536 
FXUS61 KCLE 061932
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
332 PM EDT Sun Oct 6 2024

.SYNOPSIS...
Strong cold front continues to sweep east across the area
through this evening. Canadian high pressure builds overhead
behind the cold front Monday and will persist through the week. 

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
Broad upper level trough will continue to drag a cold front eastward 
across Northern Ohio and Northwest Pennsylvania before exiting early 
this evening. Behind the front, lingering upper level energy sags 
south which will supply a brief window for lake effect clouds 
and rain showers before Canadian high pressure builds overhead. 

Already seeing much drier air upstream behind the front in Northern 
Indiana with dew points in the 30s and RH values between 
15-25%. Expect for this dry air to work itself into Northwest 
Ohio this afternoon and evening. The combination of wind gusts 
between 25 and 35 MPH, low RH values, and dry vegetation has led
to an elevated risk of fire spread through early this evening 
across Northwest Ohio. 10 hour fuels remain a bit too high for 
Red Flag criteria, so kept the Special Weather Statement in 
effect through this evening. 

At his point we are beginning to see a cu field develop along
the I-71 corridor as the cold front surges eastward into an 
unstable environment. Sufficient daytime heating has allowed 
for MLCAPE values to rise into the 1000-1500 J/kg range with 
deep layer shear of 30-40 knots. Still anticipating for 
thunderstorms to initiate fairly quickly over the next few 
hours with initiation generally occurring along a line from 
Ashtabula to Canton and points east. Strong to severe 
thunderstorms with all hazards (damaging winds, large hail, and 
a few tornadoes) remain on the table in an unstable environment 
with plentiful deep layer shear. Primary hazards continue to be 
damaging wind gusts and large hail, but can't rule out rotating 
updrafts and/or few tornadoes given ample deep layer shear and 
low LCLs. As such, portions of Northwest Pennsylvania and 
eastern Ohio remain in a Slight Risk (Level 2/5) for severe 
weather this afternoon and early evening.

The cold front quickly exits to the east tonight ushering in a 
much cooler airmass. Overnight lows tonight dip into the mid 
40s inland with low 50s in place along the lakeshore. Upper 
trough and shortwave aloft dip south tonight into tomorrow which
will allow for lake effect clouds and rain showers to develop 
downwind of Lake Erie. Northerly flow will keep cooler 
temperatures in place with highs on Monday ranging between the 
mid/upper 50s in Northwest Pennsylvania to the low to mid 60s 
across Northern Ohio. Canadian high pressure builds overhead 
through Monday which will lead to improving conditions but
another chilly night with lows dipping into the lower 40s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Low impact weather will continue through mid-week, along with 
traditionally cool Fall temperatures as deep mid/upper troughing 
persists across the Great Lakes and eastern Canada. 

The mid/upper longwave trough axis will be located across the Great 
Lakes Tuesday, gradually shifting into New England Wednesday and 
Wednesday night as the associated closed low drifts from northern 
Ontario to the Canadian Maritimes. This will allow a large area of 
cool Canadian high pressure at the surface to shift from the heart 
of the Midwest Tuesday to over the Great Lakes and Ohio Valley by 
late Wednesday and Wednesday night. This pattern all points to 
seasonably cool fall temperatures, with generally low to mid 60s for 
highs both Tuesday and Wednesday. Far NE Ohio and NW PA will stay in 
the upper 50s, while NW Ohio sees upper 60s. Lows will generally be 
in the 40s both nights, with upper 30s along the US 30 corridor and 
in interior NE Ohio and NW PA. Wednesday night has the better chance 
for 30s as the high builds in to set up better radiational cooling, 
so frost is possible in interior NE Ohio and NW PA. 

Before the high builds in, NW boundary layer flow across Lakes Huron 
and Erie combined with moderate to strong lake induced instability 
will generate some lake-effect rain showers Tuesday into Wednesday 
in far NE Ohio and NW PA. This entire window will likely see some 
showers, but late Tuesday and Wednesday morning will have the 
greatest coverage as a final shortwave drops through the mean 
mid/upper trough with 850 mb temps dropping to just below 0 C over 
the eastern basin of the lake and equilibrium levels rising to 15-16 
thousand feet. This will yield extreme instability of 650-900 J/Kg, 
so have solid chance PoPs. Also added thunder given the instability. 
Shear at times seen in NAM BUFKIT forecast soundings and pretty dry 
air overall will limit the organization of this activity.  

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The aforementioned large Canadian high will gradually settle from 
the Great Lakes and Ohio Valley Thursday to the Tennessee Valley 
Friday as a strong mid/upper shortwave trough drops through the 
Great Lakes and NE CONUS Saturday into Sunday. An associated deep 
surface low moving through northern Ontario will drag a strong cold 
front across the region Saturday night or Sunday which will bring 
the next potential for rain showers. Timing of the front is 
uncertain 7 days out, but at this point, limited moisture advection 
ahead of the front will limit QPF despite what looks to be strong 
synoptic forcing. This will unfortunately keep drought conditions 
status quo.

Highs will remain cool in the low to mid 60s Thursday, with upper 
50s continuing in far NE Ohio and NW PA and upper 60s in NW Ohio. 
Warm air advection ahead of the front will boost highs into the low 
to mid 70s Friday and possibly mid 70s to near 80 Saturday. 
Temperatures should cool into the upper 60s to low 70s Sunday. 

&&

.AVIATION /18Z Sunday THROUGH Friday/...
Cold front is continuing to move east across terminals this
afternoon with elevated wind speeds and gusts impacting every
TAF site. Ahead of the front, southerly winds 15-18 knots with 
gusts of 20-25 knots with turn westerly behind the front this 
afternoon and evening. 

As the front approaches eastern terminals this afternoon, expect
for showers and thunderstorms to develop along a line extending
from Ashtabula to Canton and points east between 19-21Z.
Introduced TEMPO groups for TSRA impacts at CAK/YNG/ERI from
20Z/Sun-00Z/Mon. Strong to severe thunderstorms remain possible
with thunderstorms capable of producing IFR vis, gusty winds, 
and hail.

After the front exits to the east after 00Z tonight winds turn
northwesterly while decreasing to 8-12 knots. Northerly to
northwesterly winds across a relatively warm lake will allow for
lake effect showers with low VFR to MVFR ceilings to enter 
downwind of Lake Erie early Monday morning.

Outlook...Non-VFR ceilings possible in lake effect clouds and
light showers across northeast OH and northwest PA Monday.

&&

.MARINE...
W to SW winds of 15-25 knots across Lake Erie will continue until a 
strong cold front crosses the lake this evening. This will veer 
winds to NW at 20-30 knots early tonight before NW winds decrease to 
15-25 knots. NW winds will gradually decrease to 10-15 knots Monday. 
These winds will build 4 to 8 foot waves late this evening and 
tonight, especially in the central and eastern basins, so Small 
Craft Advisories will continue on the entire lake through 20Z 
Monday. NW winds will then average 10-20 knots through Wednesday 
before turning light and variable by late Thursday, then SW at 10-20 
knots Friday. 

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 4 AM EDT Monday for LEZ142-143.
     Small Craft Advisory until 4 PM EDT Monday for LEZ144>149.

&&

$$

SYNOPSIS...Iverson
NEAR TERM...Iverson
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Iverson
MARINE...Garuckas