921
FXUS61 KILN 122335
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
735 PM EDT Mon Aug 12 2024

.SYNOPSIS...
A weak upper level disturbance will cross the area overnight.
Otherwise, high pressure will persist through Wednesday night. A
storm system will move through the Great Lakes late in the week
bringing a chance of showers and thunderstorms.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Short wave over Illinois late this afternoon will track east
southeast across the region tonight. This will bring a rather
extensive cloud deck with it. In addition, some light echoes
will pass across southern counties. While dry air will remain in
place in the low levels, likely keeping most precipitation very
light (sprinkles), it is not out of the question that a few
locations near and south of the Ohio River could get a bit of
measurable rainfall. Lows will generally be in the lower 60s.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Clouds will decrease on Tuesday as a short wave moves further
away from the area. Surface high will remain in place leading to
quiescent conditions. Highs will be in the lower 80s and lows in
the upper 50s to lower 60s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Surface high pressure across the Great Lakes provides light
northeasterly flow to start the long term period with temperatures
near normal for mid-August. Dry air throughout the atmosphere keeps
rainfall out of the forecast. Much of the same is expected on
Thursday morning, but the high pressure will have shifted to the
east. This results in light southeasterly winds and temperatures a
few degrees warmer, especially across the Ohio and Scioto River
regions. With the upper-level ridge axis entering the area Thursday
afternoon, deeper moisture introduces more expansive cloud cover and
the potential for rain into eastern Indiana and west-central Ohio.
Warm-air advection continue through the overnight into Friday,
increasing the potential for rain and a few rumbles of thunder area
wide.

The ridge axis moving through the region on Thursday night is quite
narrow and therefore short lived as the next trough digs into the
Midwest. A low pressure entering the Great Lakes Friday morning
places the local area within the warm sector, increasing the
potential of additional rainfall and thunderstorms. Mid-level lapse
rates are as to be expected for mid-August, quite poor, likely
limiting the overall severe threat during the afternoon. If
sufficient heating occurs, can`t rule out a few wet microbursts
during the afternoon/evening as the cold front moves through.

The low pressure moves through the Great Lakes quite slowly during
the weekend as the upper level flow becomes more amplified across
the CONUS. Ensemble suites still differ on how significant the
amplification is and with how quickly the trough propagates through,
causing lower confidence for the weekend forecast. GFS/ens are more
amplified and slower to bring ridging back into the region,
providing a longer duration to cooler than normal conditions into
middle of next week. ECMWF/ens are faster and farther north. All of
this means that the specifics for the weekend forecast are subject
to change depending on model trends over the coming days.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR will continue through this forecast as low level moisture is
scant through the period. While ceilings remain well above 3000
ft and visibility 10SM, light rain to the west should dissipate
tonight before reaching TAF sites. Winds staying light will be
mainly from the north.

OUTLOOK...Thunderstorms are possible Friday.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...McGinnis
AVIATION...Coniglio