U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 270059 
Storm Prediction Center ac 270058 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0758 PM CDT sun Mar 26 2017 

Valid 270100z - 271200z 

..there is an enhanced risk of severe thunderstorms from 
east-central Oklahoma into north-central Texas... 

..there is a slight risk of severe thunderstorms for parts of north 
and northeast Texas into eastern Oklahoma and western Arkansas and 
southeast Kansas... 

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

Scattered thunderstorms capable of very large hail, damaging winds, 
and perhaps a tornado or two are possible this evening into the 
overnight across eastern Oklahoma and north-central Texas into 
western Arkansas late tonight. 

..OK into Texas and western Arkansas and Ozarks... 
A progressive shortwave trough over Kansas/OK will continue eastward 
tonight into the Ozarks as a moist/unstable warm sector over 
north-central Texas and the eastern half of OK spreads into western Arkansas. 
A relatively narrow low-level moisture plume of upper 50s to around 
60 degrees f dewpoints beneath 7+ degree c/km 700-500 mb lapse rates 
have contributed to moderate buoyancy (1600 j/kg mlcape) as sampled 
by the 27/00z oun raob. Area VAD winds indicate flow veering and 
strengthening with height and will continue to support supercell 
development before additional storm merging and cold pool 
consolidation lead to some upscale growth across the Red River 
valley later this evening. Large to very large hail is possible 
with supercells this evening along with a risk for a tornado for the 
stronger/more persistent low-level mesocyclones. For short-term 
details concerning the severe threat over north-central Texas into 
southeast OK, refer to mesoscale discussion 338. 

The low level jet is forecast to slowly strengthen this evening and veer and 
coincidentally, upscale growth is forecast and the potential for 
severe gusts and wind damage will increase. A gradual weakening in 
storms and storm intensity is expected late this evening into the 
overnight as storms move eastward into western Arkansas and the Ozarks as 
diminishing instability leads to a more isolated severe risk. 

.Smith.. 03/27/2017 


Mesoscale Discussion

acus11 kwns 270015 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 270015 

Mesoscale discussion 0338 
National Weather Service Storm Prediction Center Norman OK 
0715 PM CDT sun Mar 26 2017 

Areas affected...parts of eastern Oklahoma and north 
Central/Northeast Texas 

Concerning...Tornado Watch 86... 

Valid 270015z - 270145z 

The severe weather threat for Tornado Watch 86 continues. 

Summary...severe weather potential is expected to continue 
into/through through the 03-06z time frame, becoming primarily a 
locally strong wind gust threat by late evening. 

Discussion...thunderstorms have increased in number within a narrow 
corridor of modest low-level moisture and cape, near/ahead of the 
dryline, now gradually shifting across/east of the Interstate 35 
corridor. Although boundary layer instability likely will begin to 
diminish shortly with the loss of daytime heating, there should be 
enough lingering instability to maintain vigorous convective 
development, aided by forcing for ascent associated with the upper 
impulse progressing through the south Central Plains. 

It still appears that there could be a period of storm consolidation 
and upscale growth into an organizing convective line, becoming 
oriented roughly along a south to southwesterly 850 mb jet that 
latest rapid refresh suggest could strengthen in excess of 40 kt. 
This may be accompanied by at least some increase in risk for 
potentially damaging wind gusts, which probably will peak in the 
03-06z time frame across parts of north Central/Northeast Texas and 
eastern Oklahoma. 

.Kerr.. 03/27/2017 

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


Latitude...Lon 32209723 33229692 34139688 34979622 35399575 36019519 
36089459 34809471 33309545 32539609 31949711 32209723