Area Forecast Discussion
Issued by NWS Cleveland, OH

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KCLE 270818
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
418 AM EDT Tue Jul 27 2021

.SYNOPSIS...
High pressure centered over the Midwest will persist over the
area into Thursday. A weak cold front will move south across the
area tonight. A stronger cold front will move east across the
area on Thursday before high pressure builds back in on Friday
and Saturday. Another cold front will approach the area for the
end of the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
High pressure centered across the Midwest will allow fair
weather to continue today. A lake breeze is expected to develop
this afternoon and persist through sunset before dissipating. High
temperatures will be quite warm in the mid to upper 80s and plenty
of sunshine.

Tonight, the aforementioned high pressure will gradually shift
south as a weak cold front approaches from the north, with much
of the precipitation dissipating before it arrives to the CWA.
There is a better area of instability and moisture over NE OH
and NW PA which may allow for scattered showers and
thunderstorms to persist along the boundary. Original data
suggested the boundary nearly stalling over Lake Erie, however
recent model runs suggest it stalls somewhere over central Ohio.
This will need to continue to be monitored as the placement of
the boundary will determine extent of precipitation. For now
have kept chance PoPs for NE OH and NW PA as confidence in this
weak boundary moving that far south is low. SPC has issued a Day
1 Marginal Risk for severe weather for the outlined areas
above, with the primary threat being wind. Overnight lows will
dip into the low to mid 60s.

On Wednesday, high pressure will allow for dry conditions ahead
of an approaching cold front. Showers will begin to approach
from the west ahead of the cold front, but shouldn`t reach the
area until later periods. High temperatures will be in the mid
to upper 80s.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
Active weather expected during the short term period as a shortwave
trough moves southeast across the Central Great Lakes Region. Low
pressure is expected to develop across southern Wisconsin Wednesday
night with a 40-50 knot low level jet providing a good influx of
moist and unstable air along a warm front extending east across
southern Lower Michigan towards Lake Erie. Models are showing robust
convection developing across central Lake Michigan and favoring a
trajectory to the southeast along the instability gradient and with
support from a 50-60 knot jet streak at 500mb moving through the
northwesterly flow aloft. Severe weather will be most likely upstream
on Wednesday night where the Storm Prediction Center has a
Enhanced/Slight Risk of severe weather. Best timing estimates at
this time have the activity approaching the Toledo area by early
Thursday morning and continuing southeast across the forecast area
on Thursday. The details are much harder to determine 48 hours out
with regards to evolution of convection, including the strength as
it approaches during the convective minimum and the resulting effect
this has on timing and re-development later on Thursday. Latest
model runs suggest we will primarily be concerned with the waning
convection that arrives Thursday morning and that the boundary will
likely be south of the area by the time convection re-develops
Thursday afternoon. It is possible that we could see a few strong to
severe thunderstorms Thursday morning. It can not be ruled out
however that if storms move through early enough that 70+ degree
dewpoints feeding in from the west may support sufficient
destabilization during the afternoon for storms to develop along any
lingering boundaries, mainly south of a line form Bowling Green to
Mansfield. This does not look like the favored outcome at this time
however. We will be monitoring trends for Wednesday night and
Thursday over the next couple days.

Have lowered high temperatures slightly on Thursday given the early
day coverage of showers and clouds and these may be too high if we
do not get any recovery into the afternoon. Have held onto some low
chance pops into Thursday evening along the actual cold front but
better chances are that we will be worked over by this point and
starting to dry out. High pressure builds in behind the cold front
for Friday as the upper level trough axis swings east across New
England. Temperatures on Friday will be below normal in the 70s with
a diurnal cu field.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
Saturday will start off quiet with high pressure overhead, shifting
south towards evening as the next cold front approaches. Uncertainty
remains in timing of this next front and amount of cooling behind it
with the GFS favoring a much cooler solution than the ECMWF and
Canadian which keep the upper low well north of the Great Lakes.
This seems much more likely to start August and have kept
temperatures on the warmer side of the temperature spread. The
strength of the cold front will also have an effect on shower and
thunderstorm potential both on Sunday and Monday so will keep a low
pop in the forecast until better timing can be resolved.

&&

.AVIATION /06Z Tuesday THROUGH Saturday/...
VFR conditions are expected to continue through this forecast
period with mostly clear skies and light and variable winds. At
KERI and KCLE, a lake breeze is expected to develop this
afternoon, allowing winds to become northerly at 7-10 knots
through sunset. An isolated chance of showers and thunderstorms
will accompany a weak frontal boundary as it moves south across
the region. As a result, have opted to added VCSH at KYNG and
KERI from around 00Z Wednesday through the end of the period.
This system is expected to weaken as it approaches the area
which should allow conditions to remains VFR, possibly MVFR in
any heavy rain.

Outlook...Non- VFR likely with thunderstorms on Thursday.

&&

.MARINE...
High pressure will be over the area again today with light lake
breezes developing during the afternoon. A weak frontal boundary will
settle south across Lake Erie late tonight with winds shifting to
the north/northeast at 10 knots or less on Wednesday. Winds will try
to shift back around to the southwest on Wednesday night as a warm
front lifts north but will be impacted by showers and thunderstorms
moving southeast out of Michigan heading into Thursday morning.
These thunderstorms will impact forecast wind and wave conditions on
the lake on Thursday. A cold front will push south of Lake Erie
later Thursday with northerly winds of 10-15 knots Thursday night
and Friday leading to 2-3 foot waves. Marine conditions expected to
improve on Saturday before another cold front pushes south across
the lake on Saturday night.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$
SYNOPSIS...Campbell
NEAR TERM...Campbell
SHORT TERM...KEC
LONG TERM...KEC
AVIATION...Campbell
MARINE...KEC


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.