Day 1 Outlook Day 2 Outlook Day 3 Outlook Days 4-8 Outlook

Day 1 Outlook Convective Tornado
Hail Wind
Categorical Day1 1630Z Outlook
Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

ACUS01 KWNS 141628
SPC AC 141627

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1127 AM CDT Tue Aug 14 2018

Valid 141630Z - 151200Z


A few severe thunderstorms are possible this afternoon into evening
over parts of the north-central Rockies/High Plains region.  Other
strong storms may occur over eastern North Carolina, portions of
Oklahoma and southern Kansas, and southern Arizona.

Morning water vapor loop shows a deepening upper trough over western
MT/WY.  This feature will track eastward across WY today, providing
large scale forcing for ascent and scattered thunderstorm
development.  Southeasterly low level winds east of the Big Horns
will maintain ample moisture, with afternoon heating yielding steep
low level lapse rates and MLCAPE values of 1000-1500 J/kg.  Given
the favorable vertical shear profiles, steep mid-level lapse rates,
and consensus of 12z guidance that several storms will form, have
upgraded portions of this region to SLGT risk for large hail. 
Activity may persist well into the evening, spreading eastward into
parts of western SD/NEB before diminishing.

Several vort maxima continue to rotate around an upper low over
western KS.  Broken cloud cover will help to destabilize a corridor
over much of OK and southeast KS today, leading to moderate CAPE
values and scattered thunderstorm development.  Deep layer shear is
marginal.  However, strengthening low level flow this
afternoon/evening and ambient vorticity beneath cyclonic flow field
may be sufficient for a few rotating cells capable of damaging wind
gusts, an isolated tornado or two, and perhaps hail.

Full sunshine and dewpoints in the 70s are leading to MLCAPE values
of 1500+ J/kg over eastern NC today, beneath moderately strong
westerly flow aloft.  Scattered thunderstorms will continue to
develop in this region and spread eastward toward the coast.  Steep
low-level lapse rates and sufficient CAPE will lead to a few
multicell clusters capable of gusty/damaging wind gusts.  Refer to
recent MCD #1285 for further details.

12z guidance is becoming more consistent in the likely development
of clusters of thunderstorms forming in southeast AZ later this
afternoon and spreading eastward across southern AZ overnight. 
Ample low level moisture and CAPE, coupled of steep low level lapse
rates, will promote strong outflow winds in the stronger cells.

..Hart/Squitieri.. 08/14/2018