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Area forecast discussion 
National Weather Service Louisville Kentucky
916 PM EST Fri Dec 26 2014

..forecast update...
Issued at 916 PM EST Fri Dec 26 2014

Current forecast remains on track for the overnight period. Mid and
high level cloud cover will continue to stream in from the southwest
leading skies to become mostly cloudy by dawn. Just made a few
adjustments the hourly temperature and dewpoints to bring them in
line with current observations. Current overnight lows still look
on track.

Short term (now through Saturday night)...
issued at 235 PM EST Fri Dec 26 2014

High pressure centered over the Carolina coast will give US another
dry and quiet night tonight. Clouds will be on the increase and
there will be some weak return flow, so patchy fog is less likely
than it was this morning. Lows will mostly be in the middle and
upper 30s...cooler in the eastern valleys, still.

Low pressure crossing the Great Lakes and heading up the Saint
Lawrence valley will sweep a weakening cold front toward US on
Saturday and through the region Saturday night. Light rain will
come in from the west by Saturday afternoon and become widespread
by evening. Rainfall amounts by Sunday morning should be on the
order of a quarter to half an inch.

Though clouds and rain will temper the potential warmth ahead of the
cold front tomorrow, we will still be able to see highs in the 50s.
Lows Saturday night should range from the middle 30s in west central
Kentucky to the middle 40s around Lake Cumberland, though that will
be dependent on when exactly the front moves through.

Long term (sunday through friday)...
issued at 245 PM EST Fri Dec 26 2014

By Sunday morning the cold front associated with the departing low
pressure system should be through the forecast area. However,
precipitation looks to still be ongoing behind the front. A
disturbance will ride northeast along this boundary through the day
enhancing precip chances, especially across the eastern half of the
forecast area. Rain will gradually taper off overnight Sunday night
into Monday morning.

Despite precipitation continuing behind the front, do not think at
this time we will have much of a chance to see a wintry mix.
Temperatures look to hold fairly steady in the upper 30s to the mid
40s through the day on Sunday. Most precip looks to move out ahead
of the deeper cold air overnight. Have therefore kept the forecast
all rain.

From Tuesday through Thursday high pressure will build in from the
west at the surface. Aloft the flow will remain mainly zonal. This
will lead to a dry period. Temperatures will be below normal for
this time of year with highs in the 30s and lows in the 20s.
Wednesday morning still looks to be the coldest of the bunch with
some areas dropping into the teens.

The next chance for precipitation will come Thursday night into
Friday as a system moves in from the southwest. With this type of
system the models will likely waffle over the coming days with the
placement of the low pressure. This will impact p-type as the low
crosses the Ohio Valley. For now it looks like we could start out
with a wintry mix Thursday night transitioning to rain on Friday.
This system will therefore need to be watched closely in the coming
days.

&&

Aviation (00z taf update)...
issued at 547 PM EST Fri Dec 26 2014

VFR conditions are expected this evening and during the overnight
hours. High cloudiness will continue to filter into the region from
the southwest. Ceilings will probably run around fl200 this evening
and into the overnight before lowering to around fl050-060 by
27/10-12z. Surface winds will remain out of the south overnight
with speeds of 4-7 knots.

A weakening cold front will approach from the west on Saturday.
Clouds will continue to lower during the morning hours with light
rain moving into the region during the afternoon. Conditions look
to be in the low end of the VFR range during the afternoon, but we
suspect ceilings will lower to MVFR by evening with MVFR
visibilities due to the rain. Surface winds will remain out of the
southwest during the day with speeds of 7-9 knots.

&&

Lmk watches/warnings/advisories...
Kentucky...none.
In...none.
&&

$$

Update.........Mj
short term.....13
long term......eer
aviation.......mj

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