Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 290552
Area Forecast Discussion
National Weather Service Louisville KY
152 AM EDT MON AUG 29 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Monday Night)...
Issued at 300 PM EDT Sun Aug 28 2016
A shortwave rounding the western edge of the ridge to our east is
helping kick off convection this afternoon in a moderately unstable
environment. Expect isld-scattered storms to continue to develop
over the area late this afternoon and lasting through the evening
hours before diminishing. The main threats with these storms will
be gusty winds and very heavy rainfall. A few storms have the
potential to become severe with wind gusts over 50 mph. Also, with
very slow storm motions and very heavy rainfall, minor flooding
issues may be a concern this evening.
For tonight, expect dry conditions by late evening and through the
overnight hours. Low temperatures will bottom out in the lower 70s
Monday will be another hot, muggy day with 20-30% chances of
showers/storms during the afternoon/early evening hrs. At this
point, the short range models don`t show a clear trigger for storms.
Think that left over boundaries from tonight`s convection may be a
determining factor for tomorrow`s. Soundings are again favorable for
pulse type storms with gusty winds and heavy rainfall. High temps
will be in the upper 80s/lower 90s with heat indices nearing 100
degrees during the late afternoon hours. Monday night lows will
range from the upper 60s/lower 70s.
.LONG TERM (Tuesday through Sunday)...
Issued at 320 PM EDT Sun Aug 28 2016
Tuesday - Wednesday...
A few more hot days ahead Tue/Wed before a front comes through late
Wed. Tue looks mainly dry with no real trigger in the area to spark
storms and a decent cap aloft. However, Wed afternoon we could see a
few storms during the afternoon/evening hours as we get some forcing
as the cold front approaches from the NNW. The exact timing of the
fropa will determine how far south we see storms push into our
region before we lose instability into the evening hours and
convection diminishes. Will focus the best convection chances over
southern Indiana for now and adjust in coming days as the forecast
becomes a bit more clear.
Thursday - Sunday...
A much more pleasant airmass will arrive behind the front for the
rest of the work week. Highs will drop back into the upper 70s to
mid 80s for Thu/Fri/Sat with lower humidities. The airmass will be
more stable as well in the upper trough resulting in dry days.
By Sunday, however, we`ll start to see a warm-up as an upper ridge
begins to work back into the region from the west. Highs will be
back into the mid to upper 80s with dewpts creeping back toward 70
.AVIATION (00Z TAF Update)...
Issued at 150 AM EDT Mon Aug 29 2016
Outflow boundaries from late Sunday afternoon thunderstorms in
central KY have pushed west of all TAF sites, pushing the 70+
dewpoints out of the area, which should reduce the likelihood of fog
development before sunrise, so have gone with only tempo 5-6SM at
LEX and SDF. At BWG however, 0.40" of rain fell yesterday, so have
dropped prevailing vsby into MVFR range from 08-13Z, and given the
local climatology, a TEMPO IFR vsby is not out of the realm of
Model soundings again show high precipitable water in the area, but
at least one model indicates a strong enough thermal cap to prevent
surface based convection breaking through. That, combined with the
impressive outflow from Sunday`s storms that not only dropped dew
points, but appears to have pushed any lingering surface boundaries
out of the area, supports considerably less thunderstorm development
for the TAF sites than yesterday. Even so, there is still plenty of
potential energy to tap into should something break the cap, so have
included a PROB30 group for the afternoon hours at all sites.