Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 051909
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
309 PM EDT Sun Jul 5 2015
.SHORT TERM (Now through Monday Night)...
Issued at 257 PM EDT Sun Jul 5 2015
Water vapor imagery this afternoon shows a well defined circulation
in the upper level flow over eastern Kentucky. At the surface low
pressure is centered near the KY/VA border. The majority of the
showers this afternoon will be across east central Kentucky where
light to moderate rains continue. There could be a few stronger
showers around the Lake Cumberland area. However, for the most part
these should only produce brief heavy rainfall and are not expected
to cause any additional flooding issues. Therefore have decided to
cancel the Flash Flood Watch this afternoon. Short term models also
have isolated to scattered showers developing across southwestern
portions of south central KY this afternoon. These should wane by
All of the rain should move out of the area by early evening. The
overnight hours are expected to be dry with light to calm winds and
partly to mostly cloudy skies. With plenty of low level moisture,
some patchy fog may develop across the region, so have added that in
to the forecast.
Southwesterly flow will set up tomorrow ahead of a cold front which
will begin to approach the region tomorrow night. There will be
little in the way of large scale forcing tomorrow. However,
relatively unstable soundings and a very weak upper level
disturbance moving through the flow could spark isolated showers
and/or thunderstorms. Rain chances will be on the increase late
Monday night as the cold front nears from the northwest.
Temperatures Monday are expected to be on the warm side with highs
in the mid to upper 80s. Lows tonight and tomorrow night will be in
the upper 60s to lower 70s.
.LONG TERM (Tuesday through Sunday)...
Issued at 300 PM EDT Sun Jul 5 2015
Tuesday still looks to be the wettest day in the long term period as
a front drops southeast into the Ohio Valley. Although the
strongest mid to upper level flow should remain to our north, there
may be enough 0-6 km bulk shear to produce some strong storms with
gusty winds. Storm strength will also depend on available
instability. While models are showing some, it may be difficult to
build much if we start the day cloudy with an initial round of
showers/storms. Will need to watch the evolution/timing of this
weather system in coming days.
For mid week, the front looks to stall over our region initially
with uncertainty still in how quickly a SE CONUS ridge will work
into the Ohio Valley and just how strong it will get. Most mid
range models continue to support shortwaves riding along the
boundary producing multiple rounds of showers/storms Tues night/Wed.
By Wed night/Thurs, most models indicate that the boundary will be
far enough north, to result in lesser POPs. Even the recent, wetter
outlier (the Euro) has trended drier on its 12Z run. However, the
door is still open for diurnally based convection peaking during the
afternoon/evening hours. This pattern looks to potentially hold
through the weekend with daily POPs. If the recent drier
model consensus holds, at least some dry periods during the
overnight hours might be added to the forecast beyond mid week.
Temperatures will generally range through the 80s for highs for
Tues-Thurs with lows in the upper 60s/lower 70s. As the ridge
builds into the Ohio Valley, it will bring a warmer airmass
resulting in high temps in the mid 80s to lower 90s for Fri-Sun with
lows in the lower 70s.
.AVIATION (18Z TAF Update)...
Issued at 1244 PM EDT Sun Jul 5 2015
Light rain over LEX will move out over the next few hours as an
upper level low shifts eastward. Ceilings are expected to rise to
VFR after the precipitation moves out. Thereafter, VFR conditions
and light winds will prevail through the evening hours. Some light
fog will be possible once again tomorrow morning at LEX and BWG.
This should dissipate by mid morning with winds out of the SW and
partly cloudy skies for the remainder of Monday.