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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 210300 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1100 PM EDT Fri Apr 20 2018

.UPDATE...
-- Changed Discussion --
Issued at 1100 PM EDT FRI APR 20 2018

Forecast still looking good so far tonight. The frost advisory was
updated with freshened up wording and was just issued. The
forecast overall was in good shape with no major changes needed.

UPDATE Issued at 729 PM EDT FRI APR 20 2018

The forecast has been on track so far this evening. Mostly clear
skies and light winds should prevail across the area overnight
through early tomorrow morning. The latest obs from the past few
hours were ingested into the forecast grids to establish new
trends. No update to the forecast is planned at this time.
-- End Changed Discussion --

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 359 PM EDT FRI APR 20 2018

Surface high pressure is currently centered across the Great
Lakes, with upper level ridging working in towards the
Mississippi Valley. Drier air has mixed down across eastern
Kentucky this afternoon, with some dew points in the teens noted
in some places. Winds will remain light tonight under clear
skies, setting the stage for another chilly night, with frost.
Consequently, have issued a frost advisory for the entire area,
with mainly valleys seeing the frost. Some of the more typically
cold spots will see lows in the upper 20s, while ridges see upper
30s.

The upper level ridge will dampen as it crosses the Mississippi
Valley into Saturday, as an upper level low currently centered
near the Four Corners region rotates east. Still, 1000-500 mb
thicknesses will continue to increase across the Ohio and
Tennessee valleys, allowing for warmer highs, generally in the 65
to 70 degree range under mostly sunny skies.

Clouds will be on the increase Saturday night, especially after
midnight, as the upper level low approaches from the west.
Another quick drop off in the sheltered valleys should allow for
some mid to upper 30s readings, with most other locations ranging
from the low to mid 40s.

.LONG TERM...(Sunday through Friday)
Issued at 336 PM EDT FRI APR 20 2018

A upper level ridge axis will still be extending across the Ohio
and Tennessee Valleys Sunday. This will help slow the progression
of rain showers activity northward and still may be too quick on
the progression northward overall. Did opt to adjust from what the
blended data provided for Sunday, but tried to remain match up
with the neighboring offices. The NAM is the wetter outlier this
afternoon for Sunday into Sunday night and this could be some
influence in the blended data. This southern stream upper level
low will remain the culprit for unsettled weather across the Ohio
and Tennessee Valleys through much of the period. This southern
stream system will eventually phase with a northern stream upper
level wave, but the guidance diverges greatly at this point on the
depth and forward progression of the northern stream feature. This
leads to a low confidence forecast from midweek onward. The slight
to chance POPs provided by the blended guidance seems reasonable
at this point and therefore little changes were made to the
forecast for this period. In general, the temperatures through the
long term will remain near normal for this time of year.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 729 PM EDT FRI APR 20 2018

High pressure will keep mostly clear skies in place, with winds
averaging around 5 kts or less out of the northeast through the
period.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
Frost Advisory until 9 AM EDT Saturday for KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
-- End Changed Discussion --

&&

$$

UPDATE...AR
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...AR