U.S. Severe Weather Forecast (Convective Outlook)

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acus01 kwns 301429 
swody1 
Storm Prediction Center ac 301427 


Day 1 convective outlook resent 1 
National Weather Service Storm Prediction Center Norman OK 
0927 am CDT Thu Mar 30 2017 


Valid 301300z - 311200z 


..there is an enhanced risk of severe thunderstorms lower Ohio 
Valley... 


..there is a slight risk of severe thunderstorms Midwest to central 
Gulf Coast to southern Appalachians... 


..there is a marginal risk of severe thunderstorms surrounding the 
slight risk... 


..there is a marginal risk of severe thunderstorms Great Basin... 


... 
scattered severe storms are most likely from the Midwest to the deep 
south with damaging winds, a few tornadoes, and hail possible from 
midday to evening. 


..Midwest to the central Gulf Coast and southern Appalachians... 
Ongoing convection from southern MS to an mesoscale convective system over the northwest 
Gulf along with scattered showers and storms over the mid-MS valley 
and Midwest renders low confidence in the potential for robust 
destabilization across the warm sector. 12z raobs sampled meager 
MUCAPE north of the central Gulf Coast where rich boundary-layer 
moisture is confined to this region. Given the degree of moisture 
farther north along with extensive cloud cover slowing diurnal 
destabilization, peak MLCAPE will likely remain weak below 1000 j/kg 
during the late afternoon. 


As a surface cyclone becomes centered over central Illinois and attendant 
cold front arcs southward across the MS valley, scattered storm 
development should occur around midday. Deep-layer winds will be 
strong, but meridional. Both the rap/NAM soundings depict 
veer-back-veer profiles and small low-level hodographs with modest 
srh. This type of setup should Foster splitting cells, 
conglomerating into clusters and short-line segments, with the 
primary severe threats being hail and damaging wind. A few tornadoes 
may occur, but the likelihood of several tornadic storms appears too 
low to warrant a broad area of enhanced probabilities. 


From the central Gulf Coast to southern Appalachians, the ongoing 
mesoscale convective system in the northwest Gulf casts considerable uncertainty in diurnal 
convective development to its immediate north. However, as a 
mid-level speed Max ejects across the region tonight, isolated to 
scattered storms should form and/or storms that initially formed 
along the cold front over MS may be sustained. While instability 
will be nocturnally waning, deep-layer shear will be adequate for 
all severe hazards with coverage expected to warrant category 1-2 
risks. 


..Great Basin... 
A band of showers and isolated storms is expected to form along a 
strong cold front attendant to an amplifying shortwave trough. 
Although buoyancy will be scant, well-mixed thermodynamic profiles 
ahead of the front should support downward momentum transport of 
robust flow aloft and may yield isolated severe wind gusts. 


.Grams/dial.. 03/30/2017 


$$ 

Mesoscale Discussion


000 
acus11 kwns 300635 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 300634 
msz000-laz000-300800- 


Mesoscale discussion 0376 
National Weather Service Storm Prediction Center Norman OK 
0134 am CDT Thu Mar 30 2017 


Areas affected...south central MS through southeast la 


Concerning...Tornado Watch 101... 


Valid 300634z - 300800z 


The severe weather threat for Tornado Watch 101 continues. 


Summary...tornado risk continues to trend downward as primary threat 
has transitioned to isolated damaging wind across remaining portion 
of Tornado Watch 101. This watch will be allowed to expire at 08z. 
While some risk for mainly a few strong wind gusts may persist from 
southeast la into southern MS for an hour or two beyond 08z, the 
overall threat is expected to remain too marginal for another ww 
issuance. 


Discussion...broken squall line from southern MS into central 
portions of coastal la is moving east at 25-30 kt, while individual 
storms embedded within the line move more rapidly northeast. A few 
loosely organized storms persist within a portion of the line 
including bowing segments across southern and south central MS. Vwp 
data show largely unidirectional wind profiles with modest size 
low-level hodographs. Tendency will be for the low-level jet to 
gradually shift north toward the Tennessee Valley and away from the more 
unstable portion of the warm sector into the early morning. While 
threat for mostly a few strong to damaging wind gusts may persist 
next 2-3 hours as storms continue through the marginally unstable 
environment, overall threat appears too marginal for an additional 
ww issuance. 


.Dial.. 03/30/2017 


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


Attention...WFO...Jan...lix...lch... 


Latitude...Lon 29769292 30149184 31209075 32369019 32728985 32368949 
30888991 29769050 29379186 29769292