650 FXUS63 KLMK 100521 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 121 AM EDT Wed Oct 10 2018 ...Updated Aviation Discussion... .Short Term...(This evening through Wednesday) Issued at 310 PM EDT Tue Oct 9 2018 While Hurricane Michael grabs the weather headlines today, the Ohio Valley can prepare for the unofficial end of summer, as the last gasp of the warm season prepares to exit after Wednesday. Before that happens, though, dewpoints in the 70s will return return to the region for one last sweaty day. Shower and thunderstorm chances will increase from the south and west after midnight, then advance across the remainder of the area through the day. Though average rainfall totals will average around a half inch or less, isolated locations could see brief heavier rainfall, especially during the afternoon, thanks to the 70+ dew points. Temperature-wise, overnight lows will bottom out in the upper 60s tonight, just a few degrees below normal highs for the date. Thanks to increasing clouds overnight as the shower chances return, fog is not expected to cause any visibility problems for the morning commute. The same clouds will help keep the last day of above normal temperatures down slightly, with highs "only" topping out around 80 - about 5-10 degrees above the climatological average. .Long Term...(Wednesday night through Tuesday) Issued at 259 PM EDT Tue Oct 9 2018 Wednesday Night... A strong cold front trailing from a Great Lakes low pressure system will be poised to slide through our area Monday evening and night. Ahead of this feature, a broken line of showers and storms is expected, so will continue with high pops for this time frame. Still thinking the severe threat will be low, but not zero. A look at SREF instability probs shows a good chance for 500-1000 J/KG of CAPE during the late afternoon and early evening, however dropping off quickly after sunset. Expect showers and storms to move into our west shortly after sunset, but will be met with a diminishing instability gradient. When you couple this with the fact that the best instability will be to the north of our CWA, think the severe/gusty wind threat is lower. Perhaps of more concern will be that PWATs will pool to around 2-2.2" through the column ahead of the front, and that brief heavy rain could be an issue. Luckily, storms look pretty progressive as the front sweeps through so don't expect many problems at this time. Thursday - Saturday... A strong Canadian high pressure builds into the area late week into the first half of the weekend, and will bring some true Fall weather to our area. Expect dry conditions with temps mostly in the low to mid 60s Thu-Sat. Thursday could still have a few locations down near Lake Cumberland holding onto 70. After lows in the low to mid 40s on Thursday night, look for lows in the upper 30s (typical cool spots) to low 40s on Saturday night as the surface high centers right over us. Saturday Night - Tuesday... Surface high pressure moves east by this time, with a more SW mid level flow developing over the Ohio River Valley ahead of a digging western CONUS trough. The remnants of Sergio (from the Pacific) look to slide in just ahead of this trough and quickly eject out of the southern Plains into the Ohio River Valley region. At this point, rain looks to slowly overspread the region later Saturday night, and be fairly widespread Sunday. Beyond Sunday, some confidence is lost in the progression/strength of the upper trough and how quickly the storm system gets out of the region. Will keep some chances for rain lingering into Monday. Regardless of the data differences, Tuesday looks to be dry with continued cool conditions. Low to mid 60s look like good bets for Sunday/Monday highs, however cooler air should be in place by Tuesday as another reinforcing shot of cool air takes hold. Temps may not get out of the upper 50s. After lows in the 40s on Saturday night, Sunday night lows will actually be milder in the warm sector of the aforementioned system. Look for low to mid 50s. Cold temps follow by Monday night with readings back down into the upper 30s and low 40s. && .Aviation...(06Z TAF Issuance) Issued at 120 AM EDT Wed Oct 10 2018 A 35-40kt LLJ is resulting in some low-end LLWS conditions across BWG/HNB this morning. Clouds and moisture are advecting into the region ahead of the LLJ, and we should see a round of showers affect the TAF sites this morning. MVFR to high-end IFR cigs/vis will be possible with these showers. Models indicate some clearing behind the showers this afternoon, though it will be short lived as a cold front approaches from the west and results in another round of showers and storms. IFR to MVFR cigs/vis will be possible with the stronger showers/storms this afternoon and evening. Winds will also be gusty at times out of the south through much of the day, and will quickly shift to the northwest behind the cold front tonight. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...JBS Long Term...BJS Aviation...DM