Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 271904
Area Forecast Discussion
National Weather Service Louisville KY
304 PM EDT MON JUN 27 2016
.SHORT TERM (Now through Tuesday Night)...
Issued at 300 PM EDT Mon Jun 27 2016
...Storms Ending this Evening, Fog Overnight?...
The main cluster of storms worked across central and southern
Kentucky through the afternoon, with a stabilizing cold pool now
established over most of the CWA. Most spots are in the 70s where
rain occurred earlier, but think some late afternoon
clearing/heating could help temps rise back up into a muggy low to
mid 80 range through the evening. Showers and storms will now be
most prevalent across the southern and eastern most tier or two of
counties through the early evening. Latest runs of the HRRR are
preferred through this time as the model had a good handle on what
evolved later in the morning through mid afternoon. With a 2-2.2
inch PWAT airmass and slow movement, any storms will be capable of
mainly locally heavy rainfall and lightning. A few instances of
gusty winds can`t be ruled out, but shouldn`t be greater than 30-40
mph in magnitude.
Conditions should be dry through the overnight in benign NW flow
aloft. May see a small uptick in isentropic potential with low level
jetting ticking up around 20 knots ahead of tomorrow`s upper
disturbance and associated cold front. However, don`t think there
will be enough lift/moisture to warrant any mentionable
precipitation. The bigger concern will be with fog potential through
the overnight as radiational cooling conditions become more
favorable through the night, and combine with recent rainfall.
Mainly concerned about the southern CWA where best rainfall fell
combined with lightest low level winds. Will consider a Special
Weather Statement to highlight the threat, or will let evening shift
Shortwave trough rotates through the eastern Great Lakes on Tuesday,
dragging a secondary cold front through the region. Models continue
to hint at just enough moisture to consider some very low/light
Pops, however prefer to keep the forecast dry as coverage will
likely be less than 20% and would struggle to measure. This is in
line with previous forecasts. Temps should rise mostly into the mid
80s, with some upper 80s down south.
Cooler/drier air ushers in behind the front on Tuesday night, with
most spots dropping into the upper 50s around 60. Southern Ky likely
stays in the low 60s.
.LONG TERM (Wednesday through Monday)...
Issued at 315 PM EDT Mon Jun 27 2016
...Low Humidity and Pleasant Summer Weather Mid/Late Week...
Wednesday - Thursday Night...
A much cooler and drier airmass will take hold behind the secondary
cold front through mid to late week. The pattern will feature dry NW
flow aloft with surface high pressure in place. Expect a mostly
sunny Wednesday with highs topping out around 80. Thursday will also
be dry with highs in the lower to mid 80s. Nights will also be more
comfortable, if not a bit chilly. Look for around 60 with many spots
in the mid and upper 50s on Wed. night. Thursday night will be
slightly milder in the lower 60s.
Friday - Monday...
A weak cold front will approach the region by later Friday as it
trails from an upper system over SE Canada. Most of Friday should be
warmer and dry, although will have to continue mention of a small
chance for an afternoon/evening T-storm mainly across our NW closer
to the front. Look for highs solidly in the mid 80s. Friday night
lows will be in the mid 60s.
Models generally agree that a deeper moisture plume will ride into
the Ohio Valley along the frontal boundary on Saturday and Saturday
night, where the best chances/coverage of thunderstorms in the
long term should occur.
Still have to leave small chances in for Sunday/Sunday night, but
the focus should be across southern KY as the frontal boundary tries
to sink south of the CWA. Confidence will be lower into Monday as
well as models disagreeon whether the boundary can lift back into
our area as a warm front.
Highs should mostly range in the mid 80s from Saturday through
Monday, with lows mostly in the mid 60s.
.AVIATION (18Z TAF Update)...
Issued at 100 PM EDT Mon Jun 27 2016
Weak cool front now just north of the LEX terminal. Instability is
best northeast of that site, so they have about another hour or two
of a chance for showers at that terminal before the front pushes the
better chances to the south. Likewise, more stable airmass over BWG
should mean just a rumble or two of thunder for another hour or two.
Winds will become light and variable overnight before becoming more
northerly Tuesday. Only other concern may be some light fog at
BWG/LEX toward daybreak.