Scientific Forecaster Discussion
fxus61 kcle 251935
Area forecast discussion
National Weather Service Cleveland Ohio
334 PM EDT Thu may 25 2017
low pressure over eastern Ohio will move off to the NE thru Fri to
allow a weak ridge of high pressure to push across the region Friday
then weaken Saturday. Low pressure will develop over the Great Lakes
Sunday and hang around the eastern part of the lakes through
Near term /until 6 am Friday/...
the slow moving low will finally head off to the NE tonight causing
the back edge of the widespread rain to start to shift east and
should be mostly from cle to zzv east by 8 am. Rainfall amounts
should mainly be a quarter of an inch or less tonight so not
expecting flooding issues. Lows will be a little cooler as winds
turn out of the west to NW helping temps to drop into the low to mid
Short term /6 am Friday through Sunday night/...
as energy from the upper low continues to shift off to the east the
lingering rain in the east should taper off Fri to provide a brief
period of dry conditions going into early Fri night.
The models continue to differ on how well convection from a
developing system to the west will hold together and spread across
the cwa Fri night into Sat morning. Will raise forecast pops more
but not to mav guidance levels.
As the next upper low digs se into the lakes Sat night and sun, it
will provide forcing for the next round of shra and possible tsra to
spread ENE across the cwa Sat night and sun. The threat for flooding
will continue to slowly increase as rounds of rain occur.
Temps should be near normal Sat and sun but cloud coverage should be
considerable making it feel cooler.
Long term /Monday through Thursday/...
series of short waves progged to rotate through the deepening trough
the first half of next week. It may be difficult to pin down
specific details very far in advance. The cold front should be east
of the area Monday and I suspect there may be enough subsidence to
keep new shower development in check. Will have a small chance (20-
35 pop) for showers.
The next short wave and surface trough/front should rotate across
the area on Tuesday. Weak high pressure is progged to build across
the Ohio Valley on Wednesday but with the trough aloft, will keep a
chance of showers in the forecast. High pressure should be more
established by Thursday.
Temperatures should drop through the first half of the week as weak
cold advection persists. 850 mb temperatures will start out about
+10c Monday and be down to about +5c by Wednesday. Forecast
temperatures will be near normal Monday then below normal Tuesday
Aviation /18z Thursday through Tuesday/...
showers with MVFR and local IFR visibilities continue to expand
in the vicinity of the upper low and surface low which are
drifting northeast across the forecast area. IFR ceilings
across Lake Erie and some sections of the counties near Lake
Erie will spread back across the forecast area as the surface
low moves to the east late this afternoon and evening. Winds
will primarily become west-northwest tonight into Friday.
Ceilings will improve to MVFR Friday late morning and afternoon
with VFR conditions developing front west to east Friday
Outlook...areas of non-VFR likely at times over the weekend.
low pressure will slowly move east of Lake Erie tonight and winds
will come around from the west northwest tonight, then back to the
southwest on Friday. The lake will get a bit choppy on the east half
but will likely remain below Small Craft Advisory criteria on
Weak low pressure will cross the lower Great Lakes on Saturday with
rather light winds but the direction will back around the dial. A
stronger cold front will cross the lake on Sunday and mariners will
have to watch for stronger thunderstorms. Winds should come around
from the west southwest behind the front Sunday night into Monday.