718 FXUS63 KJKL 281237 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 737 AM EST Sat Feb 28 2026 .KEY MESSAGES... - Above normal temperatures will persist through tonight, before a modest cool down for Sunday and Monday behind a cold front. - After low chances (20 to 30%) for measurable rain behind the cold front late tonight and early on Sunday, there is greater potential for more widespread precipitation at times next week. - There is a potential for a wintery mix in more northern locations late Sunday night and Monday, but at this time, any accumulations look to be light. && .SHORT TERM...(Today through Sunday) Issued at 535 AM EST SAT FEB 28 2026 Early this morning, an upper level low was centered in the northeastern portion of Hudson Bay with a trough across Ontario and the Great Lakes to the OH Valley and Southeast. Meanwhile an upper level ridge was centered east of Baja with the ridging extending north along the west Coast of the Conus while to the west an upper low over the eastern Pacific. Northwest flow was prevalent from the Gulf of AK across western Canada and the international border to the Great Lakes to the west of the trough axis. Also moving within the trough was a shortwave that extended from James Bay to the eastern Great Lakes. At the surface, an area of low pressure was centered southeast of James Bay with a cold front/baroclinic zone into the eastern Great Lakes to Lower OH Valley to Central Plains and then northwest to MT. A ridge of sfc high pressure was departing to the southeast and was centered over the vicinity of the Blue Ridge. The front is rather moisture starved with southern extent and clear skies and light winds under high pressure in valley locations has allowed temperatures to drop to the upper 20s to low 30s. Temperatures elsewhere ranged through the 30s to the mid or even upper 40s in the thermal belt locations such as the Pike County Mesonet station which is currently 48. The upper level trough will remain from the James Bay vicinity south into parts of the central and eastern Conus to southeast through the weekend. A dry cold front will sag into northern KY today and then as a disturbance moving through the trough interacts with the baroclinic zone and an associated sfc wave moves from the mid MS Valley to the OH Valley the boundary will sag further into eastern KY tonight, eventually dropping across eastern TN and the Southern Appalachians Sunday. Moisture will be limited with this system, but enough saturation may occur in the low to mid levels for patchy light rain or isolated to scattered showers may occur late tonight to early on Sunday, generally north of a Rockcastle to Pike County line. Any measurable rainfall would be a couple of hundredths at best. Southwest to west flow between the departing high to the southeast of the area and the approaching front will allow for temperatures to warm even higher compared to Friday with highs expected to range through the 60s to around 70 in the lower elevations downwind of VA border where a bit of extra warming may occur on modest downslope component in the low level flow. The mild temperatures and drier airmass brought into the area by the sfc high that only gradually becomes more moist by late afternoon should result in min afternoon rh in the 28 to 45% range. After any early morning showers or spotty light rain in the southeast, rain free weather is expected for Sunday as a sfc high moving into the Great Lakes noses into eastern KY. A more substantial system approaches in the start of the long term period. .LONG TERM...(After midnight Sunday night through Friday) Issued at 722 AM EST Sat Feb 28 2026 The forecast becomes more active in the long term period, starting with a marginal winter weather set up and ending in much warmer-than- normal temperatures. A series of shortwave impulses amidst a persistent regime of quasi-zonal flow aloft will push a warm front north across the Ohio River Valley early in the week. This progressively produces more potent warm air advection and moisture return processes, and spring/summer-esque convection appears possible in Eastern Kentucky by the end of the period. However, the forecast area will be positioned on the cold side of this boundary when the period opens on Sunday night. Confidence is high that northerly surface winds associated with a Canadian high pressure system centered over the Great Lakes will advect a shallow layer of sub-freezing air into the northern half of the forecast area. Probabilistic ensemble data supports this notion, with a 60-90% chance of overnight lows below 32 degrees in locations north of a line stretching from Mount Vernon to Jackson to Prestonsburg. If isentropically-forced precipitation arrives while these cold temperatures are in place, the modeled atmospheric temperature profiles will be cold enough to support snow in this corridor. Given the warm and mostly sunny conditions forecast across the area during the short term period, ground/pavement temperatures will likely be above freezing leading into the event. This will limit accumulation potential, as will the approach of the boundary's warm air advection regime. Confidence is also high that afternoon highs on Monday will rise well above the freezing point. In fact, the NBM ensemble probabilities of MaxTs greater than 40 degrees are above 90% area- wide, even in our higher-terrain locales. This gives credence to the notion that any precipitation that occurs on Monday afternoon (and beyond) will fall in the form of a plain, liquid rain. The forecast guidance suite continues to disagree upon when the precipitation associated with this frontal boundary's isentropic upglide will arrive here in Eastern Kentucky. The European guidance has trended slower/warmer/wetter, whereas the GFS camp of solutions is quicker/colder/icier. Warm air will arrive faster aloft, and this creates a "warm nose" temperature profile within the currently available forecast model soundings (GFS/NAM). When this combination of freezing surface temperatures and an inversion of relatively warmer air aloft appears together, concerns for mixed precipitation types enter the forecast. This particular warm nose does not look especially vigorous, and there remains quite a bit of spread in the corresponding dewpoint temperature profiles. Thus, the latent heat absorbed from any evaporative wetbulbing and melting processes would lead to a localized cooling effect and reduce the magnitude of the warm nose. A brief period of freezing rain cannot be ruled out as the favored precipitation type changes from frozen snowflakes to liquid rain by midday Monday, but a rain/snow mix looks to be the most probable solution. The LREF Grand Ensemble probabilities for at least a glaze (0.01) of freezing rain continue to hover in the 20-30% range, whereas the probability of measurable snowfall (>=0.1 inches) in both the NBM and LREF ensembles has increased to 40-60% along/north of the Mountain Parkway corridor. These snow probabilities drop off significantly for accumulation thresholds above 0.5 inches, and event total accumulations will likely be undercut by the wet snow ratios and mixed p-types. The current snow accumulation grids are likely overdone, but the odds of winter precipitation accumulations generally increase the further north one goes in the forecast area. The primary concern is for slushy accumulations or a light glaze of ice to overlap with the Monday morning commute. WPC currently highlights a 20-30% chance of winter travel impacts in Kentucky, which reinforces the idea that this is a low-probability but potentially impactful event. So, despite the marginal nature of this set up, we will be closely monitoring the higher-resolution CAMs and HREF ensemble data as this event enters their temporal range today. Once the warm air advection regime spreads to the surface across the entire forecast area by Monday afternoon, the pattern transitions to a wetter and warmer one. The warm front responsible for the above activity's isentropic lift is forecast to stall out just to the north of the forecast area early next week. That boundary will then serve as the focal point for the precipitation chances that linger through the rest of the period. Increasing model spread smooths the arrival time of each shortwave disturbance, but with each passing one, the stalled boundary gets pulled a little bit further to the north. This allows for increasingly effective warm/moist air advection amidst a prolonged period of southerly to southwesterly flow. Temperatures are forecast to rebound to well-above climatological averages by midweek, with highs potentially climbing into the upper 60s and 70s and lows 15-25 degrees warmer than they were at the start of the period. Thus, the precipitation that falls on Tuesday and beyond will come in the form of rain showers. Thunderstorms cannot be ruled out in the latter stages of the work week, which is appropriate given that the first week of March is Severe Weather Awareness Week here in Kentucky. Interests are accordingly encouraged to check www.weather.gov/wrn/spring-campaign- sm-plan and to monitor the NWS Jackson KY social media platforms for themed thunderstorm safety information graphics each day. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 736 AM EST Sat Feb 28 2026 VFR conditions continue across all TAF sites this morning. Patchy river valley fog is observed in this morning's satellite imagery, but should burn off in accordance with diurnal warming processes this morning. Fog may develop again in the most sheltered locales after sunset tonight, but the attention then turns towards the approach of a cold front tomorrow morning. Winds shift towards the southwest this evening, and this yields increasing clouds and low- end shower chances across northern terminals after midnight. Decided to handle this with Prob30s at KIOB and KSYM and lowering ceilings across the northern terminals after 06z, but both vsbys and ceilings are currently forecast to remain above VFR thresholds through the end of the 12z TAF period. && .JKL WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...JP LONG TERM...MARCUS AVIATION...MARCUS