U.S. Severe Weather Forecast (Convective Outlook)

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Storm Prediction Center ac 240110 


Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0810 PM CDT Fri Jun 23 2017 


Valid 240100z - 241200z 


..there is a slight risk of severe thunderstorms from portions of 
northern West Virginia east into central New Jersey... 


..there is a marginal risk of severe thunderstorms from portions of 
the middle-Atlantic region into southern New England... 


..there is a marginal risk of severe thunderstorms over portions of 
the southeast u... 


..there is a marginal risk of severe thunderstorms from the 
arklatex west across southeast New Mexico... 


... 
Damaging wind gusts and a few tornadoes will be possible tonight 
from portions of the Ohio Valley east into the northeast U.S. A few 
severe storms with strong wind gusts and hail will also be possible 
across parts of the southeast states and from the arklatex into the 
Southern Plains. 


A frontal boundary, punctuated by convective outflows, extended from 
the lower Great Lakes into the Southern Plains at 01z. Surface low 
pressure, the remnants of Tropical Storm Cindy, was located over 
north-central Kentucky. In areas near/south of the front 
unperturbed by convection, a moist/weakly buoyant air mass remains 
in place. Aloft, broadly cyclonic mid-level flow exists from the 
central/northern plains east across the mid-Atlantic region and New 
England. Stronger low- and mid-level flow will gradually shift east 
into portions of the mid Atlantic and northeast states overnight. 


..Ohio/Tennessee Valley into the northeast u... 
Reference mesoscale discussion number 1142 for latest short-term thinking 
some risk for organized storms is expected to persist into the 
overnight hours as the cold front moves steadily east and the 
surface low over northern Kentucky accelerates northeast in 
proximity to the front. Although instability will generally be 
weak, strengthening wind fields will result in increasing deep-layer 
shear in the 45-55 kt range overnight. Weak impulses aloft, 
possibly convectively modulated, will lift northeast across the 
region providing subtle large-scale ascent. High-resolution guidance 
continues to suggest additional thunderstorm development overnight, 
possible in short line segments, in an environment favorable for 
damaging winds and perhaps a tornado. Will maintain the slight risk 
overnight for this scenario. 


..north Georgia west to arklatex... 
Reference mesoscale discussion number 1143 for latest short-term thinking across the 
arklatex region. Otherwise, will maintain marginal risk areas for 
isolated damaging wind potential with ongoing storms, and some 
potential for additional development later this evening. 


..central/North Texas and southern Oklahoma... 
An increase in thunderstorm development is anticipated later this 
evening and tonight in association with weak isentropic ascent north 
of the frontal boundary. Effective shear will be sufficient for some 
degree of storm organization posing a risk for isolated strong winds 
and hail. 


.Bunting.. 06/24/2017 


$$ 

Mesoscale Discussion


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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 240026 
msz000-arz000-laz000-txz000-okz000-240230- 


Mesoscale discussion 1143 
National Weather Service Storm Prediction Center Norman OK 
0726 PM CDT Fri Jun 23 2017 


Areas affected...southern Arkansas...far northeast Texas...far northern la 


Concerning...Severe Thunderstorm Watch 367... 


Valid 240026z - 240230z 


The severe weather threat for Severe Thunderstorm Watch 367 
continues. 


Summary...some isolated damaging wind gusts are possible for the 
next few hours across southern Arkansas and adjacent far northeast Texas and 
far northern la . Anticipated limited and marginal nature of the 
severe threat is expected to preclude the need for a downstream 
watch. 


Discussion...mesoscale convective system which has moved through Arkansas 
over the last several hours continues southward/southeastward into 
southern Arkansas and far northwest MS. Eastern portion of the system has 
weakened considerably over the past hour as encountered the cloudy 
and less unstable airmass over western Tennessee and northwest MS. Western 
portion of the system continues to forward propagate 
southward/southwestward into the warm and unstable airmass of 
south-central/southwest Arkansas. Weak shear has prevent much organization 
along this portion of the mesoscale convective system with radar and satellite confirming 
the outflow-dominant storm structures. This weakly organized, 
outflow-dominant forward-propagation is expected to continue for at 
least the next few hours as the downstream airmass remains 
supportive of surface-based convection. Some isolated damaging wind 
gusts are possible with these storms but the limited and marginal 
nature of any severe threat precludes the need for a downstream 
watch. 


.Mosier.. 06/24/2017 


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


Attention...WFO...Jan...lzk...shv... 


Latitude...Lon 33879451 34129386 33809254 33569096 32709203 32979427 
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