Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 261116
Area Forecast Discussion
National Weather Service Louisville KY
616 AM EST Sun Feb 26 2017
...Updated Aviation Discussion...
.Short Term...(Today through Monday)
Issued at 248 AM EST Sun Feb 26 2017
Quiet and dry weather currently ongoing in the CWA thanks to 1023mb
high over western Kentucky. Light winds and clear skies have allowed
temperatures to fall into the mid 20s over many areas, with a few
sites reporting low 20s at this hour.
Surface high currently over western Kentucky will slide eastward
this morning toward the east coast and winds will gradually pick up
out of the south. Some warmer air will also advect into the region
during the afternoon, and should see afternoon temperatures about 10
degrees warmer today compared to yesterday. Clouds will begin to
increase this afternoon and evening ahead of a system approaching
from the west. Should see rain showers develop after sunset today in
the western part of Kentucky and Indiana before spreading eastward
during the overnight hours. Precip type for the overnight hours
should remain rain, though can`t rule out some wet snow mixing in at
times with some of the heavier showers or bands that set up across
the CWA. Any snow that does fall will likely not accumulate given
warm ground temperatures and surface air temperatures that remain
Precipitation will still be lingering around the region Monday
morning, but should see it push out by the afternoon. Might see a
few breaks in the clouds during the day Monday, but expect them to
remain around for most of the day. Despite widespread cloud cover,
temperatures will remain fairly mild, generally in the mid to upper
.Long Term...(Monday night through Saturday)
Issued at 300 AM EST Sun Feb 26 2017
...Strong to Severe storms possible Tuesday evening and Wednesday...
An active and wet weather pattern is setting up for the first
portion of the long term outlook. Multiple waves embedded within the
southwest flow aloft will bring several rounds of precipitation to
the region Monday night through Wednesday, with the greatest chance
of precipitation occurring Wednesday as a strong trough ejects off
the Rocky Mountains into the Ohio Valley. Models generally show a
widespread 1 to 3 inches of rain falling during this period.
Low level moisture will increase starting Monday night as a strong
LLJ develops over the region. A broad band of rain showers will also
develop ahead of an approaching shortwave late Monday night, and
should push out of the region late Tuesday morning or early
afternoon. We could see some clearing skies and dry air work into
the mid levels of the atmosphere Tuesday afternoon, which would help
set the stage for potentially strong to severe storms later that
evening. Both the 00z NAM and GFS have widespread 60 degree
dewpoints in Central KY and Southern IN by Tuesday afternoon, with
CAPE values ranging from 500-1000J/Kg. 0-6km deep layer shear is
quite strong Tuesday as well, with values near 60kts. Models vary on
timing of convection, but generally have a round of showers and
storms developing Tuesday evening and continuing into Wednesday
morning. Another round of showers and thunderstorms could form
Wednesday afternoon as a strong cold front approaches the region.
Thermodynamic and kinematic fields continue to look very favorable
for severe weather Wednesday ahead of the cold front, as models
advertise 700-1400J/Kg of CAPE and 70kts of 0-6km shear. As with any
setup 3 to 4 days out, there are still a lot of details that will
need to be worked out (timing, storm mode, amount of destabilization
between waves, etc)... but there is growing confidence that strong
to severe storms could occur Tuesday evening through Wednesday
afternoon in our region.
Cold front will clear the CWA late Wednesday afternoon, and should
see cooler and drier air advect into the region. Looks to be fairly
quiet and dry for remainder of long term period, with the exception
of Thursday evening/Friday morning where some very light rain/snow
showers might clip the extreme northern fringes of the CWA.
Otherwise, temperatures will gradually warm up as an upper level
ridge builds into the region next weekend.
.Aviation...(12Z TAF Issuance)
Issued at 615 AM EST Sun Feb 26 2017
Expect VFR conditions most, if not all, of this forecast period.
Will see steadily declining bases in mid and upper level clouds
later this morning through the evening hours. Winds will be variable
at first but become southerly by late morning. There is some chance
for light rains at each site early Tuesday morning.