Area Forecast Discussion

KEY MESSAGES

- Hot, muggy, and mostly dry weather takes hold for today. Afternoon highs around 90 degrees combined with high humidity will push peak heat indices between 95 and 100 degrees.

- A progressive cold front brings showers and numerous thunderstorms on Friday, with a threat for strong storms and locally heavy rainfall.

- High pressure ushers in a brief break of cooler and drier air for Saturday, before unsettled weather and rain chances return Sunday through early next week.

UPDATE

Issued at 136 PM EDT THU JUN 11 2026

No significant changes made to the forecast aside from adding in the latest surface obs and preparing grids for the 18Z TAFs. Grids have been saved and sent.

UPDATE Issued at 735 AM EDT THU JUN 11 2026

A decaying MCS is approaching northern Kentucky from Southern Indiana at update time. While continuing to weaken for now, the latest SPC mesoanalysis is suggesting a pool of better instability passing from Central Kentucky into the Mid-Ohio Valley by late morning. Shear and forcing are minimal, but it is conceivable that some of this instability may aid in maintaining some weak convection into area near and north of I-64 by late morning/early afternoon. Forecast confidence is low, but slight chance/chance PoPs were added north of the Mountain Parkway for a few hours either side of midday.

SHORT TERM

(Today through Friday) Issued at 539 AM EDT THU JUN 10 2026

Warm and muggy conditions are noted over eastern Kentucky early this morning with temperatures ranging through the upper 60s to mid 70s. Tendrils of fog are noted in the deeper southeastern Kentucky river valleys along with some passing mid-level clouds; otherwise, skies are clear. The quiet weather is courtesy of a ridge of high pressure extending westward from the Atlantic over the Southeast CONUS and up into the southeastern Ohio Valley. This is supported aloft by lingering 500 hPa ridging extending from the Southeast northward into Quebec. Meanwhile, a trough is in place over the Northern Plains and Northern Rockies. An embedded subtle shortwave is ejecting eastward from this trough across the Mid-Mississippi Valley this morning attended by an MCS, while a much more substantial digging shortwave is carving its way through the Central Rockies. Ahead of the main trough, an area of low pressure is noted over northeast Manitoba with a cold front extending southwestward to a second area of low pressure over western Kansas.

The aforementioned MCS is shown in the CAMs to continue decaying this morning as it rides through the upper-level ridging. Whatever part of this system that sustains will cross eastern Kentucky and points further north and east this afternoon. Questions remain as to how much revitalization may occur with this system as it crosses the Lower Ohio Valley, as it seems that extensive convective blowoff may tend to outpace the system's associated outflow/upper level forcing and limit overall destabilization ahead of the disturbance. It also appears that lapse rates remain weak in a layer of dry air between 850 and 600 hPa. Not surprisingly, the modeled parameter space is not all that noteworthy either -- RAP13 soundings suggest only 500 to 1500 J/kg of MLCAPE (highest north of I-64) with only weak shear. It is worth noting however, that if deep convection is able to sustain, DCAPE values in the vicinity of 900 J/kg in the north could support gusty winds, especially if the upstream MCS remains intact enough or redevelops sufficiently to impact the northeasternmost counties of our CWA. SPC has maintained a Marginal risk for severe weather from Fleming down to Pike counties. Aside from any thunderstorm potential, it will be a hot and humid day with 850 hPa temperatures in the 18-20C range, supporting highs in the upper 80s to lower 90s, which when combined with high dew points will lead to apparent temperatures in the 95 to 100F range for most of the area. Quiet weather returns area-wide for tonight as upper-level ridging begins to slowly subside aloft as the next and much more vigorous shortwave ejects northeast into Ontario. As it does so, the associated second surface low will track along with it and sweep a cold front toward the Ohio Valley, likely stretching from Detroit to Louisville to the Missouri Bootheel by 12Z Friday. With respect to the overall severe potential on Friday, there has been some question in the model guidance as to whether the front will arrive too quickly for substantial diurnal destabilization over western portions of the CWA, though the recent runs of the RAP and HRRR seem to be favoring a slower arrival than prior runs, which should allow for better instability development. The 3Z RAP13 supported 2000 to 3000 J/kg of MLCAPE building ahead of the front, highest over southeast Kentucky, while DCAPE exceeded 1000 J/kg; but overall shear will be weak. Thus if a cell can briefly become organized, localized downburst winds could soon follow. Accordingly, SPC has maintained a Marginal severe risk for the western portions of the CWA, with the eastern portions where greater destabilization should occur under a Slight Risk. PWATs will also rise back to near 2.0 inches as the front nears, but the overall progressive nature of the system should preclude anything more than some isolated high water concerns.

In sensible weather terms, look for a sultry Thursday with increasing cloud cover and a low chance of a shower or thunderstorm, with the best chances over northeast Kentucky. It will be hot with highs in the upper 80s to around 90F with heat indices 5 to 10 degrees warmer for most. For tonight, fair and dry weather is expected but it stays very warm with lows only in the 70s. For Friday, look for showers and possibly a few storms to develop in the morning to midday hours closer the Central Kentucky and then increase in extent/coverage as they drop southeast through the afternoon. Some of these storms could produce strong to damaging winds gusts and torrential downpours. It will still be warm and muggy ahead of the storms with high temperatures reaching the mid 80s in the west to near 90F in the east.

LONG TERM

(Saturday through Thursday) Issued at 155 PM EDT THU JUN 11 2026

An upper low spinning over Ontario during the short term period will persist there through most of the long term period. Short wave troughs rotating around it will be the main influence on our weather. One of these will be passing over the Great Lakes region on Sunday, working to deepen overall troughing over the eastern CONUS and supporting a cold front which will move through the JKL forecast area from northwest to southeast on Sunday afternoon and evening. Due to the deepening trough, there will be a bit stronger flow aloft and more shear (although nothing phenomenal) than during preceding recent rounds of thunderstorms. Should there be enough instability, some strong storms won't be ruled out on Sunday, but the degree of instability remains uncertain. Once the front and its inclement weather move through, noticeably less humid air will arrive Sunday night and carry into the workweek.

Multiple additional waves will rotate through the eastern CONUS trough Tuesday through Thursday. However, there is much less model agreement on their timing and strength. That being the case, forecast confidence for precipitation drops off considerably after Monday. There is a general consensus that some semblance of an eastern CONUS trough will persist, though, which would prevent any return to oppressive heat and humidity.

AVIATION

(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 143 PM EDT THU JUN 11 2026

Weak surface high pressure will keep the area dry through much of the TAF window. Widespread fair weather cumulus clouds have developed around the 3,500 to 4,500 foot level this afternoon, along with remnant low clouds from a decaying MCS but these clouds should stay VFR before dissipating overnight. Clear skies overnight will give way to increasing and lowering clouds ahead of a cold front that's forecast to dive southeast after 12Z/Friday. PROB30s are in place to account for pulse thunderstorm development ahead of the front through the end of the TAF. Any thunderstorm that develops at or near a TAF could bring brief reduction in category; as well as, gusty and erratic outflow winds. Southwesterly winds are expected throughout the afternoon with gusts upwards of 15 knots, those winds will decrease overnight before picking up again Friday morning ahead of the approaching cold front. Friday winds will be out of the southwest sustained around 10 knots with gusts to 15 knots.

JKL WATCHES / WARNINGS / ADVISORIES

None.