768
FXUS61 KCLE 211334
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
934 AM EDT Sat Sep 21 2024

.SYNOPSIS...
A cold front will continue to track east across the area through
this afternoon and exit to the east by this evening. High
pressure briefly returns tonight into Sunday morning before a
series of systems cross the region Sunday night through the
first half of the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
930 AM EDT Update...
Isolated showers have developed along a line extending from near
Ashtabula County south to Stark County. There has been lightning
reported with the cell in Stark County, but not expecting
anything to become severe. Adjusted PoPs to account for this
development a bit further west than previously forecast, but
aside from that no other changes were needed with this update.


630 AM EDT Update...
Light showers have filled in a bit so increased PoPs in NE OH
and NW PA to chance (~30 percent) for the next few hours. As of
now, it looks like the morning showers and isolated storms
could be the main show for the day, although additional showers
and isolated thunderstorms just ahead of the cold front may
develop on the eastern fringe of the CWA late this morning
before exiting to the east this afternoon.

Previous Discussion...
Showers with isolated elevated thunderstorms have developed
ahead of a weak trough axis/cold front that is currently moving
east across the local area. These showers will continue to track
east through early this morning. However, the lower levels are
still quite dry, so any showers/thunderstorms that manage to
develop over the area will be hit and miss and rainfall rates
may be on the lighter side. The front will continue to track
east across the area today; overall instability, coverage, and
rainfall chances will remain low until diurnal instability
increases this afternoon. By then, the front will likely be near
or a bit east of the OH/PA border so showers/thunderstorms may
begin to initiate in the CWA before moving east outside of the
local area. There may be a narrow corridor of marginal
instability (MLCAPE values of 500-1200 J/kg) and shear values of
20-30 knots across far eastern NE OH and NW PA so can`t rule
out a few thunderstorms. If thunderstorms do develop farther
west than anticipated, there may be a very low-end chance of
hail and gusty winds, but conditions will be more favorable to
the east of the CWA.

Dry weather is expected behind the front and this will continue
through tonight and the first half of Sunday. Patchy fog is possible
overnight, primarily in areas that receive rainfall, but cloud cover
may be a bit too high for radiational cooling. Isentropic ascent
near and behind a warm front will allow rain chances to increase
from the west starting Sunday afternoon, but the higher PoPs won`t
occur until Sunday night (see Short Term Discussion below).

Expect highs to climb into the mid to upper 80s west of I-71
today with upper 70s to lower 80s anticipated east. Tonight`s
lows will fall into the upper 50s to lower 60s. Maximum temps
will generally be in the 80s Sunday, although NW PA will likely
see highs in the upper 70s. The warmest temps in the mid to
upper 80s will once again be found west of I-71.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
The short term forecast will not be a total drought buster, but a
series of systems through the region will allow for the best chances
for widespread rainfall in some time and will at least attempt at
holding the drought at where it is through the end of the month. A
cold front will approach the region for Sunday night into Monday,
coincident with an upper level shortwave that will breakdown the
upper ridge over the region for much of the weekend. Will continue a
mix of likely to categorical PoPs for Sunday night into Monday with
the front itself. There seems to be a possible lull in precipitation
on Monday night as the front departs and another shortwave organizes
to the west for Tuesday and have a down trend in PoPs to slight
chance to chance for Monday night. The shortwave will move through
on Tuesday with a low pressure through the region and have PoPs
increasing again to likely. Overall, looking at an average of 1 to
1.5 inches of total rainfall by Tuesday night, which will help some
of the rain deficits of the region and curb the drought from
worsening. Temperatures through the period will trend toward
normal.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
Low confidence in the long term forecast as there are two divergent
solutions in the extended guidance. The forecast changes are based
on the final path of the trough that will swing through the Great
Lakes region starting on Wednesday. Some guidance members have the
trough devolving into a closed upper low that will settle over the
Midwest and Ohio Valley during the middle-to-end of the week. This
would allow for a more wet forecast with continuous rain chances
across the local area. Other guidance members have the energy of
this midweek trough splitting with some energy moving through the
region and extending a trough or even a closed low feature into New
England with the other piece of energy parting well south over the
south central United States. This would set up a blocking pattern
with the local area on the backside of a trough with subsidence and
overall drier conditions. There are therefore a wide span of options
with the forecast and general low confidence in how much rain could
occur in the region. Will go with generally lower PoPs than the
previous forecast given more solutions presenting dry. Temperatures
through the period will be near normal.

&&

.AVIATION /12Z Saturday THROUGH Wednesday/...
A cold front will continue its trek across the CWA this morning
before exiting to the east this afternoon. A few showers may
move within the vicinity of KERI early in the TAF period, but
downsloping has allowed showers to generally weaken along the
immediate lakeshore so do not anticipate any precip that would
hinder visibility/ceilings. Can`t rule out a passing shower or
thunderstorm near KYNG later this morning into the early
afternoon as the front nears the OH/PA border and diurnal
instability increases, but precip will probably be widely
scattered and might even initiate to the east of the forecast
area. VFR is anticipated at all terminals through at least
tonight; some patchy fog may develop towards the end of the TAF
period, but confidence is too low to include in the TAFs at this
point.

Light and variable winds early this morning will shift to the
northwest and increase to 5 to 10 knots behind the cold front.
Winds become light and variable near or shortly after 00Z
tonight.

Outlook...Non-VFR possible in periodic showers and thunderstorms
Sunday evening through Wednesday.

&&

.MARINE...
A front will move across the lake this morning and bring westerly
flow to the area. Winds should remain at 10 kts or so and there
could be some waves of 1 to 2 ft over the central and eastern
basins. High pressure will return for tonight into Sunday and bring
northeast to east flow tonight, followed by offshore flow on Sunday.
Likely all last week, suspect that easterly flow will develop during
the day on Sunday with a push of stronger winds in the afternoon. A
cold front will approach the lake on Sunday night and southerly flow
will take hold and increase into Monday to about 15 kt as the front
crosses the lake. The front will be east of the lake by Monday night
and west to northwest flow will be favored behind the cold front. A
low pressure system will move through the central Great Lakes on
Tuesday and southerly flow will return. Another cold front will
cross the lake behind the low for Wednesday and westerly flow will
return. Overall, low probability in any marine headlines at this
time but there could be some windows of unpleasant marine weather
conditions with the various fronts moving across the lake.

&&

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

&&

$$

SYNOPSIS...Maines
NEAR TERM...Campbell/Maines
SHORT TERM...Sefcovic
LONG TERM...Sefcovic
AVIATION...Maines
MARINE...Sefcovic