JKL issues Area Forecast Discussion (AFD) at Sep 27, 1:30 PM EDT532
FXUS63 KJKL 271730
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
130 PM EDT Sun Sep 27 2026
.KEY MESSAGES...
- High pressure brings dry and cool early autumn weather to begin
the week.
- Warmer temperatures return from the middle to end of next week,
along with our next reasonable potential for rain.
&&
.UPDATE...
Issued at 758 AM EDT SUN SEP 27 2026
Minor adjustments were made to hourly grids based on trends in fog
evident on satellite and observations. This led to no substantial
change at this time. Once valley fog lifts and dissipates through
around 930 to 10 AM, another day with temperatures a few degrees
below normal is anticipated.
&&
.SHORT TERM...(Today through Monday)
Issued at 535 AM EDT SUN SEP 27 2026
Early this morning, upper level ridging was centered over parts
of Mexico into the High Plains with another area of ridging
centered in Ontario and extended into the Central Great Lakes.
Meanwhile, a slow moving upper low and associated sfc
system/Nor'easter continued to meander near the eastern seaboard
and was located just south/southeast of the New York City area
this morning. Further west and northwest, a shortwave extending
from western ONtario to the Upper MS Valley was moving around this
ridging. Further west Northerly flow in between the ridging to
the west and the east coast system was occurring across the OH
Valley. At the surface, a ridge of high pressure extended from
Quebec across the western Great Lakes to the OH Valley and mid MS
Valley areas. Some clouds on the outer edge of the east coast
system were over WV and VA and were a bit west of the I-77
corridor. Otherwise, skies have been clear or mostly clear and
valley fog, mainly along the rivers, larger creeks, and area lakes
has become quite extensive per satellite. This fog was most
prevalent in the Big Sandy and KY basins and parts of the
Cumberland Valley and some areas of dense fog are present. An SPS
was issued for this potential through 1330Z, or 930 AM EDT.
Through Monday, the upper low should meander west to the NJ coast
or into portions of Southern New Jersey briefly before trekking to
the Long Island vicinity late tonight or early Monday morning and
then into portions of New England with sfc system meandering to a
position just south of Cape Cod by early Monday evening. Further
west, the shortwave trough initially from Ontario to the Upper MS
Valley area will track north and merge with an upper low in
western parts of Canada through this evening and in its wake,
upper ridging per the consensus of guidance should build over the
Southern Plains and parts of the Central Conus and Great Lakes
through the end of the period. Downstream, the upper low near the
eastern seaboard eventually moves a bit to the north and
northeast through the end of the period. A ridge of sfc high
pressure should remain from the Great Lakes to OH Valley.
Initial valley fog should dissipate within 2 to 3 hours of
sunrise this morning and with high pressure generally in control,
precipitation free weather should persist through Monday. Valley
fog should again develop toward midnight for tonight (Sun night)
and then expand in coverage and intensity before dissipating
within a couple hours after sunrise on Monday. The airmass will
only change subtly in temperatures and PW today will only moderate
a bit compared to Saturday into the 0.3 to 0.5 inch range or 10th
to 25th percentile per 00Z HREF. Additional moderation in PW
occurs on Monday around the outer fringes of the upper low to the
northeast into the 30 to 45th percentile in eastern sections of
the area and 20th to 30th percentile in the west. Some reductions
in peak heating dewpoints were made the next couple of days, with
the increase in moisture in the north and east later today and
into Monday more in the high or mid levels and this should result
in a bit more cloud cover by late tonight or Monday nearer to the
WV border. 01Z NBM highs again appeared too cold compared to
persistence and MOS/statistical guidance and went a couple of
degrees warmer on average compared to the NBM deterministic for
today. A ridge valley split favored by the pattern and keeps with
persistence was also included for tonight compared to the more
uniform min T in the NBM deterministic.
.LONG TERM...(Monday night through Saturday)
Issued at 425 AM EDT SUN SEP 27 2026
The start of this period will be a continuation of the pleasant
weather occurring in the near term, thanks to the approaching
upper ridge from the west and sfc high pressure ridge that
gradually shifts east of area into midweek. This pattern will keep
us dry for the first half of the week and introduce a warming
trend starting Monday, with highs increasing a bit each day. Highs
will get back into the 80s by Tuesday or Wednesday, initially in
the more southern locations. There is some model discrepancy in
what temps will be like for the second half of the week due to an
approaching trough from the west. Right now it appears most
likely that we will remain in the 80s each day and maybe even
close to 90 in some areas if the Euro is correct. Lows should also
moderate throughout the week, though the pattern favors
ridge/valley temperature splits through at least Tuesday night.
The biggest uncertainty in this period is our rain chances and
timing of the best chances during the second half of the week and
into the weekend. Model guidance and NBM accordingly over the
past couple days keeps pushing back the onset of 15 percent or
greater PoPs from Wednesday to Thursday or Thursday and now
trending toward Friday. This uncertainty originates from model
variability in the evolution of the upper level pattern which will
drive rain chances. The consensus of guidance is for the ridge
axis initially west of the area at the start of the period
migrate across the Commonwealth and then off to the east during
the second half of the week as a trough also translates from the
west coast to the central US. The trough looks to slow down or
even stall as it gets into the Central US as a ridge centered
near or east of the southeast U.S. coast and extending into the
southeast sets up. It looks like one or more subtle shortwaves
will peel off the heart of the trough in the central US and ride
the edge of that southeast ridge. The trend in the delay of PoPs
returning to eastern KY appears due to that strong southeast
ridge. The strength and positioning of that ridge will probably
result in the greatest chances of meaningful rain remaining well
off to our north and west until Friday or the weekend. NBM and
LREF ensemble guidance shows a 50-55% chance of >.1" of rain on
Saturday and a 60-75% chance of >.1" on Sunday. These higher PoPs
for the weekend have been pretty consistent over the past couple
nights so it's something worth paying attention to. Now it's worth
mentioning that although those higher PoPs have been consistent,
the upper level pattern that will deliver the active weather has
not been as consistent in the models. This will make determining
how much rain and timing of that into the region very hard to
ascertain at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 129 PM EDT SUN SEP 27 2026
VFR conditions are expected at all TAF sites, with just a few
passing cu over KSJS over the next few hours. Winds will remain
northerly at less than 10 kts before decoupling occurs around
sunset. Fog development is expected in the valleys between 04Z and
13Z, with the most persistent fog lingering past 14Z in eastern
valleys, although this is not expected to impact TAF sites.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...DISINGER/JP
AVIATION...CMC/FAGAN
Source:
JKL issues Area Forecast Discussion (AFD) at Sep 27, 1:30 PM EDT---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
