Area Forecast Discussion
Issued by NWS Cleveland, OH
FXUS61 KCLE 030910
Area Forecast Discussion
National Weather Service Cleveland OH
410 AM EST Sat Dec 3 2016
High pressure will begin to build east across the Great Lakes
region today. The high will move east over the weekend and off the
New England coast by Sunday night. A warm front will lift
northeast through the region Sunday night with high pressure
building back into the region on Monday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Lake effect has been predominantly east of Erie this early this
morning, as shown by low level trajectories with Lake Huron
contribution. Trajectories from secondary/westward Huron band
would favor an uptick in precip across Erie/NE Crawford over the
next several hours. Maintained cat/likely pops in this area over
the next few hours, with lesser chances along the NW Ohio
snowbelt. This activity is expected to taper off through the day
as flow backs westerly. Expecting mainly an inch or less in the
higher elevation in NW PA through the day. Otherwise, quiet
weather elsewhere, with cloudy conditions and seasonable
temperatures near 40 as high pressure begins to build across the
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Lake effect will continue to diminish Saturday night as high
pressure builds east across the region. Attention turns to shortwave
ejecting from the Plains towards the Great Lakes Sunday. This wave
will tap into some return flow and overspread some light precip
across the forecast area Sunday afternoon and evening. Expecting
fairly light amounts with best forcing north of the area, however a
rain/snow mix at the onset cannot be ruled out, with predominantly
rain Sunday afternoon. Thermal profiles suggest a changeover to
mainly snow for much of the area, especially higher elevations,
Sunday evening and overnight, where a few tenths up to an inch of
snow accumulation in higher elevations is possible.
After another brief shot of high pressure and dry conditions Monday,
potent southern stream shortwave will eject through the Ohio valley
Tuesday. Some difference remain between the models with respect to
precip onset timing, however confident enough in the Tuesday
time frame to raise pops a bit to likely most locations and
categorical south. This event should mainly be rain, however a
brief mix cannot be ruled out in higher elevations. This system
will begin to exit the region Tuesday night. Overall, temperatures
will remain near or slight above normal through Tuesday night.
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
Models still advertise the coldest air of the season arriving
during the extended. Some differences remain in timing and details
but very cold air with 850mb temperatures of -16 to -18C will
result in lake effect snow for the end of next week. The 00Z
GFS/GEM show the colder air arriving on Wednesday night with cold
advection continuing right through the day on Thursday. Meanwhile
the 00Z ECMWF is slower with the upper level trough and shows a
wave of low pressure moving north through the Ohio Valley on
Thursday in advance of the cold push. Not a lot of confidence in
which solution will verify but think it is entirely possible for
the whole system to slow as the trough deepens to our west. Did go
with a blended approach for now with respect to temperatures, with
highs gradually cooling from Wednesday through Friday. Models in
good agreement that there will be a prolonged period of westerly
flow across Lake Erie behind the front which will be a favorable
set-up for lake effect snow. Flow down the long fetch of the lake
does support the potential for significant accumulations for a
portion of the primary snow belt.
.AVIATION /06Z Saturday THROUGH Wednesday/...
Marginal lake effect conditions will continue thru saturday but any
rain or snow showers should mostly just affect ERI. Mix of vfr and
mvfr cigs should continue to lower some the rest of tonight into sat
morning but should still stay mostly mvfr except may higher end ifr
at yng. A little improvement in cigs is expected by late sat
afternoon but inversion should keep cigs bkn to ovc with mix of
mvfr and vfr.
OUTLOOK...Mostly mvfr cigs much of the time thru wed with areas of
rain and snow.
As of 3 AM, winds on the east end of the lake remained at or above
20 knots. Winds will decrease into the 15-20 knot range through the
morning with waves gradually following suit. The Small Craft
Advisory remains in effect east of Willowick until 10 AM. Have
extended the Advisory until 4 PM for the Pennsylvania waters where
waves are expected to be a little slower to subside.
High pressure will expand over Lake Erie tonight with winds dropping
below 10 knots late. Generally good marine conditions expected to
continue through Monday as a weak trough lifts north across the
lake. East to southeast winds will increase to 15 to 20 knots ahead
of a fast moving low that will track north from the Gulf Coast to
the eastern Great Lakes. A strong cold front will follow during the
mid-week period with strong westerly winds to end the week.
MARINE...Small Craft Advisory until 10 AM EST this morning for LEZ147-
Small Craft Advisory until 4 PM EST this afternoon for LEZ149.