CLE issues Area Forecast Discussion (AFD) at Jul 7, 1:43 PM EDT313
FXUS61 KCLE 071743
AFDCLE
Area Forecast Discussion
National Weather Service Cleveland OH
143 PM EDT Mon Jul 7 2025
.SYNOPSIS...
A cold front will slowly push south across the region today
before stalling in the Ohio Valley tonight and Tuesday as high
pressure briefly builds southward into the Great Lakes. The
front will lift back into the region Wednesday and will then
oscillate slightly through the weekend. A stronger system may
finally push the front out by Monday.
&&
.NEAR TERM /THROUGH TUESDAY/...
9:35 AM EDT Update...
Virtually all of the forecast remains valid per latest trends in
obs and model guidance. Only change was to the surface wind
direction forecast through this early afternoon since recent
surface obs indicate the cold front is moving SE'ward more
slowly than our forecast. Still expect the surface cold front to
sweep SE'ward through the rest of our CWA by about 6 PM EDT this
evening. As of 9:35 AM EDT, the surface cold front appeared to
be located just east and south of Toronto and extended SW'ward
to just east and south of Toledo and Van Wert, respectively.
Still expect additional multicell showers/thunderstorms to
blossom along and ahead of the surface cold front through this
early evening amidst weak to moderate boundary layer instability
and moderate effective bulk shear in the warm/moist sector. Also
expect isolated to scattered rain showers and thunderstorms for
several hours behind the surface cold front passage, as low-level
convergence and moist ascent along the upper-reaches of the front
release weak elevated CAPE amidst moderate effective bulk shear.
Please see discussion below for further details.
Previous Discussion...
The focus of the near term will be the cold frontal passage
expected today and the associated showers and thunderstorms. The
main message is that confidence has increased for higher
coverage of showers and thunderstorms late this morning through
the afternoon, especially for inland portions of NE Ohio and NW
PA in the 15-19Z time range, but exact locations remain
somewhat uncertain.
Early this morning, the cold front was oriented over Lake Erie
and extended southwest through southern parts of Indiana and
Illinois in a quasi-zonal mid/upper flow pattern. A few showers
were lingering near the front over Lake Erie and the adjacent
lakeshore areas, but these have struggled to hold together given
the diurnal minimum and synoptic support still well to the
north and west. A weak mid/upper shortwave trough seen on
Infrared satellite and water vapor imagery was progressing
across the corn belt. This shortwave will help to slowly push
the front southeastward through the region later this morning
through the afternoon as it lifts through the central Great
Lakes, but the strongest mid-level flow and associated synoptic
support will be displaced to the north with the deamplifying
shortwave. This points to convection developing along and ahead
of the cold front (and any outflow boundaries) today where low-
level convergence interacts with building instability, but there
will not be a lot of mid- level flow for convection to tap
into, so slow moving convection with locally heavy rainfall will
be the main impact late this morning through the afternoon.
After collaboration with WPC, a slight risk ERO was introduced
for portions of eastern Ohio and NW PA surrounded by the ongoing
marginal risk given the growing confidence for slow moving
convection with efficient rainfall rates. The sparse coverage of
showers early this morning will allow for fairly strong heating
through the morning. Forecast soundings suggest MLCAPE reaching
1000-1500 J/Kg by 16Z with little to no capping, so expect
convection to start to fire after 15Z as stated above. PWATs of
1.75 to 1.95 inches will be in the 90th percentile of daily
climatology, and this along with the overall weak mid-level
flow, deep warm cloud layers, and deep layer flow mostly
parallel to the front will support slowly moving convection with
locally very heavy rainfall, as well as potential training. As
stated above, exact locations remain uncertain, but consensus
among CAMS is for a lot of coverage in inland portions of NE
Ohio and NW PA between 15 and 19Z, so increased PoPs to likely
and categorical in these areas. The rest of the area will see
passing showers and thunderstorms too, but a lower risk compared
to inland NE Ohio and NW PA since the front should clear NW Ohio
and the lakeshore areas fairly early this morning (before the
new convection fires).
Localized severe weather remains a secondary concern. NE Ohio
and NW PA remain in a marginal risk in the SWODY1 from the SPC,
and this is reasonable with the aforementioned instability and
the frontal passage. The biggest limiting factor will be the
weak mid-level flow which results in deep layer shear under 30
knots and low-level shear under 10 knots, so organized severe
weather is not expected. However, localized downburst winds are
possible from precip loading, especially where higher daytime
heating maximizes low-level lapse rates.
Convection will gradually exit to the south and east of the
region this evening and early tonight as the front settles to
the south. Weak surface high pressure sliding south into the
Great Lakes behind the front late tonight and Tuesday will keep
most of the area dry, however, kept some slight chance PoPs from
the NBM near US 30 and points south through Tuesday given the
front nearby.
Temperatures will remain very warm and humid today, with highs
in the low/mid 80s expected. Slightly cooler Tuesday, with
mainly low 80s. Lows tonight will be more comfortable, with
low/mid 60s expected.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
The frontal boundary from earlier in the week will be the main
driver to the weather through late week as it slowly lifts back
north Tuesday night and Wednesday in response to a distinct
mid/upper shortwave trough progressing through the northern and
central Great Lakes. The best forcing looks to again be
displaced to the north, but NBM slight chance to chance PoPs
look good for Wednesday as higher low-level moisture and
instability begin to shift back northward coincident with
daytime heating. This should yield widely scattered convection.
Confidence in the placement of the front decreases Wednesday
night through Thursday night. In one respect, the front should
sink back southward behind the shortwave Wednesday night, but
even if it does, it may creep back northward Thursday and
Thursday night ahead of another upstream mid/upper shortwave
approaching the northern Plains. Kept NBM slight chance to
chance PoPs through Thursday night, which places the highest
coverage with daytime heating Thursday, but confidence is low
given the uncertainty on frontal placement.
High temperatures will generally stay in the mid 80s Wednesday
and Thursday, with lows in the low/mid 60s Tuesday night
gradually climbing into mostly mid/upper 60s Wednesday and
Thursday nights.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
Quasi-zonal flow will persist for the end of the week and
through the weekend, which will essentially keep the frontal
boundary quasi-stationary over or near the region. This will
maintain difficult to time showers and thunderstorms at times
as weak shortwaves ripple through the flow and interact with the
boundary, but there will be plenty of dry time and no wash
outs. Kept NBM temperatures and PoPs given uncertainty with the
placement of the boundary, so the main message is seasonably
warm and humid conditions with scattered showers and
thunderstorms at times through the weekend. The aforementioned
shortwave trough in the northern Plains may finally kick the
front out of the region by Monday, and this could bring the next
potential for more of an organized round of convection
depending on timing.
&&
.AVIATION /18Z Monday THROUGH Saturday/...
A cold front will continue to track across the area this
afternoon into this evening before slowing over the Ohio Valley
tonight. Scattered showers and isolated thunderstorms have
developed ahead of and along the front and will likely impact
terminals generally east of KTOL/KFDY through early evening.
Confidence is somewhat lower at KCLE since the front appears to
be south of the terminal, but latest radar trends suggest that a
cluster of thunderstorms over NW OH may clip or move just to
the south of the terminal within the first couple of hours of
the TAF period. Any showers/storms will likely remain to the
south of KERI for the remainder of today. Ceilings are generally
VFR with pockets of MVFR/IFR and expect this to continue
through the rest of the afternoon. Any showers/thunderstorms
that move directly over terminals could produce brief periods of
IFR conditions and possibly variable/gusty winds in any
stronger storms that manage to develop. Behind the front this
evening into tonight, MVFR and low-end VFR ceilings are expected
areawide with MVFR/IFR conditions likely developing in fog/low
stratus early Tuesday morning. There's some potential for LIFR
conditions at terminals that end up receiving heavy rainfall so
will need to continue to monitor forecast trends. Nearly all
terminals will likely experience fog and low stratus for at
least a brief period, however the vast majority of guidance
favors more optimistic VFR conditions at KCLE during this
timeframe. Any fog/lower stratus should generally improve to VFR
as diurnal mixing develops after 12Z Tuesday.
Winds ahead of the front will be out of the west before becoming
more northerly by this evening. Flow will become light and
variable overnight with winds along the immediate lakeshore
likely remaining northerly at around 5 knots through the end of
the TAF period.
Outlook...Non-VFR will be possible with scattered showers and
thunderstorms Wednesday through Saturday, best chance during
the afternoon.
&&
.MARINE...
Northerly winds to around 10 knots and waves of 1 to 2 feet in
nearshore zones are expected as a cold front pushes south of
Lake Erie this afternoon and tonight. Winds will likely become
more light and variable by Tuesday afternoon as high pressure
builds into the region and expect similar flow with sustained
winds under 10 knots through Wednesday. Flow will become more
east/southeasterly Thursday and Friday, but winds will remain
below 10 knots. Lake breezes may result in periods of onshore
flow and possibly a bit of choppiness in nearshore zones during
the afternoon Tuesday through the end of the week.
Marine conditions will remain relatively calm over the next
several days, although afternoon showers and thunderstorms are
possible Wednesday through Saturday. Winds/waves may be higher
in thunderstorms.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Garuckas
NEAR TERM...Garuckas/Jaszka
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...15
MARINE...15
Source:
CLE issues Area Forecast Discussion (AFD) at Jul 7, 1:43 PM EDT---------------
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