253 
FXUS61 KCLE 011145
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
645 AM EST Wed Mar 1 2023

.SYNOPSIS...
A warm front will approach the area today ahead of a low
pressure system that will move through the middle of the Great
Lakes region. This low will extend a cold front across the area
tonight. High pressure will build into the region behind the
front for Thursday as the front stalls near the Ohio River. A
low pressure system will develop over the southern United States
on Thursday night and move northeast into the area on Friday.

&&

.NEAR TERM /THROUGH THURSDAY/...
Radar flared up a bit more than expected this morning as some
light showers move through the region. The radar returns are
more bark than bite as the rain is really *just* enough to wet
the pavement and allow for a flick or two of the wipers. Have
extended chance PoPs through NE OH/NW PA over the next couple of
hours to reflect these rain showers.

Previous Discussion...
A warm front will enter the area today and allow for a quiet,
dry, and well above normal Wednesday to kick off the month of
March. Some rain showers are encroaching into NW Ohio ahead of
the front and these will cascade across the lake into NE OH/NW
PA later this morning with a bit of isentropic lift across the
area. There could be a very brief window of wet snow with this
feature in NW PA, but warm air advection will be aggressive
across the region and anything should melt quickly or lift out
of the area before becoming a problem. A drier air mass behind
the front and 850 mb temperatures approaching 10 C will enter
the region by this afternoon and expect temperatures well above
the normal of lower 40s. Record high temperatures are in the mid
to upper 60s for today and there should be enough mixing of
the warmer temperatures down to the surface to make a solid run
at them, but think most of the area will just fall short, as the
front will get hung up just a bit on the lake. The best spot of
a record may be Akron-Canton, where the record is a bit cooler
than surrounding sites at 66 degrees.

Some better moisture will advect into the region later this
afternoon into the evening hours right ahead of a cold front.
There will be quite a bit of dry air for this moisture to work
through to allow for this front to trigger rain showers as it
moves through. By the time the front approaches the southeast
counties this evening, there is a shot for some rain and have a
chance PoP, but the best setup is south and east of the forecast
area. Don't think that temperatures will quite plummet behind 
the front tonight with clouds in the area and the slow pace of 
the cold air advancing into the region so a mix of mostly 30s 
and perhaps some 40s south should be the minimum overnight. High
pressure will build into the region for Thursday and keep the 
area dry. An inversion will be in place across the region and 
should hold some low clouds through the day on Thursday. There 
is potential for some of the clouds to erode in the southern 
counties and temperatures there may make a run at 50 degrees. 
Otherwise, expect a small diurnal bump in temperatures with just
40s throughout.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
An active short term forecast period is expected, as a 
moisture-laden and fairly deep low pressure tracks from the 
southern Plains Thursday evening into the middle Mississippi 
Valley by Friday morning. This system will progress further 
into the southern Great Lakes (somewhere between southern lower 
Michigan and northern Ohio, perhaps over Lake Erie) Friday 
night with the low then drifting east towards Lake Erie. The
system will then weaken on Saturday as a coastal low becomes
favored off the East Coast. This system will bring moderate to 
heavy precipitation, largely in the form of rain, to the entire 
area Friday into Friday night. Some showery precipitation will 
linger Saturday, especially in Northeast Ohio and Northwest 
Pennsylvania. Some wintry precipitation is still possible, 
especially across northwestern Ohio and northwestern PA, though 
we're still looking at a large majority of the QPF with this 
system falling as rain across our forecast area. Gusty winds can
be expected Friday and Friday night, perhaps lingering into 
Saturday. The main concerns with this system, in order from 
largest to smallest, appear to be rainfall potentially leading 
to flooding, gusty winds, and wintry weather potential. These 
will be broken down below...

Trends in Guidance & Forecast Confidence/Uncertainty: No 
wholesale changes in recent guidance, but some subtle trends. 
The most notable trend has been for the system to arrive a bit 
slower, leading to an increasing likelihood that most of our 
area remains dry Thursday night. Locations from Northeast Ohio 
into Northwest PA may have to wait several hours into the day 
Friday to see precipitation. Feel this slower trend is 
reasonable and made some adjustments to the onset of PoPs late 
Thursday night into Friday. Another subtle trend has been for 
guidance to trend towards lower heights extending from Hudson 
Bay southeast across northern New England and into the Canadian 
Maritimes ahead of the approaching low pressure. This is likely
a result of the pattern over eastern North America feeling the 
influence of a retrograding block into Greenland later this 
week. These lower heights lead to upper-level confluence 
increasing ahead of the system. This increased confluence may be
partially responsible for the slower trend with the onset of 
precip and could allow for chilly/dry air to be slightly more 
stubborn ahead of the storm. This has led to a slight bump back 
south and chillier trend among some 0z guidance. Another source 
of uncertainty is when the system will reach peak intensity and 
begin occluding/weakening. This will help dictate QPF across our
area. The Canadian is on the late side and brings heavier QPF 
with 1.50-2.50" across most of our area. The NAM and Euro are on
the other extreme, showing the low occluding and beginning to 
fill quicker, keeping the heaviest QPF just to our south/west 
with more modest QPF of 0.50-1.50" across our area. Hard to say 
which way that will go but increased confluence ahead of the 
low could point towards it beginning to fill earlier and 
slightly lower QPF in our area.

Heavy Rainfall & Flooding Potential: A period of moderate to 
heavy rain still appears likely on Friday as a sloped warm 
frontal surface lifts across our area ahead of the approaching 
low pressure. Strong isentropic lift and frontogenesis beneath 
favorable upper-level divergence are still expected to squeeze 
out unseasonably high PWAT values of a bit over one inch with a
bit of elevated instability trying to advect as well. Precip 
rates will generally maximize during the day Friday with the 
lift described above...however, as the deep low aloft and 
occluded front sweep through from west to east Friday evening 
some rain will continue. Depending on the exact low track, the 
system's deformation zone could get into northwestern Ohio 
points east across Lake Erie into northwest PA Friday 
evening/night, which could prolong steadier precipitation in 
this area. Overall, the total QPF forecast is similar to the 
prior but slightly lower, generally in the 1.00-1.50" range but 
trending upwards of 1.75" to the southwest towards Mount 
Vernon. On the balance, this amount of rainfall would probably 
lead to some minor flooding of some streams, creeks, and poor-
drainage areas due to a period of sufficient rates to cause 
quick run-off across our saturated late-winter soils. As this 
run-off makes it into the rivers, they will sharply rise, and 
suspect we'll see a number of points reach minor to perhaps 
moderate flood when examining ensemble river forecast guidance 
and factoring in recent QPF trends. The greatest overall 
flooding potential appears to be from Northwest Ohio and into 
North Central Ohio (from near Toledo to Canton points 
southwest), lining up well with the Day 3 Slight Risk for 
excessive rainfall area from the WPC...though, some prone areas 
could see flooding farther northeast. If QPF trends back up and 
2.00"+ amounts look to work into our area, then more widespread 
flooding with more river gauges rising to moderate to perhaps 
major flood would be possible - though the risk of that appears 
to have trended down somewhat.

Gusty Winds: East-southeast winds will ramp up Friday afternoon
and early evening as a 60-70 knot low-level jet works through 
from west to east. However, a stout low-level inversion and 
general warm air advection regime argue against efficient mixing
in this window. That said, expect 30-40 MPH gusts area-wide in 
this window with 40-50 MPH gusts possible in parts of the area, 
especially west of I-71 (due to modest downsloping and general 
flat/open terrain) and along the eastern lakeshore (due to 
downsloping). It is possible that a Wind Advisory will be 
needed for part of the area in this window. Gusts briefly lull 
Friday evening as the low moves nearby or overhead with gusty 
west-northwest winds returning on the backside late Friday 
night into early Saturday. The low will be filling/weakening by 
the time these backside winds occur, so current impression is 
that 30-40 MPH gusts will largely cover the backside winds later
Friday night/early Saturday. 

Wintry Weather Potential: Still minimal for most of our 
forecast area, but Northwest Ohio (including Toledo) and 
Northwest Pennsylvania (including Erie) still appear to have 
some potential for more impactful wintry precipitation. As 
precipitation first spreads in from the south Friday morning wet
bulb cooling could allow the leading edge of precip to fall as 
some sort of rain/sleet/wet snow mix. For most of our area, 
this would be very brief and of little impact, and the slightly 
slower onset of precip should generally allow surface 
temperatures to warm more before precip moves in. Regarding our 
northwest fringes (i.e. Toledo), the slight south shift in the 
low track noted on some guidance (such as the 0z GFS and CMC 
models) could keep the 850mb low track just south of Toledo. If 
this occurred, dynamic cooling in the system's deformation zone 
may allow moderate to heavy, wet snow to continue longer there. 
There is low confidence in this occurring, as the NAM and Euro 
take the 850mb low north of Toledo and still have mainly or all 
rain. Probabilities on the 0z GFS and Euro ensembles for greater
than 3"+ or 6"+ of snow are still higher into Michigan, but 
have increased a bit in the Toledo area. On the flip side into 
Northwest PA, it seems like there should still be sufficient 
warm air advection aloft to change things over to "not snow" at 
some point...however, trends noted above for a somewhat better 
injection of chilly/dry air into the northeast ahead of this 
system may open the door for some mixed precipitation in 
Northwest PA, especially in the higher terrain away from Lake 
Erie. Introduced a bit of sleet and freezing rain for a time 
Friday afternoon in eastern Erie and Crawford Counties, but was 
conservative with this mention for now. Brisk easterly winds 
will be in place, and this could continue to advect in lower dew
points and try to prolong any mixed precipitation. As for the 
rest of our area, some ensemble members ticked south enough to 
bring some accumulating wet snow or perhaps some mixed 
precipitation into more of northern Ohio (including Cleveland 
and Youngstown), but these solutions are in the minority. 
Overall, would like to give another cycle or two to see if the 
slight colder trend noted on the 0z models and ensembles is 
legitimate or not before introducing too much snow or mixed 
precip into the forecast across some of our northern counties.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
Surface high pressure builds in Sunday and Sunday night. A weak 
shortwave does cross through the Great Lakes Sunday morning, though 
for now kept a dry forecast. Weak low pressure is expected to 
develop to our west Monday into Monday night and move through on 
Tuesday. This will lift a warm front through Monday, followed by a 
cold front on Tuesday. Forcing and moisture appear modest so just 
have low POPs for light precip (mainly rain) at the moment. 
Temperatures will be near average for Sunday but warm a bit for 
Monday and Tuesday, followed by a cooler trend towards midweek.

&&

.AVIATION /12Z Wednesday THROUGH Sunday/...
Rain ahead of a warm front is moving through NE OH/NW PA this
morning. The rain is having minimal airport impacts as ceilings
are only falling to a mid level deck between 5 and 10 kft and
vsby remains in the VFR range. The warm front will continue 
north and rain and this mid-level ceiling deck will clear the
region. Generally southerly winds will increase across the 
region behind the front, while scattered VFR clouds should be 
in place. A cold front will cross the area tonight and generate 
some showers in southeast areas before exiting. Felt a tiny bit
more comfortable in some coverage around KCAK and KYNG to have 
a vicinity shower mention, but still low confidence in something
hitting a terminal. Winds will shift to the west/northwest with
the cold frontal passage. VFR will still be favored but a low 
ceiling could try and develop to the lee of the lake, especially
locations like KCLE and KERI.

Outlook...A system will impact the area Thursday night into 
Saturday with non-VFR possible in rain and/or snow.

&&

.MARINE...
Main marine focus over the coming days will be a strong low pressure 
approaching from the southwest on Friday, moving near or over Lake 
Erie Friday night, and gradually moving east and weakening into the 
weekend. Strong east-northeast winds are expected to develop ahead 
of the low on Friday with 20-30 knots quite likely and low-end gales 
not ruled out, especially over the open waters. Winds briefly lull 
Friday evening as low pressure makes its closest approach, with 
gusty west-northwest winds (likely 15-25 knots) developing late 
Friday night into Saturday behind the low. Winds gradually diminish 
Saturday and should be light by Saturday night and Sunday. At the 
moment, high-end Small Craft Advisories appear quite likely for 
Friday through Saturday with non-zero potential that we need some 
Gale Warnings. Confidence not high enough for a Gale Watch this 
morning, though the lake will be rough either way.

&&

.CLIMATE...
High temperatures on Wednesday may be near record values. The 
following are the record high temperatures at our climate sites for 
Wednesday, March 1. 

Date    Toledo    Mansfield   Cleveland    Akron   Youngstown    Erie 
03-01  65(1997)   68(1972)    69(1972)   66(1972)   68(1939)    66(1997)

&&

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

&&

$$
SYNOPSIS...Sefcovic
NEAR TERM...Sefcovic
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...Sefcovic
MARINE...Sullivan
CLIMATE...