994
FXUS61 KILN 131941
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
341 PM EDT Tue Aug 13 2024

.SYNOPSIS...
Surface high pressure will offer mostly clear skies and light
winds tonight. This high will continue to bring fair conditions
through mid-week. The next chance of precipitation will arrive
late Thursday into Friday as a mid-level trough approaches the
Ohio Valley.


&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Surface high pressure will slowly shift across the Great Lakes
tonight. Disorganized diurnal cumulus clouds will give way to
clearing skies with light winds. Can`t rule out some patchy fog
over river valleys. Temperatures will drop into the upper 50s
to low 60s by dawn.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Light northwest flow across the downstream side of mid-level
ridging will continue to provide fair conditions Wednesday into
Wednesday night. Sunshine, dry soil conditions, and a slow
increase in mid-level heights will cause high temperatures to
lift into the middle to upper 80s in the afternoon.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
A subtle midlevel ridge axis will traverse the OH Vly into Thursday
morning, with broad W/SW flow becoming established into the daytime
as a trof digs into the upper Midwest. Ahead of the main trof axis,
S/W energy will progress to the E through the aforementioned W/SW
flow aloft, with an increase in forcing locally into the
nighttime/early Friday morning.

Moisture/theta-e advection will be on the increase Thursday
afternoon with higher PWATs surging to the NE into the evening.
This, combined with the increase in broad-scale forcing arriving
Thursday night, will promote widespread shower/storm activity across
at least a part of the region. The specifics of this still remain a
bit uncertain, but given the ingredients and the pattern, would
expect for one or more large/expansive clusters of storms to develop
initially off to the W/NW of the ILN FA before drifting to the SE/S
(potentially overspreading a larger (SW) portion of the local area)
during the heart of the overnight period. It is during this stretch
that the highest PoPs are likely to be focused as the broad-scale
trof axis may already be moving E through the region into Friday
afternoon.

The fcst for the day Friday will be largely dependent on what
happens Thursday night into early Friday morning, specifically as it
relates to a rebound in instby/severe potential. Given the still-
amply saturated environment and the trof axis moving through the
region, would still expect /some/ shower and storm activity to
persist through Friday evening as the trof amplifies and digs a bit
more into the region. While the prospects of severe storms remain a
bit uncertain at this juncture from Thursday night through Friday
evening, confidence is much higher in the potential for widespread
shower/storm activity. And despite the recent dry stretch, with
PWATs pushing 150+ % of normals, any training or persistent activity
will have the potential for bring locally heavy rainfall. This being
said, there is not much confidence on /where/ this would occur at
this point, so will maintain prob low in the HWO for now.

As we progress into the weekend, precip chances should wane with
time, but perhaps not go completely nil until we get to early next
week. This is due to the digging of the mid/upper level low in the
NE CONUS/ern Great Lakes and the establishment of broad NW flow
setting up from upper Midwest into the OH Vly with several
disturbances diving through this midlevel flow into the region
through Sunday. In fact, the negative mid/upper level height anomaly
settling in Friday night through Saturday night suggests that SHRA
activity may still be somewhat widespread into the day Saturday,
especially before the primary trof axis pivots through into early
Sunday. So despite the slightly cooler (and drier) air filtering
into the area for this weekend, there may be ISO/SCT SHRA around
from time-to-time. Temps will be held near to slightly below normal
this weekend into early next week.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected through the TAF period. Diurnal
cumulus is expected this afternoon, with a maximum near the
Columbus terminals as a weak disturbance shifts through the
Great Lakes. Can`t rule out a stray shower, but have left this
out of the TAFs due to very low forecast coverage.

Light winds from the north will become calm overnight before
becoming light north/easterly on Wednesday.

OUTLOOK...Thunderstorms are possible Friday.

&&

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

&&

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