MD 0589 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF UPPER OHIO VALLEY
Mesoscale Discussion 0589
NWS Storm Prediction Center Norman OK
0159 PM CDT Fri Apr 21 2023
Areas affected...Portions of upper Ohio Valley
Concerning...Severe potential...Watch unlikely
Valid 211859Z - 212000Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated to widely scattered convection is possible this
afternoon. Damaging winds and small hail are the main risks. The
need for a watch is not certain and will depend on convective
evolution over the next 1-2 hours.
DISCUSSION...Temperatures within the upper Ohio Valley region have
risen to around 80 F this afternoon away from mid/high-level cloud
influence. Despite boundary-layer mixing, modest moisture advection
has helped to keep (and in some cases raise) dewpoints in the upper
40s F to low 50s F along the fringe of the mid/upper cloud deck.
Convection in northern Kentucky into southern Ohio has gradually
deepened on visible satellite over the last hour or so. The
expectation is for this trend to continue. MLCAPE will likely be a
modest 100-300 J/kg. Effective shear of 30-35 kts and straight
hodographs should favor clusters/linear segments capable of
primarily damaging winds (local VAD data shows 35-45 kts in the
lowest 2 km). Temperatures aloft are cold enough to support small
hail in stronger storms, At present, convection moving out of
northern Kentucky would be the most likely to organize as it moves
northeast. Additional activity could try and develop along the
differential heating zone, but this is more uncertain.
..Wendt/Hart.. 04/21/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...
LAT...LON 37888418 38888417 40288264 40958166 41288116 41328059
41168043 39738116 38538242 37918326 37778370 37888418
