157
FXUS61 KILN 241752
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
152 PM EDT Mon Jun 24 2024

.SYNOPSIS...
A brief respite in the heat and humidity today, before warmer
and more humid air quickly builds back into the region on
Tuesday. Chance for storms returns Tuesday and increases
Wednesday ahead of the next cold front. Drier and cooler
conditions will then return for the last part of the workweek
before heat and humidity build back for this weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mid level trof over New England with a ridge over the Plains -
placing the Great Lakes/Ohio Valley in northwest flow. Surface
high pressure to build southeast becoming centered over the area
this afternoon. Drier air continues to be advected into the
region from the north with surface dewpoints dropping to between
55 and 60 by late day. Expect scattered cumulus clouds with the
best coverage across Central Ohio.

High temperatures to top out in the lower and middle 80s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
The tranquil conditions from the near term period will spill
into the beginning of the short term period, although they
won`t last too long, unfortunately. As the aforementioned sfc
high shifts to the E of the OH Vly tonight into Tuesday morning,
abrupt moisture return will begin to nose back into the area
from the W. This will occur as another S/W ejects E through the
Great Lakes region late tonight into Tuesday morning, with a
surge of higher theta-e air nosing in from the W toward daybreak
Tuesday.

The forecast for very late tonight into the daytime Tuesday
becomes incredibly complex, and will be largely dictated by
convective evolution throughout the time period. Confidence
continues to increase in the potential for a decaying MCS to be
diving in from the N/NW right around daybreak Tuesday,
eventually encountering a thermodynamically-unfavorable
environment with E/SE extent during the morning. This MCS will
be forced by the S/W tracking through the Great Lakes region,
eventually pivoting toward the pooling of better LL instby
(across IL/IN) well to the SW of the best forcing/shear. There
will still be quite a bit of LL dry air entrenched across the
local area Tuesday morning, with dewpoints only in the lower 60s
across parts of WC OH and EC IN around sunrise. The better LL
moisture transport, at least initially, will be to the north of
the local area across far nrn IL/IN/OH early Tuesday morning in
areas where the mature MCS will be better organized and perhaps
a bit more intense. However, as we progress through the heart
of the morning hours, the convective complex should track to the
SE, or even straight to the S, across wrn parts of the local
area, weakening and likely dissipating near I-71 as it does so
into early Tuesday afternoon. Of course, the convective debris
blowoff and pooling of rain-cooled air will likely throw a
wrench into the fcst temps on Tuesday, but there may be enough
late-day rebound in the wake of morning convection to
eventually reach into the upper 80s and lower 90s as currently
expected. But this is far from certain.

By later Tuesday afternoon into the evening, stronger theta-e
advection into the area will likely be underway (eroding the
probable cold pool from earlier in the day), suggesting the
rebound in temps/humidity/SB instby may be significant by late
in the day near/W of I-71. At this juncture, it is likely that
additional clusters or complexes of storms may develop,
initially to the W across IL/IN before spreading to the E into
parts of the local area by early evening. Attempting to pinpoint
timing and exact locations at this time would be imprudent.
However, the best potential for storm activity late Tuesday will
be focused near/N of I-71, with drier conditions favored across
NE KY and parts of the lower Scioto Valley. Given the robust
destabilization efforts underway in the W late Tuesday and the
expectation for at least /some/ storms, it is worth mentioning
the potential for locally gusty/damaging winds with any of this
activity given the increasingly-favorable LL/deep-layer
thermodynamic fields and potential for cold-pool driven
complexes.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
The cold front will be working its way into the area at the start of
the extended period, with the parent low moving east out of the
Hudson Bay area. Again, there is still much ambiguity as to when/if
storms will be firing Tuesday afternoon/ what the evening/overnight
environment will be like as this frontal boundary moves through.

All guidance still hints at some type of MCS feature bowing through
*somewhere* in the Mid-Atlantic region at *some time* Tuesday into
Wednesday (rather specific, we know). Persistent lack of consistency
not only between models but between runs has made for a particularly
challenging forecast. Should this MCS feature occur, it will likely
be driven by its local cold pool and primary threats will be strong
to damaging wind gusts/localized heavy rainfall.

By Wednesday, the cold front will finally be moving into the CWA and
there is the possibility of redevelopment of storms given this
additional synoptic forcing. The strongest shear will be nearer to
the Lakes and there is some question as the degree of atmospheric
recovery after any overnight convection. However, should instability
build back in, would anticipate a return of thunderstorm activity
with strong to damaging winds the primary threat. Finally, want to
note that PWATs are still coming in around 2 standard deviations
above normal for this entire time period, indicating that any storms
will likely have efficient rainfall rates and any training will
result in localized flooding or runoff.

Post frontal air on Thursday indicates high temperatures in the low
80s (possibly even upper 70s in our north) with dew points in the
upper 60s. Weak ridging and surface high pressure take over and
we`ll have mostly sunny skies with some CAA cu. Overnight lows in
the upper 50s as we head into Friday.

Friday we see yet another disturbance on the horizon and return
southerly flow helps pump warm, moist air back into the region. Mid
and upper level clouds increase and highs reach back into the upper
80s. Precip from this system looks to move into the region sometime
Friday into Saturday as the warm associated with this disturbance
lifts through the area. This keeps temperatures on the warmer side,
with highs in the upper 80s/ low 90s for Friday and Saturday.
Sunday, we dry out again and temperatures cool slightly in the post
cold-frontal air.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Drier and tranquil weather conditions are expected to continue
today as high pressure becomes centered over the Ohio Valley.
Scattered diurnally driven cumulus clouds have develop between
4000 and 5000 feet. These clouds will dissipate with the loss of
heating early this evening leaving mainly clear sky conditions.

A weakening/decaying thunderstorm complex to our northwest will
allow some debris clouds to spill in late tonight into Tuesday
morning. Additional thunderstorm development is likely Tuesday
with the best chance/threat north of the TAF sites thru 18Z.
The thunderstorm threat shifts south and will likely impact the
TAF sites Tuesday night. Will mention this threat in the
outlook period.

Expect generally VFR conditions to continue overnight into
Tuesday. Can not rule out a brief period of MVFR vsby
restriction at KLUK valley location but with drier air over the
area have elected to omit the mention in the forecast.

North-northwest winds around 8 kts this afternoon become light
and variable this evening and then southerly early Tuesday -
increasing to 10-15kts with gusts of 20-25 kts Tuesday
afternoon.


OUTLOOK...Thunderstorms possible Tuesday night and Wednesday.

&&

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

&&

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