Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 122313
Area Forecast Discussion
National Weather Service Louisville KY
713 PM EDT MON OCT 12 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Tuesday Night)...
Issued at 313 PM EDT Mon Oct 12 2015
In the near term, partly to mostly sunny skies were noted across the
forecast area. NWS and Ky Mesonet observations revealed
temperatures mainly in the upper 70s across the region. A few 80+
degree readings were noted across western KY and at Louisville.
A surface cold front was located out to the west of the region this
afternoon. The front is making progress to the east, albeit a
little slower than the models initially progged yesterday and last
night. The latest guidance continues to suggest that convective
initiation will occur along the front in the next few hours out to
the west. Convection should grow upward as combo of temps in the
upper 70s and dewpoints in the upper 50s will yield around 800-1000
J/Kg of CAPE for convection to feed on. Convective initiation looks
to be in the 21-22Z time frame and then spread quickly eastward
through southern IN and central KY. Given that the stronger
dynamical forcing is north and better moisture is to our south,
convection is not likely to be severe. However, given the wind
fields aloft and sufficient DCAPE, the strongest storms this
afternoon/evening will be capable of producing some gusty winds and
possibly some small hail.
Convection is expected to diminish by mid-evening and drier air will
filter in late this evening and overnight resulting in skies
clearing out and winds shifting to the west. Overnight lows look to
cool into the upper 40s to around 50 in most locations.
Dry and cool weather is expected on Tuesday as high pressure builds
in from the west. Afternoon highs will top out in the mid-upper 60s
in the north with upper 60s to lower 70s in the south. West winds
will be breezy during the afternoon. Mostly clear skies are
expected Tuesday night with lows dropping into the upper 30s in the
typical colder spots and lower 40s elsewhere.
.LONG TERM (Wednesday through Monday)...
Issued at 251 PM EDT Mon Oct 12 2015
A broad trough will remain in place across the northeastern CONUS
through the long term period. At the surface we will see alternating
high pressure and mainly dry cold fronts moving through.
Wednesday through Thursday high pressure will slowly work its way
across the region. We should see mostly sunny skies during this
period and temperatures around or just a bit below normal. Highs
will range from the upper 60s to lower 70s with lows in the lower to
A cold front will approach Thursday evening and swing through on
Friday morning. The models are not in good agreement with how much
moisture will accompany this system. For now have opted to keep the
forecast dry, but some showers Friday morning are not completely out
of the question. Temperatures on Friday will be a bit cooler,
topping out in the mid to upper 60s.
Stout high pressure will build in once again for the weekend. With
it a much colder airmass will settle in as well. Model guidance
continues to trend lower with the temperatures this weekend and with
that the potential for frost grows. Saturday morning winds will
likely stay up a bit as the high pressure will still be to our
northwest. Lows will range from the upper 30s to lower 40s. Thus,
while there may be isolated some instances of frost in sheltered
areas, it is not expected to be widespread. For Sunday morning high
pressure will be right over the Ohio Valley with low temperatures
dropping into the 30s across the forecast area. Much of southern IN
and north central KY, excluding the metro areas, could dip into the
mid to lower 30s. Thus, have expanded the mention of patchy frost in
the grids. Some areas in the far northern Bluegrass may even dip to
around freezing. Highs through the weekend will be chilly as well,
topping out in the mid 50s to lower 60s. Temps will them begin to
moderate a bit by early next work week.
.AVIATION (00Z TAF Update)...
Issued at 710 PM EDT MON OCT 12 2015
Convective line working its way across central Kentucky at this
time, with conditions already starting to improve behind it at SDF,
while it still is closing in on BWG and LEX. Southern part of the
line is weaker, and the part that will reach LEX should be weaker by
the time it gets there, but will include TEMPO groups for some
shifting and gusty winds in the thunderstorms, along with the brief
restrictions to visibilities. Will take it down to MVFR, but know
that a very quick drop into IFR is possible especially at LEX.
Storms should push out around midnight, with light WSW winds and
only cirrus for the overnight. Decent gradient on Tuesday, so will
kick winds up to 10-12 kt out of the west, with a few gusts just
short of 20 kt at SDF and LEX.