070 FXUS63 KLMK 200714 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 314 AM EDT Wed May 20 2020 .Short Term...(Today and tonight) Issued at 314 AM EDT Wed May 20 2020 Stacked low pressure is centered over the TN Valley this morning, and deep/moist easterly flow continues over KY on the north side of the cyclone. SE 40 kt LLJ over eastern KY and WV is nosing into the I-75 corridor early this morning, fueling scattered light to moderate showers. Rainfall totals since midnight have been around a tenth of an inch or less with this activity so far. The current batch of scattered light rain will continue drifting northwest, mainly across the eastern portions of the forecast area through 12z. A lull in precip coverage is then likely during the mid to late morning hours as forcing diminishes. Diurnal heating this afternoon should be enough to help spark additional isolated to scattered showers over central KY, with SCT coverage south of a line from Frankfort to Bowling Green. Weak instability may support a few lightning strikes near and south of the Cumberland Pkwy in southern KY. Highs will likely stay in the low 60s in the Bluegrass Region today, with mid and upper 60s common further west. Areas south of the WK Pkwy near I-65 could hit 70. Tonight, the closed low moves northwest toward the KY/TN border, and the LLJ does intensify once again over Huntington, WV. Another batch of light showers looks likely, moving NW through eastern, east- central, and northern KY. Basin average rainfall amounts over the 24 hour period ending 12z Thu are expected to range from 0.10-0.30 inches through the I-75 corridor. Given the scattered, light nature of the precip, will go ahead and cancel the Flash Flood Watch this morning. Lows tonight will drop into the low to mid 50s. && .Long Term...(Thursday through Tuesday) Issued at 250 AM EDT Wed May 20 2020 Thursday - Friday Night... The closed upper low will wobble back northward over our CWA to end the work week, continuing to bring heavy cloud cover, scattered shower and storm chances, and below normal temperatures Thursday moderating by Friday. As mentioned in the previous discussion, pops should mainly follow a diurnal peak/valley as lapse rates steepen each afternoon. Models show pretty good agreement that the low will center along and west of the I-65 corridor as it works northward, which puts the best moisture feed to the east over our eastern CWA. Will continue highest coverage there, which is where we don't need any additional rainfall! Look for highs in the upper 60s and low 70s Thursday, with lows Thursday night in the mid to upper 50s. As the upper low begins to exit the area Friday, we'll have a chance to get some more heating with highs back toward normal in the mid to upper 70s. Milder overnight lows follow Friday night in the upper 50s and low 60s. Saturday - Tuesday... The holiday weekend looks to feature a building upper ridge which will likely center just to our east over the mid Atlantic states. Meanwhile, central CONUS troughing looks to take hold. This upper pattern will allow for warmer temps with highs back in the 80s each day, and milder lows in the 60s. The pattern will allow for Gulf moisture to work between the two upper features into our area, which will help instability values and overall shower and storm chances each day. Looks to be a mainly diurnal type of setup at this point, so will continue to maximize pops each afternoon/evening. Repeated showers and storms each day may continue to agitate ongoing wet conditions, so may have to monitor isolated flood/flash flood potential into and through the weekend. && .Aviation...(06Z TAF Issuance) Issued at 155 AM EDT Wed May 20 2020 Stacked low pressure is slowly drifting southeast early this morning over the Tennessee Valley. Deep, moist easterly flow continues to advect moisture into the region. The primary concerns this TAF period are widespread MVFR ceilings and breezy easterly winds. Scattered light showers will also be possible through the period, especially at LEX. Ceilings are flirting with the IFR threshold currently at SDF and HNB. A band of low level moisture drifting westward looks to bring 1- 2 hours of IFR, with ceilings then likely lifting back to Fuel Alternate. Fuel alternate looks likely through the morning hours, with a brief improvement this afternoon. Breezy ENE winds are forecast today, with gusts 19-25 kts possible. Strongest gusts are expected at SDF and LEX, with slightly lighter winds further south and west. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...Flash Flood Watch until 8 AM EDT this morning for KYZ036-037- 041>043-049-057. && $$ Short Term...EBW Long Term...BJS Aviation...EBW