871
FXUS63 KLMK 160525
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
125 AM EDT Thu May 16 2024

.KEY MESSAGES...

*   Patchy dense fog possible late overnight into early morning.

*   Widespread showers and storms Friday into Saturday, with gusty
    winds and heavy rain possible in the stronger storms late Friday
    and Friday night.

*   Dry and very warm Sunday and Monday.

*   Rain chances return Tuesday and Wednesday.

&&

.UPDATE...
Issued at 948 PM EDT Wed May 15 2024

Few showers and storms are dissipating over the region with fleeting
daytime heating. Through the remainder of the evening, winds will
become calm to light and skies will continue to clear. These
ingredients coupled with recent precipitation, will lead to fog
development in the early morning hours. Reduced visibilities are
possible from about 6Z through 14Z. The lowest visibilities would be
right around dawn. An SPS has been issued through 14Z for fog and
low visibilities. As fog develops in the overnight hours, a Dense
Fog Advisory may be needed.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 310 PM EDT Wed May 15 2024

Sfc low and associated upper trough will continue to work eastward
this afternoon and evening towards the Mid-Atlantic coast. Model
soundings show instability this afternoon but very little shear with
mid-level weak mid-level lapse rates. We can see an area of showers
and thunderstorms working from the north-northeast out of southern
IN towards north central KY. This activity will be around through
the rest of the afternoon into the early evening. Storms will remain
sub severe with small hail and a few wind gusts.

Upper level ridge will build in from the west tonight into tomorrow
along with a weak area of sfc high pressure. This will allow for
precipitation to diminish with the loss of daytime heating and allow
clouds to clear as we go overnight. With clearing and lingering low-
level moisture patchy dense fog is possible thanks to all the rain
the last couple of days and cooling temperatures. Many of the models
also strongly suggest that fog is a possibility across most of the
CWA so feel confident about dense fog developing. Lows will fall
into the mid/upper 50s with our urban locations near 60.

As ridging builds and high pressure moves in we will get a break
from the rain with even some sunshine tomorrow. While it is expected
to be brief it will help to warm temperatures to near 80. Clouds
will start to increase towards the afternoon as a mid-level vort max
works in ahead of the approaching shortwave trough. This will also
increase shower storm chances from the west late afternoon and
towards evening.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 310 PM EDT Wed May 15 2024

Upper trof will kick out of eastern New Mexico and western Texas
Thursday night, crossing the Ozarks on Friday night and finally
pushing through the Ohio Valley late Saturday. Widespread
showers and storms are expected, mainly Friday afternoon into
Friday night with a healthy Gulf moisture feed pushing PWATs to
around 1.5 inches. Severe wx potential is low given modest
instability and weak mid-level lapse rates, but deep-layer shear
does increase after 00Z Sat. The main hazard will be brief
locally heavy rainfall, which could result in ponding or
localized minor flooding. However, a few strong to severe storms
can`t be ruled out if enough sfc-based instability hangs on to
overlap with the increasing shear.

Most likely dry days will be Sunday and Monday under shortwave upper
ridging. Temps will be quite warm both days with highs well into the
80s. Rain chances return Tuesday and Wednesday as an upper trof digs
into the Plains, with some degree of phasing possible.

&&

.AVIATION /06Z TAFS THROUGH 12Z FRIDAY/...
Issued at 125 AM EDT Thu May 16 2024

Impacts/Confidence:
- Medium to high confidence in MVFR/IFR cigs and vis through 16/13Z
- Increasing confidence in showers and storms tonight.

Discussion...Current satellite imagery indicates stratus layer
forming over central Kentucky while surface observations show a
saturated boundary layer with falling visibilities. Wet antecedent
conditions and light surface winds support continuing stratus/fog
through sunrise with a possibility of LIFR conditions for all
terminals except SDF, which should stay MVFR. That being said, there
is still some uncertainty related to the effects of upstream cloud
coverage and boundary layer warming that could negatively impact the
current forecast. Finally, surface heating and daytime mixing will
allow returning VFR after 14 or 15Z while winds remain light and
from the west-southwest.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE...SRM
SHORT TERM...BTN
LONG TERM...RAS
AVIATION...ALL