U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 190051 
Storm Prediction Center ac 190050 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0750 PM CDT Sat Aug 18 2018 

Valid 190100z - 191200z 

..there is a slight risk of severe thunderstorms this evening 
across parts of northeastern New Mexico...the Texas and Oklahoma 
panhandles and adjacent southwestern Kansas... 

Thunderstorms may continue to be accompanied by a risk for severe 
wind and hail across parts of the plains this evening. 

..01z outlook update... 
East of the High Plains, thunderstorm activity appears generally in 
the process of weakening in the presence of waning instability. 
Similar trends are expected with ongoing thunderstorm activity in 
the vicinity of the northern rockies, and near the Mogollon Rim of 
Arizona into the mountains of New Mexico by around 03-04z. 

Across the south Central High plains, moderate boundary layer Cape 
May maintain convection now spreading southeast of the Raton Mesa 
area, and activity near the Kansas/Colorado border area, through 
this evening. It still appears possible that forcing for ascent 
associated with lower/mid tropospheric warm advection could support 
further convective development and upscale growth southeastward 
across the Texas/Oklahoma Panhandle vicinity and adjacent portions 
of New Mexico, southwestern Kansas and western Oklahoma. Aided by 
southerly nocturnal low-level jet strengthening up to 30-35 kts, 
this could be accompanied a risk for at least localized severe wind 
gusts and perhaps some hail into the overnight hours. 

Near the surface trough across the central Dakotas into southern 
Nebraska, scattered vigorous thunderstorm development is ongoing, 
aided by a seasonably warm and fairly deeply mixed boundary layer 
(temps still near 90, dew points in the lower/mid 60s) characterized 
by moderately large cape on the order of 2000+ j/kg. This 
environment may remain conducive to the risk for locally strong to 
severe convective gusts into the 03-04z time frame. 

.Kerr.. 08/19/2018 


Mesoscale Discussion

acus11 kwns 182334 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 182334 

Mesoscale discussion 1321 
National Weather Service Storm Prediction Center Norman OK 
0634 PM CDT Sat Aug 18 2018 

Areas affected...the southern High Plains 

Concerning...severe potential...watch possible 

Valid 182334z - 190130z 

Probability of watch issuance...60 percent 

Summary...storms are expected to continue developing southeastward 
toward the OK/Texas Panhandle region, with an overall increase in 
coverage through evening. A few storms may produce severe wind or 

Discussion...scattered storms currently exist from western Kansas into 
northeast nm, ahead of a weak cold front and shortwave trough aloft. 
The area is characterized by a moderately unstable air mass with 
modest lapse rates aloft, and weakly veering winds with height. 
Storm Mode has been mixed through early evening, but a more linear 
structure has formed over northeast nm, which will be entering into 
the western panhandles shortly. Other slow-moving cells persist over 
western KS, with isolated severe hail cores noted on radar. 

As the shortwave trough continues to shift southeast, lift will be 
maintained over the region. Visible satellite imagery shows a 
substantial cumulus field over the Texas/OK panhandles, indicative of little 
if any inhibition and likely supportive of continued storm 
formation/sustenance. As such, a watch will be considered. 

.Jewell/Thompson.. 08/18/2018 

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


Latitude...Lon 35850475 36790370 37670274 38360237 38660204 38490155 
38150100 37650046 37220028 36270003 35470029 34990085 
34640185 34410275 34740363 35080434 35300463 35850475