textproduct: Jackson

KEY MESSAGES

- A clipper system is winding down across the area this morning.

- Another light to moderate snowfall is increasingly likely Saturday night and early Sunday, mainly north of the Mountain Parkway.

- An arctic airmass with significantly below normal temperatures moves into our region for Sunday.

UPDATE

Issued at 1105 AM EST FRI DEC 12 2025

Snow was winding down from west to east and at 10 AM EST, snow was lingering in our eastern counties. With that in mind, the Winter Weather Advisory was extended there, but even that activity is ending now. That extended advisory will likely be ended early. Other than related adjustments to pops, temps and dewpoints no other changes were made.

UPDATE Issued at 630 AM EST FRI DEC 12 2025

No significant changes were made to the forecast with mainly just the inclusion of the latest obs and trends for the T/Td/Sky grids. Did also touch up the PoPs per the current radar and CAMs guidance. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones and SAFs.

LONG TERM

(Saturday night through Thursday) Issued at 316 AM EST FRI DEC 12 2025

The forecast period commences with the passage of the third and final Alberta clipper through the Ohio Valley. This well-defined shortwave trough is projected to track eastward through the Ohio Valley before ejecting northeastward toward New England. Consistent with previous model iterations, significant changes have not occurred with respect to the temporal and spatial evolution of this rapidly propagating feature. As this system translates southeastward across the Ohio Valley, the PoP will increase, but the northerly trajectory of the low-pressure center remains consistent. This track is favorable for the heaviest precipitation and snow accumulation to remain north of the CWA, mainly focusing along the Ohio River. Model uncertainty remains subtle, with minor north-south oscillations in the track evident in successive model runs. Such small-scale track adjustments would have notable implications for projected snowfall totals, the precise placement of the freezing line, and the distribution of frozen versus liquid precipitation. Nonetheless, the greatest snow accumulations are forecast to occur outside and north of the CWA. Within the CWA, a Winter Weather Advisory criterion is anticipated to be met for locations generally along and north of a line extending from Powell to Pike Counties through Sunday morning.

Lingering stratiform snow showers and flurries will be possible through the day on Sunday. However, forecast emphasis shifts rapidly to the arrival of unseasonably cold temperatures following the passage of the Arctic front. Synoptically, surface high pressure will rapidly build into the region in the wake of the departing low- pressure system. Correspondingly, upper-level northwesterly flow will facilitate the CAA of the coldest air mass of the season thus far through the early portion of the succeeding week. Maximum temperatures on Sunday are projected to range from the mid-teens Fahrenheit across the northern extent of the CWA to the mid-20s Fahrenheit nearer the Tennessee border. Overnight minimum temperatures will be substantially colder, particularly for the Sunday night/Monday morning period. The confluence of factors including sustained CAA, radiational cooling under clear skies, and residual snow cover will allow minimum temperatures to fall into the negative single digits Fahrenheit (primarily in the Bluegrass region and sheltered valley locations) to positive single digits Fahrenheit elsewhere. Mid-level flow is forecast to shift from a northwesterly to a southwesterly component beginning Monday, which will induce a gradual warming trend anticipated by the middle of next week, ahead of the next significant synoptic-scale system approaching the region near the end of the forecast period.

Predominantly quasi-zonal flow will persist across the region through much of the upcoming week. This pattern is forecast to undergo trough amplification commencing Thursday morning as a shortwave trough develops rapidly off the Rockies and quickly traverses the CONUS. This trough will lead to increasing PoP through the day on Thursday. In conjunction with increasing precipitation potential, surface winds are forecast to become strong, with LREF probabilities indicating a widespread 50 to 60 percent chance of wind gusts exceeding 30 miles per hour (mph) in advance of Thursdays frontal passage. Winds will subsequently diminish behind the front, but residual rain showers are anticipated to linger through the end of the forecast period.

In summation, an Alberta clipper system is forecast to bring light snow accumulations to areas generally north of the Mountain Parkway from Saturday night into Sunday. Strong post-frontal surface high pressure will subsequently establish itself over the region on Sunday, driving minimum temperatures down into the upper single digits and mid-teens Fahrenheit. A gradual warming trend will commence on Monday, but the next significant system will arrive late in the week, bringing rain and strong winds.

AVIATION

(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 105 PM EST FRI DEC 12 2025

Low and some mid level clouds remain across much of the region following the snow last night and this morning. VFR was reported at issuance time in southwestern portions of the area including near KJKL, KLOZ, and KSME with MVFR and even some IFR in the more northern and eastern locations including KSYM and KSJS. Guidance lingers low level moisture through the period and after the improvements over the past few hours in the southwest that may spread toward KSJS, a gradual deterioration in categories is expected by the 20Z to 02Z timeframe into the more southwestern locations first through the MVFR ranges and eventually IFR 03Z to 09Z. The more southwestern locations may improve back to MVFR before the end of the period. However, KSYM should experience prevailing IFR through the period. Generally light and variable winds are expected through the period.

JKL WATCHES/WARNINGS/ADVISORIES

None.