[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 311720
SWOMCD
SPC MCD 311719
KYZ000-OHZ000-INZ000-TNZ000-ILZ000-311915-

Mesoscale Discussion 1766
NWS Storm Prediction Center Norman OK
1219 PM CDT Wed Jul 31 2024

Areas affected...Southeast Illinois into southern Indiana and
central Kentucky

Concerning...Severe potential...Watch possible

Valid 311719Z - 311915Z

Probability of Watch Issuance...60 percent

SUMMARY...Re-intensification of a weak MCS appears to be underway
across southeast Illinois and southern Indiana. The threat for
severe winds may increase over the next few hours downstream into
Kentucky. A watch may be needed this afternoon.

DISCUSSION...Over the past 30-45 minutes, GOES one-minute imagery
shows gradual but persistent convective development along the
leading edge of an outflow boundary associated with a weak MCS
across southern IN. Additionally, steadily intensifying convection
is noted across southeast IL. Temperatures ahead of the southeast IL
convection (and immediately behind the primary outflow boundary)
remain in the low 80s, which should still support buoyant parcels
rooted near the surface per modified RAP forecast soundings. This
also implies that the deeper cold pool remains further northwest
across southeast IL where temperatures are in the mid-70s. These
trends suggest that gradual re-intensification of the MCS may be
underway.

West/southwesterly flow across the lower OH River Valley is
advecting a plume of higher theta-e air (characterized by
temperatures in the upper 80s with mid-70s dewpoints)
east/northeastward immediately downstream of the MCS. The
west/southwesterly low-level winds, coupled with steady 25-30 knot
northwesterly flow aloft, are supporting effective bulk shear values
on the order of 25-30 knots. Given an improving thermodynamic
environment and adequate wind shear, the recent intensification
trend should continue with an attendant increase in severe wind
potential (with an isolated large hail threat with more discrete
leading cells) over the next several hours as the MCS continues to
move generally southeast. It is unclear how far southeast this
threat will persist given a residual cold pool from prior convection
across eastern KY and northeast TN, but watch issuance may be
necessary as the MCS continues to re-intensify.

..Moore/Gleason.. 07/31/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...JKL...ILN...LMK...OHX...IND...PAH...ILX...

LAT...LON   39848727 39208495 38928451 38368442 37818445 37288470
            36918489 36698514 36568549 36628585 37918773 38298815
            38518835 38698843 38978845 39208841 39408830 39678803
            39798772 39848727
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