textproduct: Jackson

KEY MESSAGES

- Mainly dry weather is expected into Friday, with temperatures averaging around 5 degrees below normal.

- Unsettled weather is forecast to return this weekend, with temperatures warming to near normal by early next week.

LONG TERM

(Saturday through Thursday) Issued at 428 PM EDT THU JUL 23 2026

The long term period will be characterized by anomalously strong upper level ridging over the central/western CONUS, with well defined upper level troughing dominating the East Coast. This amplified pattern will place Kentucky in a region of northwest flow aloft for the entirety of the long term period, allowing for a series of shortwaves to pass through the area. Multiple rounds of showers and storms are expected over the course of the forecast period, although the exact timing of this activity remains uncertain at this time, owing to increasing model spread in the progression of these smaller impulses (especially near the end of the period).

On Saturday, southwesterly winds will continue to advect better moisture into our area, with dewpoints rising into the upper 60s for much of the forecast area by Saturday evening (and perhaps even the low 70s for our southwestern counties). Concurrently, a stalled boundary initially located over Tennessee will begin to lift north, finding itself near the KY/TN line by the evening hours, with weak WAA in the low levels in our southernmost counties. This, in addition to the potential for assisting shortwave perturbations, will lead to a chance for scattered showers and storms throughout the weekend, with the highest rain chances near the KY/TN line. Shear will remain fairly weak, so any storms that do form will not bring a risk for organized severe weather, and will more so be typical pulse storms. However, the air mass in place ahead of this convection will be anomalously moist; LREF mean PW is generally in the range of 1.6-1.8 inches in the southern portion of the forecast area, representing 75th to 85th percentile PW values when compared to climatology. Given this juicy environment, any storm that forms would be capable of producing efficient rainfall. Accordingly, the Weather Prediction Center has introduced a Marginal (Level 1/4) Risk for Excessive Rainfall for our counties closest to the TN line; this represents a chance for isolated flash flooding should a storm be able to capitalize on this moist environment, although the overall flash flood risk appears quite low at this point. There is some model disagreement regarding overnight activity going into Sunday morning, with an additional subtle wave represented in some models. Should this come to fruition, cloud cover would prevent any ridge/valley temperature split from developing overnight. However, if skies can clear out some, a modest ridge/valley temperature split could develop, with this outcome most likely in our northern counties that remain somewhat removed from the best rain chances. For now, have held off on the introduction of any ridge/valley split into the forecast grids due to cloud cover uncertainties; however, this may need to be adjusted as the timing of shortwave energy becomes more certain.

Rain chances decrease again on Sunday as the upper level ridge over the Great Plains amplifies and expands slightly east. Meanwhile, the trough to the east of the forecast area will continue to deepen. At the surface, winds will become more northwesterly, tapping into a very muggy upstream air mass that will drive further moisture advection. Temperatures will also continue to warm, with high temperatures in the upper 80s expected across the forecast area, marking a return to hot and muggy weather, although nearby high pressure should keep rain chances fairly low during the day. Then, model guidance begins to diverge significantly by Sunday night, and especially next week.

Looking ahead, a period of active weather appears to be increasingly probable next week. Notably, the upper level pattern will be favorable for MCS type activity, with eastern Kentucky remaining on the eastern periphery of the highly amplified ridge over the Plains. In fact, the 12Z GFS shows a signal for a convective complex through the Commonwealth as early as overnight on Sunday, although this solution remains an outlier at this time. Any MCS type activity will remain dependent on the upstream evolution of convection, which is subject to tremendous uncertainty at this stage in the forecast; however, with dewpoints in the upper 60s to low 70s and temperatures generally expected to rise into the upper 80s and low 90s (barring convective interference), the thermodynamic environment will be capable of supporting severe weather. Kinematics will also noticeably improve early next week as mid and upper level flow strengthens, with LREF mean 0-6 km shear generally in the range of 30-40 kts on Monday and Tuesday. Notably, machine learning guidance has picked up on some severe potential in this time frame, with probabilities peaking on Monday and Tuesday. The Storm Prediction Center has introduced a Day 5 (Monday) 15% contour just north of Kentucky, including much of Indiana and the western half of Ohio, reflecting increasing confidence in MCS activity; however, uncertainty still remains high, and SPC notes that the location of this outlook may shift in coming days. Of note, the Weather Prediction Center has also introduced a broad Day 5 (Monday) Marginal (Level 1/4) Risk for Excessive Rainfall, including approximately the northern half of our forecast area. However, similarly to the severe threat, any flash flooding risk would remain highly dependent on the progression of upstream convective activity, and significant uncertainty exists in the forecast at this range.

AVIATION

(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 207 PM EDT THU JUL 23 2026

Fog should affect valleys in southeast KY overnight and early Friday, bringing localized IFR or worse conditions. If TAF sites were to be affected, the most likely candidates are KLOZ and KSME. However, at this time, all TAF sites persist with a VFR forecast through the period.

JKL WATCHES/WARNINGS/ADVISORIES

None.