Lancaster, Ohio 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

978
FXUS61 KILN 291405
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
1005 AM EDT Sun Jun 29 2025

.SYNOPSIS...
Warm and humid conditions will continue today and Monday, with
chances for showers and thunderstorms continuing. A cold front will
move through the area early Tuesday, with drier conditions expected
through the middle of the week. Warmer temperatures are then expected
again going into next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Ongoing fcst remains on track regarding expectation for scattered to
numerous slow-moving SHRA/TSRA to again develop this
afternoon/evening. This is likely going to be focused near/S of I-70
where the best instby will reside. In the meantime, a stratus layer
in these areas will slowly lift/scatter out, with diurnally-driven
convection expected to sprout by noon.

PREVIOUS DISCUSSION...
The overall weather pattern today will remain very similar to the
past several days. The ILN CWA remains on the northern periphery of
ridging over the southeastern states, with weak westerly flow aloft,
and weak theta-e advection through the boundary layer. The atmosphere
is likely to be uncapped, with around 2000 J/kg of SBCAPE, and lapse
rates through the mid-levels that are not overly impressive, but
sufficient for robust deep convection. Storms will be most likely
during peak diurnal timing, as has been the case for the past few
days. Storm chances will also be maximized near and especially south
of the aforementioned boundary -- roughly putting the southern half
of the ILN forecast area in the higher chances for storms today.

The main threats for today will once again be damaging winds and
heavy rainfall. As has been the case, these threats should remain
isolated. For the damaging wind threat, favorable DCAPE values with
steep low-level lapse rates will support a threat of isolated
downbursts. For the heavy rain threat, precipitable water values of
1.8 to 2.0 inches will combine with weak steering flow to allow for
heavy rain -- with some storms backbuilding or not moving much.
Overall, storm organization should be rather poor, with little in the
way of shear -- only about 15 knots of deep-layer bulk shear.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Storms should diminish at the end of the diurnal cycle Sunday
evening, leading to mostly dry conditions to start the overnight
hours. However, as the overnight hours progress, height falls will be
ongoing -- and a weak shortwave in the 500mb flow may spark some
scattered convection in the 09Z-12Z time frame in the western ILN
CWA. It isn`t clear if this will hold together through the forecast
area during the morning, though storm chances will begin to increase
as the day progresses anyway.

The overall setup on Monday is similar to Sunday from a thermodynamic
perspective -- the soundings look quite similar, with precipitable
water values approaching 2 inches, and uncapped SBCAPE approaching
2000 J/kg. The difference in the convective potential on Monday is
two-fold. For one, there will be a more well-defined source of
forcing, as a shortwave moves east through Illinois and Indiana and
provides a source of large-scale ascent. For two, the deep-layer wind
flow will be a bit stronger, with 25-30 knots of 0-6km bulk shear.
While not a particularly high value, it will be enough to support
some storm organization, and perhaps a little bit of a greater chance
for damaging winds. Heavy rain will remain a concern as well. So,
while the threats expected from storms on Monday are generally
similar to the past few days, the overall coverage of storms will be
greater -- with a little higher probability of storms becoming
severe.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Thunderstorms will be ongoing at the start of the long term with a
disturbance moving through the region. Already have severe wording in
for this system in the HWO and will continue severe mention as this
system moves through. Damaging winds will be the primary threat.
Cannot rule out isolated flooding concerns as well with heavy
downpours.

Late Monday night into Tuesday a cold front will work through the
region and precipitation chances will taper off through the day from
northwest to southeast. Temperatures will be noticeably cooler with
the passage of the front Tuesday night with lows in the low to middle
60s. Dry conditions are expected Tuesday evening through Wednesday
night. Expect some CAA cu on Wednesday.

A weak disturbance will bring a slight chance of precipitation to
the region for Thursday. Friday and Saturday will have the potential
for some isolated pop up thunderstorms primarily in the afternoon to
early evening hours along with high temperatures in the 80s and 90s.

Heading into Sunday expect a little better coverage of thunderstorms
as the heat and humidity continue to increase and the next system
begins to approach the region.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
Dry conditions are expected this morning, but stratus will continue
at most of the TAF sites, with IFR to LIFR conditions expected. MVFR
to occasionally IFR visibilities are also occurring. These should
improve after 14Z.

VFR conditions are expected after 14Z. Once again, showers and
thunderstorms will be possible during the afternoon and early
evening, as indicated by a PROB30 group at each TAF site. After that,
generally VFR conditions are expected going into the overnight,
though some MVFR fog may develop.

OUTLOOK...Thunderstorms are possible again on Monday, mainly in the
afternoon and evening.

&&

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

&&

$$

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