Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
203 am EDT Tuesday Sep 16 2014
an upper level disturbance and associated weak cold front will
pass through the Great Lakes and Ohio Valley overnight. High
pressure and a dry airmass are anticipated for Tuesday night through
Saturday. A cold front is expected to provide a chance of showers
and thunderstorms on Sunday.
Near term /until 6 am this morning/...
majority of showers have evolved in the Post-frontal environment
to become scattered in nature. There is a large swath of drizzle
behind it which will move across County Warning Area and end northwest-southeast late in the
Temperatures and other forecast parameters were generally unchanged other
than blending current trend to the forecast.
Short term /6 am this morning through Wednesday night/...
a few showers may linger Tuesday morning south of the Ohio River
behind the departing front. Otherwise...high pressure will begin
to build in from the northwest. Considerable cloudiness will
linger through the morning with skies gradually becoming partly
cloudy through the afternoon hours. The high will remain over the
region through Wednesday. The associated dry airmass and downward
motion will result in period of mainly clear and rather cool
conditions. Highs Tuesday mainly in the 60s will be bumped up a
couple degrees toward 70 on Wednesday. Lows will be primarily in
the 40s...with some 50s south of the Ohio River on Wednesday
Long term /Thursday through Monday/...
highly amplified middle/upper level flow characterized by strong ridge
over The Rockies and mean trough over eastern North America at middle
week. This places the Ohio Valley in northwest flow regime.
A weakening cold front to drop south across the Great Lakes
Wednesday night and wash out. Broad surface high pressure of Canadian
origin to build southeast across the Great Lakes through the end of the week.
Dry and cool weather to continue Thursday with highs again from
the upper 60s north to the lower 70s south.
Middle level flow will become more westerly with the center of surface high
pressure tracking into New England. A low level southerly flow will
develop on the backside of re-treating surface high. This will allow for
a slight modification of temperatures with highs on Friday from the
lower 70s north to the upper 70s south.
Middle level flow backs southwesterly ahead of middle level trough
developing over the north central US. Will keep the area dry on
Saturday and will allow for a warm up. Expect highs from the upper
70s north to around 80 south.
Progressive middle level trough to translate east with associated surface
cold front pushing into the Ohio Valley Sunday. Will introduce
chance probability of precipitation late Saturday night and into the northwest and across the
entire forecast area Sunday.
Aviation /06z Tuesday through Saturday/...
500 mb short wave has is working east of the region quickly tonight. At the
surface...cold front has pushed through the tafs...leaving an area of Post
frontal drizzle across the middle. The drizzle should move
through the tafs in the next 2 to 3 hours....but ceilings will lower
to IFR behind it. MVFR to IFR visibilities will be possible before
After 12z...the low level moisture will linger through the morning hours
leaving MVFR ceilings across the tafs. During the afternoon...the clouds
will start to mix as drier air moves in.
Surface high pressure will build into the area tonight...resulting
in clearing skies.
Outlook...MVFR/IFR visibilities are possible tonight.