textproduct: Jackson

KEY MESSAGES

- Another light, to possibly moderate, snowfall is on its way for this evening into early on Sunday, mainly north and east of a Stanton to Jackson to Whitesburg line.

- An arctic airmass moves into our region for late tonight and Sunday with significantly below normal temperatures and bitterly cold wind chills on tap.

- Nearer to, if not above normal, temperatures can then be expected from Tuesday through the end of next week.

UPDATE

Issued at 130 PM EST SAT DEC 13 2025

Only minor adjustments have been made based on recent observations and satellite trends. Some clearing or scattering of low clouds has occurred in the south while low clouds are holding on further north. That trend should hold over the next few hours. The forecast challenge remains the upcoming clipper system that the region will generally be on the southern and southwestern fringe of. The convective allowing models, especially the HRRR remain more pessimistic with snowfall with that system this evening into early on Sunday while. The recent RAP runs and NAMNEST are generally a bit higher as are the global models. This leads to uncertainty in snowfall totals. However, some snow expected to fall in the advisory area combined with falling temperatures travel impacts are anticipated even if totals end up only marginal for advisory criteria on the southern and western edge of the advisory.

UPDATE Issued at 650 AM EST SAT DEC 13 2025

Watching the area web and traffic cams there appears to be signs of improvement to the dense freezing fog situation. Will keep monitoring for a possible temporal extension to the current advisory. Otherwise, have included the latest obs and trends for the T/Td/Sky grids with this update. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones and SAFs.

LONG TERM

(Sunday night through Friday) Issued at 530 AM EST SAT DEC 13 2025

While one more night of bitterly cold weather is expected at the beginning of the long term forecast period, a prominent pattern shift is poised to produce much milder conditions for the upcoming work week. The northwesterly flow responsible for the advection of an arctic airmass into the forecast area at the end of the short term forecast is expected to back towards the west and then the southwest as the week progresses. The resultant return of ridging and midlevel height rises favor a warming trend before two late- period storm systems approach. Warmer antecedent temperatures will limit the potential for widespread winter weather with these two systems, a welcome relief from the snowy and cold start to December.

When the period opens on Sunday evening, the ground will likely be covered in a dry, powdery snow. Northwesterly mid-/upper-level flow will remain in place for one more night around the backside of an eastward-propagating trough. At the surface, a high pressure system will be passing directly overhead. Together, these features favor efficient radiational cooling, and MinTs are accordingly forecast to drop in the single digits area-wide by Monday morning. However, the surface high's proximity will keep winds light and variable and reduce the wind chill effect. Models collectively depict 850mb temperatures warming above the -10 degrees Celsius threshold in this time frame. Therefore, confidence in reaching Cold Weather Advisory criteria is lower on Sunday night than it is on Saturday night/Sunday morning. Higher-terrain locations near the Virginia state line are most likely to do so, but decided hold off on issuance for now. Interests are still encouraged to bundle up for the Monday morning commute though, as these low temperatures are 20- 25 degrees cooler than climatological averages for mid-December in Eastern Kentucky.

Surface flow becomes southwesterly on Monday as the high pressure system settles into the Southeastern CONUS. The winds aloft will weaken and adopt more of a westerly component, and 850mb temperatures should finally climb above freezing on Monday afternoon. Under mostly clear skies, surface temperatures in the southern half of the forecast area should recover into the mid 30s. The cold air will hang on for the longest in areas north of the Mountain Parkway, where the snowpack is highest and where there could be some cloud cover. Thus, one more day of freezing high temperatures appears likely in our northern counties. There is some model disagreement on the magnitude of potential ridge-valley MinT splits on Monday night into Tuesday. Some of the available deterministic MOS guidance drops valley locations into the single digits again, but the ensemble probabilities for temperatures less than 10 degrees Fahrenheit are less than 20 percent. The coarser- resolution long term forecast guidance doesn't necessarily pick up on small-scale local geographic effects, but the bias-corrected baseline NBM guidance populated widespread MinTs in the lower half of the 20s. For this forecast package, temperatures were bumped into the upper teens in the typically colder shaded/sheltered valley locales as a middle-ground solution. If higher-resolution guidance reinforces confidence in the more dramatic splits, future forecast packages may require further edits.

Quasi-zonal flow aloft and the southern surface high will keep the sensible weather quiet on Tuesday and during the daytime hours Wednesday. Southwesterly winds will become breezy in response to a system passing well to the north of the forecast area. This displaced disturbance looks rather weak and moisture starved, but it should still foster a noticeable mid-week warming trend. The entire forecast area should warm up above freezing and perhaps into the 40s on Tuesday afternoon, allowing any remaining snow to melt off. Increasing cloud cover could limit the amount of radiational cooling on Tuesday night, and ridge-valley temperature splits look less likely then. Pre-midnight lows near freezing are possible, but the persistence of warm air advection should result in temperatures in the mid 30s by the time the run rises on Wednesday morning. Expect afternoon highs to warm further into the upper 40s/lower 50s.

A second, stronger disturbance will dig into the Great Plains on Wednesday night into Thursday, leading to renewed precipitation chances in the forecast area. With surface temperatures well above freezing, any overrunning precipitation with this system's warm frontal passage will fall as rain. The warm air advection regime is expected to strengthen behind that boundary. The flow aloft will become southwesterly ahead of the approaching trough axis, and southerly to southwesterly surface winds will strengthen amidst a tightening pressure gradient. Southwesterly wind gusts of 25-30mph are possible out ahead of the system's cold front. High temperatures in the mid/upper 50s will yield widespread rain showers, and some convective activity cannot be ruled out. The negative tilt of the parent troughing aloft and a strengthening 850mb jet points towards potentially favorable shear parameters, but modeled instability remains meager due to slower dewpoint recovery. Model trends will need to be monitored closely with this late-week system, but for now, the set-up favors generic gusty rain showers amidst seasonably warm highs in the upper 50s/near 60. Once the cold front sweeps through the area on Thursday night, temperatures should quickly drop into the 30s. The colder airmass will also be drier though, and a widespread changeover to snow on Friday is not anticipated.

AVIATION

(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 135 PM EST SAT DEC 13 2025

Low clouds have cleared or scattered for the most part near a line from KSME to KLOZ to KCPF to near KPBX and this should creep toward KJKL and KSJS. Thus uncertainty during the first 6 hours of the period for ceilings is greatest at KJKL, KLOZ, and KSJS as MVFR was forecast though there may be several hours of VFR at these locations. Otherwise, low clouds should prevail in the north such as KSYM with MVFR anticipated for the first 6 hours of the period. Some snow from the clipper system incoming could affect KSYM and norther locations as early as 21Z or 22Z with snow steadier snow developing there nearer to 00Z. However, the area of snow should shift southeast across the entire area between 00Z and 12Z, with a 2 to 4 hour of impact on VIS and ceilings down into the MVFR and IFR range. Briefly lower ceilings or vis are possible in any more intense snow showers. Generally, light and variable winds are expected initially before winds become northwest at 5 to 10KT by the 03Z to 06Z timeframe and then maintain that magnitude and direction to end the period.

JKL WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 10 AM EST Sunday for KYZ044- 050>052-059-060-104.

Cold Weather Advisory from 1 AM to 1 PM EST Sunday for KYZ044- 050>052-058>060-068-069-079-080-083>087-104-106-108-111.

Winter Weather Advisory from 7 PM this evening to 1 PM EST Sunday for KYZ106>110-112-113-115-118>120.