


Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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304 FXUS63 KLMK 160725 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 325 AM EDT Wed Jul 16 2025 .KEY MESSAGES... * Warm and humid conditions with scattered thunderstorms are expected today. Torrential rainfall, gusty winds, and lightning will be the main threats with today`s storms. * Unsettled weather pattern likely shaping up for the remainder of the week and into the weekend. Daily chances of showers and thunderstorms are expected with torrential rainfall, gusty winds, and lightning. Localized flooding could become a problem across portions of southern IN and into northern Kentucky. && .SHORT TERM /THROUGH TONIGHT/... Issued at 325 AM EDT Wed Jul 16 2025 Early this morning, a weak upper level shortwave trough axis was pushing through the lower Ohio Valley. This feature is driving the current convection moving through portions of southern IN and north- central KY this morning. Convection thus far has been somewhat strong, mainly producing torrential rainfall, some gusty winds, and quite a bit of CG lightning. Current convection in the I-65 corridor will continue to move off to the northeast this morning. Additional convective development will be seen across portions of western KY and southwest IN this morning as the mid-level wave passes through. Quick rainfall amounts of a quarter to a half inch will be possible with this activity. Some very isolated three quarter inch to perhaps an inch may occur in some spots. For today, scattered convection will likely be ongoing at the start of the period across portions of southern IN and northwest KY as aforementioned mid-level wave moves on through. Additional development may occur east of I-65 later this morning as the wave heads into OH. After that, we may have a bit of suppression across the region in the wake of the upper level wave passing through due to trailing subsidence. However, that probably will not hold off additional convective development in the afternoon/eve as temps warm into the upper 80s to around 90 and dewpoints in the 70s. Afternoon instability will likely climb in to the 2500-3000 J/kg range with PWATs running around 2 inches. Wind shear through the column continues to look rather week despite rather deep layer flow. Clusters of pulse type storms producing torrential rainfall, some gusty winds, and quite a bit of CG lightning will be the main threats with this activity. Rainfall amounts in thunderstorms will be in the 0.25-0.75 inch range, though some very localized amounts of 1-2 inches will be possible in some locations. For tonight, some scattered showers/storms will likely be found across the region this evening, though if I had to pick an area of highest concentration, it would be across southern IN and into northern KY. This convection looks to diminish after sunset with overnight temps dropping into the lower-middle 70s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 325 AM EDT Wed Jul 16 2025 By Thursday, deep layer flow across the region looks to remain fairly zonal as faster belt of westerlies suppresses the southeast ridge. The latest NCEP models continue to bring a slow moving frontal boundary further south towards the Ohio River during the daytime hours. South of this front, a very moist airmass is expected to be in place with afternoon highs topping out in the upper 80s to near 90 and dewpoints firmly in the 70s. This will produce adequate instability to drive convection across the region. Convection looks to be focused along the front and will be aided by remnant MCVs moving along the boundary. Vertical shear is stronger across our northern CWA with a quick drop off in shear with southern extent. Most concentrated area of showers and storms for Thursday will likely be along the front. Current projections suggest that the area at most risk for storms will be along and perhaps just south of the I-64 corridor. Here afternoon instability should result in CAPE values of 2500-3000 J/kg. Warm cloud depths up to 13000-14000 ft AGL are expected with PWATs running up near 2-2.1 inches. Thunderstorms capable of damaging winds, mainly due to waterloaded downdrafts will be the main severe threat, along with torrential rainfall and intense cloud to ground lightning. Rainfall amounts could become problematic in spots Thursday afternoon/evening mainly across southern IN and into portions of northern Kentucky if training of convection develops and areas see repeated rainfall. Along the I-64 corridor rainfall amounts of 1-2 inches could develop with localized 3-4 inch amounts being possible in some areas. If subsequent forecasts continue to suggest heavy rainfall, a Flood Watch for portions of the area may be required in future forecasts. For the weekend and into next week, the upper level pattern is not expected to change all that much. SE ridge will remain in place with a rather deep west to east flow across the Ohio Valley. Remnant frontal boundary will likely remain in the vicinity of the Ohio River, but am not sure it will make it south of that. Episodic bouts of convection are likely as remnant MCVs move along the boundary. Model soundings continue to show rather weak shear thorugh the column through this period, so waterloaded downdrafts capable of producing strong winds will be the main threat along with torrential rainfall and plenty of lightning. Upper level ridge may attempt to build a little more to the west with a more northwesterly flow pattern developing across the Midwest and Ohio Valley as we move into next week. This could set the stage for some MCS clusters to trail down along the periphery of this ridge and into the region. The overall synoptic pattern is one that can produce excessive rainfall in the Ohio Valley during the warm season and we`ll be watching the evolution of the pattern very closely. Daytime highs will remain in the upper 80s to around 90 with overnight lows in the low-mid 70s. && .AVIATION /06Z TAFS THROUGH 12Z THURSDAY/... Issued at 128 AM EDT Wed Jul 16 2025 VFR conditions are expected through much of the overnight hours across the region. The exception will be at KSDF where a band of showers/storms to the southwest of the terminal may pass through between 16/07-09Z. Current thinking is high enough to include a tempo group for SDF for the storms. Elsewhere, will continue a PROB30 group for overnight convection as mid-level wave rotates through the Ohio Valley. Winds will be light overnight out of the south/southeast. Expect another repeat performance this afternoon with scattered convection moving across the region. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...MJ LONG TERM....MJ AVIATION.....MJ