738 
FXUS61 KCLE 131941
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
341 PM EDT Mon Sep 13 2021

.SYNOPSIS...
A stalled front across northern Ohio will remain across the area
this evening before lifting north tonight. Low pressure will
move through the northern Great Lakes on Tuesday and extend a
cold front across the area. This front will clear the area on
Wednesday and stall over the Ohio Valley on Wednesday night.
High pressure will enter from the north for Thursday.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
A stalled front remains across the northern portion of the area,
hugging the lake in Northwest and North Central Ohio and then
moving slightly inland across Northeast Ohio and Northwest
Pennsylvania. To the south of this front, conditions remain warm
in the lower 80s and some scattered cumulus has developed. To 
the north, conditions remain a touch cooler and a touch cloudier
with northerly flow off Lake Erie. Over northern Lake Erie, a 
complex of showers and thunderstorms continues its march towards
NW PA and far NE OH. This complex is taking advantage of a 
strong mid-level jet and associated wind shear across the 
region. Have maintained categorical PoPs for NW PA late this
afternoon/early this evening. There is a strong to severe storm
threat with this complex with how it has performed so far in 
Michigan. However, cooler temperatures and some cloud cover may 
pose some limits, so trends will be watched as storms cross Lake
Erie. The atmosphere in NW PA is a bit more stable than earlier
in Michigan as clouds have kept temperatures in check. This will
help keep any thunderstorms weaker. Conditions should settle 
overnight with departing upper level support and the diurnal 
minimum across the region.

For Tuesday, the front should lift north as a warm front with
low pressure moving through the northwest Great Lakes region.
Winds and temperatures should increase across the warm sector 
and have high temperatures into the 80s for all areas. The area 
seems like it should be slightly capped and needing the 
prefrontal trough to trigger convection and have a mostly dry 
forecast for Tuesday afternoon. The prefrontal trough and low
level jet arrive on Tuesday night and will bring widespread
showers and thunderstorms to the region. There is a conditional
severe threat to primarily the western portion of the area as
lingering instability and the incoming jet could support
organized convection. The late arrival of the front may allow
for instability to quickly wane across the area and the severe
window could quickly diminish on Tuesday night.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
On Wednesday a cold front will be moving southeast across the area, 
becoming the focal point for convective development through the 
daytime hours. A line of showers and thunderstorms is expected from 
Marion to Erie, PA during the morning hours, shifting southeast Knox 
County to Crawford, PA County during the afternoon hours. Given mid-
level southwesterly flow of 35-45 knots and instability potential of 
around 1000 J/kg MUCAPE, there is a marginal chance for severe 
weather with the afternoon thunderstorms. The cold front, along with 
precipitation chances, should clear the forecast area by midnight.

The aforementioned cold front sags just south of the forecast area 
early Thursday morning before lifting north across the area as a 
warm front during the daytime hours. Weak southerly winds will allow 
for temperatures to rise back to near normal with high temperatures 
in the upper 70s. Partly cloudy skies expected Thursday and 
Thursday night.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Mid-level heights steadily rise through the long term forecast as an 
upper-level ridge builds across the eastern third of the CONUS. This 
will result in a general increase in temperature through the weekend 
with highs potentially reaching the mid to upper 80s by 
Sunday/Monday. Diurnally driven scattered showers/thunderstorms are 
possible Friday and Saturday.

&&

.AVIATION /18Z Monday THROUGH Saturday/...
Clouds bases remain low across the area this afternoon and
warming conditions has allowed for some MVFR cumulus across the
area. Most of the cu field remains scattered but some MVFR
ceilings linger northeast of a warm front in NW PA and these
lower ceilings could persist for a bit longer this afternoon.
The main aviation concern in the near term is the progression of
a line of showers and thunderstorms. This line will move east-
southeast on the north side of a stalled warm front and will
impact the KERI terminal late this afternoon. Outside of this,
convection should wane overnight with a lack of forcing and the
diurnal minimum and have dry and VFR TAFs. The front will push
away from the area for Tuesday and winds should increase with
better mixing across the area.
 
Outlook...Non-VFR likely Tuesday night and Wednesday in showers
and thunderstorms associated with a cold front.

&&

.MARINE...
Winds out of the east today will shift to out of the southwest 
tomorrow as a warm front lifts north across Lake Erie. Southwest 
winds may strengthen to 15 to 20 knots by Tuesday night and perhaps 
a Small Craft Advisory may be needed for a short window during this 
time. Winds shift to out of the northwest as a cold front crosses 
Lake Erie Wednesday morning, weakening to less than 10 knots on 
Wednesday. Winds become predominantly out of the east on Thursday as 
high pressure moves east across the Great Lakes region. Winds become 
southerly on Friday as high pressure moves off to the east and a 
warm front lifts north across the area.

&&

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

&&

$$
SYNOPSIS...Sefcovic
NEAR TERM...Sefcovic
SHORT TERM...Saunders
LONG TERM...Saunders
AVIATION...Sefcovic
MARINE...Saunders