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Area forecast discussion
National Weather Service Jackson Kentucky
400 PM EDT Wed Oct 23 2019

Short term...(this evening through Thursday night)
issued at 400 PM EDT Wednesday Oct 23 2019

19z sfc analysis shows high pressure over eastern Kentucky and
that has kept the skies cloudfree and winds relatively light. In
addition, plenty of sunshine sent temperatures up into the upper
50s and lower 60s. Meanwhile, dewpoints are generally dry in the
upper 20s to lower 30s resulting in relatively humidities in the
upper 20 and lower 30 percent ranges.

The models are in good agreement aloft through the short term
portion of the forecast. They all depict fairly fast southwest
flow at mid levels at the base of a broad trough. This trough
reloads through the southern rockies on Thursday maintaining the
downstream southwest flow. The bulk of the energy with this
pattern will be contained west and north of Kentucky through 12z
Friday - closer to the center of the trough and mid level lows.
Given the small model spread have favored a robust blend as
represented by the nbm with no large scale adjustments.

Sensible weather will feature a clear, calm, and dry night with
good radiational cooling. This will likely result in a decent
ridge to valley temperature split later tonight into dawn. The
southeast valleys will drop through the upper and middle 30s with
areas of frost expected. For this, a frost advisory is in effect
across our southeast tier of zones. Elsewhere have issued an Special Weather Statement
for patchy valley frost late tonight. Additionally, some patchy
fog will be possible in the river valleys. The frost starts to
clear out by 9 am with another beautiful autumn day on tap as
temperatures top out in the upper 60s to lower 70s Thursday -
just some high clouds possible late in the day from the northwest.
More clouds will arrive for Thursday night and this will keep any
frost or fog at Bay for most locations with another ridge to
valley temperature difference.

Used the nbm as the starting point for grids through the short
term. Did make some significant adjustments to temperatures each
night based on relative elevation differences. Pops and quantitative precipitation forecast are
non-existent through 12z Friday so kept them that way through the
short term portion of the forecast.

Long term...(friday through wednesday)
issued at 335 PM EDT Wednesday Oct 23 2019

The overall pattern trend in the extended remains the same, with a
slower than nbm onset of precipitation across eastern Kentucky on
Friday. The best chance of precipitation will be from Friday night
through Saturday night, as a vigorous area of low pressure moves out
of the Southern Plains, across the middle Mississippi Valley and
eventually through the Ohio Valley region. The issue this time
around has been the timing differences between the nbm and wpc
fronts/weather system timing forecasts and the majority of the rest
of the operational model runs for the Sunday through Tuesday time
frame. The nbm was holding onto precip across eastern Kentucky
through next Wednesday, which seemed quite unreasonable. Based on
the number of other models that were taking precipitation out of the
area Sunday night, it seemed reasonable to go that Route instead,
which is what we did. The new extended forecast will have rain
exiting the area no later than 5 or 6z Monday. For now we will be
keeping the forecast dry from late Sunday night through Tuesday. We
may have another round of rain moving in late Tuesday night, but the
models are not in good agreement on that, so we'll take it with a
grain of salt for now. General rain showers will be on tap as
instability and strong lift will be lacking.

The temperature forecast is trending toward cooler than normal
daytime highs through out the period. Nightly lows will likely start
out slightly above normal the first few nights, due to the presence
of widespread and persistent cloud cover. We may see below normal
lows Monday night and Tuesday night, as cloud cover scatters out,
winds become light and shift to the west or northwest across the
area. Daily highs should generally be in the low to mid 60s, with
nightly lows starting out in the upper 40s and lower 50s, with lows
ranging from the upper 30s to lower 40s Monday night and Tuesday
night.

&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 145 PM EDT Wednesday Oct 23 2019

High pressure and rising heights aloft will result in mostly
clear skies and dry weather through the taf period. Decent mixing
during the rest of the day could result in some SW to west winds,
with sustained winds between 5 and 10 kts. By evening, winds will
become more southerly and quickly subside once we start to lose
daytime heating. This will make way for another calm and clear
night. Can't rule out some patchy valley fog, but coverage will be
very limited given another day of drying, and mainly confined to
locations near bodies of water. VFR conditions will continue
through the day Thursday with winds picking up from the southwest
at 5 to 10 kts toward noon.

&&

Jkl watches/warnings/advisories...
frost advisory from midnight tonight to 9 am EDT Thursday for
kyz080-084>088-110-113-115>118-120.

&&

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