U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 231937 
Storm Prediction Center ac 231936 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0236 PM CDT Fri Jun 23 2017 

Valid 232000z - 241200z 

..there is a slight risk of severe thunderstorms from the central 
Gulf states into the middle Atlantic... 

..there is a slight risk of severe thunderstorms from the Ozark 
Plateau into northeast Texas... 

..there is a marginal risk of severe thunderstorms from the 
southern High Plains to New England... 

Damaging wind gusts and a few tornadoes are possible this afternoon 
into evening from the Tennessee Valley toward parts of the 
Appalachians. A few severe storms with strong wind gusts and hail 
will also be possible across parts of the northeast states and from 
the Ozark Plateau into northeast Texas. 

..update discussion... 

1. Cindy: severe threat continues in association with the remnants 
of Cindy. The only appreciable changes made regarding this threat 
have been to reduce severe probabilities west of the circulation 
center over portions of KY/TN. 

2. Ozark plateau: mesoscale convective system is currently maturing over the Ozark Plateau 
in association with a weak short-wave trough digging southeast into 
this region. Leading edge of this complex of storms is beginning to 
surge southeast at roughly 35kt and latest hrrr guidance suggests 
this activity may propagate across much of Arkansas into the evening 
hours. For this reason have expanded severe probs to account for 
wind/hail with this complex of storms. 

3. Elsewhere: minor changes were made to account for ongoing 
convective trends. 

.Darrow.. 06/23/2017 

Previous discussion... /issued 1140 am CDT Fri Jun 23 2017/ 

..TN valley vicinity... 
The remnants of Cindy will continue to spread east-northeastward 
through the afternoon and evening, with a corridor of low/mid-level 
winds preceding these remnants. A moist and increasingly uninhibited 
boundary layer this afternoon should allow for the intensification 
of a mixed Mode of storms, including bands/clusters and the 
possibility of some cluster-preceding semi-discrete supercells. 
Given the magnitude of the low-level shear, especially from northern 
Alabama into middle/eastern Tennessee and eastern KY, the potential will exist 
for a few tornadoes aside from some wind damage potential. Reference 
mesoscale discussion 1130 for additional short-term details. 

..middle/upper Ohio River valley to Delmarva/mid-Atlantic... 
As moisture continues to increase into the region, it appears that 
pockets of locally stronger heating will occur today ahead, and on 
the southern fringes, of upstream precipitation/thicker cloud cover. 
A steadily strengthening wind field will overspread the region 
through the afternoon and evening, with increasingly favorable wind 
profiles for organized storms including a few supercells/bows. 
Damaging winds should be the primary risk, but some hail and/or a 
tornado are possible as well. 

..Southern Plains/Ark-la-tex/mid-south... 
Steep lapse rates and diabatic warming of the boundary layer will 
promote moderate instability in this region. Storms will likely 
develop along the south/southeastward-advancing cold front as well 
as over the higher terrain over nm/West Texas. Additionally, ongoing 
storms across southwest MO may gradually increase in 
coverage/intensity as they progress southeastward into Arkansas. The warm 
sector resides well south of the stronger winds aloft, but vertical 
shear will be supportive of multicells capable of producing a few 
strong to damaging wind gusts and marginally severe hail this 
afternoon into evening. 

..northern New York/New England... 
At least a few strong/severe thunderstorms are expected this 
afternoon across northeast New York into northern New England. 


Mesoscale Discussion

acus11 kwns 232150 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 232150 

Mesoscale discussion 1141 
National Weather Service Storm Prediction Center Norman OK 
0450 PM CDT Fri Jun 23 2017 

Areas affected...Kentucky...far western Virginia...southwestern West 
Virginia...far southern Ohio 

Concerning...Tornado Watch 368... 

Valid 232150z - 232345z 

The severe weather threat for Tornado Watch 368 continues. 

Summary...an isolated tornado threat should continue for a few more 
hours across parts of central and eastern Kentucky. The threat is 
expected to remain mostly confined to the area covered by ww 368 and 
no additional weather watch issuance is expected. 

Discussion...the remnants of Cindy are currently moving into the 
Ohio Valley with the center of circulation located in the 
southwestern part of ww 368 across southern Kentucky. Ahead of the 
circulation, instability is weak but the airmass is very moist with 
surface dewpoints in the lower 70s f and precipitable water values 
in the 2.00 to 2.25 range according to the rap. In addition, the 
WSR-88D vwps at Charleston, WV and Tri-Cities, Tennessee show 0-6 km shear 
near 40 kt with 0-3 km storm relative helicity around 250 m2/s2. The 
low-level shear over south-central Kentucky appears to be even 
stronger associated with a low-level speed Max at 850 mb. The 
low-level shear will continue to support a tornado threat across 
central and eastern Kentucky into early evening. The greatest 
tornado threat would be associated with the smaller more discrete 
cells that remain along the edge of the rain shields currently 
moving through central and eastern Kentucky at this time. The 
low-level speed Max is forecast to move across eastern Kentucky and 
into southern West Virginia later this evening but the tornado 
threat is expected to become marginal by then. 

.Broyles/Hart.. 06/23/2017 

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


Latitude...Lon 38408185 38628402 37408569 36778571 36628498 36768269