Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 131430
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
930 AM EST Sat Jan 13 2018

.Forecast Update...
Updated 929 AM EST Sat Jan 13 2018

Some light snow has developed across south central KY this morning.
This snow caused visibilities to drop briefly below half a mile at
BWG. Did a quick update to include a chance for snow across south
central KY over the next few hours. An additional tenth of an inch
or two of snow or so with this will be possible.

&&

.Short Term...(This afternoon through Sunday evening)
Issued at 340 AM EST Sat Jan 13 2018

Winter storm is quickly winding down this morning.  Deformation band
continues to push across the Bluegrass region.  This should exit the
region in the next 2 hours or so.  Elsewhere, scattered snow
flurries have developed over southern IN and portions of northern
KY.  These will stream southward out of IN and down through the I-65
corridor.  The flurries are light and are not expected to bring any
additional accumulations.  Temperatures this morning were in upper
teens to the lower 20s.  So hazardous road conditions are expected
to continue early this morning.

For today, partly to mostly cloudy skies are expected.  We could see
some periods of partial sunshine at times.  Some scattered flurries
will be possible over the Bluegrass region this morning but should
diminish by late morning.  Temperatures will be cool today with
highs only topping out in the lower 20s.

High pressure will build into the region tonight.  With skies
clearing and fresh snow pack, have gone under the guidance and will
be taking lows in the single digits.  Areas west of I-65 may end up
going sub-zero in spots where deeper snow pack resides.  Additional
downward adjustments may be required in subsequent forecasts.

Dry and cold weather is expected to continue on Sunday with highs in
the lower to middle 20s.

.Long Term...(After midnight Sunday night through Friday)
Issued at 337 AM EST Sat Jan 13 2018

Sunday Night - Tuesday...

...Light Snow Accumulations Possible Later Monday - Tuesday...

A clipper system will move from the upper Midwest through the Great
Lakes during this time. On Sunday night, a "warm" front will develop
over our area with weak isentropic lift helping to squeeze out some
flurries and/or very light snow across southern IN. Given that the
snow will have to overcome very dry air at the surface, expect
little to no accumulation. Temps will bottom out mostly in the 15 to
20 degree range, which will actually be milder than the night before
given the light warm advection south of the warm front.

We`ll remain in the mini-warm sector of the clipper through the rest
of Monday morning into Monday afternoon, before the Arctic cold
front begins to slide into our region. Expect strong forcing beneath
the exit region of an upper jet, combined with saturation up the a
good portion of the DGZ. Thermal profiles should support all snow
after wet-bulbing occurs, except for across far southern KY where
some rain could mix in. Nevertheless, steep low level lapse rates
should be enough to keep p-type all snow, and will also help to mix
the 20-25 knot gusts down to the surface with the snow showers. So,
expect gusty snow showers later Monday, lingering into Tuesday. QPF
is light, but snow ratios should be good enough to squeeze out a
half an inch to an inch in most spots. Suppose a localized 2 inch
amount could occur across our north where the best forcing will be.

Lows crash  into the single digits Monday night, and will only reach
the mid and upper teens on Tuesday. Expect some snow to linger
across southern and eastern KY on Tuesday as the front begins to
slow it`s progress.

Tuesday Night - Friday...

Expect the rest of the week to be dry and cold, although modifying a
bit toward the end of the work week. Arctic high pressure builds on
by Wednesday with the upper trough axis slowly shifting east of the
area. By late in the week, upper flow becomes split with mentionable
features passing well to the north and south of our region. This
will keep us dry. Expect we will see a warm up in around 10 degree
increments each day. Highs on Wednesday should be around 20, with
highs around 30 by Thursday, and around 40 by Friday. Lows will be
around 0 on Tuesday night, in the single digits on Wednesday night,
and then around 20 by Thursday night.

&&

.Aviation...(12Z TAF Issuance)
Issued at 634 AM EST Sat Jan 13 2018

A few lingering flurries will mainly impact BWG over the next 1 to 2
hours. Otherwise, expect VFR with a few low and mid clouds around
through the day. By later afternoon and early evening, there is some
confidence that a secondary deck of stratocu will develop over the
area, just on the high side of the MVFR/VFR threshold. Will stay
optimistic, but will need to monitor this. Otherwise, look for a
steady N wind between 10 and 15 mph.


&&

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

$$

Update...EER
Short Term...MJ
Long Term...BJS
Aviation...BJS



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