Scientific Forecaster Discussion
fxus61 kcle 111814
Area forecast discussion
National Weather Service Cleveland Ohio
114 PM EST Mon Nov 11 2019
low pressure over southwest Ohio will track northeast through
the evening reaching the New England states by Tuesday morning.
High pressure will then build into region from the southwest
Tuesday night. This high will quickly shift to the East Coast of
the US by wedneday evening. This will allow a clipper storm
system to dive across the central Great Lakes region on Thursday.
Near term /through Tuesday/...
cold front has stalled near a line from southwest Ohio to near
Pittsburgh. Low pressure will track along this boundary through
the evening reaching the central southern tier of New York overnight.
Good isentropic upglide across the region this afternoon into
the evening will bring increasing chances of rain across the
eastern half of County Warning Area. It will take some time for the colder air
to spill into the region and change the rain/drizzle over to
snow through the evening. Already seeing a mix across Northwest Ohio with
some patches of freezing rain being reported. We may see this
freezing rain across several locations as the colder air drifts
south in the wake of the low overnight. Best chances of freezing
rain may be across extreme NE Ohio into northwest PA. Fortunately this
will be brief as the low passes.
There should be a decent swath of synoptic snow that develops
overnight, persisting the longest across the east. We then
transition to a lake effect event around 09z tonight that
persists into Tuesday. Slight concern that snow amounts will be
lower with the warmer air lingering into the evening across the
east. However for now we will not tweak them lower and remain
consistent with the previous forecast. However across the mid
Ohio area the the later change over to snow will impact snow
amounts. We will go lower amounts but justify the advisory with
a brief period of freezing rain possible through the evening
then 1 to 3 inches overnight.
Lake effect snow will wobble across the area with multiple bands
anticipated. Heaviest amounts will be across NE OH, eventually
reaching northwest PA late Tuesday into Tuesday night. It will be cold
on Tuesday with highs in the 20's. Single digit to teen wind
chills will be possible Tuesday morning.
Short term /Tuesday night through Thursday night/...
strong upper level low pressure system and trough will shift east of
the area Tuesday night into Wednesday as a slowly amplifying ridge
builds east over the Great Lakes region by Wednesday afternoon. The
amplification of the ridge is a result of another upper level trough
diving into the Central Plains states. The trough axis will shift
east across the local area by Thursday evening and cause troughiness
across the eastern half of the United States. Surface high pressure
will build east toward the Ohio Valley Wednesday. This will
continue the favorable flow from the Great Lakes into the snowbelt
region during the morning hours. As the surface high pressure moves
east, the flow will become gradually less favorable Wednesday
afternoon into Wednesday night. Initially, with 850 mb temperatures
around -16 degrees c, area can expect to see extreme instability
between lake surface temperature and 850 mb temperature. Deep
moisture will also be present with lake induced cape around 1000.
Inversion hangs around 8000 to 9000 feet above the surface resulting
in relatively deep convection. As surface high moves east of the
area Wednesday, this should result in a fairly rapid retreat of the
snow bands back north away from the area. Expecting to see
dwindling snowbands late afternoon Wednesday. The upper level ridge
will build into the region forcing surface high pressure to move
east of the area by Thursday morning. Another low pressure system
will lift north into northern Ontario, Canada by Thursday morning
forcing a cold front east across the area Thursday afternoon. The
front appears to be limited in moisture and will have limited impact
on the local area. Temperatures will warm slightly on the west side
of the high after some pretty chilly temperatures Wednesday. Some
locations could see lows in the single digits out west while mostly
teens in the east. Highs on Wednesday still remain in the upper 20s
to near 30 degrees but will drop back into the 20s for lows Thursday
and Friday mornings. Otherwise, highs Thursday will be in the
middle to upper 30s.
Long term /Friday through Sunday/...
upper level troughiness will shift east of the area allowing a weak
ridge to build east across the Great Lakes by Saturday. A more
vigorous and potent trough will slide east toward the area Sunday. A
cold front will push southeast across the area Friday followed by
another quick blast of Arctic air. As surface high builds east
toward the area, flow could become favorable for More Lake effect
snow across the area Friday night into Saturday morning. Surface
high will move over the region Saturday afternoon and bring a return
southerly flow to the area Sunday. Otherwise, other than the lake
effect possibility, period should remain for the most part dry.
Aviation /18z Monday through Saturday/...
low ceilings and the development of rain and snow are expected
through this taf period as low pressure moves across the region
through the evening. Most locations will become IFR this
afternoon and remain that way into tonight. Rain changes to
snow from northwest to southeast through the evening. All snow across
the region on Tuesday as we evolve to a lake effect snow event.
Winds will be east to northeast this afternoon across the east.
Northwest Ohio is already northerly and expect this to spread eastward
in the wake of the low. As winds become northerly expect the
precipitation to change over to snow.
Outlook...non-VFR expected Tuesday into early Wednesday across
NE Ohio/northwest PA in lake effect snow. Non-VFR possible Wednesday night
into Thursday, mainly NE Ohio/northwest PA.
deepening low pressure is expected to move northeast across the area
through Tuesday and this will bring some gusty winds to the Lake.
Small craft advisories will likely remain in effect through Tuesday
as a result of the low. Winds diminish Wednesday as high pressure
moves east across the area during the day and then wind shifts to a
southerly direction Wednesday night into Thursday. A cold front will
slide southeast across the lake Friday and result in winds shifting
to a northwest direction. May need another Small Craft Advisory
again on Friday.
Arctic air will move southeast into the local area Monday night
into Tuesday and then begin to shift east Tuesday night. The
unseasonably cold air will cause temperatures to plummet to some
of the coldest readings so far this season.
Below are the coldest temperatures on record for selected dates
at our six climate sites:
Tuesday, November 12:
Coldest high (year) coldest low (year)
Akron-Canton area: 28 (1920) 16 (1950)
Cleveland area: 31 (1920)18 (1911)
Erie area:34 (1996)18 (1911)
Mansfield area:29 (1996)16 (1976)
Toledo area:30 (1995)15 (1976)
Youngstown area: 30 (1996)19 (1950)
Wednesday, November 13:
Coldest high (year) coldest low (year)
Akron-Canton area:25 (1911)12 (1911)
Cleveland area: 22 (1911) 15 (1911)
Erie area: 23 (1911)16 (1911)
Mansfield area:27 (1986)13 (1986)
Toledo area:22 (1986)13 (1911)
Youngstown area:29 (1996)17 (1986)
Ohio...Winter Storm Warning from 4 PM this afternoon to 10 am EST
Wednesday for ohz011>014-089.
Winter Weather Advisory from 4 PM this afternoon to 7 PM EST
Tuesday for ohz010-020>023.
Winter Weather Advisory until 1 am EST Tuesday for ohz003-006-
Winter Weather Advisory until 7 am EST Tuesday for ohz007>009-
Winter Weather Advisory from 4 PM this afternoon to 7 am EST
Tuesday for ohz029>031-037-047.
PA...Winter Storm Warning from 4 PM this afternoon to 1 PM EST
Wednesday for paz001>003.
Marine...Small Craft Advisory until 4 am EST Wednesday for lez144>149.
Small Craft Advisory until 11 PM EST Tuesday for lez142-143.