897 FXUS63 KLMK 130227 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 1027 PM EDT Sat Oct 12 2024 .KEY MESSAGES... * Warmer temperatures and dry weather continues into tonight. * Breezy and very isolated showers along and east of US-127 on Sunday. * Turning much cooler next week with widespread frost likely Tuesday and Wednesday nights. && .UPDATE... Issued at 1027 PM EDT Sat Oct 12 2024 Evening satellite imagery shows mostly clear skies across the region. Temperatures were in the lower to middle 60s across the LMK forecast area. We do have some of our cooler valley locations coming in a bit cooler with lower-middle 50s. Current forecast remains on track for the overnight hours. Products have been refreshed with new observational data and blended into the ongoing forecast. && .SHORT TERM /THROUGH SUNDAY/... Issued at 314 PM EDT Sat Oct 12 2024 An upper level trough over central Canada this afternoon is forecast to amplify as it drops southeast over Ontario, the Upper Midwest, and Great Lakes tonight and Sunday. A 1012 mb sfc low currently over southern Iowa is forecast to move east along an existing quasi- stationary boundary through northern portions of IL/IN/OH. This wave of low pressure will gradually deepen tonight through Sunday with the arrival of stronger divergence aloft downstream of the upper trough. Central KY and southern IN will be positioned south of the sfc low and trailing cold front through Sunday morning. Low-level SW flow will continue to increase this evening and overnight in the warm sector. Despite the arrival of a potent 40+ kt SW low-level jet early Sunday, dry weather remains likely. Low-level moisture return is relatively meager, and a strong low-level inversion will be in place. In fact, this inversion will remain in place through much of Sunday. As for sensible weather, tonight will be dry with mostly clear to partly cloudy skies. It will be notably milder than previous nights due to increasing southerly winds. Sunday morning lows will be in the mid 50s to lower 60s. Sunday morning will start off dry and breezy with partly sunny skies. The sfc cold front pushes southeast through the forecast area during the afternoon and evening hours. Forecast soundings show some weak CIN lingering even into the late afternoon. Sfc dewpoints creep up to near 60 F in a narrow pool of moisture along the front. We could realize 1000+ J/kg of CAPE above the weakening inversion across south-central KY and the Bluegrass Region. Our far eastern and southeastern CWA will have the best chance at seeing a brief shower/storm late in the day. However, low-level forcing isn't all that strong and moisture availability is decent at best. Most areas will stay mainly dry with fropa, with only a 10-15% chance for rain late in the day southeast of a BWG to LEX line. Sunday will be the last warm day, with highs topping out in the upper 70s to lower 80s prior to fropa. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... Issued at 314 PM EDT Sat Oct 12 2024 Sunday Night - Thursday Night... An anomalous trough envelops the eastern CONUS through the early week timeframe. This will result in below normal temperatures through mid week, and mostly dry conditions. One exception to the dry conditions will be Tuesday, where a shortwave embedded in the parent trough rotates through the area. This will drag a secondary cold front through to reinforce the cold air, and could trigger some light shower activity as well. Will be introducing a 20% chance of light rain showers across our NE CWA to account for this as models have been fairly consistent with this chance the past few runs. Outside of that, the main focus will be on the cool days and cold nights, and their respective frost/freeze potential through mid week. Still looks like the coldest nights of the forecast period, and of the season so far, will be Tuesday and Wednesday nights. Strong 1028- 1030mb Canadian high pressure builds into the area by then with good radiational cooling prospects both nights. The surface high looks to be settled a little more directly overhead on Wednesday night/Thursday morning, so have been trending that night a bit cooler as pattern recognition would suggest this should yield some cooler spots than Tuesday night. Regardless, either night should have a high likelihood of frost potential. Although the chance for freezing temperatures is a bit lower, LREF probabilities suggest a 20-30% chance in the eastern CWA either night. The bottom line is that Frost headlines are likely, while Freeze headlines remain possible both of these nights. Daytime highs will also be notably cooler early to mid week. Steady cold advection and some lingering stratocu across our NE CWA will only allow for upper 50s and low 60s. Farther SW outside of the stratocu deck, look for a better chance at mid 60s across the SW CWA. Highs on Monday will be around 20 degrees cooler than Sunday! Even cooler highs follow on Tuesday and Wednesday as more of the area will be confined to the mid and upper 50s. Only areas down around Bowling Green are expected to still reach into the lower 60s. The upper pattern begins to transition on Thursday as a ridge axis begins to build in from the SW. Meanwhile, the surface high will be shifting east, and heights/thicknesses will slowly begin to rise. As a result, highs on Thursday recover back into the mid and upper 60s after a cold start Thursday morning. Thursday night, some patchy frost may still be a possibility in the coolest spots. Friday - Saturday... Milder and dry conditions continue late week into the first part of the weekend as the upper ridge becomes established over our area, and a slight warm advection component kicks in on the western edge of the retreating surface high. Highs back in the low to mid 70s seem reasonable by this time. && .AVIATION /00Z TAFS THROUGH 06Z MONDAY/... Issued at 717 PM EDT Sat Oct 12 2024 VFR conditions are expected for the upcoming TAF period. For the overnight period, the main issue will be low-level wind shear. With a cold front approaching from the northwest late tonight, model soundings show the flow in the lower part of the atmosphere ramping up. It appears that we'll see LLWS in the 13/06-13/12Z time frame. After sunrise, we'll see good mixing which will allow that higher momentum air to reach the surface. Surface gusts of 20-25kts are expected during the day on Sunday after 13/14Z and will continue into the evening before slacking off. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE.......MJ SHORT TERM...EBW LONG TERM....BJS AVIATION.....MJ