sounding from Springfield MO, could support some stronger updrafts 
this afternoon. Marginally severe and gusty winds could occur, and 
sufficient low-level moisture/ambient vorticity could allow for a 
few funnels. 

.Guyer/Mosier.. 03/25/2017 


Mesoscale Discussion

acus11 kwns 251708 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 251708 

Mesoscale discussion 0330 
National Weather Service Storm Prediction Center Norman OK 
1208 PM CDT Sat Mar 25 2017 

Areas affected...southeast la...southeast MS and southwest Alabama 

Concerning...severe potential...watch unlikely 

Valid 251708z - 251945z 

Probability of watch issuance...20 percent 

Summary...a few instances of strong to damaging wind gusts and 
marginally severe hail will remain possible through mid afternoon. 
At this time the overall threat appears marginal, and a ww will 
probably not be necessary in this area unless storms begin to show 
evidence of greater organization and intensification. 

Discussion...as of mid day a broken line of pre-frontal 
thunderstorms extends from west central Alabama through southeast MS into 
southeast la and is moving east at 15-20 kt. Diabatic warming of the 
boundary layer and modest low-level moisture advection have resulted 
in marginal instability with MLCAPE at or below 500 j/kg over west 
central through southwest Alabama to around 1000 j/kg over southeast MS. 
The primary low-level jet will remain north of this region, and 
winds aloft will gradually weaken in wake of a vorticity maximum 
moving through the base of the upper low circulation. Thus vertical 
wind profiles will become less favorable for storm organization as 
the atmosphere destabilizes this afternoon. Primary threat will be 
from a few strong to damaging wind gusts with stronger storms within 
the line. 

.Dial/guyer.. 03/25/2017 

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


Latitude...Lon 29619129 30009096 30338962 30768885 31268828 32248765 
33268728 33138660 31368705 29178943 29229056 29619129