textproduct: Jackson

KEY MESSAGES

- Temperatures steadily warm through the end of the week, climbing into the 70s on Friday/Saturday and towards the 80s on Sunday.

- A passing disturbance will bring chances for showers and perhaps a thunderstorm to northern and eastern portions of the forecast area on Friday evening/night.

- Expect gusty winds up to 35mph on Friday afternoon ahead of that system.

- A better-defined cold front on Sunday night will bring more widespread shower and thunderstorm chances and a noticeable cooldown to the area.

UPDATE

Issued at 724 AM EDT THU MAR 19 2026

Sky cover was adjusted upward as we move into the day. Still expected clearing toward evening.

LONG TERM

(Friday night through Wednesday) Issued at 604 AM EDT Thu Mar 19 2026

The long term forecast period is defined by a transitioning synoptic weather pattern over the contiguous United States. The amplified ridging over the Desert Southwest is expected to steadily flatten throughout the upcoming weekend. As it does so, a series of shortwave disturbances navigating around its northern/eastern periphery will propagate into the Ohio and Tennessee River Valleys. The approach of these disturbances will help push the antecedent longwave Atlantic Coast troughing out to sea. At the surface, this pattern initially translates to a blocking high over the Gulf Coast states and a couple of low pressure systems moving through those two valleys. The proximity of those lows introduce low-end rain chances to the forecast in Eastern Kentucky on Friday night (<40% PoPs) and Southern Kentucky on Saturday afternoon/evening (<20% PoPs), but these initial systems look rather moisture starved. As their parent shortwaves propagate east, so will that blocking high. This allows for a brief period of more effective warm air advection and marginally better low-level moisture return to persist into Sunday evening. Then, a cold front moves through the region on Sunday night. While its parent troughing aloft looks better-defined than the first two systems, that troughing does not look particularly deep. 40-60% PoPs and a noticeable cooldown are still in the forecast for Eastern Kentucky on Sunday night/Monday morning, but the quasi-zonal nature of the associated flow aloft will likely limit both the intensity of this system's convection and the longevity of its postfrontal cold air advection. Expect sensible weather conditions to return to near climatological averages in its wake across Eastern Kentucky early next week.

When the period opens on Friday night, that first disturbance will be impacting the forecast area. The best forcing for showers/storms will be in the northeastern half of the forecast area, closer to the system's surface low moving through the Eastern Great Lakes. There, chance PoPs (25-40%) are outlined. Elsewhere, the chance for measurable rain looks low. The lack of deep moisture (mean PWAT values are less than an inch) and declining diurnal heating after sunset will limit the amount of surface based-instability for any convection forced by that system's frontal boundary. Still, the couple hundred J/kg of mean MUCAPE and marginal bulk shear values depicted in the currently-available forecast guidance could allow for sub-severe thunderstorms to move across NE KY on Friday evening.

That first system's frontal boundary is poised to push south into the Tennessee Valley on Saturday, but with little to no effect on the temperatures. Shortwave ridging will foster mostly clear skies and highs in the mid 70s across our forecast area, but the approach of a second, subtle shortwave impulse to our south could allow for renewed rain chances in the Cumberland River basin later in the day. PoPs have begun to show up there in a few more recent pieces of forecast guidance, with the greatest chances aligning with peak diurnal heating. Future runs of the NBM will likely trend towards slight chance PoPs and perhaps a slight chance of thunder in Southern Kentucky on Saturday afternoon/evening, but this isolated activity is expected to be well below severe limits. Most of the commonwealth should stay dry, and Saturday night looks like a good night for ridge-valley temperature splits. Expect lows to remain in the 50s on ridgetops, but to cool into the mid/upper 40s in the typical valley locals.

Breezy southwesterly surface flow out ahead of Sunday evening's better-defined system should allow temperatures to quickly rise on Sunday morning. Afternoon highs are forecast to peak in the low to mid 80s across much of the forecast area. Diurnal mixing will lead to 25-30 degree dewpoint depressions and 30-45% minimum RH readings on Sunday afternoon, and the currently-available forecast model soundings suggest that the atmosphere will be capped while the sun is up. Therefore, mentionable precip chances are forecast to hold off until after dark. The persistence of the southwesterly surface winds into should allow for some marginal low-level moisture recovery after sunset and before the better frontal forcing arrives. LREF Grand Ensemble mean PWAT values rise to just above 1 inch around midnight and immediately ahead of the cold front. Those values are about a quarter of an inch higher than they were with Friday night's front, which supports the notion that the convective ceiling is slightly higher with this third system. However, unlike some of the more memorable events earlier this season, the southwesterly winds are not replicated aloft, where the flow looks quasi-zonal. Therefore, the lack of truly deep moisture and the limited amount of related instability will act as major limiting factors for any frontally-forced convection on Sunday night.

Despite this, strong to marginally severe storms cannot be entirely ruled out with this third system. The misalignment with peak diurnal warmth will likely mitigate the amount of available surface-based CAPE, and there is a great deal of spread noted in the modeled instability for Sunday evening/night. For example, there is well over 500 J/kg spread between the 25th and 75th percentiles for MUCAPE across the entire state of Kentucky at 8PM Sunday in the 00z LREF Data. Mean values at that time stamp currently range from 500- 1000 J/kg, with approximately 40 knots of bulk shear. Any stronger or more organized prefrontal convection could pose a marginal risk for hail and/or damaging wind gusts, but the potential is limited by the likely elevated nature of the activity. SPC has noted this potential in their Day 4 forecast discussion, as do various convective forecasting tools. The EFI/SOT for CAPE continued its upward trend with tonight's 00z run. There are now EFI values of 0.7 to 0.9 noted in the Bluegrass region alongside a small SOT contour of 1. Likewise, the NCAR AI, CSU ML, and CIPS analog guidance tools continue to draw 5-15% severe probability contours over much of the region. A few of the NCAR AI models are notably more aggressive with the probabilities for northern portions of the forecast area closer to the Ohio River, but these look overdone compared to the rest of the currently-available pieces of guidance. The overarching synoptic set-up does not scream widespread severe weather, but a more marginal event is plausible. As such, we will continue to closely monitor Sunday's convective potential in subsequent forecast packages.

Deterministic models continue to trend towards a quicker frontal passage on Monday morning, and the time-lagged NBM will likely trend PoPs downward in future forecasts. Postfrontal northerly wind components and surface high pressure will advect a cooler airmass into the region for Monday and Tuesday, with highs near seasonal averages and slightly below normal overnight lows. Yet another passing shortwave disturbance to the north will bring an increase in clouds and low-end rain chances by midweek, but also a shift in wind direction. This allows for warming temperatures by the second half of the work week, and CPC's 8-14 day temperature outlook suggests that the end of March will be marked by a return to above-normal temperatures.

AVIATION

(For the 12Z TAFS through 12Z Friday morning) ISSUED AT 625 AM EDT THU MAR 19 2026

VFR conditions are forecast through the period, with only mid- upper level ceilings at times.

JKL WATCHES/WARNINGS/ADVISORIES

None.