Area Forecast Discussion
Issued by NWS Cleveland, OH
FXUS61 KCLE 282347
Area Forecast Discussion
National Weather Service Cleveland OH
747 PM EDT WED SEP 28 2016
Low pressure over Indiana will drift to the Ohio Valley tonight
where it will remain through Friday. The low will drift back north
across the Great Lakes this weekend.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The upper low and surface low continue to drift south. The first
batch of showers has pretty much dissipated as it encountered ridging
and the downslope southeast flow across eastern Ohio. The next
batch will rotate northeast late this afternoon and this evening
and should make a little better progress to the east but still
not sure if it will make it to the OH/PA border. Will mention a
chance of thunder into early tonight west of I-77 where the dew
points will come up. Additional showers will redevelop tonight as
the jet rotates around the east side of the upper low. The
majority of the showers will likely remain on the Ohio side and
will have somewhat lower PoP NW PA. Forecast low temperatures will
be toward the higher guidance given the rising dew points and the
southeast breeze tonight.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
The models are in pretty good agreement dropping the upper low into
Kentucky where it is progged to wobble for a day or so and then
drift back north across Indiana on Friday and Michigan on
Saturday. That being said, the details of the forecast are not
easy other than there being at least a chance of rain pretty much
the rest of the week.
Most of the models try to draw some of the deep tropical moisture
from the east coast into the system on Thursday. Combine that with
the upper diffluence across the lower Great Lakes and showers should
increase across the northern counties on Thursday into Thursday
night. Instability will increase as the boundary layers moistens up
and it cools off aloft and will mention a chance of thunder
Too early to try and pin down much in the way of specific details
for Friday into Saturday. Will keep the Pop in the "likely" range
for Friday and then begin to gradually back down on the PoP for
Saturday as the upper low starts to lift out.
Forecast temperatures were derived using raw model guidance, not so
much the MOS guidance, given the non-climatological pattern.
Forecast temperatures not all that cool given the time of year
with the dew points being relatively high.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Long standing upper level low will finally begin to make its exit
stage right late Sunday. The low will bring one more day for a
chance of rain and the threat for rain will end Sunday night. Drier
air will begin to spill into the region as high pressure begins to
build into the forecast area. However, flow off Lake Erie could keep
a few residual showers going Sunday night into Monday. Then, high
pressure will be the dominant weather feature for Tuesday into
Wednesday. Another cold front is set to push toward the area by
Thursday but expecting any rain from this feature to not affect the
local area on Wednesday. Temperatures will be on the gradual climb
back up to above normal readings in the 70s for highs as slightly
warmer air begins to push into the region. Lows will remain steady
state in the 50s through the period.
.AVIATION /00Z Thursday THROUGH Monday/...
Variable conditions will continue in space and time over the next
24 hours. Low pressure currently near the SE IN and SW OH border
will wobble/remain somewhat stationary across the region for the
rest of the week. Bands of showers and some thunder will rotate
around the low. The majority of the rain will stick across the OH
terminals for this round of TAFs. MVFR conditions will become
more widespread with time tonight across all but YNG/ERI and
possibly CAK with easterly flow helping to keep the lower levels
dry a while longer. Temporary IFR conditions in any heavier
shower...but also more likely late tonight for MFD and towards
00Z Fri for TOL. Winds across the eastern terminals will get
breezy on Thursday with 25 to 30 knot gusts possible. Confidence
in exact details low due to the variable nature of this system.
OUTLOOK...Periods of non-VFR through Sunday.
Winds will be slowly increasing over the next 24 to 36 hours and we
will eventually need a small craft advisory by Thursday morning. The
highest waves by that time could remain just off shore in the 3 to 5
mile range from shore as the flow becomes more easterly. The
western basin could start out with the small craft advisories as
early as early tomorrow morning. The advisory will likely stay up
through at least Friday as surface low pressure system begins to
weaken. Generally light and variable winds at 10 knots or less
expected through Monday.
Holding off on mentioning waterspouts at this time. Nomogram for
waterspouts shows a chance in the western basin over the next couple
days but not significant enough to mention at this time.