000
FXUS61 KCLE 181333
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
933 AM EDT Wed May 18 2022

.SYNOPSIS...
High pressure over the area will move east today as a low
pressure moves northeast towards the region. An associated warm
front will move north across the area this evening, followed by
a cold front moving east tonight into Thursday morning. Weak
high pressure will move in on Thursday, followed by another warm
front on Thursday night into Friday. Another cold front will
follow on Saturday before high pressure builds over the area
again for the end of the weekend into the beginning of next
week.

&&

.NEAR TERM /THROUGH THURSDAY/...
9:30 AM Update...
Light rain showers have begun to approach the region from the
west this morning. Only a few sties in northwest OH, Toledo and
Findlay, are observing light rain. Dry air near the surface
across much of our CWA means that any reflectivity seen on
radar is likely virga, as seen from our office window. Freshened
temperatures and dewpoints to reflect current temperatures.
Adjusted PoPs to reflect current observations and hi-res models.


6:30 AM Update...
Light reflectivities have moved over the western counties,
however with a dry airmass still present near the surface,
nothing is reaching the ground yet. Onset of precipitation
should be late morning/early afternoon, near 16Z. Adjusted
temperatures to reflect the warmer temperatures across NW OH
than previously forecast, but the remainder of the forecast was
unchanged.

Previous Discussion...
High clouds have gradually begun to build over the area ahead of
an approaching low pressure system moving northeast towards the
region from the south-central US. Temperatures this morning have
not decreased as quickly as forecast before, likely resulting in
patchy frost across NW PA and not widespread.

As the low pressure approaches today, increased moisture is
expected to push north across the area, providing for a better
environment for showers to develop. The best forcing has again
slowed with this update, resulting in the western counties
seeing shower development closer to 18Z compared to the late
morning hours as previously forecast. Isentropic lift will
be the primary source of lift ahead of the boundary and will
transition to more synoptic forcing late afternoon into the
overnight hours as the warm front lifts north and WAA increases
behind it. The area remains under the right- entrance region of
the upper level jet, coupled with a vorticity max as the
shortwave moves east today. A cold front will be quick to
follow, moving east across the area overnight, allowing showers
to begin to taper from west to east by Thursday morning as the
best synoptic forcing shifts east. Models suggest marginal
instability across the southern tier of counties, which may be
enough to get a few rumbles of thunder, however widespread
thunder and severe weather are not a concern at this point.
Today`s high temperatures will climb into the mid-60s with
overnight lows only falling into the mid-50s as widespread cloud
cover and WAA moderate temperatures.

A brief period of high pressure will build over the area on
Thursday, allowing for dry conditions to move over the area.
With the drier airmass, partly cloudy skies are expected along
with much warmer temperatures as highs approach the mid-70s to
low-80s.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
Short term models now increasing the chances for convection with the
passage of a warm front Thursday night. See this in the mid level f-
gen and isentropic ascent fields with the former strengthening as it
moves through the eastern CWA. Strong warm air advection in behind
the warm front brings the warmest day of the year on the whole for
the CWA, and expect to see locations hit 90F or just above. Still
some pretty good spread in the MOS guidance values, but with 850mb
temps eclipsing 20C in places, 90F should be doable Friday.
Convective potential will be very limited due to low level capping
and poor layer RH, but weak upper level vort maxima pushing through
could initiate isolated convection across the northern CWA.
Meanwhile, stalling out frontal boundary makes a slow push towards
the CWA Friday, gradually increasing the POPs Friday night. Upper
trough axis digging over the northern plains region will finally
accelerate the cold front into the CWA from the northwest on
Saturday. Lingering warmth in the eastern zones, but cooler back to
the west.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
Cold front continues the relatively slow push through the CWA as
Canadian high pressure dives into the Mississippi Valley.
Thunderstorm threat is largely gone Sunday with only showers
lingering with the activity clearing by the Sunday evening time
frame. Much cooler air compared to the heat on Friday builds in for
the beginning of the work week with the aforementioned high pressure
system dominating. As the surface high tracks across the CWA, and
then east northeastward into New England, will see the slow
moderation of temperatures back towards normal on Tuesday. The back
end of the extended forecast will be dry.

&&

.AVIATION /12Z Wednesday THROUGH Sunday/...
VFR conditions will continue into the late morning/early
afternoon hours as a low pressure system approaches from the
southwest. Clouds near 8kft have begun to build over the western
terminals and are expected to continue to build east this
morning. As showers begin to develop, near 15Z for western
terminals, expanding east today, ceilings and visibilities will
also reduce to MVFR conditions. Brief periods of lower
visibility are possible in the heaviest showers, however
shouldn`t be long lived. There is an isolated chance that some
thunder may occur, especially for the southern tier of counties,
however confidence in the timing and location of thunder
potential is low so opted to keep any CU and mention of thunder
out of the TAF. As the low pressure shifts east of the area
near the end of the TAF period, clouds will lower to IFR heights
along the cold, rebounding to MVFR behind the boundary. Some
models continue to bring ceilings to LIFR heights, however
confidence in this is low so opted to only go as low as IFR.

Winds will increase from the southeast later this morning to
5-10 knots. A warm front is expected to move north across the
area this evening, shifting winds to be southwesterly but
remaining at 5-10 knots. A cold front near the end of the period
will again mark a shift in winds to become westerly at 5-10
knots.

Outlook...Non-VFR possible in showers and/or thunderstorms
Thursday afternoon and evening. Non-VFR possible again late
Friday and Saturday in showers and/or thunderstorms.

&&

.MARINE...
Winds variable 10-15kts today and tonight as low pressure with rain
passes west to east near Lake Erie with a weak cold front crossing
late Wednesday night kicking the wave heights up to 2-3ft. Behind
the front, westerly winds back to southwesterly Thursday less than
10kts and decreasing wave heights again. A warm front passing
Thursday night increases the southerly flow, and by Friday, winds 10-
20kts out of the southwest will be in play where wave heights will
increase away from shore. A cold front will slowly move in from the
northwest, and likely will not completely clear the lake until later
in the weekend with northwest winds 10-15kts and increasing wave
heights by Sunday.

&&

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

&&

$$
SYNOPSIS...Campbell
NEAR TERM...Campbell/Iverson
SHORT TERM...26
LONG TERM...26
AVIATION...Campbell
MARINE...26

NWS CLE Office Area Forecast Discussion