259
FXUS61 KCLE 290602
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
202 AM EDT Tue Sep 29 2026

.WHAT HAS CHANGED...
Increased fog potential in north central and NE Ohio and NW PA
early this morning, especially inland from Lake Erie.

&&

.KEY MESSAGES...
1) Mainly dry conditions with slowly warming temperatures
expected through Thursday.

2) Widespread showers expected Thursday night into Friday with
the passage of a cold front.

3) High pressure brings brief drying Saturday and much cooler
temperatures before another cold front brings additional
showers Sunday into Monday and even cooler temperatures.

&&

.DISCUSSION...
KEY MESSAGE 1...
The picture perfect stretch of Fall weather will continue for a
few more days, but a changing mid/upper air pattern will result
in warming temperatures. The persistent surface high over the
Great Lakes will drift into the Mid Atlantic today as the big
East Coast low finally weakens and ejects toward Nova Scotia.
This will allow the mid/upper ridge over the center of the
country to build east across the Ohio Valley and eastern Great
Lakes today through Thursday, eventually resulting in a strong
eastern CONUS mid/upper ridge and strong surface high over the
Carolinas and western Atlantic by Thursday. At the same time, a
closed mid/upper low over the Desert Southwest today will slowly
lift into the central Plains by Thursday and begin to phase
with a deepening northern stream mid/upper trough over the
northern Rockies and northern Plains.

This set up will result in deepening southerly flow and
resultant warm air advection. Highs will warm into the low/mid
70s areawide today, then mid/upper 70s Wednesday. Upper 70s/low
80s are expected by Thursday, and it will be noticeably more
humid, with dew points in the low/mid 60s.

Much of this time period through Thursday should stay dry with
just increasing clouds Wednesday and Thursday, but increasing
moisture advection and isentropic ascent ahead of a cold front
slowly sinking south through the central Great Lakes in
response to the digging trough could lead to some rain showers
in the far northern counties Wednesday night. The NAMNest and
RRFS bring some showers across the area Wednesday night into
Thursday morning, while other CAMS, the NAM12, ECMWF, and GFS
remain mainly dry. At this time, stuck with dry NBM POPS
Wednesday night into Thursday morning, but may need to
eventually introduce some showers if the trend continues.

KEY MESSAGE 2...
The aforementioned cold front will begin to sag south through
the region Thursday night and Friday. The front will be very
slow to progress through due to the aforementioned closed low
phasing with the digging northern stream trough, resulting in a
weak surface wave on the front Thursday night and Friday. This
surface wave will have synoptic support from the right entrance
region of a 100-120+ knot H3 jet streak over Lower Michigan, so
expect enhanced moisture advection and isentropic ascent along
the front to drive a band of widespread showers. Isolated
thunder cannot be ruled out, but given the time of year and very
little instability projected, this will mainly be a stratiform
rain event. Early QPF estimates give 0.25 to 0.75 inches across
the region, so no flooding is expected. The greatest
probabilities to exceed 1 inch appear to be in NW Ohio and near
the lakeshore areas. The clouds and precip will hold
temperatures down Friday, so expect highs in the upper 60s/low
70s.

KEY MESSAGE 3...
Canadian high pressure building down across the Great Lakes in
the wake of the cold front will allow the area to dry out Friday
night and Saturday, but it will be much cooler as the longwave
mid/upper trough carves out across the northern Plains, Great
Lakes, and Northeast. Highs Saturday will only reach the mid
60s. A strong, reinforcing shortwave trough dropping through the
broader longwave trough Sunday will further deepen the broad
trough and push another cold front through the region. Showers
are expected with the frontal passage, but the shortwave and
deepening trough may lead to cyclogenesis over the
Appalachians/Mid Atlantic that would have a larger shield of
rain. Confidence is low 5 days out, so NBM POPS look reasonable
Sunday, with the highest chances in eastern Ohio and western
PA. Nevertheless, it will dry out Sunday night and Monday, but
some of the coolest temperatures of the season so far are
expected as an impressive 1035 mb surface high drops into the
Upper Midwest. Highs Monday will only be in the upper 50s/low
60s. This could set up frost potential early next week.

&&

.AVIATION /06Z Tuesday THROUGH Saturday/...
A few clouds around 5kft linger across southern and eastern fringes
of the forecast area, but otherwise clear skies are observed. Patchy
BR/FG is possible through just after sunrise this morning, with the
most likely place for fog development at KYNG. VFR is otherwise
expected as mostly clear skies persist alongside light and variable
winds through the rest of the TAF period.

Outlook...Non-VFR possible with rain showers Thursday night through
the weekend.

&&

.MARINE...
High pressure slowly drifting toward the Mid Atlantic today will
bring one more day of light winds on Lake Erie before SSW winds
increase to 10-15 knots late tonight into Wednesday in response
to the gradient tightening between the high setting up along the
East Coast and a cold front slowly sinking into the Great Lakes
from the Northwest. After a brief lull Wednesday afternoon and
evening, SSW winds will increase again to 10-20 knots Wednesday
night and Thursday while turning more SW. The cold front will
slowly sink across the lake Thursday night turning winds to the
N, and expect N winds to increase to 15-20 knots Friday, then
turn NE and further increase to 15-25 knots Friday night into
Saturday. This will build at least 2-4 foot waves Friday night
and Saturday in the central basin, and winds and waves will
likely trend higher, so expect that Small Craft Advisories will
be needed.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$

DISCUSSION...Garuckas
AVIATION...Saunders
MARINE...Garuckas