Area Forecast Discussion
Issued by NWS Cleveland, OH

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KCLE 091533
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
1033 AM EST Sat Dec 9 2017

.SYNOPSIS...
Low pressure over Lake Michigan will move east through the
central Great Lakes today dragging a cold front across the
region. Surface high pressure will expand northward into the
Ohio Valley on Sunday before another area of low pressure
tracks across the southern lakes Monday night, forcing another
cold front through the region Tuesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Snow has been falling in the Toledo area this morning with web
cams showing around a half inch of snow in some areas. The
dewpoint in Findlay was considerably lower where snow has yet to
begin with a 16 degree dewpoint depression. Snow has been
approaching from the west and expecting it to fill in along the
I-75 corridor this morning. Snow will be slow to expand eastward
as drier air aloft can be seen wrapping around the base of the
trough but will increase this afternoon as the low level trough
and cold advection finally shifts eastward. Primary change to
the forecast with this update was to increase pops in extreme NW
Ohio with around an inch of accumulation expected towards
Toledo.

Relevant Previous Discussion...
A potent vort max can be seen on water vapor imagery diving
south across eastern Iowa/northern Illinois. The associated
surface low is located near central Lake Michigan as of 3 AM
with a cold front draped south near the Illinois/Indiana border.

This cold front will continue to move east this morning through
this afternoon as the positive vort max and associated surface
low move east-southeast and weaken. The weakening is due to a
developing surface low off the Mid-Atlantic Coast, towards which
a portion of the available energy will transfer.

A broad area of snow showers can be seen on radar imagery ahead
of the cold front, but much of it is not reaching the ground
thanks to the dry air in place at the surface. This dry air will
delay the onset of snow showers across the area and will thus
lead to slightly reduced snowfall amounts outside of the
Snowbelt. Look for snow showers to start along the I-75
corridor late this morning into early this afternoon, the I-71
corridor near or a little after sunset, and across northwest
Pennsylvania later this evening into early tonight. As winds
turn around to the northwest behind the cold front tonight we
should see a several hour period of decent lake-enhanced
snowfall across the Snowbelt. This will begin to taper off from
west to east Sunday morning into Sunday afternoon as drier air
moves in and winds back to the west.

From this afternoon through Sunday morning a widespread trace
to 1 inch of snow is expected for everyone with higher totals on
the order of 2 to 5 inches through the Primary Snowbelt (totals
closer to 2 inches near the lakeshore and 5 inches in the
typically favored locations). A Winter Weather Advisory may be
needed for a portion of the snowbelt for tonight into early
Sunday.

Southwest flow returns by Sunday afternoon/evening and should
push much of the lake-effect snow out over the water, but
eastern parts of Erie County PA may still see snow showers
through the day.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
A trailing short wave is progged to drop across the eastern Great
Lakes and OH Valley early Sunday night and a few snow showers will
probably continue, mainly east of I-71. Winds are progged to veer a
bit more westerly or perhaps even a touch northwest and some lake
effect snow will continue. Hard to say whether there will be enough
convergence to generate a primary band or two or whether we will be
dealing with multi band snow. Will be somewhat generalized and
conservative with snow amounts for now with the highest amounts in
Erie County PA.

Subsidence and shear should be increasing by Monday morning and the
lake snow will taper off on Monday morning as boundary layer winds
back. High clouds will thicken and there is a chance of some warm
advection snow developing ahead of the next clipper Monday
afternoon. The snow would probably be patchy and mostly light until
perhaps the short wave and cold front swing across the area late
Monday or Monday night, at which time perhaps there can be some
moderate or heavier snow. An inch or two would seem likely across
the southern counties with a few inches north and perhaps more in
the snowbelt.

Strong cold advection is progged by Tuesday and temperatures on
Tuesday will not go up much. Lake effect snow should continue
including snow off lake Michigan and in the hills. Highs in the mid
and upper 20s Tuesday.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
Lake effect will taper off on Wednesday as winds begin to back again
ahead of the next clipper. It will remain cold and will forecast
highs only from around 20 to the mid 20s Wednesday.

The models are not in agreement on the track of the next clipper on
Thursday. It is too early to tell if there will be a distinct
surface low or just another fast moving wave/front. Will have a
chance or slight chance of snow showers over the entire forecast
area. Temperatures will recover to the upper 20s and lower 30s.

Will keep a chance of snow showers in the snowbelt on Friday
behind the system as another chunk of arctic air slides across the
Great Lakes. Ridging is progged to build across the plains states so
early indications are that the arctic plunge will not be as
significant.

&&

.AVIATION /12Z Saturday THROUGH Wednesday/...
VFR conditions continue through this morning across western
terminals and into this afternoon and evening for eastern
terminals. Ceilings will lower from west to east late morning
through the evening as a weakening area of low pressure moves
into the area. Areas of snow will develop ahead of the low with
MVFR/IFR conditions spreading from west to east across the
region. Chances for IFR won`t arrive until tonight east of a
line from KCLE to KCAK.

Southwest winds at 10 to 15 knots expected through today. Winds
become westerly by late in the day and eventually to the
northwest by tonight.

OUTLOOK...Non-VFR persisting downwind of Lake Erie into Sunday
morning. Another clipper storm system will likely cause non-
VFR conditions in snow Monday into Tuesday.

&&

.MARINE...
Lake effect will taper off on Wednesday as winds begin to back again
ahead of the next clipper. It will remain cold and will forecast
highs only from around 20 to the mid 20s Wednesday.

The models are not in agreement on the track of the next clipper on
Thursday. It is too early to tell if there will be a distinct
surface low or just another fast moving wave/front. Will have a
chance or slight chance of snow showers over the entire forecast
area. Temperatures will recover to the upper 20s and lower 30s.

Will keep a chance of snow showers in the snowbelt on Friday
behind the system as another chunk of arctic air slides across the
Great Lakes. Ridging is progged to build across the plains states so
early indications are that the arctic plunge will not be as
significant.

&&

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

&&

$$
SYNOPSIS...Mottice
NEAR TERM...KEC/Mottice
SHORT TERM...Kosarik
LONG TERM...Kosarik
AVIATION...Mottice
MARINE...Kosarik



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.