507 
FXUS61 KCLE 221017
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
617 AM EDT Thu Aug 22 2024

.SYNOPSIS...
A ridge affects our region today through this weekend.
Simultaneously, the embedded high pressure center wobbles 
southeastward from the western Great Lakes toward the Carolinas.

&&

.NEAR TERM /THROUGH FRIDAY/...

6:17 AM EDT Update...

Forecast remains valid per latest trends in obs and model
guidance. No changes appeared necessary.

Previous Discussion...

Aloft, NW'erly to N'erly flow impacts our region through Friday as a 
low wobbles NE'ward from near the Quebec/northern New England border 
area to near Newfoundland and a ridge builds from the Upper Midwest 
and vicinity. At the surface, a ridge continues to affect our CWA as 
the embedded high pressure center wobbles SE'ward from the western 
Great Lakes toward the central Appalachians. A weak synoptic MSLP 
gradient will allow our regional surface winds to be light and 
variable or calm. However, sufficient nocturnal cooling and daytime 
heating of land surrounding ~73F Lake Erie along with the 
aforementioned weak MSLP gradient will allow a land breeze to occur 
during the early to mid-morning hours of today and Friday, and a 
lake breeze to occur during the late morning through early evening 
hours of today and Friday. The land and lake breeze circulations 
will impact locations over and within several miles of Lake Erie. 

A net warming trend is expected through Friday due, in part to 
diurnal convective mixing of the boundary layer amidst a 
lowering/strengthening subsidence inversion accompanying the 
building ridge. Plus, the aforementioned weather pattern evolution 
at/near the surface will allow a low-level WAA regime on the 
synoptic scale to develop across our region overnight tonight and 
especially on Friday. High temperatures late this afternoon are 
expected to reach mainly the lower to mid 70's in NW PA and NE OH, 
and mainly the mid 70's to 80F farther west. Considerably clear sky, 
light or calm surface winds, and limited humidity at/near the 
surface will promote efficient radiational cooling this evening 
through daybreak Friday morning, when low temperatures are forecast 
to reach mainly the upper 40's to mid 50's. The coolest readings 
will be found inland from Lake Erie. Similar to this morning, river 
valley steam fog is expected between about 4 AM and 9 AM EDT. Patchy
radiation fog is possible during the same time period, when 
surface dew points are expected to be in the 40's to lower 50's.
Thus, air at and very near the surface may cool to supersaturation
at a few locations. Any fog is expected to dissipate soon after
the onset of daytime heating and associated convective mixing 
of the boundary layer. Friday's late afternoon highs will be 
near-average for late August. Maximum temperatures are forecast
to reach the mid 70's to lower 80's in NW PA and NE OH, and 
mainly the lower to mid 80's farther west.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
Despite continued northwest flow aloft, a warming trend is forecast 
for the short term period. The pattern becomes quite amplified with 
a ridge building well north across the Upper Midwest and into Canada 
while an upper level closed low develops over New England by 
Monday. Before this happens, shortwave energy will move through the 
flow aloft bringing some mid and high level cloud Friday night into 
Saturday. Surface high pressure will continue to influence the area 
as it slowly builds east through the weekend with dry air remaining 
in the low levels. Will continue with a dry forecast and 
temperatures trending warmer with the building heights, ranging from 
90 in the west to 80 in the east by Sunday.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
The long term forecast starts off dry but with the potential for 
scattered showers and thunderstorms early next week as a system 
eventually tries to round the upper level ridge. We will be watching 
a trough cross the northern Rocky Mountains and attempt to flatten 
the ridge, bringing an increase in moisture and potential for 
showers and thunderstorms. At this time the most likely window is 
focused in the Monday night-Tuesday time frame but adjustments may 
be needed. Confidence remains low as models have struggled with 
timing and strength of this feature but have included slight chance 
pops for the most likely 24 hour window. The hottest temperatures 
are forecast for Monday and only drop back a degree or two for 
Tuesday with the added chance of precipitation and cloud cover.

&&

.AVIATION /12Z Thursday THROUGH Monday/... 
Mainly VFR and fair weather expected through 12Z/Fri as a 
surface ridge continues to affect our region and the embedded 
high pressure center wobbles SE'ward from the southwestern Great
Lakes toward the Upper OH Valley. Our regional surface winds 
will primarily be variable around 5 knots. However, a land 
breeze around 5 knots is expected over/near Lake Erie through 
~13Z/Thurs and again after ~03Z/Fri. In addition, a lake breeze 
around 5 knots is expected over/near Lake Erie between ~15Z and 
~23Z/Thurs. KCLE and KERI will be impacted by these land and 
lake breezes.

Note: Patchy river valley steam fog is expected and patchy 
radiation fog is possible between ~08Z and ~12Z on Thurs and 
Fri, respectively. Confidence in fog impacting any TAF site is
very low.

Outlook...Fair weather and VFR very likely through this Monday.

&&

.MARINE...
A prolonged stretch of good marine conditions are expected as high 
pressure overhead slowly becomes established towards the Mid-
Atlantic over the weekend. Winds will tend to be 10 knots or less 
most days with lake breezes developing each afternoon through at 
least Saturday. A system moving into the western Great Lakes on 
Monday may bring chances of showers and thunderstorms early next 
week along with some increase in winds/waves but timing and 
confidence are low at this time.

&&

.CLIMATE...
Low temperatures in the 40's and 50's are expected this morning.
Below are record cold low temperature values for all six 
climate sites valid for August 22nd.

Toledo        Low     Year 
08-22         45      1923

Mansfield     Low     Year  
08-22         37      1940

Cleveland     Low     Year
08-22         45      1982

Akron/Canton  Low     Year
08-22         40      1895

Youngstown    Low     Year
08-22         39      1988

Erie          Low     Year
08-22         42      1957

&&

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

&&

$$

SYNOPSIS...Jaszka
NEAR TERM...Jaszka
SHORT TERM...KEC
LONG TERM...KEC
AVIATION...Jaszka
MARINE...KEC
CLIMATE...CLE