734
FXUS63 KJKL 132021
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
421 PM EDT Sat Jul 13 2024

.KEY MESSAGES...

- Hotter conditions make a comeback this weekend and into early
  next week.

- The next significant chance of rain will hold off until the
  middle of next week.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 420 PM EDT SAT JUL 13 2024

Current 18Z surface analysis continues to show surface high pressure
situated over much of the eastern CONUS. A surface low is moving
across southern Canada with cold front extending southward into the
US. This will fire off pockets of severe weather across much of the
Upper Midwest; however, in eastern Kentucky, high pressure remains
dominate with mostly sunny skies. Radar has been a little active
over the last hour or so with pop-up showers developing along and
southwest of the Mountain Parkway.

Aloft, mostly zonal flow is building into the region which will
advect drier air into the region but forecast SBCAPE from 500 to
1,000 J/kg could and has allow for a few pop-up thunderstorms across
the area. Mainly along and south of the Mountain Parkway. Showers
will taper off toward sunset with skies largely expected to clear.
This clearing could allow for valley fog development but could be
very dependent on the amount of clearing expected overnight.

Upper-level flow turns northwesterly with the approach of a trough.
Height falls are forecast to arrive early Sunday. At the surface,
high pressure will remain present but CAM guidance has been very
persistent bringing a potential MCS into the region toward the late
afternoon into evening hours Sunday but with the ambient environment
rather dry and void of moisture, the lack of moisture could keep the
area dry. Opted to keep the area largely dry aside from a few
isolated showers and storms mainly along and north of I-64. For the
overnight Sunday, surface high pressure building in could allow for
clearing skies leading to radiational cooling in the river valleys.
Thus allowing for the development of areas of valley fog through the
early morning hours of Monday.

Otherwise, the period will be mostly dry aside from a few isolated
showers or storms this afternoon and again Sunday afternoon/evening.
Highs are forecast to be in the low to mid-90s today and Sunday.
Overnight lows will remain mild across the area too, as lows tonight
will drop into the mid to upper-60s for tonight and again Sunday
night.

.LONG TERM...(Sunday night through Friday)
Issued at 450 AM EDT SAT JUL 13 2024

The 13/00z model suite upper level analysis continues to show broad,
low amplitude troughing over the Northeast US/Great Lakes/Upper
Midwest at the start of the period Sunday evening. Subtle
disturbances embedded in the flow maybe supportive of MCS activity,
though the better forcing looks to largely be north of the Jackson
CWA. Looking to our west, a robust ~596 dam high is parked over the
Four Corners. To the east of this upper high, surface high pressure
continues to dominate the weather over the Southeast US and over
much of the Ohio Valley.  North of this high, an ~553 dam low is
spinning near/over Churchill, Manitoba while a North Pacific
Shortwave dives across the Canadian prairies.

For the first 24 to 36 hours of the period, the upper level high
over the western CONUS will elongate and nose eastward while ridging
also tries to build northward from the Gulf of Mexico. This will
lead to weak height rises through Tuesday morning, and keep deep
convection in check over eastern Kentucky though a few very
isolated showers cannot be ruled out, mainly in those counties
adjacent to Virginia. Meanwhile, the Pacific shortwave and
Canadian low will phase and deepen into a stout trough (by July
standards) that will dig into the Northeastern CONUS and Ohio
Valley and push a robust cold front through eastern Kentucky
later Wednesday and into Thursday. Model agreement worsens later
in the week, especially in regard to how quickly and far the cold
front clears eastern Kentucky by Thursday and Friday. If the
front stalls out too soon, then lingering rain chances are
probable over the far southeastern portions of Kentucky not only
on Thursday but also on Friday as well.

Ahead of the cold front, heat and humidity is still expected to
build and reach its maximum intensity on Monday and Tuesday. Which
day actually is hotter is less certain; Monday may very well have
the warmest temperatures, courtesy abundant sunshine; yet Tuesday
may end up being the most oppressive due to higher humidity levels.
At any rate, it will be quite hot with widespread high
temperatures flirting with the middle 90s for both days. There
should be more in the way of cloud cover and also slightly better
rain chances(20-30% vs. 10-20%) on Tuesday vs. Monday. The best
opportunity for rain comes on Wednesday with passage of the cold
front (70-80% chance). Thereafter, the rain chances become
increasingly confined near and south of the Hal Rogers Parkway/
Highway 80 corridor by Thursday as especially on Friday as the
cold front stalls out along the Southern Appalachians. Once the
cold front passes, refreshingly cooler air can be expected for
Thursday and Friday with widespread highs in the lower to middle
80s. Nighttime lows in the mid 60s to mid 70s for the first half
of the forecast period retreat to he lower and middle 60s for many
locations late in the week, with even some upper 50s are forecast
in the cooler valleys on Thursday night and Friday morning.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 134 PM EDT SAT JUL 13 2024

VFR conditions are prevailing across all TAF sites. Mid-level
moisture and surface heating have allowed for a widespread deck of
cumulus clouds to develop early this afternoon. Clouds are above
VFR but ranging from 3,000 to 5,000 ft. Scattered showers may
develop again this afternoon but confidence and coverage is very
low; therefore, opted to keep VCSH out of the TAF. Also, guidance
is continuing to be aggressive with the potential for overnight
fog and did opt to add fog across all TAF sites but kept all sites
MVFR from 08Z-12Z before returning back to VFR. Light and
variable winds will persist through the duration of the period.

&&

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

$$

SHORT TERM...VORST
LONG TERM...GEERTSON
AVIATION...VORST