Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
436 am EDT Wednesday Oct 1 2014
high pressure north of the lakes will spread south to Lake Erie
today and then shift off to the east Thursday. Low pressure will
move northeast across the western Great Lakes and take a strong
cold front across the local area on Friday. This will make for a
much cooler weekend.
Near term /until 6 PM this evening/...
upper low still affecting the region but will be drifting east
today. A ridge will build in from the west by late in the day.
A mix of fog and stratus has developed across the area during the
pre-dawn hours as expected. After a cloudy start...expect some
breaks in the cloud cover as ridge slowly builds in. Guidance is
putting out a 5 to 8 degree range in temperatures today between
the NAM and GFS and the difference is with the expected sky cover.
Airmass is not particularly cool and will likely end up somewhere
in the middle with a mix of clouds and some sun. Therefore split
the difference and have upper 60s and a few 70 degree readings for
today. Moisture is not too terribly deep so even with some
lingering cyclonic flow across the east not expecting any
Short term /6 PM this evening through Saturday night/...
upper trough across the central U.S. Deepens further as it
translates eastward for the weekend. Low pressure will develop
across the Southern Plains and move northeast to the western lakes
by Friday and become fully occluded/stacked across central Ontario
Saturday night. This will take a seasonably strong cold front
across the local area on Friday. Cool conditions and a lingering
trough will perpetuate showers in its wake on Saturday.
In the meantime on Thursday surface high shifts east and southerly
flow will allow temperatures to regain above normal status. Again
there is a several degree difference with guidance temperatures...but
have leaned toward the warmer side.
Rain chances begin across western Ohio Thursday night...likely not
until after midnight. The majority of the rainfall will fall
during the daylight hours on Friday...but there are some
differences in frontal timing that may leave some
lingering showers across eastern Ohio/northwest PA into Friday evening.
The colder air rushes in Friday night. 800 mb temperatures forecast to be
between 0c and -3c by Saturday morning. Will bring lows down into
the 40s even with some remaining cloud cover Friday night.
Saturday will be difficult to recover and only expect highs in the
lower 50s. Still need to keep at least a chance of showers in the
forecast with the upper trough and such cold air aloft. Flow
remains southwest through Saturday so any lake influence should be
targeted up the lake toward Buffalo/western New York. There are some
differences amongst the models but they do suggest a trough
passage Saturday evening with flow more onshore into the
snowbelt. So showers likely to linger into Saturday night there.
Otherwise high pressure builds over the lower Ohio Valley. Quite
Cold Saturday night...with middle/upper 30s expected. Any decrease in
cloud cover and winds could lower those numbers.
Long term /Sunday through Tuesday/...
the upper low will lift out by Sunday but the upper trough is
prognosticated to stay put over the Great Lakes. Cold enough for lake
effect showers to continue on Sunday but the boundary flow should
begin to back to the southwest and the majority of showers should
eventually slide up the Lakeshore into western New York. With any
Luck we may see some sunshine mix in on Sunday although there may be
an increase in high clouds as the day GOES on.
The next short wave is prognosticated to slide through the trough early in
the week and should bring an increasing threat of showers by Monday.
The 00z European model (ecmwf) tries to dry things out by Tuesday but with the trough
remaining overhead will keep a small chance of showers in the
forecast. It will be cold enough for lake effect showers again by
Monday night but the flow may be south to southwest so it may not be
Temperatures are a bit tricky depending on the amount of clouds and
showers. The GFS is warmer early in the week while the European model (ecmwf) keeps
850 mb temperatures generally between +1c and +6c suggesting that
high temperatures will range mostly from the middle 50s to the lower
Aviation /06z Wednesday through Sunday/...
just enough subsidence for breaks in the cloud cover but plenty of
low level moisture and IFR stratus ceiling will develop in many
areas overnight along with fog...some of which will be dense
(lifr). The fog and stratus will lift to a MVFR stratocumulus
ceiling Wednesday morning then improve to VFR in the afternoon
with gradual clearing developing as the upper low pulls out and
the surface high builds in.
Outlook...non VFR Friday. Non VFR likely Saturday NE Ohio/northwest
PA...perhaps lingering into Sunday morning.
high pressure centered over the upper Great Lakes will spread
southeast today. The flow on Lake Erie will remain generally
easterly with an onshore component by this afternoon. The flow will
back to southeast and south by Thursday ahead of the next cold
front. The front should sweep across Lake Erie on Friday. The south
wind will shift to southwest and eventually west after the cold
front and winds will increase to near gale force Friday night into
Saturday. The wind will back toward the southwest on Sunday and the
larger waves will be focused across the eastern half of the lake. It
is possible that the Small Craft Advisory could come down on the
western basin on Sunday but the lake should remain stirred up
elsewhere. Unsettled weather will likely continue next week.