Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 150507

Area Forecast Discussion
National Weather Service Louisville KY
1207 AM EST Wed Feb 15 2017

...Updated Aviation Discussion...

.Forecast Update...
Issued at 930 PM EST Tue Feb 14 2017

Rain shield is spreading into south-central Kentucky pretty much on
schedule. Currently the northern edge is near the Cumberland
Parkway, but expect a slight northward expansion through the night
as the upper low over eastern Oklahoma opens up and pushes eastward.
Still think precip will remain south of the Bluegrass Parkway, and
should be tapering off just prior to daybreak as the trof axis
scoots past. Current forecast is well on track so no updates other
than small tweaks to hourly trends.


.Short Term (Now through Wednesday Night)...
Issued at 300 PM EST Tue Feb 14 2017

500mb analysis reveals strong ULL over TX/OK with broad band of
moisture stretching from the Southern Plains to the Gulf Coast
region and lower Ohio Valley. Near the surface, a 1007mb low was
located close to the TX/LA border and had a warm front just south of
the TN border. A broad band of precipitation has developed north of
the warm front, and will slowly propagate northward late this
afternoon into our CWA.

Should see precipitation increase this evening across portions of
Southern KY as the TX/LA low and associated warm front lift
northeastward. Precipitation overnight should remain all liquid, but
it`s possible we could see a few isolated reports of wet snow mixed
in with the rain toward the early AM hours of Wednesday as
temperature profiles cool aloft.

The system moves out of the region quickly Wednesday morning, and
cooler and drier air from the northwest will advect in behind a cold
front. High temperatures should be near climatological averages.

Wednesday night is also looking to be dry and cool, as light winds,
clear skies and dry air will allow temperatures to drop into the mid
to upper 20s for many locations.

.Long Term (Thursday through Tuesday)...
Issued at 300 PM EST Tue Feb 14 2017

A somewhat complicated upper level pattern will take place during
the long term period. In general, the region will experience above
climatological normal temperatures and remain dry, with the
exception of a system that could bring rain showers Saturday through
Sunday AM.

A high amplitude ridge with a southern stream ULL will be in place
Thursday morning across the Central US. Over the course of a couple
of days, the southern stream ULL will slowly move into the Southern
Plains and eventually reach the lower Ohio Valley by Saturday. The
operational 12z GFS and ECMWF are in decent agreement with the
temporal and spatial progression of the system, and have rain
showers beginning Saturday morning near the TN/KY border before
spreading northward through the afternoon. The rain showers will
continue through the evening hours on Saturday before ending Sunday

By Sunday afternoon, the southern stream ULL will begin exiting the
region, and broad ridging will begin to build back into the CWA.
Long range models agree that warm and dry conditions will prevail
for at least a couple of days, but begin to differ with upper level
flow by the Tuesday/Wednesday timeframe. Given uncertainty and
differences in long range models, have decided to blend solutions
for Tuesday and beyond.


.Aviation...(06Z TAF Issuance)
Issued at 1206 AM EST Wed Feb 15 2017

Rain continues at BWG tonight as an upper level disturbance moves
through the region. This rain should move out by around 08-09Z.
However, some light fog may continue until around sunrise. Ceiling
have improved to VFR at BWG the latest guidance has them remaining
VFR through the TAF period. The rain looks to stay well to the south
of LEX through the night and guidance is more optimistic for
ceilings there as well, so have bumped up the cigs in the forecast
to keep them VFR.

Winds at all sites will shift to northwesterly overnight as a cold
front pushes through. Winds will become gusty by mid morning and
remain gusty through most of the afternoon. Gusts should relax by
around sunset.




Short Term.....DM
Long Term......DM
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