Scientific Forecaster Discussion
fxus61 kcle 241357
Area forecast discussion
National Weather Service Cleveland Ohio
957 am EDT Sat Aug 24 2019
high pressure centered east of Lake Superior across central
Ontario Canada will drift eastward and reach New England by
later Sunday. Low pressure will move east north of the lakes and
take a cold front across the local area Tuesday night. High
pressure follows in the wake of that front for Thursday.
Near term /through Sunday/...
minor changes to the cloud cover and hourly temperatures were
made to reflect current trends. Area of convergence remains
offshore with still a slight chance of seeing a waterspout.
Satellite imagery shows some vertical development to the clouds
from Ashtabula to Ripley where the slightly cooler air is
located aloft. If we see a spout this would be the most
Lake effect stratocumulus are developing downwind of the lake
primarily across northeast Ohio/NW PA early this morning. Other
than a few sprinkles late last evening, convergence has been
lacking for any precip. Have lowered the chances and reduced the
already narrow coverage of any light shower this morning as
winds on the lake have been uniformly northeast around 15 to 20
knots much of the night. Will continue to see the lake clouds,
but as we head toward midday this will transition to an inland
cumulus field before fading toward evening. Flow more easterly
tonight so would expect mostly clear skies. Temperatures ran a
few degrees warmer than guidance yesterday with this airmass so
have gone a few degrees warmer than guidance for today. This
places US in the low/mid 70s. Somewhat cooler tonight with
low/mid 50s and a few upper 40s possible. Back to the mid/upper
70s for Sunday.
Short term /Sunday night through Tuesday night/...
the first half of the short term forecast period will remain
quiet with an upper ridge over the region and high pressure just
east of the area. Expecting dry conditions and seasonable
temperatures for Sunday into the first half of Monday. The
pattern shift for the week will occur on Monday into Monday
night as an upper trough enters the Great Lakes region and will
support a surface cold front. Some pre- frontal showers and
thunderstorms are possible late Monday into early Tuesday, but
the main show will be with the frontal passage on Tuesday into
Tuesday night. Have likely pops for the forecast area timed with
the front as the guidance has fairly good agreement on the west
to east progression across the area. While there is some slight
warm air advection ahead of the front on Tuesday, think that
the area will be too worked over with clouds to push
temperatures over the 80 degree mark, so will keep upper 70s
for tuesday's highs.
Long term /Wednesday through Friday/...
for the most part, the long term forecast period appears dry
and quiet over the region. Some lingering showers are possible
on Wednesday as the cold front departs the region. The
supporting upper trough lifts north on Wednesday and flow
becomes fairly zonal over the region. High pressure nudges in
from the south for Thursday and wobbles slowly eastward on
Friday. From here, there are several solutions from the extended
guidance members with some showing a pattern shift for next
weekend and others keeping quiet weather in place. Will hedge
for Friday with a slight chance pop for now. Temperatures
remain seasonable through the period.
Aviation /12z Saturday through Wednesday/...
cool high pressure has spread across the terminals. Scattered/broken VFR
stratocu deck holds across northeast Ohio/NW PA. Expect fair
weather VFR cumulus to dot the sky this afternoon, scattered to broken at
times. Continued fair through Saturday night. Northeast winds
around 10 knots, with locally higher around 15 knots near the
Outlook...non VFR possible with a chance of showers and
thunderstorms on Monday afternoon and Tuesday.
northeast flow will be present on the lake today and tonight,
as high pressure builds in from the north. Flow has increased on
the lake overnight to 15 to 20 knots, resulting in waves of 4
to 5 feet over much of the Central Basin, expanding east towards
the PA water. Will expand the Small Craft Advisory and
associated beach hazards statement to the Ashtabula Ohio and Erie
PA nearshore waters and land zones through 10 am to account for
the current conditions that will persist through the next
several hours. Expect unfavorable flow to continue for much of
today and will extend the Small Craft Advisory/bhs in the Central Basin until 10
High pressure wobbles east for Sunday, allowing for light easterly
flow and eventually weak southeast and offshore flow. Winds will
shift around to the south ahead of a cold front on Monday and
increase to 15 to 20 knots. The front will cross the lake on Tuesday
and flow will become light out of the southwest for Tuesday night
and beyond. An Small Craft Advisory may be needed for the frontal passage, but too
early too tell at this time.
Ohio...beach hazards statement through this evening for ohz007-
Marine...Small Craft Advisory until 10 PM EDT this evening for