Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
432 PM EDT Thursday may 28 2015
a more humid and unstable airmass will return on Friday and
Saturday...with increasing chances for showers and thunderstorms.
Another cold front will move into the area on Sunday...continuing
the chances for storms through the weekend.
Near term /until 6 am Friday morning/...
with weak forcing and marginal instability...showers have yet to
pop this afternoon. Will keep an eye on radar trends and adjust
the probability of precipitation accordingly.
As the night progresses...high pressure over the eastern Great
Lakes will drift to the East Coast. Southerly flow on the back side of
the high will pull more unstable air into the region. There are
numerous differences between the models for tonight. Most of the
larger scale models are trying to bring or keep isolated
convection going all night long. Decided to keep much of the night
dry...but brought some 20 probability of precipitation into the SW corner of the forecast area around
Temperatures tonight will drop back into the middle 60s...with a few
rural locations making the lower 60s.
Short term /6 am Friday morning through Saturday night/...
the broad SW flow continues on Friday. Scattered convection should
develop during the day. The forcing looks to be broad and equal
across the forecast area...making it difficult to give any one location a
higher pop. Best timing will be during the afternoon...but cant
rule it out in the late morning hours. Decided to go with just a
low chance pop.
Probability of precipitation should drop a little Friday night...due to the diurnal
cycle...but will not go dry Friday night.
By Saturday morning...a cold front will be approaching from the northwest.
The instability will increase ahead of the cold front. Convection
should increase rapidly in coverage Saturday afternoon. Kept the
categorical probability of precipitation across the northwest by late Saturday afternoon...and
high chance in the southeast. The front drops down into the forecast area Saturday
night...so increased probability of precipitation a little. Went with the better probability of precipitation in the
northwest early Saturday evening. Expect the convection to weaken a
little by late Saturday night...so only went with likely probability of precipitation in
High temperatures tomorrow will work back into the lower to middle
80s depending on where the precipitation develops. Low temperatures Friday
night should be warm with much of the region only falling into the
upper 60s. Temperatures on Saturday will be slightly cooler than
Friday...with highs in the lower 80s. By Saturday night the
effects of the cold front will be felt across the northern half of
the region. Lows will be down into the middle to upper 50s across
the northern half...with southern sections in the lower to middle 60s.
Long term /Sunday through Thursday/...
a cold front will be actively exiting the Ohio Valley at daybreak
Sunday with some lingering showers or thunderstorms during the
morning due to potential timing issues. In its wake...a large area
of high pressure will situate itself over the Great Lakes region and
Northern Ohio valley Sunday and slide eastward Monday. As the winds
shift around the departing high...east winds will prevail over the
region as an inverted surface trough may be a focus for shower
activity over Kentucky.
HPC showing a warm front lifting NE through the region on Tuesday
which is not apparent in the surface depictions for either Tuesday
or Wednesday next week. Southerly flow begins to take a more
pronounced hold on the region Wednesday which may help support the
argument for a warm front north of the Ohio Valley Wednesday and Thursday.
Temperatures will be cool to start with. Sundays highs middle 60s north to middle
70s south...warming to the lower and middle 80s by Thursday and
Friday. Overnight lows in the 50s Sunday night will nose to the
lower 60s Tuesday night. By then there should be increased moisture
to the region so that middle and upper 60s are more indicative of
overnight lows for the latter part of next week.
Precipitation will be pushed to the south Sunday and never quite leave the
forecast entirely as the northern push of colder and drier air may
be a strong enough convergent force over Kentucky where some more moist
air will reside. Initially thought thunder for the forecast but
toned back to just showers beginning Sunday night and lasting
through early Wednesday...coinciding with the lower chances of
precipitation. After this time daytime heating and a return to south flow
would necessitate inclusion of thunder to the forecast.
Aviation /19z Thursday through Tuesday/...
clouds bases will continue to lift with all locations becoming VFR
early in the taf period. Cumulus will diminish with the loss of
heating. Middle clouds will spread north across the region overnight.
This should limit potential for visibility restrictions although
still allowed for that possibility at kluk. As middle clouds move out
a scattered to broken cumulus deck will develop late in the
period. Could be some storms developing by then but the chance is
too low to include in the tafs that far out in time.
Outlook...thunderstorms will be possible Friday afternoon into
Saturday evening. MVFR ceilings possible Saturday night through