043 FXUS63 KLMK 271029 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 629 AM EDT Sun Apr 27 2025 ...Updated Aviation Discussion... .KEY MESSAGES... * A cold front will bring storms to the region Tuesday and Tuesday night. Some strong to severe storms will be possible, especially in southern Indiana and north central Kentucky in the afternoon and evening. * Showers and thunderstorms will continue into Wednesday and Thursday as Tuesday`s cold front stalls over the area. Localized flooding will be possible under stronger storms, especially Thursday. Additional strong storms will be possible as well. * Dry weather is forecast to return for Saturday with temperatures right around normal for early May. && .SHORT TERM /THROUGH TONIGHT/... Issued at 303 AM EDT Sun Apr 27 2025 Pretty quiet in the short term as high pressure centers to our north this afternoon, and then slides to the mid Atlantic Coast by tonight. Meanwhile, subtle upper ridging will build in. This is a dry setup, although we will see partly to mostly cloudy skies as mid to upper moisture filters through the region. Forecast soundings and time heights do show a very dry low level airmass today, so any returns on radar off to our west will likely not hit the ground over our region. Temps are expected to be a little below normal today, but still seasonable in the upper 60s to around 70. Could get a little warmer, but the variable mid/upper cloudiness combined with a steady easterly surface wind hurts confidence on temps overachieving today. Temps cool off pretty quickly tonight as the steady easterly wind is lost, and surface winds find a light or nearly calm NE component. Valleys will likely decouple and could drop well into the 40s, while the more coupled areas may stay in the upper 40s to low 50s. Could the coolest eastern valleys see some upper 30s? There is at least some chance. HREF probs less than 40F are around 10-20% for the coolest spots. Suppose a few patchy spots of frost can`t be ruled out if we do dip into the 30s. Will also make one final note that there is still a loose signal for some light QPF across south central KY heading into Monday. There does appear to be an inverted surface trough down in that area, and perhaps some weak convection triggers on that boundary. Doesn`t seem to fit the pattern when you would expect to have a subsidence inversion there thanks to the upper ridging. As a result, will keep a dry forecast with less than 15% pops, but won`t rule out a stray shower down there toward sunrise. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 303 AM EDT Sun Apr 27 2025 Monday and Monday night upper ridging will move overhead as a surface high stretches out along much of the East and Gulf coasts, providing the region with mostly dry weather other than perhaps a stray shower in the Lake Cumberland region where there will be isentropic upglide on the 305K surface and some meager moisture to work with. Thunderstorms will develop by Monday evening from the Plains into the Midwest ahead of low pressure over the upper Mississippi Valley and a cold front trailing southward to the Texas Panhandle. These storms will push to the east and will pose the first challenging variable in how this week`s weather will play out in the middle Ohio Valley. How far eastward these storms make it before they outrun the best forcing and bump into the aforementioned upper ridge will determine how much cloud and rain we receive Tuesday morning. This, in turn, will have a significant effect on how much destabilization occurs Tuesday afternoon and evening for additional storm development. Whether or not we`ll have showers and storms in the area Tuesday and Tuesday isn`t the main question -- confidence is fairly high in that and we have likely PoPs in the forecast for much of the area. The main uncertainty is in just how strong or severe those storms will be. The most likely timing for any strong to severe storms still appears to be in the afternoon and evening hours at the time of diurnal max instability and as the cold front comes in from the northwest, reaching the Ohio River around midnight. Deep layer shear doesn`t look overly impressive but will still be plenty enough for storm organization. Would prefer to have greater confidence this close to the potential event, but there are still several pieces on the meteorological chess board that are in play. The bottom line, though, is that there is still a threat of strong to severe storms Tuesday afternoon and evening and folks in the area, especially southern Indiana and north central Kentucky, should continue to monitor the latest forecasts. The front is still expected to lay out in an east-west orientation Wednesday, continuing our shower and thunderstorm chances with additional strong storms possible. The boundary may then lift north as a warm front Wednesday night and Thursday in response to low pressure crossing the Midwest and upper Great Lakes. That low`s cold front would then pass through the region late Thursday night or early Friday morning with another round of showers and storms. With the uncertainty in the evolution of these waves of showers and storms, plus the convective nature of the precipitation, it`s difficult to ascertain with any degree of certainty just how much rain will fall. As it stands now, it looks like there might be enough of a break between waves for some recovery to take place between bouts of rain, and we have greened up nicely which will help to take up some of the water. NAEFS/HEFS/GEFS are not indicating a return of river flooding. So, it appears that the main flood threat would be local flash flooding with heavier thunderstorms or training storms. It`s not a slam dunk, but it continues to look like we may dry out just in time for the weekend with Saturday temperatures right around normal for early May as high pressure glides through the Great Lakes and Ohio Valley. && .AVIATION /12Z TAFS THROUGH 18Z MONDAY/... Issued at 629 AM EDT Sun Apr 27 2025 VFR is expected to prevail through this forecast cycle as high pressure centers to our north, but retains control of the region. We`ll keep a light but steady ENE/NE surface wind for the remainder of the morning, along with some BKN upper clouds. As we get into the daylight hours, look for winds to find a steady easterly component. Upper sky cover should diminish somewhat by late afternoon, however will keep some scattered mid clouds around. Winds slacken again tonight and become more NE or Calm. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...BJS LONG TERM...13 AVIATION...BJS