SPC AC 161253

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0753 AM CDT Sun Jun 16 2019

   Valid 161300Z - 171200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS CENTRAL TX...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OH VALLEY TO LOWER
   MID-ATLANTIC STATES...

   ...SUMMARY...
   Severe storms are most likely across parts of central Texas during
   the late afternoon and evening. A few tornadoes along with damage
   from both wind gusts and hail are possible.

   ...Central TX...
   Primary change is to increase both tornado and wind probabilities,
   yielding an upgrade to Enhanced Slight Risk.

   Gravity waves and convective outflow from a decaying MCS over
   northeast TX have reached roughly a Midland to San Angelo to
   Corsicana line as of 12Z. While some recovery north of this line
   will occur through the day, a strong to extremely unstable air mass
   will develop south of it. Beneath very steep mid-level lapse rates
   (as sampled by 12Z Midland and Del Rio soundings), a plume of MLCAPE
   above 3500 J/kg is expected by peak heating. Late afternoon storms
   should initiate along the dryline bulge near the Concho Valley and
   east-northeast along residual outflow boundaries. A belt of modest
   mid-level westerlies (20-30 kt at 500 mb) will be adequate for a few
   supercells and multicell clusters amid the large buoyancy reservoir.
   All severe hazards will be possible, including destructive hail and
   wind, as storms consolidate into a potentially massive MCS this
   evening with embedded bows and supercells. A severe threat may
   persist tonight southeast towards the Gulf Coast despite increasing
   MLCIN.

   ...Lower Mid-Atlantic States to the OH Valley...
   Primary change is to increase wind probabilities, yielding an
   expansion of Slight Risk west.

   A weak MCS is ongoing across northern KY to southern OH within a
   broad warm conveyor. Remnant MCV will likely cross the central
   Appalachians during the early afternoon, with increase in convective
   intensity possible through peak heating. Some uncertainty does exist
   in the Lower Mid-Atlantic region given that the MCV may outpace
   greater low-level moisture return. With weak mid-level lapse rates,
   this moisture increase will be critical to the degree of
   destabilization.

   Farther west in the OH Valley, adequate separation is anticipated
   between the ongoing MCS and the remnants of an MCS in MO/AR to yield
   much more substantial destabilization relative to the Mid-Atlantic
   region. Here, 2000-3000 J/kg of MLCAPE should become common and will
   support intensifying convection that probably emanates from the
   remnants of the MO/AR activity. A belt of enhanced mid-level
   westerlies beneath weaker upper-level flow should foster several
   multicell clusters with scattered damaging winds as the primary
   hazard. 

   ...Central High Plains...
   No change to previous forecast.

   A deep mixed boundary-layer amid a combination of modest buoyancy
   and shear could foster a few storms capable of marginally severe
   hail and wind for a few hours during the late afternoon and early
   evening.

   ..Grams/Dial.. 06/16/2019

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z