U.S. Severe Weather Forecast (Convective Outlook)

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000 
acus01 kwns 191632 
swody1 
Storm Prediction Center ac 191630 


Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1030 am CST Tue Feb 19 2019 


Valid 191630z - 201200z 


..there is a marginal risk of severe thunderstorms across the 
arklatex region and lower Mississippi Valley... 


... 
Isolated, marginally severe storms are possible today from East 
Texas to southern Arkansas and central Mississippi, and overnight in 
the eastern Louisiana and southwestern Mississippi vicinity. 


..East Texas/arklatex to lower Mississippi Valley... 
Very isolated marginally severe hail is a possibility through the 
afternoon and early evening primarily across far East Texas toward the 
arklamiss vicinity. Elevated buoyancy and strong shear through the 
cloud-bearing layer could support hail growth, although the modest 
nature of the elevated buoyancy and the commonality of updraft 
interference will curb the overall hail potential. 


Later tonight, as the upper trough glancingly influences the region 
and weak height falls begin to occur, steady boundary-layer 
moistening and destabilization are expected in conjunction with weak 
surface cyclogenesis (~1010 mb) across the lower Mississippi Valley. 
Although the more consequential forcing for ascent will be focused 
to the north, thermodynamic profiles should trend more conducive for 
near-surface based convection late tonight coincident with 60s f 
dewpoints. 


That said, relatively weak lapse rates progged by various forecast 
soundings suggest the bulk of the convection may be subtly rooted 
atop shallow near-surface stability. 12z-based convection-allowing 
models imply only limited storm intensity/organizational character 
through the period, and if anything, indicate a slight downward 
intensity trend from prior 00z runs. Regardless, given strong 
deep-layer/low-level shear, at least a conditional risk for damaging 
wind and/or some tornado potential will exist after 06z/midnight 
local time through the early morning hours of Wednesday. 


.Guyer/Wendt.. 02/19/2019 


$$ 

Mesoscale Discussion


000 
acus11 kwns 191221 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 191221 
msz000-laz000-txz000-191445- 


Mesoscale discussion 0108 
National Weather Service Storm Prediction Center Norman OK 
0621 am CST Tue Feb 19 2019 


Areas affected...eastern Texas into northern Louisiana and western 
Mississippi 


Concerning...severe potential...watch unlikely 


Valid 191221z - 191445z 


Probability of watch issuance...20 percent 


Summary...storms will gradually increase in coverage during the 
morning with a few capable of large hail. 


Discussion...warm advection just off the surface will become quite 
strong this morning with southerly 850 mb winds increasing from 30 
to over 50 kt by 15z across the Sabine valley. Thunderstorms were 
already increasing as of 12z from East Texas into central MS, with 
mainly short-lived hail cores as instability is weak. However, 
elevated instability will increase throughout the day, and a few 
severe storms will be possible especially from Texas into la within a 
zone of strong warm advection. Ample deep-layer effective shear 
along with cool boundary-layer temperatures will support hail 
potential with cells embedded within a broader zone of 
precipitation. 


.Jewell/Edwards.. 02/19/2019 


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


Attention...WFO...Jan...lch...shv...hgx...fwd... 


Latitude...Lon 31349254 31179348 30779463 30679550 31259600 31929586 
32379548 32819435 32939290 32939186 32889101 32699064 
32389045 32039054 31649137 31349254