685
FXUS63 KJKL 061810 AAC
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
210 PM EDT Thu Jun 6 2024

.KEY MESSAGES...

- Isolated showers should occur through early this evening ahead
  of a secondary cold front.

- Cooler and noticeably less humid air will arrive behind this cold
  front and reside over the area Friday and Saturday.

- A rapid succession of more frontal boundaries will keep a
  potential for showers or thunderstorms in the forecast at times
  next week.

&&

.UPDATE...
Issued at 1201 PM EDT THU JUN 6 2024

Hourly grids were updated based on recent observations and trends.
This led to a decrease in pops over the next couple of hours
behind the departing front and ahead of the secondary front. With
that sky cover was also decreased a bit over the central portion
of the CWA based on satellite trends with additional temperature
adjustments based on recent observations. Chances for thunder have
decreased and were lowered to below 15 percent for the remainder
of the day. Although showers may develop with the secondary front,
enough capping is expected to keep the cumulus limited in depth.

UPDATE Issued at 828 AM EDT THU JUN 6 2024

Early morning obs have been blended into the forecast without
substantive changes.

&&

.SHORT TERM...(Today through Friday)
Issued at 608 AM EDT THU JUN 6 2024

A band of showers and a few thunderstorms is continuing to
progress south southeast across the forecast area early this
morning. The precipitation is occurring ahead of a weakening cold
front and is also supported by a weakening wave aloft rotating
around an upper low near Lake Superior. The precipitation and
cold front will continue moving through the area today, and will
exit southeast into VA this afternoon. Slightly drier low level
air will arrive behind today`s front, along with much drier air
aloft. A second cold front will approach from the northwest late
today and pass through tonight. Models continue to suggest enough
low level moisture remaining for a few more isolated showers to
develop ahead of the second front. However, forecast soundings
look capped around 600-700mb, which would prevent thunder. This
activity then diminishes as it exits to the southeast this
evening. More noticeably less humid air will arrive behind the
second front, with high pressure then building in from the west
with abundant sunshine for Friday.

.LONG TERM...(Friday night through Wednesday)
Issued at 436 AM EDT THU JUN 6 2024

The 06/00z model suite begins the long-term period in good synoptic
agreement, leading to a high confidence forecast through the
upcoming weekend, before increasing model spread results in lower
forecast confidence heading into the new work week. Initially,
500H ridging will be solidly in place over northern Mexico and the
Southern Plains. Meanwhile two sub-550 dam lows lie in a
northwest-southeast oriented trough from the Upper Mackenzie
Valley to Lower Great Lakes. Subtle disturbances aloft are riding
through the northwest flow over the Central Plains between the
ridging further south and the troughing further north. At the
surface, a developing wave of low pressure is found over the
Dakotas with a trailing cold front across the northern Rockies,
while high pressure is meanders east of the 500H ridge across the
Lower Ohio/Tennessee and Mississippi river valleys.

The surface high pressure will shift east, cresting over the
Central/Southern Appalachians late Friday night. As that high
continues to press east on Saturday, focus will turn toward the weak
low pressure passing through the Southern Great Lakes and dragging a
cold front into the Ohio Valley. Meanwhile, the more easterly
upper level low (over Quebec) will elongate and rotate toward the
Ohio Valley, shoving the cold front south of the Commonwealth and
allowing cool Canadian air to pour across eastern Kentucky on
Sunday night and Monday. Height rises return Monday night and
Tuesday as the trough axis shifts to our east and high pressure
passes over the Ohio Valley/Central Appalachians. The second upper
level low and/or an associated trough may then impact eastern
Kentucky during the middle of next week but the specifics are
uncertain due to significant model spread.

Sensible weather will feature fair conditions through Saturday along
with seasonably cool temperatures. Morning low temperatures are
forecast to range from the lower to mid 50s while afternoon highs
top out in the mid 70s to lower 80s. A few of the coldest
northeastern valleys could briefly dip into the upper 40s early
Saturday morning. Shower chances rise again Saturday night as the
cold front drops into the Ohio Valley and peak ~40 to 60 PoP as
that cold front passes over eastern Kentucky on Sunday. A weak
thunderstorm cannot be ruled out ahead of or along the front.
Behind that front, diurnally-driven showers (20-30 PoP) are again
expected to bubble up on Monday, along with a possible rumble of
thunder. After one more day with highs in the mid to upper 70s on
Sunday, Monday`s maximum temperatures will be noticeably cooler,
primarily in the lower to middle 70s. A few of the cooler locales
may fail to even reach 70. A downright chilly night for mid-June
is in store for Monday night, likely deep into the lower and
middle 50s for most locations and perhaps even in the 40s through
the more sheltered valleys and hollows. (Normal highs for June
11th at the lower elevations range from ~79 to 83 while normal
lows range from 56 to 64.) Once the high pressure crests overhead,
winds will turn southerly on Tuesday leading to a quick warming
trend -- high temperatures return to the 80s by Wednesday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 210 PM EDT THU JUN 6 2024

Mainly VFR was observed across the region at issuance time with
some MFR near the VA border and likely some brief VFR reductions
were occurring in isolated light showers located generally
southeast of the TAF sites. A secondary cold front may lead to
additional isolated showers generally after 20Z moving from
northwest to southeast through about 03Z. Some very localized
brief reductions to MVFR cannot be completely ruled out in these.
Otherwise, VFR should generally prevail to end the period,
although some valley fog between 06Z to 13Z could lead to MVFR or
perhaps lower visibility. Winds will average west to northwest at
10KT or less through the period.

&&

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

$$

UPDATE...JP
SHORT TERM...HAL
LONG TERM...GEERTSON
AVIATION...JP