Marine Weather and Tide Forecast for Shepherdsville, KY

SHORT TERM /THROUGH TUESDAY/
Issued at 356 PM EDT Mon Jul 14 2025

This Afternoon and Evening...

Scattered clusters of showers and thunderstorms have developed across the area this afternoon, with the stratus layer that was along a decaying front now scattering out into a stratocu field over central KY and southern IN. Temperatures have warmed into the mid 80s in most areas, with dewpoints typically in the low-to-mid 70s as low-level moisture pools along the front. This has allowed for modest amounts of instability, generally between 1500-2000 J/kg MLCAPE on latest SPC mesoanalysis. Latest hi-res guidance suggests that shower/storm coverage should remain isolated to scattered this afternoon, especially as the mid-level wave associated with the sfc front lifts to the north and east. The greatest coverage of showers and storms according to CAMs will be over southern KY, with coverage decreasing around sunset as we lose sfc-based instability.

Tonight...

The muggy air mass overhead will keep temperatures mild tonight as low-level moisture settles after sunset. While an isolated shower is possible across southwestern portions of the CWA, most of the area should remain dry overnight. The main forecast challenge will be if/how much fog develops tonight. While at least patchy fog looks like a good bet for rural areas and valleys, there is still some uncertainty if lingering cloud cover will keep fog from being more widespread. For what it's worth, the strongest fog signal in the 12Z HRRR guidance extends across the Bluegrass region and into eastern KY, with more of valley fog signal present elsewhere. Lows Tuesday morning should end up in the low 70s in most locations, with a few upper 60s possible in the cooler valleys.

Tuesday...

No significant changes are expected in the large scale pattern for tomorrow, with the warm and humid air mass remaining in place. Short range models depict another convectively-enhanced mid-level disturbance moving from the ArkLaTex to near the confluence of the Ohio and Mississippi River tomorrow. This should provide some additional support for showers and thunderstorms during the afternoon, with several hi-res models showing greater coverage in the vicinity of the MCV. Deep-layer shear values will still be fairly weak on the order of 15 kt, so mostly disorganized showers and storms are expected, with water-loaded stronger cells producing gusty winds, heavy rainfall, and lightning. While cells should move at around 15-20 mph, areas which have greater residence time of heavy rain could see localized flooding. Highs on Tuesday should be fairly similar to today in the upper 80s and lower 90s.

LONG TERM /TUESDAY NIGHT THROUGH MONDAY/
Issued at 356 PM EDT Mon Jul 14 2025

Medium-range guidance consensus continues to show a fairly static synoptic pattern late this week and through the weekend as a belt of faster zonal flow continues across the northern US and southern Canada while ridging shifts back and forth between a typical Bermuda high setup and a southern Plains setup. With no large-scale forcing to shift the pattern, like the way the previous forecast describes the "rinse and repeat" setup, as each day should be fairly similar weather-wise. In general, expect seasonally hot and humid conditions with temperatures ranging from the upper 80s to the mid 90s for highs and low-to-mid 70s for lows. With dewpoints remaining in the low-to-mid 70s through the extended period, afternoon heat indices should peak in the upper 90s and lower 100s, with the highest heat indices expected Thursday afternoon. While conditions should be fairly uncomfortable each afternoon, expected heat indices aren't out of the ordinary for mid July and should be below advisory criteria.

Daily scattered shower and thunderstorm chances will peak in the afternoon and evening and diminish for the nighttime and morning hours. With the band of stronger mid- and upper-level westerlies staying well to the north, wind shear will remain weak, and convection will remain largely disorganized. Coverage will likely be variable from day-to-day as increased coverage would be expected in the vicinity of smaller-scale shortwaves in the zonal flow aloft. In general, garden-variety showers and storms with localized gusty winds and heavy rainfall can be expected each day. The main threats from these storms should be localized flash flooding due to longer residence time of heavy rainfall.

AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/
Issued at 756 PM EDT Mon Jul 14 2025

Quite a bit less convective activity showing up compared to the last two evenings, mainly due to the relative lack of forcing. A few tall showers, perhaps with a few rumbles of thunder, are ongoing over southwest Indiana and merit an early TEMPO group in HNB. Would expect that any lasting restriction to vis would likely be MVFR, though we can't rule out a brief IFR vis in the heaviest rain.

Stagnant and humid air mass overnight will support at least some fog formation, but we'll go with a prevailing MVFR for all except SDF, and include a TEMPO for IFR vis at RGA around daybreak. Any fog at the terminals will be short-lived, with conditions recovering to VFR by mid-morning. SW winds less than 10 kt with a mid-level cig in the afternoon.

LMK WATCHES/WARNINGS/ADVISORIES
KY...None.
IN...None.