-- Discussion containing changed information from previous version are highlighted. --
799
FXUS61 KILN 181806
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
206 PM EDT Sat May 18 2024

.SYNOPSIS...
Seasonably warm conditions are on tap today. Cannot completely
rule out a stray shower or thunderstorm late afternoon through
early evening, but most spots should remain dry. Much above
normal temperatures and mainly dry conditions are expected for
Sunday and Monday, with a chance of showers and storms returning
as early as Tuesday. The next widespread chance for showers and
storms is likely to evolve midweek, with slightly cooler
conditions for the second half of the workweek.

&&

.NEAR TERM /THROUGH SUNDAY/...
Southern stream mid level trof/low to pass thru the TN Valley
today with a narrow ridge building into the region overnight.
Dense fog continues to improve and lift into a stratus deck
this morning. This improving trend to continue with stratus
scattering out by afternoon and developing into a cu field.

A warm day is on tap with highs in the upper 70s to around 80.
A lack of forcing today but with ML instability approaching 1000
J/KG and mid level trof moving thru can not rule out a few
spotty showers or thunderstorms - mainly southeast of I-71. Any
convection that does develop will be short lived with rather
weak wind flow.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
Tranquil conditions are expected this evening/tonight once any
diurnally-driven spotty SHRA/TSRA activity wanes by about 02z.
Lows tonight dip into the upper 50s and lower 60s once again
amidst weak northerly sfc flow. Could see some fog develop in
area-river valleys and sheltered locales tonight, but the setup
for widespread fog development tonight appears to be less
favorable than is the case this morning.

Temps rebound nicely again on Sunday, topping out in the mid
80s with plentiful sunshine (and a few afternoon Cu) on tap.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
On Sunday evening, a narrow ridge of high pressure will extend from
the western Gulf Coast through the Ohio Valley, with an axis on a
southwest-to-northeast orientation. A surface high over the Great
Lakes will be moving off to the east, as the upper pattern shifts
into something a bit more progressive by Monday. Broader ridging
over the far southeastern CONUS will persist through the middle of
the week, but a more active WSW flow pattern will develop on the
periphery of the ridge, extending from the central plains through
the Ohio Valley.

Monday appears likely to be dry, with any forcing still upstream of
the area. By Tuesday, instability will be building into the region
from west to east, with deep-layer SSW flow and dewpoints getting
well into the 60s. However, forcing will still be mainly upstream of
the area, so convection will be limited -- though more likely to
occur in the northern and northwestern sections of the CWA, closer
to the forcing and further away from the stronger cap to the
southeast.

The most active stretch of the extended forecast will be some time
Tuesday night through Wednesday night. There is model agreement on a
compact upper low moving into the Lake Superior area, with an
associated cold front moving across the upper midwest and eventually
into the Ohio Valley. The timing forecast for the shortwave and the
surface front remain far from certain at this distance in the
forecast cycle. One notable change to recent model runs is further
displacement of the surface low from the Ohio Valley, which is
leading to a more southwest-to-northeast oriented frontal boundary.
This may not be as favorable from a forcing perspective, and winds
ahead of the front also appear rather veered (southwesterly) which
would limit directional shear if that were to verify. Nonetheless,
it is fair to say that instability and deep shear could support a
severe threat at some point in this time frame. A drier and cooler
air mass will follow the front to end the week, with very low
confidence on when the next progressive shortwave may move into the
area after Friday.

Monday and Tuesday will be the warmest days of the extended, with
highs possibly reaching the upper 80s on Tuesday. As convection and
a cold front move into the area, slightly cooler conditions are
expected for Wednesday and beyond.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
Fog has lifted to a VFR cumulus deck. A few showers or perhaps a
thunderstorm will be possible this afternoon. The best
threat/coverage looks to occur across central Ohio - where low
end moderate instability exists along with weak low level
convergence. Due to the limited coverage have not mentioned pcpn
in the TAFs at this time.

Any pcpn and clouds will decrease quickly early this evening.
Light east to northeast winds will become variable/calm
overnight. Mostly clear skies and light winds will lead to
some patchy fog development overnight. Have MVFR vsby
restrictions at KCVG, KDAY, KLUK with IFR conditions at KILN and
KLUK.

Ridging over the area Sunday with fog improving quickly after
sunrise. Once fog improves VFR conditions are expected thru the
remainder of the TAF forecast period.

OUTLOOK...MVFR CIGs, along with thunderstorms, will be possible
Wednesday into Wednesday night.
-- End Changed Discussion --

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...KC
NEAR TERM...AR
SHORT TERM...KC
LONG TERM...Hatzos
AVIATION...AR