Lorain, Ohio 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

812
FXUS61 KCLE 061345
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
945 AM EDT Sun Oct 6 2024

.SYNOPSIS...
A strong cold front will push across the area this afternoon and
evening. Canadian high pressure will gradually build in behind this
front on Monday and persist through the upcoming week.

&&

.NEAR TERM /THROUGH MONDAY/...
9:45 AM Update...
Forecast remains steady this morning with the primary focus
being the strong cold front that will track eastward across the
region today. Warm and gusty ahead of the front with wind gusts
across Northern Ohio and Northwest Pennsylvania already between
20-25+ MPH this morning. Very dry air behind the front coupled
with gusty westerly winds of 25-35 MPH will lead to elevated
fire weather concerns across Northwest Ohio this afternoon and
early evening where a Special Weather Statement is in effect. As
the front tracks eastward, showers and thunderstorms will
develop across Northeast Ohio and Northwest Pennsylvania (along
and east of I-71) between 3-5 PM. There remains the potential
for some thunderstorms to become strong to severe given ample
deep layer shear and SBCAPE. All severe hazards are on the table
with damaging wind gusts and large hail as primary hazards but
the potential for rotating updrafts and tornadoes remains
plausible.

Previous discussion...
A sharp negatively-tilted trough and associated deep low pressure
will work east across the upper Great Lakes and Ontario today,
pushing a strong cold front across the local area this afternoon and
evening. The main focus for impactful weather with this frontal
passage will be thunderstorm develop and potential severe weather in
parts of northeast OH and northwest PA during the late afternoon and
early evening...however, a brief window elevated fire danger in
northwest Ohio behind the front later this afternoon and gusty
synoptic winds area-wide at times will also be in play.

It will be warm and breezy today. Highs will reach the low to
perhaps mid 80s in much of Ohio, with upper 70s to near 80 expected
in PA. Gusts will quickly increase after sunrise as we begin to warm
the surface and mix into a 35-45 knot 925mb jet this morning. A
period of southwesterly gusts to 25-35 MPH (strongest Northwest OH)
is anticipated this morning through about midday. Gusts will briefly
lose a bit of their edge early this afternoon as the low-level jet
exits northeast. We will see another brief push of gustier winds
behind the front into the early evening hours. Gusts immediately
behind the front will again peak 25-35 MPH outside of any convection,
with a brief period of 40 MPH gusts appearing likely along the Ohio
lakeshore between Vermilion and Ashtabula this evening, driven
35-40kt of flow at 925mb and strong cold air advection. A forced
band of showers and thunderstorms is expected to develop along the
advancing front across northeastern OH and northwestern PA as early
as 1-2 PM, but more likely around 3-4 PM, before quickly sweeping
east and out of our forecast area by 7-8 PM. A dry slot will move in
behind the front. A chilly and somewhat moist low-level airmass
arrives late tonight into Monday amid northwesterly flow. This will
support lake effect clouds and light showers late tonight through
much of Monday, with clouds and showers gradually starting to erode
from the west later Monday. This is not a robust lake effect setup
and am only expecting light/intermittent showers southeast of the
lake pre-dawn Monday through much of the afternoon. Lows will
generally range from the mid 40s to mid 50s tonight, warmest near and
downwind of Lake Erie. Highs on Monday will range from the mid 50s
to mid 60s, coolest in the higher terrain of northwest PA.

Not too much has changed with the thinking regarding severe wx
potential later today. A tongue of low 60s dew points just ahead of
the cold front and strong daytime heating will yield 1000-1500 J/KG
of MLCAPE this afternoon, with the instability aided by an elevated
mixed layer (EML) aloft characterized by 500-700mb lapse rates of
7-8C/km. A cap at the base of the EML should preclude initiation
until the mid-afternoon hours. Most models continue to blow the cap
quickly around or just after 18z/2 PM, and given strong frontal
forcing and assistance from the left-exit quadrant of a 80-100kt
upper jet streak we should see convection quickly initiate and
intensify once the cap erodes. There has been a subtle trend to slow
the front down and initiate convection slightly farther west in
guidance compared to prior runs. Convection could begin developing as
far west as the I-71 corridor, though confidence remains highest
east of I-77. Strong shear and forcing in tandem with sufficient
instability will support organized and strong to severe convection
once initiation occurs. 40-50 knots of effective bulk shear, 30-40
knots of 0-3km bulk shear, and 100-200 m2/s2 of effective inflow
layer SRH (highest over extreme northeast OH and northwest PA) are
expected to be in place which supports organized/rotating updrafts.

The strong bulk shear and EML will support a large hail (quarter to
golf ball sized) threat with robust discrete or semi-discrete cells.
Fairly steep low-level lapse rates and 700-900 J/KG of DCAPE also
support a wind damage threat, especially with organized or bowing
lines. There`s enough shear for some tornado potential with any more
dominant right-moving supercells and with mesovorts within bowing
segments, though fairly high LCL heights are a potential limiting
factor. Thus the tornado threat is more marginal than the hail and
wind threats though is still in play. The exact severe threats will
come down to storm evolution/mode. The strong frontal forcing argues
for quick growth into a linear mode, though favorable shear vectors
across the front and a lingering cap early in the convective
evolution could allow for a mixed/semi-discrete mode to prevail for
the first 2-3 hours of the convection before it becomes mainly
linear. A more cellular mode would increase the hail and supercell
tornado threats...a more linear mode would increase the wind threat.
The SPC Outlook maintains a Slight Risk (level 2/5) from roughly east
of an Ashtabula to Canton line, buffered by a Marginal Risk as far
west as an Eastlake to Mount Vernon line. The SPC highlights winds
and hail as the main threats with lower (but still worth mentioning)
potential for tornadoes, which is in line with our thinking.

Drought, gusty winds behind the front, and RH values falling below
30% behind the front will support a window of conditions favorable
for fire spread across Northwest OH later this afternoon into the
early evening. A Special Wx Statement is out to highlight that.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A cooler airmass will be in place through the short term with an
upper level trough over eastern Canada. We will see a return to
cooler overnight lows dropping to near 40 inland while lakeshore
areas will be in the upper 40s. Can certainly expect to see a few
cooler locations dip into the 30s with potential for even a few
pockets of frost both Monday and Tuesday nights. Most areas will
experience a good deal of sun with high temperatures ranging from
the mid to upper 60s west to upper 50s east, where they are more
entrenched in the cooler air.

As for clouds and precipitation, there will be a low chance of
showers in NW Pennsylvania as a shortwave moves through the flow
aloft late Monday night into Tuesday. Scattered clouds are expected
in the east while western areas will primarily be sunny as high
pressure builds in from the west.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
Thursday will still feature below normal temperatures with a dry
airmass followed by a warming trend through the long term forecast.
Surface high pressure settles southeast of the area by Friday with
warm advection heading into the weekend. At the same time we see a
gradual break down of the upper level ridge over the Upper Midwest.
The long term forecast remains dry but will be watching for a front
that may try to sag south into the area for next Sunday.

&&

.AVIATION /12Z Sunday THROUGH Thursday/...
The primary focus of this TAF period will be a cold front
working west to east across the area this afternoon. Shower and
thunderstorm development will likely occur along the advancing
front near or just east of CLE and likely a bit east of MFD
between 18-20z, sweeping east out of eastern sites such as ERI
and YNG by 0z. Only included a VCSH mention at CLE as confidence in
thunder is low that far west. Maintained a PROB30 for TSRA at CAK.
Confidence in thunderstorms is high enough at ERI and YNG to go with
a TEMPO in the TAF. Any thunderstorms can produce brief IFR or lower
vsby, gusty winds and hail along with lightning. The highest
confidence in potential severe thunderstorms is in the YNG vicinity.
A brief dry slot will move through this evening behind the front.
Some low VFR to MVFR ceilings will likely develop southeast of Lake
Erie into Monday morning, mainly impacting ERI and YNG but perhaps
getting CAK, CLE, and possibly MFD as well.

Southerly will pick up to 10-20 knots and begin gusting 20-30 knots
this morning. Winds will turn more westerly this afternoon and
evening behind the cold front and more west-northwest tonight. Gusts
20-30 knots will continue into early this evening, with a brief
period of 35 knot gusts possible along the lakeshore (including CLE)
this evening. Low-level wind shear out of the gate at TOL and FDY
will improve as mixing deepens by 13-14z.

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

&&

.MARINE...
Southerly winds will continue to increase this morning ahead of a
cold front that will cross the lake this afternoon. Southerly winds
will increase to 20-25 knots then winds will veer to westerly and
eventually northwesterly by this evening. Winds behind the front
will be stronger with speeds of 20-30 knots, peaking on the western
and central basin. Small Craft Advisories go into effect this
morning and continue through tonight west of the Lake Erie Islands
and through Monday afternoon east of the Islands where it will take
longer for waves to subside.

A cooler northwest flow pattern continues through the first half of
the week with winds of 10-20 knots on Tuesday and Wednesday, keeping
conditions choppy but likely just below advisory criteria. High
pressure builds over the lake Wednesday night and Thursday with
conditions improving for the second half of the week.

&&

.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...Sullivan
NEAR TERM...Iverson/Sullivan
SHORT TERM...KEC
LONG TERM...KEC
AVIATION...Sullivan
MARINE...KEC