Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
150 PM EDT Tuesday Oct 21 2014
upper level low pressure will linger over the eastern Ohio Valley
today and tonight. High pressure both at the surface and aloft
will then settle over the region and bring a threat for frost
Thursday morning. After this...each successive day will see a
slight rise in temperatures as the high moves east and flow turns
Near term /until 6 PM this evening/...
an upper level trough axis will pivot down across the area through
early afternoon. Expect isolated to scattered shower activity
across northern Indiana and Northern Ohio to work its way south
into our area through the rest of the morning hours and could
even see it fill in a bit as low level lapse rates increase a
little more. Precipitation should be fairly light but will none the less
nudge up probability of precipitation into higher chance category across the northeast...tapering
back to isolated across our southwest. Given a fair amount of
clouds and some low level cold air advection...do not expect too much of a rise
in temperatures today with highs generally in the lower 50s.
Short term /6 PM this evening through Friday/...
the upper level low will still be found in close proximity to the
County Warning Area tonight. Cloud cover with the low will limit runaway low
temperatures but there is the possibility that skies could clear
more and temperatures would need to be adjusted downward towards
the values that would support frost. However...wind should stay up
to limit the potential for this to occur...even if skies clear and
Cloud cover will be on the increase Thursday night as a middle level
shortwave weakens as it drops from the upper Midwest to the Ohio
Valley. This will limit the dropoff in temperatures Thursday night
to be a few degrees warmer than on Wednesday night...also limiting
the potential for frost.
High pressure will build in at the surface with ridging aloft
Wednesday afternoon and night...bringing a more significant threat
for frost for Thursday morning. After this cool start...flow will
turn southerly and a warmup will occur through the weekend and
into next week.
Long term /Friday night through Monday/...
northwest flow aloft around the periphery of large ridge over The
Rockies. Surface high pressure to re-establish itself over the Ohio
Valley offering continued dry weather Saturday into Monday. A
warming trend is expected...with highs on Saturday generally in
the middle 60s...in the middle 60s NE to near 70 SW on Sunday and in the
upper 60s NE to the lower 70s SW on Monday.
Aviation /18z Tuesday through Sunday/...
isolated to scattered light rain showers are pivoting down across
the area this afternoon in association with short wave energy
rotating down the back side of the upper level low. Ceilings will
continue to vary between lower VFR and MVFR through the remainder
of the afternoon hours and will cover precipitation threat with just a
vcsh...primarily at the northern/eastern taf sites. Visible
satellite imagery is suggesting that some of the cloud cover
across Indiana is more diurnal...but it still looks pretty solid
farther north and east across lower Michigan and Ohio. Think
kcvg/kluk may end up near the edge of at least some partial
clearing...but in a cyclonic low level flow pattern...will lean
toward the more moist NAM solution for overnight and hang on to a
good deal of primarily MVFR ceilings across the area through tonight.
Ceilings should then scatter out later Wednesday morning into the
afternoon as high pressure and a drier airmass builds in from the
Outlook...no significant weather expected.