Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 200947
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
547 AM EDT Fri Apr 20 2018

...Updated Aviation Discussion...

.Short Term...(Today through Saturday)
Issued at 225 AM EDT Fri Apr 20 2018

A pleasant day is in store for the Ohio Valley as we close out this
work week. It will start chilly though, with areas of frost and some
pockets of temperatures below freezing. Ridging moving in from the
west will bring a warmup today. Highs today will be roughly 10
degrees warmer than Thursday. Tonight and Saturday cloud cover will
increase as the ridge axis aloft shifts over us.  We will stay
relatively warm, though highs will be a little below normal for this
time of year. Lows will be a little warmer Saturday morning, perhaps
cool enough for additional patches frost, but don`t think it will be
as widespread as this mornings.

.Long Term...(Saturday night through Thursday)
Issued at 225 AM EDT Fri Apr 20 2018

Saturday night, an upper level low pressure system will be over the
Central Plains. Models are in pretty good agreement on this
placement. This system is the reason for our ridging for the
weekend, but also the increasing upper level cloud cover. By Sunday
afternoon, this system may split into a couple of upper lows, with
the deeper one over Arkansas and the weaker one near Kansas City. At
the surface, a warm front will lie somewhere over the Tennessee
Valley. We should see some overrunning along this boundary, bringing
some rain chances to south KY in the afternoon hours.

Sunday night, the southern low will stall over western TN, keeping
rain chances higher across our southern counties. It may start to
wobble northward Monday, pulling up those rain chances farther into
KY, even as a deformation zone sets up over the Ohio River. This
pattern will continue to Tuesday night before another impulse looks
to drop down from our northwest, keeping rain chances in play
through Thursday.

Given persistence of cloud cover and lower heights aloft, not
expecting any one particularly warm day.  Highs should remain a
little below normal, while lows stay at or a little above
normal...away from any threat for further frost.

&&

.Aviation...(12Z TAF Issuance)
Issued at 547 AM EDT Fri Apr 20 2018

Dry weather and clear skies are expected through this TAF period as
high pressure builds in from the north. Light NNE winds early this
morning will become more steady and NE after sunrise. A few upper
clouds could be noted later in the TAF period, but will be of little
consequence.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...Freeze Warning until 10 AM EDT this morning for INZ076>079-083-
     092.

     Frost Advisory until 10 AM EDT /9 AM CDT/ this morning for
     INZ084-089>091.

KY...Freeze Warning until 10 AM EDT this morning for KYZ031>037-
     039>043-047>049-056-057.

     Frost Advisory until 10 AM EDT /9 AM CDT/ this morning for
     KYZ023>030-038-045-046-053>055-061>067-070>078-081-082.

&&

$$

Short Term...RJS
Long Term...RJS
Aviation...BJS



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