Scientific Forecaster Discussion
fxus61 kcle 220026
Area forecast discussion
National Weather Service Cleveland Ohio
726 PM EST Thu Nov 21 2019
low pressure will continue northeast into Quebec tonight, pulling a
cold front southeast across the area. High pressure will expand
across the southern Great Lakes tonight. Another low pressure system
will track northeast through the Ohio Valley on Saturday before
shifting to the East Coast on Sunday.
Near term /through Friday/...
the main batch of showers are limited to the far eastern parts
of our forecast area, such as northwest Pennsylvania and
Youngstown and should move east out of the forecast area over
the next couple of hours. Scattered light showers and drizzle
will still around until the cold front sweeps through. Also
adjusted pops for the system that is expected to move through on
Saturday. Mostly rain and later timing is expected on Saturday.
showers continue to quickly race east
across the area ahead of a pronounced mid-level dry slot. At 4
PM low pressure was located across Eastern Lake Superior with a
cold front extending south across Lake Michigan. A few gusts to
40 mph have been noted in the warm sector across Indiana or
western counties already with a peak wind to 41 mph so far at
Findlay. Wind gusts are expected to expand eastward with gusts
of 35-40 mph through about 8 PM before starting to drop off. Can
not rule out a couple gusts to 45 mph but these should be few
and far behind. Mixing depths are already decreasing in far
western Ohio as stratus expands denoted by cloud deck of 1500
feet or less. As the lower clouds arrive, wind gusts will begin
to come down except along the northeast Lakeshore where they
will remain up overnight as flow shifts more onshore. Light
showers can be seen across northern Indiana and will accompany
the front tonight. Moisture aloft strips away quickly overnight
with just limited showers lingering across the snowbelt and
mainly PA into Friday morning. Strong subsidence will allow the
stratus to gradually scatter from the northwest and expanding
into inland areas. Clearing will be slower closer to Lake Erie.
Temperatures will be approximately 10 degrees cooler on Friday.
Surface high pressure builds in by Friday night which should provide
a window of good cooling. Went with temperatures closer to MOS
guidance except downwind of Lake Erie where a few clouds may remain
with slightly warmer temperatures.
Short term /Friday night through Sunday night/...
a pair of upper troughs, one over the upper Midwest and one over the
Central Plains, will propagate east on Saturday and phase together
by Saturday night over the eastern Great Lakes region. This trough
will support a low pressure system over the Tennessee Valley on
Saturday which will move northeast through the upper Ohio Valley on
Saturday night and then towards the East Coast on Sunday. This
system will bring a round of precipitation to the region with snow
changing over to rain and then perhaps back to snow as temperatures
hover in the 30s late Saturday night. This system departs on Sunday
and high pressure ridges into the region from the south. The area
will dry out and temperatures will slowly warm throughout the period
eventually reaching the 50s on Monday.
Long term /Monday through Thursday/...
the long term period continues to have some active weather over the
region ahead of the Thanksgiving Holiday. The extended guidance
continues to show a low pressure system developing over the Southern
Plains and trekking northeast as a trough digs into the Midwest. The
European model (ecmwf) has come back to show this feature and become more in line
with the GFS, showing a deepening low over the central Great Lakes
region on Tuesday night into Wednesday. However, there has been
enough movement with this system over the last several runs, where
confidence in going than higher than 50/50 chance pops is tough.
High pressure builds in behind this system by Thursday and would
mean a dry Holiday at this time.
Aviation /00z Friday through Tuesday/...
MVFR conditions will continue to overspread all taf sites this
evening with a chance for brief IFR conditions, mainly at the
western taf sites such as ktol, kfdy, and kmfd. Main batch of
showers still around Keri but shouldn't last too much longer.
Some lingering light showers and drizzle will still be around
most taf sites until the cold moves sweep through tonight. Southerly
winds of 15 to 20 knots with gusts up to 35 knots will persist
until the cold front moves through. A few isolated gusts to 40
knots could be possible especially at eri overnight. After the
cold frontal passage tonight, winds will shift to out the west
eventually northwest on Friday. Westerly will will sustain the
elevated winds for a few more hours before gradually decreasing
tonight and tomorrow. Low level clouds will scatter out from
west to east tomorrow.
Outlook...non-VFR possible with rain on Saturday, lingering
into Sunday across NE Ohio/northwest Pennsylvania. Non-VFR possible
once again on Tuesday afternoon with widespread rain.
conditions on the lake will remain dangerous tonight into Friday as
deepening low pressure over northeast Wisconsin will continue
northeast over northern Michigan to just north of the Georgian Bay
in Canada. This system will continue to bring strong winds over the
basin tonight into Friday with sustained winds likely reaching gales
on the eastern basin of the lake. High pressure builds in for Friday
into Saturday and should allow for calmer conditions over the lake.
Low pressure arrives from the southeast for Saturday evening into
Sunday and could bring some stronger northwest flow for the end of
the weekend. High pressure returns early next week and marine
conditions will be fairly benign to begin the Thanksgiving Holiday
Marine...Small Craft Advisory until 7 PM EST Friday for lez144>149.
Gale Warning from 11 PM this evening to 7 am EST Friday for
Small Craft Advisory until 10 am EST Friday for lez142-143.