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Office: CLE

FXUS61 KCLE 210235

Area Forecast Discussion
National Weather Service Cleveland OH
935 PM EST Tue Feb 20 2018

A cold front will move east across the area late tonight through
Wednesday. As the front settles just south of the area, low pressure
will track northeast along the front Wednesday night through
Thursday. The front will lift back north through the area as a warm
front Thursday night into Friday as another low pressure system
develops and tracks northeast into the Great Lakes.


No significant changes for the 930 update. Low pressure now
centered over Northern Lake Huron with the leading edge of the
cold front into NW OH. Wave entering Mid Mississippi Valley will
slow the progression of the front.

Original discussion...
Rain chances are taking a pause across the area late this
afternoon, as much of the early afternoon precip has lifted
northeast out of the forecast area. Rain chances will increase
from the west later this evening through the overnight as a cold
front pushes towards the area. Kept a mention of slight chance
thunder in the grids through 06Z, although instability and
forcing will be diminishing, and upstream lightning trends have
greatly diminished. The front will push through the area, with
rain continuing behind the surface frontal passage for a period
of time tonight through Wednesday. Only minor changes to pops
and hourly temperature trends from the previous forecast. Will
keep the Flood Watch up for Lucas County for this forecast
update, however flooding risk has greatly diminished, with
additional rainfall amounts tonight of a half to three quarters
of an inch. The heaviest rainfall will occur along and just
ahead of the front, but only light to occasionally moderate rain
is expected behind the front.

Main forecast challenge for this period is Wednesday night in
the wake of the surface cold front. Surface temperatures are
expected to fall to around 30 degrees across much of the area,
with some upper 20s possible across the northern part of the
area. A wave of low pressure will track northeast along the
front through the Ohio valley, with precip overspreading the
area from southwest to northeast, and greatest precip chances
across the southeast part of the forecast area. P-type issues
and impacts will remain fairly tricky, with rain expected south
of the surface boundary where temps will remain above freezing,
a thin line of mixed precipitation just northwest of the front,
and then light snow further north, if any precip makes it that
far north. This thin transition zone is the main concern, with a
period of freezing rain and sleet possible. Forecast soundings
support freezing rain, but north/northeast flow will usher in
fairly dry air into this transition zone, so expecting some wet
bulbing to occur as the precip saturates the column. This may
support more of a partial melting and more of a sleet/snow
concern vs. freezing rain. Compounding the impact uncertainty,
ground temperatures will be fairly warm where freezing rain
potential exists, after record high temperatures today. Any
freezing rain impacts may be limited to overpasses and elevated
surfaces at this point, with other road surface impacts being
fairly limited if existing at all. Any snow/sleet accumulations
should be less than an inch through early Thursday morning.


Abundant moisture will continue to stream northeast into Ohio
on Thursday as strong upper level high pressure sits off the
Carolinas coastline while a broad upper trough dominates the
Great Basin. Cold air will begin to slowly settle south with
snow possible generally across the northern half of the area and
a wintry precipitation mix across the southern half of the
area. The best chance for this wintry precipitation mix will
occur early Thursday morning through around noon on Thursday. We
will continue to fine tune details leading up to Thursday
morning as the GFS is a bit faster than the ECMWF with
precipitation timing.

Either way...expect generally an inch or less of snow across the
northern portion of the area and only minor accumulations of
freezing rain and/or sleet across the southern portion.

After the brief cool down on Thursday...a warming trend is expected
Friday into Saturday with temperatures generally in the mid 40s to
mid 50s as 850 mb temperatures rebound to nearly 10 C.

A few rounds of rain are expected to impact the area Friday and
Saturday...with subtle timing difference between the GFS and ECMWF.
Either way there will be at least a chance of precipitation from
Friday morning through Saturday.


Precip will be ongoing at the start of the period as the last in a
long series of low pressure systems impacts the area.  The surface
low will move northeast across the central Great Lakes Saturday
night into Sunday forcing a front across the local area. The usual
difference is the track and timing of the main features exist but
this will have little impact on the practical weather. It's going to
rain everywhere and some of the rain...especially at the southern
end of the area could be heavy.  The rain should end from west to
east Sunday afternoon and evening.  High pressure will move over the
region for the start of the new workweek and Monday and Tuesday but
should be dry.  Temperatures will be cooling during the period but
will still be a little above normal on Tuesday.


.AVIATION /00Z Wednesday THROUGH Sunday/...
Rainshowers will move over Western half of forecast area
overnight ahead of approaching cold front. Enough shear for
isolated TSRA possible NW OH. LLWS possible early this evening.
Surface winds have decoupled and 925mb winds 20040-45kt. The 925
MB winds will increase to 50kt overnight but expect surface
winds to pick up by then.

OUTLOOK...Non-VFR Wed morning ins -shra. More Non- VFR Fri and
Sat with the next front.


Brisk south to southwest winds will continue tonight ahead of a
slow moving cold front. The front will cross Lake Erie
Wednesday morning and winds will shift to northwest and north.
Wind speeds should diminish relatively quickly within a few
hours of frontal passage. Winds will veer all the way to ENE as
high pressure slides across eastern Canada into the weekend. A
cold front will cross the lake on Sunday and winds will become
southwest and a more seasonable and drier air mass will spread
across the lake early next week.


OH...Flood Watch through Wednesday afternoon for OHZ003.


NEAR TERM...DJB/Greenawalt
LONG TERM...Kubina

Office: ILN FXUS61 KILN 210303 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 1003 PM EST Tue Feb 20 2018 .SYNOPSIS... Unseasonably warm conditions will continue into tonight. A cold front will move through the area late tonight through Wednesday, bringing widespread showers and cooler temperatures. An unsettled weather pattern will then persist through the rest of the week as a series of disturbances affect the region. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... No major changes to the forecast overnight. A cold front will push into the northwest late tonight. The majority of the rain will be along and behind the front. This means categorical PoPs for areas nw of I-71 by sunrise, with just chance PoPs farther southeast. Models are still showing some elevated instabilities in the southern areas ahead of the front. This may be enough for a few embedded thunderstorms to develop across our southwest late. There will be a large temperature range across the region by the end of the night. The far nw sections will be down to 40-45 degrees, while locations southeast of I-71 will still be in the lower 60s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... The cold front will continue to push southeast across the area Wednesday morning and should be southeast of our area by early afternoon. With a narrow ribbon of elevated instabilities remaining just ahead of the front, will continue with an isolated thunderstorm across the southeast through the morning hours. Otherwise, fairly widespread shower activity is expected through much of the day and into Wednesday night as a series of additional waves work east along the cold front that will stall out to our south. As we get on the backside of the front and into some CAA, temperatures will drop off through the day on Wednesday. This will eventually allow for some below freezing temperatures to possibly work into our north later Wednesday night. There are some disagreements in the models as to how far south this will get though with the 12Z ECMWF not as aggressive with the cold air. As a result, ptype may become an issue Wednesday night as the colder air at the surface undercuts the warmer air aloft. This could lead to some freezing rain across parts of our north, primarily north of the I-70 corridor but confidence is not terribly high given some of the model discrepancies. Considered going with a flood watch to match up with our western neighbors but with the models generally showing a weakening QPF footprint across our area with the front tonight into Wednesday, think we will be okay flood wise through this first round. Later shifts can then try and pinpoint where/if a flood watch will be needed for the additional rounds of pcpn later in the week. && .LONG TERM /THURSDAY THROUGH TUESDAY/... The long term continues to be advertised as active with multiple rounds of precipitation possible and above normal temperatures. Thursday morning precipitation will be spread over the area with the GFS and NAM indicating the potential for freezing rain. The ECMWF is slightly further north with the freezing rain. During the day Thursday temperatures will quickly warm with highs in the mid 40s to near 50 degrees across northern Kentucky. Thursday afternoon it looks like we might get a brief break in the precipitation with the old ECMWF still showing a wetter pattern. The latest CMC appears to be a compromise between the GFS and ECMWF with precipitation confined to our southeastern zones. The issue has to deal with how strong the subtropical ridge is forecast to be off the Carolina coast. The ECMWF shows a slightly stronger ridge, while the GFS shows slightly weaker ridging. Due to this, the track of the corresponding shortwave changes. Friday, yet another surface low will push across the area and ripple along a stalled front. This means more heavy rainfall will be possible as PWATs remain around 1.30" or near record territory. Late Friday into Saturday the pattern will finally begin to change as the subtropical ridge off the east coast breaks down and the upper level low off the west coast pushes east. A secondary surface low is then forecast to move across the area Saturday morning ahead of a more potent surface low that is forecast to form Saturday evening across the plains. This surface low (or third) will then push across the area Sunday with a cold front pushing across the area Sunday morning. Due to the multiple rounds of precipitation forecast there is a threat for flooding which includes river and creek rises. Everyone should continue to watch for updates for the Friday through Sunday morning period. Any slight change in the strength of the ridge can easily change the QPF footprint. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Broad southerly flow will remain over the region tonight. Skies will be VFR with a cirrus deck through about 09Z. Strong gusty winds will settle down due to the loss of daytime heating. A cold front will push southeast across the region late tonight through Wednesday morning. Ceilings will drop quickly to MVFR as the precipitation comes in. Have this timed at around 09Z in the wrn tafs and 12Z along I-71. There is some instability at CVG/LUK as the pcpn comes in, so added a VCTS for a couple of hours. After fropa, ceilings will drop into IFR. As the morning progresses, the models are suggesting that the pcpn becomes a little more scattered in nature. This should last into the afternoon. For the extended CVG taf, next push of rain starts to come in after 00Z, lowering vsbys to MVFR. OUTLOOK...MVFR/IFR ceilings and visibilities are likely into Thursday. At least MVFR conditions are likely to continue through Saturday. && .CLIMATE... Record High Minimum Temperatures for February 20... CVG...52 degrees...1994 CMH...49 degrees...1930 DAY...49 degrees...1930 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...JGL NEAR TERM...Sites SHORT TERM...Novak LONG TERM...Haines AVIATION...Sites CLIMATE...