UPDATE
Issued at 738 AM EDT SAT JUL 27 2024

The forecast is in good shape, with the only updates being to blend in early morning observed temps and dew points.

SHORT TERM
(Today through Sunday)
Issued at 529 AM EDT SAT JUL 27 2024

Upper level ridging is present from the upper Great Lakes southward over the southeast CONUS early this morning, while surface high pressure is centered near the lower Great Lakes. The surface high has brought a somewhat cool and dry air mass (by mid summer standards) into northeast KY. The front at the leading edge of the air mass has dropped well to our southwest in TN, but dew points increase from northeast to southwest in KY as you get closer to the boundary. The air should be dry enough to preclude showers/thunderstorms in our area today, but they may be close to our southwest this afternoon.

An upper level low currently centered over eastern OK will move north northeast to the upper Mississippi Valley by late Sunday.
Troughing extending south from the low will approach our area from the west. As this happens, we will have deep moisture advect over our area. This will bring a return of showers/thunderstorms on Sunday, especially for our western counties.

LONG TERM
(Sunday night through Friday)
Issued at 336 AM EDT SAT JUL 27 2024

Upper level troughing will be the name of the game throughout the extended period for eastern KY. A strong upper level low will be present across the Atlantic Seaboard on Sunday. A second incoming trough will begin to impact the Ohio Valley from the west by Sunday evening, quickly merging with the stronger system to the east by the start of the extended period Sunday night into Monday morning. This upper level low is expected to slowly shift northward into New England through mid-week, but will leave much of the eastern Conus in a deep troughing pattern as a result. This pattern also leaves much of the region vulnerable to additional shortwaves passing through during this time.

Meanwhile, a strong area of ridging will be in place across the far south-central portion of the Conus through much of the week. Models do try to show some of this ridging finally spreading its way into the southeast, including rising heights across Kentucky, for Thursday, but our location on the northern fringes likely won't be enough to stop waves of energy from moving through much of the Ohio Valley during this time. Models then show the upper level troughing re-establishing its hold across the eastern Conus once more, resulting in lowering heights once more and the return of a more active pattern for Friday and heading into the weekend.

Given the trough set up through the majority of the period, and eastern KY's general location on the SW flow side, it's not a surprise that SW flow will descends all the way to the surface and persists through much of the extended period. This will result in two things - moisture and heat. Not expecting any large-scale airmass changes or frontal boundaries during this pattern, so hot and humid conditions with increased moisture and instability will be the name of the game. Shower and thunderstorm chances are on tap nearly every day. Even Thursday into Friday, as heights rise some across the region, we will still not be immune to some instability and generally diurnally driven convection during the afternoon.

Monday will be the coolest day according to the NBM, with temps maxing out in the low 80s. This is also likely one of our wettest days, with abundant cloud cover/rainfall inhibiting higher temperatures. But once the SW flow regime sets up and precip chances lesson, expect temperature to trend higher, topping out in the upper 80s to around 90 by mid-week, persisting into the weekend. Humidity will make it feel somewhere between the mid 90s and 100 degrees during this time.

In addition, as mentioned before, there will be daily chances for showers and thunderstorms. Did not have enough confidence to deviate away from the NBM pops at this point, but did try to peak them during the afternoon when instability and lift will be their highest, without the presence of a passing boundary. WPC has placed much of the JKL CWA in a slight risk for excessive rainfall from 12Z Sunday through 12Z Wednesday. Their main concern is the increased precipitable water which could lead to heavy downpours and multiple storms moving over the same location. That being said, much of eastern KY has received very little rainfall over the past month, with a few exceptions, so most locations should be able to handle decent rainfalls. There isn't a very defined boundary setting up for which these storms will likely train, though can't rule out that if storms do develop and move over the same location with heavy rain rates/amounts, this could lead to some isolated concerns. Will continue to monitor this as we get closer to time, but right now confidence isn't very high in a widespread flash flood concern.
Meanwhile, SPC has eastern KY in a general thunderstorm risk throughout the period, again without lack of forcing. Generally expect diurnally driven pulsy showers and storms.

Finally, given the clouds and moisture in place, and without the presence of a high pressure system moving overhead (subsidence), chose not to include any ridge/valley splits for temperatures during the extended period. There could be moments of clearing in the clouds overnight, especially late in the week, which may result in temperature drops. However, confidence on when and where this would happen is quite low, so just kept with the modeled temperatures at this time. Will make tweaks with future forecasts as we get closer to that period. The same goes for fog as well. It is likely with so much moisture that we could see some fog overnight in places, but exactly when and where this will set up is unknown, and may not be confined to just the valley locations.

AVIATION
(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 738 AM EDT SAT JUL 27 2024

Late night and early morning fog will affect many valley locations with IFR or worse conditions, but will likely avoid TAF sites during the period. Otherwise, VFR conditions and light winds are forecast.

JKL WATCHES/WARNINGS/ADVISORIES
NONE.