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000
FXUS63 KJKL 250625
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
225 AM EDT Fri Sep 25 2020

.UPDATE...
Issued at 225 AM EDT FRI SEP 25 2020

Lowered PoPs for the remainder of the overnight. Downslope is
just too strong for the more widespread rainfall expected earlier.
However, as the storm system shifts eastward downslope effects
should weaken enough to warrant an increase in PoPs across the
area for several hours centered around sunrise. Only minor
adjustments to other grids, temps, dew points, etc. to adjust to
hourly trends.

UPDATE Issued at 756 PM EDT THU SEP 24 2020

Forecast seems to be in pretty good shape so far, with the pops
matching up with the ongoing precip according to the latest radar
trends. Clouds are also in place across much of eastern
Kentucky, generally in the low to mid range. Where there is some
clearing in the cloud deck taking place in the far north and
western CWA, high clouds are still intact. Loaded in the latest
observations for temps, dew points, and winds to make sure the
near term forecast was on track with the current conditions. This
only resulted in minor edits, and any changes made during this
update are not substantial enough to warrant another zone forecast
at this time. All updates have been published and sent to
NDFD/web.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 524 PM EDT THU SEP 24 2020

The remnants of Beta have moved further inland to the north and east
and now sits over the Mississippi and Alabama border. This low
continues to be the main driver of our weather in eastern kentucky.
Outside of a brief period of thinning this morning in the north,
skies have been consistently cloudy through this afternoon. The bulk
of the associated precip currently skims the Tennessee border, and
continues to struggle to push into our CWA.

Going forward into tonight and tomorrow, the surface low will
continue to approach from the southwest, supported aloft by a trough
digging in from the northwest. As mentioned above, the associated
precip has stayed south and out of the large majority of our area
this afternoon. The downslope flow that prevails at the lower levels
has suppressed the moisture enough to keep the better precip from
progressing further into the area. This looks to continue to be the
case for at least a couple hours going forward. A few models tried
to maintain the better precip earlier, though they have struggled to
resolve the impact of that downslope flow, and so have gone less
aggressive with extent of the PoPs in the near term. The better
chances for rain will be late tonight and tomorrow morning when the
low moves closer to our area and supplies the better moisture. Even
then, the greatest chances will be limited to our south.

Dry weather will return by tomorrow evening as the upper level
trough lifts and starts to move out to the east, pushing Beta`s
remnants out along with it. The ongoing cloudiness will continue to
suppress the diurnal range. Lows tonight and tomorrow will be mild
in the upper 50s, with highs tomorrow in the low to mid 70s. Some
patchy fog may be seen tonight, especially across areas that see
more of the rainfall. There will be better potential for more
widespread low stratus/fog developing late Friday night into early
Saturday, as subsidence and very dry air builds in overtop lingering
low level moisture.

.LONG TERM...(Saturday through Thursday)
Issued at 454 PM EDT THU SEP 24 2020

The models remain in general agreement regarding an amplifying
long wave pattern into next week, as the northern stream becomes
active. Unfortunately, specifics regarding the evolution of
deeper troughing that will become established across the central
CONUS by the early and middle part of next week remain murky at
best, so confidence on PoP timing remains lower.

Saturday will begin with short wave ridging in place across our
area. Low stratus and fog will be see early, before burning off
by the mid to late morning hours. Highs will be in the upper 70s
to around 80. Dry weather will continue through Sunday, with highs
a few degrees warmer still. A series of cold fronts will then
approach and move through our region from late Sunday through
Tuesday. The ECMWF is more held back with the short wave energy
and therefore slower with the frontal progression. The GFS is more
progressive; however, the ensemble members show a lot of spread
in the amplitude and timing. Given the more amplified pattern,
have leaned a bit closer to the slower idea. This results in a
period of PoPs from Sunday night through Wednesday. Drier weather
then returns by Thursday.

Confidence continues to grow concerning a more significant cool
down to move in by the middle of next week. Highs will fall back
into the low to mid 60s, with lows in the low to mid 40s by
Wednesday night.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 225 AM EDT FRI SEP 25 2020

VFR conditions will gradually give way to MVFR ceilings from the
south through much of the morning as the remnants of Beta move
through the Tennessee Valley and southern Appalachians. Lowest
ceilings and greatest threat for rain will be along the KY/TN/VA
state line. These showers will taper off and shift eastward out
of the state during the day Friday, with improving conditions to
close out the TAF period. Winds will average less than 5 kts
through the period.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

UPDATE...RAY
SHORT TERM...HAS
LONG TERM...GEOGERIAN
AVIATION...RAY