textproduct: Jackson

KEY MESSAGES

- Light snow accumulations are anticipated behind a cold frontal passage late tonight/Monday, primarily north of the Cumberland River Basin. The highest totals are forecast east of US-23.

- Southwesterly winds will become gusty on Tuesday and Wednesday ahead of a stronger mid-week system.

- The pattern remains active through the end of the work week, although confidence remains low in each passing system's precipitation type forecast.

- A much colder airmass is forecast to move into the region next week, with widespread low temperatures in the teens likely.

LONG TERM

(Monday night through Saturday) Issued at 509 AM EST SUN DEC 7 2025

Ridging builds back into the commonwealth at the beginning of the long term forecast period, but the resultant reprieve from active weather looks quite brief. A series of systems will move through the Greater Ohio River Valley in quick succession during the latter half of the work week. A tightening pressure gradient ahead of the first systems will lead to strengthening southwesterly winds on Tuesday and Wednesday. Winds could flirt with advisory criteria on Wednesday, and the resultant warm air advection will position Eastern Kentucky in the first system's warm sector. This makes rain the favored precipitation type with the initial midweek wave, although the cold air advection behind it could set the stage for potential winter precipitation during the late-week systems. Models signal that a much deeper trough will dig into the region by the weekend, and it is becoming increasingly likely that this period of active weather will culminate in the coldest temperatures of the season thus far.

When the period opens on Monday night, a post-frontal surface high pressure system will be positioned directly over the forecast area. This favors clear, calm, and seasonably cool sensible weather conditions. Modest ridge/valley temperature splits appear possible, but most of the forecast area is poised to see lows in the 20s. Expect ridgetop MinTs closer to 25 while the conventional cold spots (the sheltered and shaded valleys of NE KY) dip down into the upper 20s. These temperatures could trend a little bit cooler if the snow from the short-term forecast period lingers around for one more night. By Tuesday morning, the aforementioned surface high will have propagated eastward into the Appalachians. This will shift winds to the southwest, and winds are forecast to progressively strengthen throughout the day as an Alberta Clipper deepens and dives into the Upper Midwest. The strengthening winds will kick-start warm air advection processes, and temperatures should quickly moderate into the 40s by Tuesday afternoon. Increasing cloud cover and the persistence of these winds will keep temperatures relatively warmer on Tuesday night. Expect widespread lows in the mid to upper 30s, with only the top of Big Black Mountain left below freezing.

That clipper system will approach the forecast area on Wednesday, allowing the southwesterly low-level winds to both persist and further strengthen. Confidence in wind gusts of at least 30 knots is increasing, but winds may not make it all the way to advisory criteria (gusts of at least 40 mph). The latest BUFKIT momentum transfer model soundings continue to depict wind gusts around 30 knots out ahead of Wednesday afternoon's frontal passage. This is a slight decrease from the BUFKIT guidance at this time yesterday, when a few sites had readings closer to 35 knots. Along these lines, the latest EPS probabilities for wind gusts in excessive of advisory criteria have actually decreased relative to the previous run. While there is still a 20 to 40% chance of seeing an isolated 40 mph gust, this particularly data source tends to have a high bias. Nevertheless, Wednesday's winds will likely cause nuisance-type impacts to outdoor holiday decorations and temporary structures like tents. Continued WAA will allow temperatures to climb into the 50s across much of the area by Wednesday afternoon, and these warm temperatures point towards liquid precipitation as PoPs increase ahead of the system's cold frontal passage on Wednesday night.

A second clipper-type system will approach the forecast area at some point on Thursday. This disturbance generally looks weaker than the first one, although it will need to be monitored closely for winter precipitation potential given the antecedent cold air advection on Wednesday night. Some thermal recovery is possible on Thursday afternoon if a more northerly track is realized, but the exact evolution of this system is highly uncertain. If it takes a southerly track and/or its arrival aligns with colder temperatures on Thursday night, winter weather would be more likely. Thus, the late week precipitation type forecast is difficult to pinpoint at this temporal range.

Models resolve a third low pressure system moving through the Great Lakes States on Friday into Saturday, with much deeper troughing digging into the Ohio River Valley aloft during this time frame. Such a pattern favors the advection of a much colder, but drier continental polar airmass into the region for the end of the forecast period. Guidance collectively depicts 850mb temperatures falling below freezing (0 degrees Celsius) on Friday and then below negative 10 degrees Celsius on Saturday. This supports snow chances in the grids on Friday, but the more noticeable impacts will come from the cold temperatures in the forecast for next weekend. Lows are poised to drop into the teens area-wide on Friday night, and blustery NW flow will allow cold air advection to persist into Saturday. Saturday looks just plain cold as the Canadian-sourced air settles into the region. Expect highs to only reach the the 20s on Saturday afternoon before temperatures potentially drop into the single digits on Sunday morning. Ensemble probabilities reinforce the notion that the coldest air of the season will arrive behind these three late-week systems. The CPC has outlined most of Kentucky in its Days 8-14 Hazards Outlook for "Much Below Normal Temperatures" on December 14th and 15th, and the first sub zero wind chills of the season cannot be ruled out in this time frame. Brr.

AVIATION

(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 1245 AM EST SUN DEC 7 2025

Low clouds linger north of of I-64 at TAF issuance while patchy fog is developing under high clouds further south. Additional erosion of the low clouds is expected over the north, leaving just mid and high clouds over the area for remainder of the overnight. Patchy fog may lead to MVFR visibility reductions at some valley terminals, including SME, and even outside valleys (most likely SYM and LOZ) through sunrise. Improvement to VFR can be expected area-wide after sunrise but will gradually give way to lowering ceilings late in the afternoon and evening as an approaching front brings increasing rain chances. Light and variable winds should prevail through 14Z, with winds becoming southwest to west at less than 10KT thereafter.

JKL WATCHES/WARNINGS/ADVISORIES

None.