National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 191733
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
133 PM EDT Wed Sep 19 2018

.SYNOPSIS...
A weak front will bisect the region today and then lift back
north tonight. A stronger cold front will cross the area Friday
afternoon and evening. High pressure will build across the Great
Lakes over the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A few stray/spotty showers continue to weaken across south-
central Ohio this morning with the associated band of mid clouds
slowly progressing southeast. In its wake, mainly clear skies
will overspread the local area through the late morning and
early afternoon hours, including in the far northwest ILN FA
where some low clouds continue to erode.

Some diurnally-driven Cu development will occur near and after
the noontime hour, with a very stray popup shower or storm
possible during the middle and late afternoon across the central
ILN FA. The coverage of this will remain extremely isolated even
at its best, but felt it was prudent to maintain the slight
chance PoP near and just north of the Ohio River during peak
heating hours.

With a gradual increase in sunshine through the late morning
hours, temperatures will warm quite quickly through early
afternoon. Temperatures near 90 degrees will be common once
again this afternoon south of the I-70 corridor, especially in
the absence of any widespread cloud of precipitation coverage.
Near and north of I-70, temps will top out in the mid and upper
80s near and behind (north of) the weak surface boundary.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Weak boundary across the area will lift north late tonight into
Thursday morning. Cannot rule out a few showers and
thunderstorms near this retreating front in the northwest
counties. A weak disturbance riding along the periphery of a
building mid level ridge could result in a few more storms later
in the day. Given subtle forcing, confidence is low on
precipitation occurring. Very warm temperatures will continue
with lows tonight and highs Thursday being 10 to 15 degrees
above normal.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Global models in generally good agreement with a deamplifying mid
level ridge and broad shortwave across the upper great lakes
bringing an intensifying shortwave and associated frontal boundary
through the region by Friday evening. While overall bulk shear
favorable for some storms containing damaging winds, instability
will be somewhat marginal. Will continue to include mention of
strong to isolated severe storms Friday afternoon through early
evening. Increasing clouds and precipitation will bring the above
normal temperatures back down to closer to seasonable values, and
then seasonable lows in the mid 50s to low 60s with the passage of
the frontal boundary Friday night.

Both the deterministic GFS and ECMWF hanging up the frontal boundary
in the Tennessee valley through the day on Saturday. There are still
several members of the GEFS which linger the precipitation further
north.  Previous runs had been more consistent with lingering
precipitation further north and affecting the far southern forecast
area, but the trend with each run has been slightly south. Lingering
frontal boundary and associated precipitation may more likely remain
in central KY given the deterministic trends, but keeping slight
chances for precipitation through Saturday very close to and south
of the Ohio River.

Seasonable temperatures with just the southern forecast area at risk
for scattered to isolated showers and storms through the day on
Sunday as a more zonal flow pattern sets up over the upper CONUS
while the washed out frontal boundary lingers over the TN/southern
OH valley.

For Monday into Tuesday, a deepening trough over the upper plains
combines with the lingering/flattened ridge over the SE CONUS to
allow for a prolonged period of southwesterly flow and increased
moisture into the forecast area. Differences between the
ECMWF/GFS/GEFS with just how active the early part of next week will
be. ECMWF more generous with the precipitation potential, whereas
the GFS is more scattered. Given the favorable upper level pattern
to a more prolonged period of precipitation potential with a slow
moving trough and the lingering ridge in the SE CONUS, have raised
chances for precipitation Monday into Tuesday. Near normal
temperatures during this period in the upper 70s for highs and
50s/low 60s for lows with ample cloud cover and rainfall
potential.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Early morning VSBY restrictions and spotty -SHRA coverage has
ended, yielding VFR and dry conditions for the local terminals.
Although a very spotty afternoon/early evening -SHRA cannot be
completely ruled out, particularly for KCVG, KLUK, and KILN,
coverage will be sparse enough as to not include a VC at this
time.

FEW to SCT VFR Cu/stratocu will slowly be on the increase from
the south/southwest after 06z, but should any CIGs develop, they
are expected to remain VFR.

With the skies not expected to be completely clear overnight,
BR/FG development may end up being a bit more limited than would
otherwise occur under clearer skies. However, still expect that
KLUK could see IFR or lower VSBYs briefly in the several hour
period around sunrise. Some brief MVFR VSBY restrictions may
also occur at KLCK.

Light and variable winds will transition to a steadier (albeit
still light) easterly and eventually southeasterly surface flow
late tonight into the early morning hours of Thursday. Southerly
winds of around 5-8kts will develop towards the end of the
period.

OUTLOOK...Thunderstorms possible Friday afternoon into Friday
night.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...
NEAR TERM...KC
SHORT TERM...
LONG TERM...JDR
AVIATION...KC