textproduct: Jackson

KEY MESSAGES

- Strong environmental winds are expected Wednesday evening into early Thursday. Gusts of 30 to 40 mph are increasingly likely and could be stronger near and north of I-64.

- 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.

LONG TERM

(Thursday through Tuesday) Issued at 318 PM EDT TUE JUN 16 2026

The long-term period opens Thursday morning with a complicated weather pattern unfolding across the Ohio and Tennessee Valleys and adjacent regions. The 16/12Z model suite analysis shows, with high confidence, a deep late-season upper-level trough over Central and Eastern Canada with a potent shortwave pivoting over the Great Lakes and broad cyclonic flow on the southern fringes of the upper-level trough extending across the Lower Ohio Valley and Central Appalachians. Meanwhile, a tropical low will be sluggishly drifting along the Central Gulf Coast. Between these features, the cold front responsible for the decaying late Wednesday and early Thursday morning squall line (the boundary itself trailing from an ~990 mb surface low over Lower Ontario) will likely extend roughly northeast to southwest, roughly along the main stem of the Ohio River.

Through the day on Thursday and into Thursday night, the aforementioned surface low will drift over southern Quebec and eventually start to weaken after reaching its max depth. North of this boundary, an unseasonably strong 250 hPa jet with transient jet streaks will provide upper-level divergence while the cold front itself slows to a crawl, oriented nearly parallel with deep unidirectional WSW-ENE-oriented flow. The final wild card remains to what degree the tropical system and its associated copious moisture interact with the frontal boundary. The broad consensus among the model data suggests there is potential for training convection to develop along the nearly stationary cold front for a time on Thursday and Thursday evening, probably south of I-64, but the duration and intensity remain quite uncertain. Longer-range CAMs such as the experimental MPAS RRFS offer solutions where localized 2 to 4 inch rainfall totals occur while other solutions suggest a mere tenth or two will occur. The blended QPF guidance for the entire event has remained relatively conservative on this forecast issuance, ranging from 0.6 to 1.4 inches and representing a reasonable but low confidence middle ground solution.

The threat for flooding as well as severe weather appears quite conditional upon the ability of the deep tropical moisture to extend sufficiently northward into the Ohio Valley while also coinciding with better destabilization -- all dependent upon an overall more northward propagation of the tropical system/associated moisture and slower progress of the incoming cold front. Though there are many moving parts, this concerning potential combination of a stalling front with adjacent upper-level support in tandem with a surge of deep tropical moisture warrants keeping all eyes focused on this system. Hopefully, confidence in overall impacts will increase in the coming 12 to 24 hours as we move into the range of the full operational HREF CAM suite and receive better overall sampling of both systems. On a positive note, the dry D1 to D3 drought conditions for nearly all locations south of I-64, plus most rivers and streams flowing at the 5th to 25th percentile for this time of year, and high FFGs (2.0 to 3.0 inches in 1 hour and 2.5 to 3.5 inches in 3 hours) all suggest rainfall amounts would need to be toward or in excess of the higher end of modeled QPF guidance for any widespread flooding impacts to occur outside of urban areas. Urban flooding is of greater concern if substantial training occurs over larger communities where surfaces tend to be largely impervious regardless of drought or streamflow status.

As the tropical remnants press east toward the Southeast Atlantic seaboard Thursday night, a shortwave trough embedded within the broader cyclonic flow aloft will move into the Ohio Valley and provide a decisive southeastward shove to the stalled cold front and associated rainfall. In its wake, LREF mean 850 hPa temperatures dip into the 12 to 14C range for Friday and Friday night with dew points slipping back into the 50s. This will set the stage for a pleasant first half of the weekend. Guidance then diverges heading into the second half of the weekend as another low pressure system approaches our region with a warm front and subsequent cold front. In general, this will set the stage for a return of more warm, humid conditions (at least briefly) and also for multiple rounds of rainfall.

In sensible terms, expect strong environmental winds to subside on Thursday morning though remaining breezy throughout the day with gusts of 20 to 30 mph commonplace. It will also be quite muggy with a threat of showers and thunderstorms throughout the day, though likely becoming more focused on southeastern Kentucky with time. Look for high temperatures in the lower to mid 80s. There is a possibility for at least isolated severe storms and flash flooding though the extent is uncertain. Cooler and drier conditions follow by Friday with much lower humidity levels and temperatures in the 70s to around 80F. Saturday looks to be the pick of the weekend with mostly clear conditions and highs in the lower to mid 80s. Unsettled weather then returns for early next week with briefly warmer and more humid weather, potentially followed by a return to drier and cooler conditions by Tuesday.

AVIATION

(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 148 PM EDT TUE JUN 16 2026

A field of cumulus clouds continues to move across the forecast area this afternoon with VFR conditions expected at all TAF locations. A cold front will approach the Ohio Valley near 00Z. this approaching front could lead to some showers or a stray storm between 04Z and 10Z overnight, which could affect KIOB or KSYM. 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. Additionally, patchy valley fog could develop overnight leading to a reduction into MVFR conditions. However the fog is not expected to affect the TAF sites.

JKL WATCHES/WARNINGS/ADVISORIES

None.