U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 220044 
Storm Prediction Center ac 220042 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0742 PM CDT Mon may 21 2018 

Valid 220100z - 221200z 

..there is a slight risk of severe thunderstorms from east-central 
nm southward into far West Texas... 

Isolated to widely scattered strong to severe thunderstorms are 
possible this evening over east-central New Mexico southward into 
far West Texas. Isolated severe gusts and large hail will be the 
main severe threats. 

..southern rockies... 
Radar mosaic early this evening shows a north-south band of cellular 
storms located within a surface trough extending along the I-25 
corridor. Easterly upslope low-level flow will maintain a moisture 
feed within this general region for the sustenance of thunderstorm 
activity well into the late evening hours. Kepz VAD data estimated 
0-6 km shear around 50 kt around 00z which will support storm 
organization and intensity given the steep lapse rate environment. 
As storms gradually move east with time, the loss of surface heating 
and increased convective inhibition will favor a lessening of a 
large hail/severe gust risk by late evening. 

..central Ohio... 
A convective line over central Ohio is located on the southern fringe 
of stronger mid-level flow per kcle VAD information. The strength 
of flow decreases rapidly with south extent (mainly south of I-70) 
and the 00z iln radiosonde observation sampled this weaker flow regime. Nonetheless, 
the organized character of the convective line lends the possibility 
for localized damaging gusts for the next few hours before 
convective inhibition and a cooling boundary layer diminish this 
risk. A risk for marginally severe hail may persist in the near 
term before ceasing by mid evening. 

.Smith.. 05/22/2018 


Mesoscale Discussion

acus11 kwns 220223 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 220223 

Mesoscale discussion 0488 
National Weather Service Storm Prediction Center Norman OK 
0923 PM CDT Mon may 21 2018 

Areas affected...central and southwest Ohio 

Concerning...Severe Thunderstorm Watch 113... 

Valid 220223z - 220400z 

The severe weather threat for Severe Thunderstorm Watch 113 

Summary...severe-weather threat across central Ohio will undergo 
further weakening, while a short-term (through 11 PM edt) severe 
risk remains possible from southwest into south-central Ohio. 

Discussion...thunderstorms will continue through the evening and the 
early overnight across southwest, central, and southern Ohio as a weak 
midlevel trough and height falls spread through the upper Ohio 
Valley and southern Great Lakes region. In addition to ongoing 
storms extending into Wayne and Holmes counties OH, new storms 
developed after the merger of two convective outflow boundaries 
extending from Madison to Brown counties Ohio. Objective analyses 
indicated an increase in surface-based inhibition and an overall 
decrease in available instability which should limit an increase in 
storm intensity into east-central Ohio. 

Objective analyses indicated some increase in surface vorticity from 
southwest into central Ohio (near Brown to Fayette counties) that 
could locally enhance the potential for low-level storm rotation. 
However, this threat too should be short lived, as the 
thermodynamics become unfavorable to sustain new updrafts. 

.Peters.. 05/22/2018 

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


Latitude...Lon 39128419 40018327 40618249 40828181 40788164 40128178 
39578263 39128328 38918380 39128419