506 
FXUS63 KJKL 132044
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
444 PM EDT Mon Sep 13 2021

.SHORT TERM...(This evening through Tuesday night)
Issued at 351 PM EDT MON SEP 13 2021

A slow motion transition of weather regimes is underway. Ridging
aloft stretches east/west across the southern CONUS, while the 
prevailing westerlies are just to our north. There is a weakness 
in the ridge over the south central CONUS, which Tropical Cyclone
Nicholas is heading north into. There is also a wave in the
westerlies over the far northwest CONUS. As the wave moves east,
it will deepen southward into the weakness in the ridge on Tuesday
and Tuesday night. Nicholas will move slowly inland and
weaken/degrade, with deep tropical moisture getting picked up
ahead of the trough. The moistening atmosphere will support a
potential for deep convection. After dry weather through Tuesday
morning, diurnal destabilization may be enough for a few showers
or thunderstorms in our southwest counties in the afternoon. If
these occur, they should fade in the evening. However, a  
weakening cold front supported by the trough will also approach 
from the northwest and could result in showers/thunderstorms by
dawn Wednesday, especially in our northwest counties.

.LONG TERM...(Wednesday through Monday)
Issued at 440 PM EDT MON SEP 13 2021

After a nice dry stretch of weather, the moisture and rain chances 
will return for the extended. The first round will come from a cold 
front dropping southeast into the state starting off the day 
Wednesday, which should bring increasing pops just ahead of the 
boundary. This boundary will then stall heading into Thursday as a 
Tropical Depression Nicholas makes landfall in the western Gulf and 
begins to meander slightly northward, combined with strong area 
of high pressure parking itself to our east. The return flow off 
the high to our east will tap into the moisture from the tropical
system, advecting it into the region and resulting in pops through
Thursday, peaking during the afternoon hours. 

WPC shows the surface boundary eventually dissipating as we head 
towards the weekend, but the high will remain in place to our east 
and then southeast in some capacity. Furthermore, the tropical 
moisture from the dissipating system will continue to infiltrate 
northward into the Ohio Valley. Another tropical low may also ride 
along the Atlantic Coastline as we head into the weekend. For 
sensible weather, this will mean daily chances for showers and 
thunderstorms under a continued warm and moist environment. 
Convection will dissipate overnight with the loss of daytime 
instability/heating. Temperatures should see a slow warming trend 
through the weekend, topping out in the low to mid 80s under 
continued southerly flow. While these temperatures aren't the 90s we 
saw a few weeks ago, it is still construable higher than the normals 
for this time of the year. These temperatures would also likely be 
higher if it wasn't for the elevated humidity. Overnight lows will 
be mild/above normal as well, generally in the mid 60s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 217 PM EDT MON SEP 13 2021

Valley fog will occur during the late night and early morning
hours once again, bringing localized VLIFR conditions. TAF sites 
will probably be affected to some extent around dawn, but at this
time nothing worse than MVFR is in the forecast as prevailing
conditions for those airports. Otherwise, VFR conditions are 
expected. Winds will be generally from the southwest at less than 
10 kts.

&&

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

$$

SHORT TERM...HAL
LONG TERM...JMW
AVIATION...HAL