textproduct: Jackson

KEY MESSAGES

- Cooler than normal temperatures will continue for highs today, which will average about 5 degrees below normal.

- Storm chances return for the latter portion of the work week (Wed night-Fri). Some storms could approach severe limits, especially on Thursday.

- The primary threat will be damaging wind gusts. Isolated flash flooding is also possible should locations see repeated rounds of heavy rainfall.

UPDATE

Issued at 1055 AM EDT TUE JUN 16 2026

Populated the latest observational data from around the region and tweaking some temperature curves through this afternoon. No major changes were made to the forecast for today and tonight. The wind and wind gust forecast grids Wednesday evening and overnight were adjusted up using a blend of the CONSShort and the NBM.

UPDATE Issued at 737 AM EDT TUE JUN 16 2026

Hourly grids were freshened up based on recent trends in observations. No changes were made to weather grids for fog. Where breaks in the clouds are present, valley fog remains evident. This should lift and dissipate through around 9 AM EDT and give way to mostly sunny to sunny skies with temperatures trending warmer.

LONG TERM

(Wednesday night through Monday) Issued at 400 AM EDT TUE JUN 16 2026

Active weather remains the central theme of the long term forecast period, with the period opening on the precipice of the well- advertised Wednesday night into Thursday storm system. However, compounding forecast uncertainty looms large over this setup, which will likely be governed by mesoscale features that models struggle to resolve this far out. Adjustments to the SPC and WPC outlooks for severe storms and excessive rainfall are likely as these finer scale details are worked out, but there remains a synoptic signal for potentially impactful weather in the second half of the work week.

An anomalously strong 850mb jet streak is poised to develop over the warm sector of a deepening surface low on Wednesday night. The tightening surface pressure gradient will allow southwesterly winds to strengthen to 10-20mph, with non-thunderstorm gusts potentially as high as 35mph. Models collectively resolve 45-65 knots of southwesterly flow at that 850mb level, and together, this sets up an efficient warm air advection and moisture return conveyor belt. These processes look to impede the traditional overnight radiational cooling processes and thus prevent our area from experiencing the conventional overnight ridge-valley temperature splits. Sheltered southeastern valleys and hollows could still cool off into the upper 60s after sunset, but the strengthening wind fields will likely keep most of the CWA mixed at night. Expect widespread MinTs in the lower half of the 70s. This would place the record maximum lows at the KJKL (72) and KLOZ (71) in jeopardy, and these unseasonably warm overnight temperatures give credence to the notion that the atmosphere may remain unstable enough for strong to severe storms on Thursday morning.

The initially semi-discrete convection on Wednesday night is progged to congeal into a QLCS moving south-southeast towards the commonwealth overnight. By dawn, the evolving line of storms should be on the doorstep of the I-64 corridor. This means that the initial phases of the event have entered the window of time that gets resolved by the higher-resolution, convection-allowing models. As of the time of writing, a few of these CAMs (the NAM and the experimental RRFS) resolve 850-1250 J/kg of surface-based CAPE in the Bluegrass region for the 6am-8am time frame. These marginally- favorable thermodynamics could combine with the anomolously-strong kinematics to present a HSLC-esque environment (High Shear, Low CAPE) for this first round of storms. There are 40-50 knots of shear and steeply curved/hooked hodographs in forecast model soundings ahead of the line, which suggests that if the line stays organized, both damaging wind gusts and isolated QLCS tornadoes would be possible. However, it is crucial to note that some guidance also resolves the line falling apart as it approaches our forecast area. By the time it reaches Fleming County, the line of storms will have outrun the parent frontal boundary and become displaces from the NE- propagating surface low. Thus, it could lose its synoptic forcing and weaken in an environment with improper CAPE/shear balance. If the line develops enough of a mesoscale cold pool and is subsequently able to create its own localized forcing mechanism, it could sustain itself within a volatile environment. SPC has accordingly outlined counties along/NW of the Mountain Parkway in a Marginal (Level 1/5) Risk on Thursday morning. We will need to closely watch radar as storms enter our CWA, but in the meantime, we will be laser focused on trends across the hi-res guidance suite. We encourage readers to make sure that they have multiple ways to receive weather updates and warnings ahead of time. It also might be a good idea to take advantage of the pleasant weather leading into the event to secure any loose outdoor objects, as both the breezy non-thunderstorm wind gusts and any convectively-enhanced wind gusts would be strong enough to cause at least nuisance-level impacts.

The evolution of that AM activity will prove crucial to the forecast for the rest of the day. It is plausible for a remnant outflow or differential heating boundary to create a locally-favorable convergence corridor for additional convection on Thursday afternoon/evening. The mid/upper level synoptic features responsible for the strong wind shear parameters will steadily lift off to the northeast as the day progresses, with the trailing cold front steadily sagging south into Kentucky. There should be enough frontal forcing for showers and storms to develop, but the magnitude of the warmth and the depth of the moisture ahead of the boundary remain uncertain. Leftover cloud debris from any AM convection could inhibit the diurnal heating curve and cause temperatures/instability to under-perform current expectations. A developing low pressure system over the western Gulf introduces further forecast uncertainty, as models are clustered around two groups of tracks with it. The slower/western cluster would funnel a plume of modified tropical moisture into the region out ahead of the slowing boundary, whereas the faster/eastern solution could keep the richest/deepest tropical moisture confined to the south in the Tennessee Valley. Models should begin to come to a consensus regarding this system as the Hurricane Hunters begin to sample its core in the coming days and provide better initialization conditions. At the very least, a modified continental tropical airmass will be in place, and as of the time of writing, the LREF ensemble resolves a mean 1.5 to 1.75 inches of PWAT across the CWA. Areas closer to I-64 are closer to the synoptic boundary and on the lower side of this range, whereas areas along the TN state line are on the higher side.

The synoptics of the setup still suggest at least a Marginal Risk (1/5) for strong/severe storms on Thursday afternoon/night. This portion of the forecast period remains outside the temporal range of the hi-res CAMs, but medium-range guidance still portrays those aforementioned PWAT values, 30-50 knots of zonal flow aloft, marginal amounts of CAPE, and high freezing levels. Barring any mesoscale boundary enhancements, there should be less directional/speed shear during the PM hours than there was on Thursday morning. Still, damaging straight-line wind gusts could emerge within any organized storm clusters or water-loaded downdrafts in the warm sector on Thursday afternoon/evening. SPC has drawn an extensive slight risk outlook, but notes that potential is more for isolated line segments with a wind threat.

There is also an area-wide Slight (2/4) Risk for Excessive Rainfall on Thursday and Thursday night. The parent cold front will likely stall out and adopt a quasi-zonal WSW/ESE orientation in this time frame. Such an orientation parallels the flow aloft and points towards potentially training convection. That training behavior will be the root of any localized hydro issues that develop through Friday morning, which WPC notes is most likely to set up in Southern Kentucky. Training storms are not necessarily accounted for in the current QPF grids though. The model blend used to populate the long term forecast grids does not explicitly account for convective processes like training, so the QPF grids have stagnated in the 1- 1.5 inch range after the previous day's downward trend. Expect further adjustments to these forecast rainfall amounts as the event approaches and convection-allowing guidance becomes incorporated. It is plausible for some embedded streaks of higher QPF values to emerge in future forecast packages, especially within any favored mesoscale corridors for convergence and/or training that emerge.

There are a few limiting factors that could mitigate the flood risk in Eastern Kentucky with this event. Antecedent drought conditions and lackluster accumulations from the past few rain events have kept Flash Flood guidance on the higher end of things, with 1 hour guidance in the 1.75 to 2.5 inch range and 3 hour guidance between 2.5 and 4 inches. Area hydrographs are running below normal flow values, so the rain from this system should initially prove beneficial. Widespread flooding on the mainstem rivers appears highly unlikely, but more localized flash flooding and/or nuisance pluvial flooding cannot be ruled out if stronger convection trains over the same few locales. The risk for flooding is highest in places that see multiple rounds of activity by the time the front finally starts to push south on Friday morning. WPC maintains a Marginal ERO for SE KY on Friday, but that is largely an artifact of Thursday's activity persisting past the 12z outlook transition time. WPC also notes that additional adjustments may be needed to the Slight portion of Friday's outlook, which is currently just across the state line in SW VA/NE TN. Those adjustments will depend upon the evolution of the tropical system and its related moisture plume, which further demonstrates how this particular long term forecast package is shrouded in compounding uncertainty.

Current expectations are for precipitation to taper off from northwest to southeast on Friday as the front finally exits to the Tennessee Valley. Post-frontal, vertically-stacked northwesterly flow will advect a cooler and drier airmass into the area from Friday night into Saturday. Friday night is primed for widespread fog formation and ridge-valley splits, and highs are expected to be slightly below normal values (upper 70s/lower 80s) for the first two days of the holiday weekend. The upper atmospheric pattern flattens back out to zonal flow on Sunday, and the resultant height rises correspond with temperatures moderating back towards near-normal readings in the mid 80s. Passing disturbances will return rain chances to the grids to close out the period, but it is too early to determine what (if any) significant sensible weather impacts might arise with them.

AVIATION

(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 745 AM EDT TUE JUN 16 2026

High pressure will shift east of the area to start the period while a cold front will approach the OH Valley toward 00Z and after. At issuance time there were a few areas of mid clouds in the north with mid and high clouds in spots in the south. Valley fog with reductions to MVFR and perhaps lower was present in valleys, but not at the TAF sites. This fog should lift and dissipate through 13Z. Otherwise, some diurnally driven cumulus is anticipated between 15Z and 23Z. A few showers or a stray storm associated with the approaching front could affect KIOB or KSYM between after 23Z and 06Z. Brief reductions to MVFR would be possible if a location were to be affected, but confidence was too low to include a PROB30 at this point.

JKL WATCHES/WARNINGS/ADVISORIES

None.