WATCH LIKELY TO BE ISSUED
The National Weather Service in Louisville is likely to issue a Severe Thunderstorm Watch soon.... Details below
Probability of Watch Issuance...80 percent
SUMMARY...Severe threat will increase into the early afternoon hours
ahead of progressive cold front. Severe thunderstorm watch will be
issued by 18z to account for this potential.
DISCUSSION...Strong 12hr mid-level height falls will overspread the
OH Valley and mid-south region this afternoon ahead of a progressive
cold front. Large-scale forcing for ascent will be focused across
this region but environmental capping is expected to restrict
appreciable pre-frontal convection, except for the warm advection
corridor across the OH Valley. Latest visible satellite imagery
suggests strongest boundary-layer heating is noted just ahead of the
front from central AR into southwest IL. This is supported in OA
fields where surface-3km lapse rates are now on the order of 6.5
C/km where partial sunshine is observed. Given the strong capping
observed, thunderstorms are expected to initiate along the surging
cold front. Latest radar data supports this scenario with convection
gradually increasing along the wind shift from east-central IL into
southeast MO where lightning is currently observed. Damaging wind
threat will increase with frontal convection as it matures,
potentially encouraging strong environmental winds to mix to the
surface with stronger downdrafts.
-Katie McGraw
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