textproduct: Jackson

KEY MESSAGES

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

- Temperatures will average below normal through at least the next week.

UPDATE

Issued at 523 PM EST FRI DEC 5 2025

Late afternoon update is out with a primary focus on Sky grids, as only the HRRR seems to be representing the widespread overcast conditions across our forecast area. Utilized the most recently available HRRR through much of the overnight period, with little in the way of any significant cloud breaks anticipated.

LONG TERM

(Sunday through Friday) Issued at 400 PM EST FRI DEC 5 2025

The period is expected to begin with an upper level low in the Hudson Bay vicinity and a trough extending south across the Great Lakes to the MS and OH Valleys to eastern TX while an upper level ridge is expected to extend from the eastern Pacific into portions of the western Conus. A shortwave associated with that system is expected to be moving into the Northern Great Lakes with another in mid MS Valley vicinity a that point. At the surface, ahead of these shortwaves, a sfc low is expected to be over southern MI with another sfc wave in the mid MS Valley vicinity along a frontal zone that should extend across Southern New England and the mid Atlantic states to southern MI to the mid MS Valley to the Southern Plains.

The more northern shortwave crossing the Great Lakes and the second nearing the Lower OH Valley should progress east and northeast to begin the period into Quebec and the Northeast to Mid Atlantic and TN and OH Valleys through Sunday and Sunday night. This should result in the 500 mb trough axis shifting into the eastern Conus and nearing eastern KY by late Sunday night. As this occurs additional shortwaves should move into the trough in northwest flow aloft this weekend. West to northwest flow should remain through much of next week as the ridging remains from the Pacific into western portions of the area with troughing from Canada into Central and eastern portions of the Conus. Additional shortwaves should move through this troughing through the period. The first frontal zone should move into eastern KY later Sunday and southeast of the area Sunday evening into Sunday night. Moisture should gradually increase ahead of it on Sunday.

By the time the atmosphere saturates enough for precipitation to fall on Sunday, late in the morning to early afternoon, just plain rain is anticipated. Colder air will arrive behind the cold front later Sunday evening through Sunday night, and any remaining precipitation should change from rain showers to snow showers. 12Z LREF probabilities for more than a dusting/tenth of an inch of snow are in the 30 to 60 percent range for the 24 hour period ending at 7 PM EST on Monday, while the 12Z LREF probabilities for more than a half of an inch of snowfall during that timeframe are currently in the 10 to 30 percent range. Thus with these grand ensemble probabilities and 12Z operational runs of the GFS and in particular the 06Z and 12Z ECMWF also suggesting a chance for some light accumulations for some locations, opted to add this potential to the HWO.

A brief window of sfc and shortwave upper ridging follows later Monday into early Tuesday before the next shortwave and associated system in northwest flow aloft move to the Great Lakes to OH Valley region for midweek. As this system approaches, the pressure gradient and winds aloft will both increase, as early as Tuesday afternoon, and especially later Tuesday night and Wednesday. The 12Z BUFKIT momentum transfer suggests that wind gusts in excess of 30 mph and nearing the 40 mph wind advisory threshold could be reached. Mean wind gusts midday Wednesday into the afternoon in EPS based guidance are mainly 30 mph or stronger in central to eastern KY. This would be the initial forecast concern with mid to late week systems across eastern KY. Otherwise, precipitation chances should again return at midweek for Wednesday into Wednesday night, initially in the form of rain. Then as colder air moves in Wednesday night to early Thursday, lingering rain showers could mix with or change to snow showers. A third cold front and shot of colder air should arrive from later Thursday night into next Friday as yet another system nears in west to northwest flow aloft. This front should bring additional chances for showers and pending the thermal profile these could fall as rain or snow showers or a mix thereof.

Highs should average near 5 degrees below normal, in the 40s, on Sunday ahead of the cold front, with highs in the 30s or about 15 degrees below normal forecast for Monday. Lows should be seasonably cold for Monday night with high pressure dominating, mainly in the upper teens to mid 30s. Temperatures should again have a moderating trend from Tuesday into Wednesday with highs nearing normal for this time of year on Wednesday. Otherwise, temperatures return to below normal levels to end the work week behind the second cold front in the long term period.

AVIATION

(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1223 PM EST FRI DEC 5 2025

LIFR to low-end MVFR conditions are expected to prevail through much of the forecast period as a layer of moisture is trapped under an inversion. Until this inversion breaks, low-CIGS can be expected. A few breaks in the clouds will be possible this afternoon but those breaks will be short-lived. Otherwise, the period will be LIFR to MVFR. Guidance does have improvement to VFR toward 18Z/Saturday and opted to trend that route in the TAF. Lastly, winds will be light and variable.

JKL WATCHES/WARNINGS/ADVISORIES

None.