Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 082003

Area Forecast Discussion
National Weather Service Louisville KY
303 PM EST Thu Dec 8 2016

.Short Term...(This evening through Friday night)
Issued at 300 PM EST Thu Dec 8 2016

Temps in the low to mid 30s at this hour will drop off rapidly early
this evening, especially with dew points in the low to mid teens.
Surface winds will also slacken as surface high pressure builds into
the region toward dawn. Main concern for the overnight will be
stratocu deck dropping down across the region. 925mb moisture
analysis reveals that the broken to overcast skies should stay along
and north of I-64, with the potential for a few flurries in the
mainly along and east of a Madison, IN to Richmond, KY line between
4 AM and Noon EST. Expect most overnight lows in the upper teens and
lower 20s.

As mentioned above, a few flurries will be possible in the east
through midday, along with mostly cloudy skies. This should keep
high temps down a bit in that area. Elsewhere, plenty of sunshine
could help temps rise to near freezing. Temps will likely not get
out of the 20s in southern IN and east central KY. Otherwise, dry.

Surface high settles over the area Friday night, and will lead to
cold lows in the mid to upper teens in most spots.


.Long Term...(Saturday through Thursday)
Issued at 315 PM EST Thu Dec 8 2016

Saturday - Saturday Night...

A low amplitude NW flow pattern will transition to a more zonal
component through this time period, meanwhile surface high pressure
shifts east. Expect to be dry during this time, although will see
increasing cloud cover later Saturday afternoon into Saturday night
as moisture from a weak Great Lakes system passes to our north, and
deeper moisture begins to pool ahead a developing southern Plains

Most Saturday highs should range in the mid to upper 30s, with
milder Saturday night lows in the mid to upper 20s.

Sunday - Monday...

Surface low quickly accelerates from the southern Plains to the
eastern Great Lakes during this period ahead of a progressive
shortwave racing through the zonal flow. The column should steadily
saturate through the day on Sunday, with an isentropic component
providing some ascent. Perhaps a brief mix will be possible at onset
given the thermal column being marginal. No accums anticipated at
this point. Deepest moisture arrives late afternoon through Sunday
night where likely to categorical pops will exist. Should be all
rain by Sunday afternoon, and with surface low passing to our north,
will continue the idea of non-diurnal temps Sunday night into
Monday. This should keep us mostly rain across the CWA, although a
light mix may exist across our far north for a bit.

Cold front trailing from the surface low racing NW will pass through
on Monday with chances for rain showers ending from West to East.
Highs in the upper 40s to around 50 may begin to drop off by early
afternoon as WNW winds kick in behind the front.

Monday Night - Thursday...

Confidence decreases for the mid week portion of the forecast as
models disagree on the exact evolution of disturbances moving
through our generally zonal flow aloft. There remains a chance for
some snow during the Tuesday night through Wednesday time frame, but
would like to see more consistency before getting too excited about
it. Will maintain low chance mention for now.

After Tuesday highs in the 40s, we`ll see temperatures return to
below normal values with highs barely making it to freezing
Wednesday and Thursday. Lows Wednesday night should be around 20.


.Aviation...(18Z TAF Issuance)
Issued at 1230 PM EST Thu Dec 8 2016

Cold W to NW low-level flow has overspread the area this morning.
There have been occasional low clouds affecting SDF and LEX, but not
much. High clouds are streaking ENE across central KY as well. For
this afternoon, VFR conditions should prevail with W or WNW surface
winds of 10-15 kts.

For tonight, an area of low clouds (generally MVFR) currently over
central IL and central IN is forecast to slide southeast and should
clip SDF and LEX after roughly 02 or 03z, and may continue into the
morning hours Friday. There is some question whether ceilings will
affect SDF or stay just north and east, but TAF does include broken
ceiling around 3 kft. Main area of clouds will stay north and east
of BWG, but could see few/scattered clouds at times at BWG late
tonight. Surface winds will be W to NW at or below 10 kts.


.LMK Watches/Warnings/Advisories...


Short Term...BJS
Long Term...BJS
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