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Area Forecast Discussion (AFD)

Issued by Jackson, KY (JKL)

FXUS63 KJKL 171905

National Weather Service Jackson KY
305 PM EDT Sat Aug 17 2019

.SHORT TERM...(This evening through Sunday night)
Issued at 305 PM EDT SAT AUG 17 2019

18z sfc analysis shows high pressure holding on over eastern
Kentucky keeping the convection away - at least for now. A decent
cu field developed this afternoon for the area but that did little
to slow the temperature rise most places with readings currently
peaking in the mid to upper 80s along with a few 90 degree
reports. Dewpoints, meanwhile, are in the mid 60s most places - a
far cry better than they where the last time it was this warm.
Winds have been rather light today - mainly out of the southwest. 

The models are again in pretty good agreement aloft through the 
short term portion of the forecast. They all depict moderately
fast flow over the area tilting more southwesterly in the near
term as ridging builds slightly to the southeast. By the end of 
the period the flow will be more northwest and divergent coming 
from just north of the core Southern Plains ridge. A couple of 
shortwaves will pass by to the north of Kentucky during this time
as well, but likely staying far enough away to affect eastern 
Kentucky much. Given the agreement, have favored the model blend 
as represented by the NBM for this time frame. 

Sensible weather will feature a very small chance of a 
thunderstorm in the northwest parts of the area into the first 
part of the evening, but below mention in the weather grids for
now. Then look for clearing skies and quiet conditions tonight
along with some river valley fog developing. Similar conditions
take hold Sunday and Sunday night with temps a notch higher in the
afternoon and slightly milder at night - still with a chance for
valley fog along with some ridge to valley temperature

Again used the NBM as the starting point for all the short term 
grids with some adjustments for terrain differences both nights 
and a tempering of the highs on Sunday from guidance owing to 
some cloud cover. For PoPs, kept them just below 15% into this 
evening - slightly above the guidance - otherwise dry. 

.LONG TERM...(Monday through Saturday)
Issued at 240 PM EDT SAT AUG 17 2019

The extended period looks to be fairly active, as a trough of low 
pressure aloft and a slow moving frontal boundary move across the 
region. The trough is forecast to move slowly across the Great Lakes 
and Ohio Valley regions through out the period, while the surface 
front is more likely to move slowly across our area from late 
Wednesday through the end of the upcoming work week. We will see 
lower chances of rain to begin the period, with the highest chances 
of rain on tap while the front lingers about the area from late 
Wednesday through Thursday. Thunderstorms will be possible each day, 
mainly during the afternoon and early evening hours.

Temperatures will run well above normal Monday, Tuesday, and 
Wednesday, with highs on those days forecast to reach the upper 80s 
or perhaps even 90 for some locations. After that, the weather 
should cool off quite a bit, as the front stalls over the area and 
cooler air filters in from the north. Widespread cloud cover and 
persistent precipitation from mid week onward will also have an 
impact on daily temperatures. Nightly lows will range from the upper 
60s to slightly over 70 the first few nights, and will cool into the 
lower 60s to end the week. Winds should be generally light and out 
of the south or southwest to start things off, before shifting to 
the west and then north toward the end of the week after the front 
drifts south of the area.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)

VFR conditions will prevail through the majority of the period.
Will be watching the potential for a stray shower or storm to
develop - those these will likely stay off to the north and west
of the area through early evening before clearing our - so have 
left them out of the TAFs, ATTM though some cigs around 4 to 5k
will be possible for a time from the cu development this
afternoon. Tonight, some MVFR or worse fog will be seen in the 
deeper river valleys. This will clear off by 13z on Sunday. In 
general, any fog will likely steer clear of the TAF sites. Once 
the fog clear off on Sunday, some diurnally driven cumulus ranging
from 4-6k feet agl will again be seen. Winds will average less 
than 5 kts through the period mainly from the southwest to west.