Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 290051
Area Forecast Discussion
National Weather Service Louisville KY
851 PM EDT THU JUL 28 2016
Issued at 851 PM EDT Thu Jul 28 2016
Just a quick update on what is currently going on across the region.
A disorganized line of showers roughly along the I-64 corridor
continues to sink slowly SSE. A few rumbles of thunder have also
been noted, but the overall trends are weakening. A few quick bursts
of heavy rainfall are still possible along with a few gusts between
20 and 30 mph.
West of I-64, the environment remains slightly better for some
organized and stronger storms. In fact, current Severe Warned Storm
near Evansville, IN sits on the nose of an instability axis where
deep layer shear is around 30 knots. Good wind signature off the VWX
radar in an environment supporting 1200 J/KG of D-CAPE is likely
producing a wind threat. Will keep a close eye on this feature as it
approaches our western CWA, but will note that outflow has alredy
gotten a bit ahead of the reflectivity, so anticipate it being sub-
severe when it arrives. Still gusts over 35 mph cant be ruled out
for what will likely be the Hancock/Ohio/Breckinridge county region.
Overall, think the flood threat will remain low through the
overnight as storms have decent motion, coverage is limited, and
overall rates are weaker.
Issued at 525 PM EDT Thu Jul 28 2016
...Flash Flood Watch for East Central KY Cancelled...
Cancelled the Flash Flood Watch for the remaining portions of our
CWA as rainfall has ended. Can`t rule out a few pop up showers or
storms this evening and overnight, but overall Flash Flood threat
Main focus for the rest of the evening will be on cluster of storms
over south central IN. Latest Hi Res data takes the cluster to the
Ohio River before weakening, but seems a bit overdone with initial
coverage. Given an unstable environment and a weak trigger in the
form of a surface low over the lower Wabash River Valley will
mention 40% chance of showers and storms into southern IN and north
central KY around sunset. Some of these areas do have lower Flash
Flood guidance given recent heavy rainfall, and with slow movement
localized hydro problems can`t be ruled out. However, don`t feel
there is enough concern or confidence to issue a new headline at
.SHORT TERM (Now through Friday Night)...
Issued at 330 PM EDT Thu Jul 28 2016
...Rain tapering off this evening...
Have continued to trim back the Flash Flood Watch to the west of
what should be the final area of precip to move through central KY
this afternoon and evening. Out of an abundance of caution have
kept the Watch going in the eastern part of the CWA. Rainfall rates
in the last batch of rain are not nearly as high as what has
occurred over the past 24 hours, but given that precipitable water
continues to exceed 2 inches, will let the evening shift make the
final call on trimming the last of it once the rain has exited.
With all but a few areas to the west of Louisville having had an
inch or more of rain since yesterday, patchy fog is likely late
tonight. Rather than split hairs on location, will include it in
all areas, which matches up with neighboring WFOs.
With the passage of the vort lobe responsible for today`s rain, we
get about a 24-hr reprieve of any organized precip. Dew points
generally remain at or above 70, though, so disorganized precip - in
the form of afternoon pop-up storms will occur again Friday. 30-40
POPs may be a bit high considering lack of dynamics, but with
abundant moisture, any breaks in the clouds should be enough to warm
the surface to convective temps, which are right at forecast highs,
in the mid 80s.
Overnight lows tonight and tomorrow night will be mainly 70-75.
.LONG TERM (Saturday through Thursday)...
Issued at 330 PM EDT Thu Jul 28 2016
Little overall change in the upper level pattern is forecast for the
bulk of the extended period. The large, relatively flat ridge
stretching east-west across the southern 1/4 of the country remains
in place, with a series of short waves moving across the country to
our north. The ridge does flatten a bit out west over the weekend,
with hints that the axis will shift east in to the central plains
and reintensify somewhat. All in all, however, the daily forecasts
will vary little. Max temperatures will fluctuate from the mid 80s
to around 90, while minimum readings stay in the 70-75 degree range.
While POPs are included in every forecast period, this does not mean
daily rain for everyone, as the hit-or-miss nature of the storms
will mimic that of the past week.
.AVIATION (00Z TAF Update)...
Issued at 700 PM EDT THU JUL 28 2016
Main concern for the start of this TAF cycle will be a broken line
of showers and a few storms approaching SDF. These storms are in a
weakening state, but expect a few rumbles of thunder in the vicinity
along with some brief vis reductions are possible. Additionally a
few gusts out of the NW between 20 and 25 mph are possible.
Otherwise, conditions should return to VFR at SDF by 03z with broken
ceilings slightly above the VFR/MVFR threshold. Some fog related vis
restrictions in the MVFR range are then possible toward dawn.
VFR/MVFR stratocu is also possible toward dawn. As we move past
daylight conditions will slowly improve back to VFR with a steady
WSW wind gradually taking hold. Scattered showers and storms are
again possible on Friday but will hold off nailing down any details
this far out.
LEX should be VFR by the time the new forecast cycle goes into
effect. However, expect the MVFR vis/cigs should be possible around
or just before midnight, going into IFR vis/cigs in the pre-dawn
hours. Slow improvement on Friday, but do expect an eventual return
to VFR by midday or early afternoon. A steady WSW wind will also
take hold with scattered showers and storms again possible in the
afternoon and early evening.
BWG should expect to see decreasing visibilities and cigs around
Midnight CDT, followed by a likely trip into IFR toward dawn. After
slow improvement through the morning, a return to VFR is expected
with a steady WSW wind. Scattered shower and storm chances will
apply to this site as well through the afternoon/evening.