125
FXUS63 KPAH 070711
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
211 AM CDT Tue May 7 2024

.KEY MESSAGES...

- Several rounds of showers and thunderstorms are expected
  through Wednesday night. Strong to severe storms are possible
  early this morning and may fire up again later in the day and
  evening.

- A more significant and widespread severe thunderstorm
  outbreak is expected Wednesday-Wednesday night.

- After the big storm system`s passage, a markedly cooler and
  drier air mass will spread over the region, returning more
  Spring-like temperatures with highs generally in the 70s and
  refreshingly lower humidity for the week`s end.

&&

.DISCUSSION...
Issued at 200 AM CDT Tue May 7 2024

Isentropic upglide shower initiation in our northeast is ongoing
at this writing, while a strong-severe convective line
approaches from the west. Models all drive this line toward us
thru the morning, generally waning in intensity with time, but
as we evolve with an uptick in lapse rates and bulk shear,
particularly in our western counties, there may be enough to
continue fueling for a strong-severe threat over western ptns
of the FA past daybreak.

Afterwards, there could be a general lull in activity until
diurnal destabilization fires additional convective growth this
afternoon. The models all suggest the prime axis of this
development will be across the Ohio Valley, along/ahead of the
approaching cold front, with increasing pops across our north
and east. As a result, the day1 outlook now dips the ENH risk
into a few of our southwest IN/northwest KY counties for the
all hazards afternoon/evening severe risk. The nearing presence
of the upper jet max increases bulk shear and 700-500 mb lapse
rates best in this region to heighten severe concerns.

After the aforementioned wave plays out, the later Tuesday night
lull period is still expected, as the atmosphere continues
explosive growth to 40-50+ kts bulk shear as lapse rates balloon
to 8C by Wednesday afternoon/evening. All model data indicates a
widespread all hazards severe event that could last into the
better part of the night. Caution, warm sector convective
initiation could begin the severe threat over portions of the
region as early as mid-late Wednesday morning, as we warm sector
again; but the more widespread/significant severe expectation
remains for the broader system approach/passage Wednesday
afternoon/evening into Wednesday night.

In addition to the anticipated all hazards severe, a threat of
localized flooding Tue-Wed exists over the course of time with
multiple rounds of heavy rainfall possible. And non thunderstorm
gradient winds are still forecast with upwards to 30-35 mph gust
potential, generally in the afternoons.

The parent long wave trof driving this entire system rotates
across the FA thereafter, transitioning our almost summer-like
warmth/humidity to a significantly cooler/drier air mass by
week`s end. We`ll see highs in the 80s drop thru the 70s (some
upper 60s still possible north) while dew points plummet from
values near 70 at their peak, thru the 50s to the 40s by
Friday into the weekend. While this period will be drier, we
won`t necessarily be devoid of pops while the long wave trof
maintains its heart over the Ohio Valley, with mainly daytime
destabilization showers retained in some form/fashion until its
passage. Note, the 6-10 day outlook continues with a projection
of below normal temperatures as well.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 200 AM CDT Tue May 7 2024

VFR CIGS will lower to/thru MVFR as the convective line
approaches this morning. Accompanying threat of TSRA will drop
VSBYS into restricted categories as well. A mid morning-early
afternoon lull in the by then waning activity will offer the
next chance for improvement to VFR, which may be temporary as
diurnal destabiliation heightens storm chances again this
afternoon. Further deterioration in CIGS/VSBYS to restricted
categories are forecast then. In additiona, increasingly gusty
south winds outside of thunderstorms will see peak gusts
approach 30 kts this afternoon.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$