U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 221242 
Storm Prediction Center ac 221240 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0640 am CST Fri Feb 22 2019 

Valid 221300z - 231200z 

..there is a marginal risk of severe thunderstorms this afternoon 
through tonight from the Arkansas-la-miss region to East Texas... 

Isolated large hail and/or damaging gusts will be possible today 
through tonight across The Ark-la-miss region, and early Saturday in 
East Texas. 

..Ark-la-miss to East Texas through early Saturday... 
Lee cyclogenesis is expected today across northeast nm, within the 
left-exit region of a strengthening mid-upper jet streak that will 
rotate northeastward from northern Mexico to west central Texas by 
early Saturday. The surface warm sector and a moist air mass across 
the lower MS valley and near the northwest Gulf Coast will begin to 
spread north-northwestward in response to the cyclogenesis later 
today into tonight. Diurnal convection within the warm sector is 
quite uncertain given no clear forcing for ascent. Much of the 
convection is expected to remain on the immediate cool side of the 
boundary through tonight, where low-level warm advection will be 
strongest. There will be sufficient vertical shear for some 
organized/supercell structures, with an attendant threat for 
marginally severe hail and isolated strong/damaging gusts with storm 
close to the surface warm sector. 

By tonight, steeper midlevel lapse rates will begin to overspread 
the low-level moisture from East Texas to The Ark-la-miss, as vertical 
shear increases in advance of the ejecting midlevel trough and 
surface cyclone. Isolated large hail will be possible with the 
slightly elevated storms, with sufficient effective bulk shear 
(generally 45-55 kt) for some supercell structures. The more 
concentrated convection tonight and early Saturday should be along 
the warm conveyor belt from southeast Arkansas into northwest MS/western 
Tennessee. The steeper lapse rates to the west will also likely be 
associated with some midlevel convective inhibition, which could 
delay the majority of stronger storm development in East Texas until 
the d2 period as forcing for ascent increases. 

.Thompson/Jewell.. 02/22/2019 


Mesoscale Discussion

acus11 kwns 212340 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 212340 

Mesoscale discussion 0119 
National Weather Service Storm Prediction Center Norman OK 
0540 PM CST Thu Feb 21 2019 

Areas affected...portions of central Alabama into central Georgia 

Concerning...severe potential...watch unlikely 

Valid 212340z - 220145z 

Probability of watch issuance...5 percent 

Summary...risk for a brief tornado associated with low-topped 
convection will exist over the next few hours. Watch issuance is 
not expected. 

Discussion...latest radar continues to show generally 
weak/low-topped convection -- producing little in the way of 
lightning -- across portions of Alabama and Georgia. Ample 
low-topped cape and sufficient shear for storm rotation exists 
across this region, near a weak central Alabama frontal wave and the 
associated/eastward-extending warm front. However, the larger-scale 
environment remains generally unsupportive of stronger/more 
organized convection, with short-wave ridging aloft to gradually 
increase across the region tonight. 

However, a few stronger cells near the aforementioned warm front 
have exhibited organization/low-level rotation over the past hour or 
so; specifically, a cell which is exiting northeast Harris County Georgia 
and moving into southern Meriwether County has exhibited sustained 
low-level rotation and appears capable of producing a weak tornado 
as it interacts with low-level vorticity in the vicinity of the 
surface warm front. 

Though a few additional cells may also follow a similar evolution 
this evening, overall risk is expected to remain limited/local -- 
and thus watch issuance is not anticipated. 

.Goss.. 02/21/2019 

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


Latitude...Lon 33308294 32938259 32798198 32538295 32678388 32468497 
32138616 31688724 31838806 32858702 33198635 33638535 
33548394 33648307 33308294