Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
1120 am EDT Mon Oct 24 2016
a dry pattern is expected today into Wednesday as high pressure
builds from the northwest. A potent low pressure system tracking
across the Great Lakes will bring the likelihood for showers and
maybe a thunderstorm Wednesday night into Thursday.
Near term /until 6 PM this evening/...
24.12z Kiln sounding showed the airmass we'll be in today in the
wake of the strong cold front which has shifted east of the area.
Deep dry air above the boundary layer /below normal precipitable water per
sounding climo/ will favorably mix to the surface on cold
advection this afternoon under plenty of sunshine. Going forecast
was on track and only cosmetic adjustments to sky cover and temps
/allowing for a little cooler air mainly southern half of the
forecast area/. Raised wind gusts a little as well in favored
terrain areas as north/northeast winds will be a little gusty
through peak heating.
Short term /6 PM this evening through Wednesday night/...
high pressure will settle down over the region tonight in NW flow
aloft. Skies should be mostly clear and winds will be light. A few
cirrus might try to filter in towards sunrise in the W. The good
radiational cooling conditions should allow temperatures to fall
in the upper 30s for much over the region. Some of the normal cold
spots could drop down into the mid 30s. Nrn Kentucky counties could
stay in in the lower 40s. Expect some frost development tonight.
Will hold off on any advisory as it should be patchy except for
the colder locations.
Clouds will be on the increase Tuesday as isentropic lift brings
high clouds into the region. Highs Tuesday will be limited by the
cool start and by the increasing cloud cover, so kept them in the
mid 50s to lower 60s.
Tuesday night will remain dry as 500 mb ridge reaches the Ohio Valley.
Mid and high clouds will continue to thicken as the isentropic
Fast moving 500 mb S/W will swing out of the plains and into the
lower Ohio Valley Wednesday. The consensus of the models is for
the region to stay dry Wednesday, so delayed the pcpn chances
until Wednesday night. Highs on Wednesday will see a large range
across the region. Extreme SW portions of nrn Kentucky could make the
upper 60s, with srn OH and se in making the mid 60s. Meanwhile
across west central Ohio and central Ohio temperatures will stay
in the upper 50s.
Low pressure system and cdfnt push through the region Wednesday
night. Went with likely pops across the N, but kept chance pops
for the extreme srn counties. Instability is marginal across the
area with this system. Did add slight chance of thunder to the NW
counties for the first few hours of Wednesday night.
Long term /Thursday through Sunday/...
precipitation to end from west to east Thursday with highs from
the upper 50s north to the middle 60s south.
Surface high pressure to build in at the end of the week, offering a
return to dry weather conditions. Highs to range from the upper 50s
north to the mid 60s south.
Next surface low to approach the area later Saturday. Model solns
showing differences in strength and timing. Have held off any
precipitation until late Saturday night. On warm side of this system
and back side of retreating surface high pressure expect
temperatures to be a few degree above normal. Saturdays highs to
range from the lower 60s far north to the upper 60s south. Will
spread pops across the entire forecast area Saturday when the low and
associated front is expected to impact the area. Have opted to go
with more progressive solution ending precipitation Sunday but if the
system is slower then pops will be required.
Aviation /15z Monday through Friday/...
the cold front and associated wind shift have moved through the
taf sites this morning. MVFR Post-frontal stratocu have developed
across central and west-central Ohio that will move south through
the terminals through 18z. Brief MVFR cigs are possible area-wide through
15z before lifting to a few/scattered VFR clouds by this afternoon. Any
lingering clouds are expected to dissipate this evening, with sky clear
anticipated past 00z Tuesday for all sites as high pressure
settles into the area.
Winds will be out of the north-northwest through the day at about
10 kts. As high pressure moves in this evening and the gradient
relaxes, light winds are expected past 00z Tuesday. Mid/high
level clouds will be on the increase from the west towards the end
of the taf period.
Outlook...MVFR ceilings and visibilities are possible from
Wednesday night through Thursday afternoon.