Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
425 am EDT Tuesday Jul 28 2015
a weak frontal boundary will linger over Kentucky today and
tonight. A cold front will provide the focus for thunderstorm
development later on Wednesday. High pressure and a drier airmass
are expected for Thursday and last into the weekend.
Near term /until 6 PM this evening/...
humid air with dewpoints lingering within a few degrees of 70 will
continue to permit the development of showers and isolated
thunderstorms for yet another day. The focus today will be late
day and evening showers sprouting south of the I-70 corridor with
daytime heating and then diminishing. With very little flow aloft
storms that develop will be slow movers and contain very heavy
rainfall...then rain themselves out.
Highs will top out in the upper 80s to around 90 and be a bit
uncomfortable with the high dewpoints and apparent temperatures in
the middle to upper 90s for southern half of County Warning Area.
Short term /6 PM this evening through Friday/...
showers will diminish significantly in the evening and die out
entirely before daybreak. With the approach of a cold front on
Wednesday...the airmass will be ripe for another round of
thunderstorms spreading in from the west Wednesday evening. Storms
overnight will spread southeast and drier air behind the front
will mark an end to the humid airmass for Thursday into Friday.
Overnight lows through the period will be around 70 with the
higher dewpoints...then drop to the middle 60s Wednesday night in
the Post frontal atmosphere...lower to middle 60s Thursday night
with generally clear skies.
Highs will top out in the upper 80s to around 90...middle 80s
Long term /Friday night through Monday/...
progressive middle level trough/upper low to move from the northern plains/southern
Canada across the Great Lakes at middle week flattening out the northern
portion of the ridge. This will allow an associated surface cold front
to push through the region late Wednesday night/early Thursday.
Will continue mention of low chance probability of precipitation for thunderstorms Wednesday afternoon
as moisture and moderate instability returns. On the warm side of the
system...warm temperatures to continue Wednesday ahead of the front
with highs from the upper 80s northwest to the lower 90s southeast.
Will bump up probability of precipitation to high chance Wednesday night with the approach and
passage of the front. Model solutions a little faster with the cold frontal
passage. Therefore...will end all precipitation very early in the southeast.
As surface high pressure begins to nose in Thursday...dry conditions
will return. Temperatures will be a little cooler with highs from the
lower 80s northwest to the upper 80s southeast.
Northwest flow aloft with surface high pressure building across the region
late in the week into next weekend. High temperatures on both Friday
and Saturday will be close to normal with highs in the lower 80s
to upper 80s.
Model solution differences exist regarding precipitation late next weekend
associated with surface front dropping into the Great Lakes. Will limit
probability of precipitation to slight chance across the north Sunday afternoon and then bring
chance probability of precipitation County Warning Area wide Monday. Highs Sunday and Monday will be close
to normal ranging from the lower 80s north to the upper 80s south.
Aviation /08z Tuesday through Saturday/...
weak front has stalled around the Ohio River. Higher dewpoints
pooling around the front will combine with light winds to provide
good conditions for fog development in the southern tafs. Went LIFR visibilities
at kluk...and some IFR at iln and MVFR at cvg.
Fog will burn off after sunrise...bringing a return to VFR
conditions. 500 mb ridge begins to build NE into the region. This will
begin to inhibit thunderstorm development. There should still be
enough convergence around the front that there will be some
isolated convection over the southern taf sites closer to the frontal
boundary. Only mentioned a vcsh at kcvg and kluk this afternoon. Convection
should end around sunset.
Outlook...thunderstorms are possible from Wednesday into