Scientific Forecaster Discussion
fxus61 kcle 201335
Area forecast discussion
National Weather Service Cleveland Ohio
935 am EDT Thu Jul 20 2017
a front near Lake Erie will move back and forth across the area
today into the weekend before finally moving to the southeast
on Monday. High pressure will spread east over the region for
Tuesday and Wednesday.
Near term /through tonight/...
mesoscale convective system to the west is plunging south and convection north of Lake
Erie continues tracking east. Expect both to continue to weaken
this morning and be the focus for redevelopment this afternoon.
That said removed all mention of convection for this morning and
early afternoon. Since no convection bumped afternoon temps up
a couple of degrees.
Original...remnants of mesoscale convective system reduced to showers near The Fort
Wayne area. Showers were moving southeast and believe they will
miss the County Warning Area. Second mesoscale convective system now formed over srn WI and was moving
southeast. The hrrr has this convection approaching the area
12-14z however it appears to be diminishing as it does, never
actually reaching the area. Will need to continue to watch this
evolution. Otherwise, there is a cold front just north of the
area that should drop south across the area during the day.
Expect this front to become the focus for afternoon/evening
convection. Brought chance pops to the area late morning/towards
noon from the north and reaching likely east half around 00z.
Storm Prediction Center continues to have the area under a slight risk of severe
thunderstorms as CAPES of 3,000-4,000 j/kg expected over the
area tomorrow afternoon. Convection should move south/southwest
and diminish late this evening and overnight as high pressure
and drier air move in from the north behind the boundary. Friday
the high will move east and allow the front to return from the
southwest as a warm front. Models show moisture and instability
returning through the afternoon. For now will have chance pops
west/southwest. Highs today upper 80s to near 90. Thursday highs
from around 80 far northeast to the mid/upper 80s elsewhere.
Short term /Friday through Sunday night/...
active period expected this weekend with energetic, quasi-zonal
upper level flow and moist low level return flow. Periodic
showers and thunderstorms are expected, with the remnants of
upstream convection/decaying mesoscale convective system tracking into the region late
Friday night into Saturday morning. Shower and thunderstorm
chances continue Saturday into Sunday as a surface low track
into the Great Lakes region, ahead of a diving upper shortwave
from Manitoba through the upper Midwest. For now, have keyed in
on the highest pops from late Friday night through Saturday
night, with widespread likely pops in the grids. Hard to
pinpoint exact convective evolution this far out, but exact
placement and severity of Saturday/Saturday night convection
likely contingent on the late Friday night convection remnants,
with the focus of the late Saturday convection likely along a
remnant outflow boundary/composite warm front. The
aforementioned low will drag a cold front through the area
Sunday, with precip chances diminishing from west to east as the
front passes but low chances continuing through Sunday night
until a secondary front/trough swings through the area. No major
changes to temps during the weekend, with a bit of uncertainty
for Saturday highs given potential cloud cover/convective debris
and uncertainty with the location of the warm front.
Long term /Monday through Wednesday/...
a quiet first half of the week is expected as a large area of high
pressure build southeast across the Great Lakes Monday through
Wednesday. Some lingering showers are possible Monday as a cold
front exits the region, but mainly dry conditions are expected
Monday night through Wednesday. Temperatures will be a bit cooler
and conditions less humid during the period, with Monday and Tuesday
only in the upper 70s and lows near 60 for many locations. A warming
trend will begin Wednesday as the ridge axis shifts east of the
region, with highs near 80. Widespread precip chances don't return
until at least Thursday or Friday.
Aviation /12z Thursday through Monday/...
for today expect an increasing chance of thunderstorms through
the day as a cold front drops into the area and becomes the
focus for low level forcing and convective development. High
pressure will build in from the north overnight forcing any
remaining convection south and southwest through the evening and
early overnight hours as drier air moves in from the north.
Expect VFR today outside of thunderstorms. Overnight lingering
convection south and southwest could continue restrictions.
Toward morning Friday non VFR possible due to morning fog.
Outlook...non-VFR possible Friday night through Sunday in early
morning fog/mist or scattered thunderstorms.
winds will increase out of the southwest today, but remain in the 10-
12 knot range, as a frontal boundary sits just north of the lake.
The front will drop south across the lake tonight with winds veering
northerly less than 10 knots. Winds will become light and variable
Friday into Friday night as high pressure drifts across the lake.
The frontal boundary will lift north as a warm front late Friday
night into Saturday with winds increasing out of the south around 10
knots Saturday, veering southwest Saturday night. The flow will
increase to 10-15 knots Sunday as low pressure approaches the lake,
veering northwest as the low pulls a cold front across the lake
Sunday night through Monday.