438
FXUS61 KILN 160710
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
310 AM EDT Thu May 16 2024

.SYNOPSIS...
Mainly dry conditions are expected through today before periods
of showers and storms return again tonight through at least
Friday night. The potential for a few showers and storms may
linger into the day Saturday and potentially even Sunday, with
drier conditions briefly returning into early next week. Near
to above normal temperatures are expected for the foreseeable
future.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The few patches of clouds that had been lingering about through
late evening have essentially dissipated, leaving mainly clear
skies throughout the local area early this morning. The lone
exception to this is in parts of NE KY and the lower Scioto
Valley where some low stratus/FG are already beginning to take
shape.

The fog potential is going to be the main item of interest
through daybreak, with the antecedent ground moisture and clear
skies and light winds. There is the expectation for patchy fog
to develop across at least the srn/ern half of the ILN FA, with
indications for areas of fog in NE KY and south-central OH,
some of which could be locally dense. This being said, do think
that the most widespread VSBY reductions should focus in the
lower Scioto Valley and NE KY and in other sheltered locales
(such as river valleys) within the area. Could see the potential
need for at least and SPS, and maybe even a DFA, should
trends/obs dictate. But for now, will mention here for awareness
purposes.

Temps will dip into the mid/upper 50s... very close to sfc
DPs...by daybreak before rebounding nicely through the day
into the upper 70s to around 80 degrees. Some Cu development is
expected by this afternoon amidst a few cirrus, but clouds
should increase more substantially from the west toward sunset
and beyond as several clusters of weakening SHRA/TSRA approach
from IN. Mostly cloudy conditions will evolve near/W of I-75
into early evening.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
A S/W embedded within the midlevel zonal flow draped across the
OH Vly will serve as a focus for a few SHRA/TSRA to move into
the ILN FA around/after sunset this evening. This being said,
the environment should be slightly less favorable for
maintenance of storm activity with eastward extent, so would
expect that any clusters that make it into the local area this
evening should be on a weakening trend and pose little to no
severe threat. But, a few rumbles can`t be ruled out from time
to time, with a gradual /increase/ in coverage of SHRA expected
past midnight as the S/W progresses E and a subtle LLJ impinges
to the NE into the ILN FA, providing a bit of speed/convergence
and lift amidst a saturating LL profile.

The activity tonight should be largely non-impactful, with
questions even on whether it will contain any lightning/TS.
Additionally, although the steering-layer flow is still somewhat
weak, the activity should be moving and is not likely to be
stationary, meaning that the potential for prolonged heavy rain
in one location is also rather low through Friday morning. But
conditions should be increasingly wet/soggy toward daybreak
Friday as temps dip into the lower 60s area-wide.

Periods of SHRA/TSRA should continue about the area during the
day Friday, with the best instby focusing around any larger area
of SHRA activity (where instby should be more convectively-
contaminated/limited). So we will probably end up with a larger
area of steady SHRA (likely near/S of the OH Rvr) surrounded
(especially on the nrn periphery in the local area) by a
slightly better instby profile and ISO/SCT cellular/disorganized
TSRA activity. The steering-layer flow will become increasingly
weaker late into the day/evening and beyond, suggesting that
storm motions should slow and could become a bit more erratic by
late day, especially along a weakly-convergent axis stretching
across nrn parts of the area. This could lead to some very
isolated localized heavy rain/flooding, but confidence on a
favored location at this juncture is very low.

Highs on Friday will be tempered quite substantially by
prevalence of clouds/pcpn, with temps only reaching into the
lower/mid 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
On Friday evening, the Ohio Valley will be just upstream of a broad
mid-level trough, which will extend from Illinois through the
southern plains. As this trough slowly moves east, displacing
ridging over the east coast, a continued feed of moisture will bring
showers and storms into the region. With the forcing and moisture
transport involved, it does appear that some nocturnal convection
may occur on Friday night, with additional diurnal development on
Saturday afternoon. Still seeing some timing differences in how
quickly this slow-moving trough makes it out of the area, but this
forecast will have to keep some PoPs in on Sunday, especially in the
eastern and southeastern sections of the CWA.

In terms of hazards through this part of the forecast period, narrow
CAPE profiles and a lack of shear will preclude a threat for severe
weather. However, the moist profile and slow motions could lead to a
threat for some flooding, especially on Saturday.

A narrow ridge will move into the area late Sunday into Monday,
providing a brief period of dry weather. However, this respite will
not last long, as the flow pattern over the region will turn to
something a bit more progressive. As it looks now, some
precipitation chances may return on Tuesday, with no significant
forcing but a gradual increase in instability. By the middle of the
week -- although timing is far from certain at this distance in the
forecast cycle -- a stronger trough and a cold front will likely
move into the region. Whenever this occurs, it may provide the next
chance for strong storms.

A gradual warming trend is expected from Saturday through the middle
of next week, as the upper trough moves away, and warmer air moves
into the region behind it. Highs are likely to reach the 80s by
Sunday for most of the ILN CWA, and for the whole area by Tuesday
and Wednesday.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Patches of FEW/SCT VFR cloud cover continue to linger about the
area, but there is a slow dissipating trend and skies should
trend clearer toward/beyond 09z. This will set the stage for the
development/expansion of some BR/FG, which has already
developed in a few spots where skies have trended clear. Expect
that widespread MVFR/IFR VSBYs should develop past 09z, with the
potential for some localized LIFR VSBYs, especially in the
lower Scioto Valley and NE KY. Still some uncertainty regarding
whether the VSBYs will dip to LIFR at any of the local sites,
but would expect that the prone terminals of KILN/KLUK have the
most favorable setup for IFR/LIFR VSBYs through sunrise.

Any BR/FG should dissipate toward/beyond 13z, with FEW/SCT IFR
clouds possible as the LL moisture gradually mixes out through
15z. VFR Cu should sprout once again toward/beyond 18z, but the
daytime should remain dry. Weakening ISO/SCT SHRA/TSRA will
approach from the W after 00z, with the most widespread
SHRA/TSRA activity likely to hold off until around daybreak
Friday.

Light northerly winds will go more light/VRB early afternoon
before going out of the SW at around 5kts or less toward/beyond
00z.

OUTLOOK...MVFR CIGs/VSBYs are possible with showers and possible
thunderstorms on Friday.

&&

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

&&

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