Scientific Forecaster Discussion
fxus61 kcle 192018
Area forecast discussion
National Weather Service Cleveland Ohio
318 PM EST Fri Jan 19 2018
a large area of high pressure centered over the southeastern
United States will move off the Carolina coast by early Sunday.
A ridge stretching north from the high will linger over the
local area through tomorrow night. An area of deepening low
over Oklahoma Saturday will move to the western Great Lakes by
Monday evening forcing a cold front east across the local area
Monday night. High pressure will build into the area from the
west through the middle of the week.
Near term /through Saturday night/...
just some high clouds expected across the area overnight. Temps
have struggled to get much above freezing today except in the
good downslope areas. Strong southerly winds will continue so
not expecting much of a temperature drop off tonight. Most
locations will drop 5 to 8 degrees and that is about it.
Tomorrow moistening finally occurs in the lower levels. Forecast
soundings showing a sharp inversion persisting at under 5000
feet during the day so a layer of strato cumulus will likely
form by midday. The warm air advection will continue Saturday
night and models continue to show some light precip developing
overnight. Most of this will have a hard time reaching the
surface given the dry mid levels above the inversion. Will
continue with small chance mention of very light precip. More
than likely it will be just some patchy drizzle or sprinkles.
Temps tomorrow night will likely drop off a few degrees after
sunset and then should hold steady or even rise a few degrees.
This is important because this means any precip that does form
will be liquid and not freezing or frozen precip. Only the
southern end of the area has a legitimate chance to see
measurable precip by 12z Sunday.
Short term /Sunday through Tuesday/...
persistent warm air advection into the region will bring above normal temperatures
to the area Sunday into Monday. Isentropic ascent will lift north
into the forecast area on Sunday, with increasing chances for light
rain and/or drizzle. Expecting any precip to be light and more of a
drizzle through most of the day Sunday, however even with any rain
quantitative precipitation forecast amounts will be light, generally under a tenth of an inch. A
little better forcing move north through the region late Sunday
night into early Monday, with could lead to some rain showers, with
high chance to low likely pops during this period. Rain chances
decrease a bit Monday morning across the area, especially east of I-
71, as a cold front approaches the region from the west. Pops
increase through the day as the front moves toward the area. Models
still a bit off with timing, but are coming to better agreement. The
highest pops will be from 18z Monday through 06z Tuesday. Most of
the precip will remain rain as the front passes with a brief
transition to snow with any lingering precip behind the front.
Continued with chance/likely pops on Tuesday as the upper low tracks
east across the area. Some lake enhancement is possible across the
snowbelt, especially in the wake of the low, but will be dependent
on the amount of open water over the lake. No major changes to
temperatures through this period, with highs on Monday possibly
reaching the low 50s across the area ahead of the frontal passage.
Temperatures will generally be falling through the 30s during the
day Tuesday behind the front.
Long term /Tuesday through Friday/...
little change in the extended. Lingering surface trough across
the eastern Great Lakes will continue to produce snow showers in
the snowbelt through Wednesday. Trough will finally shift east
as a large dome of Arctic air will moves across the Ohio Valley
Thursday. The high quickly shifts east setting up warming trend
across the forecast area. Temperates warm into the lower to mid
30s Thursday, and into the lower 40s on Friday.
Aviation /18z Friday through Wednesday/...
just some high thin clouds expected through tonight. Lower
levels will begin to moisten tomorrow morning and will see a
layer of strato cumulus begin to develop during the morning
hours. Some of the guidance is showing MVFR cigs by the end of
the period. Think better chances for that will exist after the
taf period ends. Gusty S to SW flow will continue. Peak gusts
will be around 25 knots most locations.
Outlook...non-VFR Monday through Tuesday.
persistent southwest flow will continue through the weekend. Winds
15-25 kts tonight and Saturday will subside Saturday night and
Sunday. Southerly flow increases ahead of a cold front on Monday
with winds veering southwest by Tuesday. Light westerly flow will
continue through the rest of the week.