637 FXUS63 KLMK 260109 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 909 PM EDT Sat May 25 2019 .Forecast Update... Issued at 909 PM EDT Sat May 25 2019 Evening convection across southern Indiana has dissipated as the boundary layer cools and stabilizes. Temperatures this evening ranged from the mid to upper 70s with a few 80+ degree readings out over far NW KY. We expect a quiet period of weather for the remainder of the evening and overnight. Lows will range from the upper 60s to the lower 70s. A few spots of river valley fog are possible as well. The forecast has been updated with the latest observations along with a refresh of the latest consensus blends for the overnight period. Updated text and grid products are in production and will be available shortly. && .Short Term...(This evening through Sunday) Issued at 317 PM EDT Sat May 25 2019 We are currently hot and dry across the CWA with most everyone in the upper 80s and low 90s. Most of the cu on satellite imagery looks underwhelming, although there is a notable enhancement up over south central IN where some convective cells have fired. Forecast soundings across our CWA do show a potentially unstable airmass, however a stout subsidence inversion looks to be in place later this afternoon, so thinking we will continue to stay mostly dry. In addition, there is a relative PWAT minimum over most of our region at this hour. The one area that appears to have some convective potential for later this afternoon/evening is up over our SW IN counties where deeper moisture is starting to be noted, along with a tight instability gradient. Assuming a few stray storms are able to fire, this would be in an environment characterized by moderate instability and 30-35 knots of deep layer shear. Given those values, some marginal storm organization could occur where gusty winds to 40 mph and small hail can't be ruled out. The more likely scenario would be a few garden variety storms with brief heavy rainfall and cloud to ground lightning as the main threats. Any convective activity should die off later this evening with the loss of heating. This will lead to a mild and quiet overnight with most lows in the upper 60s and low 70s. Some patchy valley fog can't be ruled out. The upper ridge centered over the SE CONUS breaks down a bit more on Sunday, allowing less subsidence over our area and a weak frontal boundary to sag closer to the region. As a result, expect to see precipitation chances a bit higher across the northern half of our CWA. The day should still remain mostly dry and hot, however the afternoon and evening time frame should still yield scattered coverage of showers and storms. Overall highs should range mostly in the upper 80s, although a few southern spots should still touch 90. .Long Term...(Sunday night through Saturday) Issued at 315 PM EDT Sat May 25 2019 Sunday Night through Tuesday Night... Convection across southern IN and northern KY will probably be ongoing at the beginning of the period and will wane in the late evening hours with the loss of heating. Lows Sunday night will likely drop into the mid-upper 70s. For Memorial Day, the multi-model consensus has continued to trend a little drier with a set up similar to Friday afternoon. The models are suggesting that the mid-level ridge axis may build a little further north on Monday which would supress convection. However, there is uncertainty where the periphery of the ridge will set up. The best chances for convection Monday afternoon and evening look to be across southern IN and the Bluegrass region of central Kentucky. So will continue with isolated-scattered storm chances there. Otherwise, it will be warm with afternoon highs topping out in the mid-upper 80s over southern IN and northern KY. South of the WK and BG Parkways will likely warm into the lower 90s. Lows Monday night will only cool into the upper 60s to the lower 70s. For Tuesday, we're not seeing much change in the model forecasts for this time period. This day looks to be the driest of the week as the mid-level ridge axis should hold sway across the region resulting in another hot and sunny day. Highs will range from the upper 80s to near 90 across southern IN and northern KY, with southern KY in the 90-93 degree range. Overnight lows will drop back into the upper 60s to lower 70s. Wednesday through Saturday... By mid-week, an upper trough over the western US will move into the Plains and eventually into the Ohio Valley. This will result in the upper ridge being displaced much further south. The trough axis will swing through the region late Wednesday and into Thursday with the possibility of a few surface waves moving northeast along the slow moving boundary. Thus, we could see some decent rainfall as this system pulls through. This afternoon's solutions are a bit more progressive with the feature allowing it to push south and east of the region by Friday leading to a cooler and drier pattern as we head into the first days of June. As for temperatures, it will be warm Wednesday highs in the 85-90 degree range. Temps will cool off on Thursday due to expected clouds and precipitation. Highs look to be a good 10 degrees cooler on Thursday with readings generally in the 78-84 degree range. Some moderation may occur on Friday with highs sticking close to 80, with lower-mid 80s expected by Saturday. Overnight lows will start off in the upper 60s to around 70, but finish the week in the lower-mid 60s. && .Aviation...(00Z TAF Issuance) Updated at 705 PM EDT Sat May 25 2019 Steady southwest winds will continue through sunset and then begin to die off. A couple of showers/storms will drift close to KHNB over the next hour or two, so will insert a VCSH group in there to account for that. Expect convective activity to diminish after 26/01-02Z or so. Otherwise, light southwest flow and VFR conditions are expected for the remainder of the overnight period. Southwest winds will pick up again on Sunday with some gusts to 20-25 MPH at times. Some scattered convection will skim just to the north of our region. Therefore, will keep dry forecast going at this time. However, will need to keep a close eye on radar trends tomorrow afternoon as some isolated storms can't be ruled out at our northern TAF sites. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update.......MJ Short Term...BJS Long Term....MJ Aviation.....MJ