Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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494 FXUS63 KLMK 222024 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 324 PM EST Fri Nov 22 2024 .KEY MESSAGES... * Isolated rain showers and patchy drizzle will be possible across the Bluegrass region this afternoon and evening. * After a cloudy and cool start tomorrow, a gradual clearing and warming trend is expected over the weekend. * Increasing rain chances Monday and again for the middle of next week. && .SHORT TERM /THROUGH SATURDAY/... Issued at 323 PM EST Fri Nov 22 2024 Across the region this afternoon, a large area of stratus continues to sprawl overhead as low-level moisture remains trapped below a subsidence inversion. A fairly strong pressure gradient remains in place over the region between 990 mb sfc low over the Poconos and 1025 mb sfc high extending across the eastern Great Plains, allowing for continued gusty west-northwest winds. Temperatures over central KY and southern IN are mainly in the 40s this afternoon, and most locations should remain fairly steady through the rest of the afternoon as clouds continue to fill in. Later this afternoon, an area of deeper moisture moving in from eastern IN and western OH should saturate to sufficient depth for a few light rain showers or areas of patchy drizzle to form across the Bluegrass region. Other than temporarily reduced visibilities and light precipitation amounts, this shouldn`t be too impactful given temperatures are well above freezing and should subside by midnight. Tonight, low clouds should linger over the region with weak cold advection continuing around 925 mb and the mid-level subsidence inversion strengthening. These clouds should keep temperatures fairly steady overnight, with lows Saturday morning only expected to fall into the upper 30s to around 40 degrees. Winds should gradually ease during the late evening hours, though a persistent 5-10 mph west wind should continue overnight. Tomorrow should be a transition day as the upper low exits into the Canadian Maritimes and ridging moves into the Ohio and Tennessee Valleys. Low-level cold advection should slowly end during the day tomorrow, which should begin the process of clearing pesky low clouds. However, this will be a gradual process from southwest to northeast, with clearing expected earlier in the day along the TN border and clouds holding on longer across southern IN and north central KY. It is even possible that areas along and north of I-64 do not clear out until Saturday night. Temperatures will be highly dependent on the amount of low cloud clearing, and there is a fair amount of spread in short-range progs. For this forecast, have tended on the cooler/cloudier side of guidance since low clouds tend to hang on longer than most model depictions. This gives a range of highs from the mid 40s over the Bluegrass region to the low 50s across south central KY. Winds should be westerly tomorrow, with speeds lighter around 5-10 mph. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 323 PM EST Fri Nov 22 2024 The medium range forecast starts off cool and dry Saturday night. Flattening ridging aloft will gradually build eastward toward the region as sfc high pressure moves across the Southeast. We`ll see light SW flow, and steady low-level WAA should help promote a gradual clearing trend. Partly cloudy to mostly clear skies Saturday night may allow to fog to form as the BL decouples and temps drop. Lows should reach the low to mid 30s in most areas. Low-level SW flow increases Sunday as low pressure develops eastward over OK/KS. Look for warmer and dry conditions, with afternoon highs in the upper 50s to lower 60s. Low pressure is forecast to continue lifting NE into the Lower Great Lakes Sunday night and Monday, with a trailing cold front cutting southeast through the Mid-MS Valley, Ozarks, and eventually Ohio Valley. It appears we`ll most likely stay dry into Monday morning, with deep moisture confined to a zone just along and ahead of the sfc cold front. Stout SW LL flow and dry conditions will result in a milder night, with Monday morning lows in the mid 40s to lower 50s. A round of light to moderate showers looks likely Monday afternoon and evening as the cold front sweeps through the region. High temps should range through the 60s. Around 0.10-0.25 inches of rain looks possible through Monday night. Precip shuts off quickly Monday night as much cooler, drier air pours into the region. Temps will drop into the 30s by early Tuesday. Tuesday looks dry and chilly. Upper level flow transitions to a more zonal pattern as sfc high pressure builds east toward the region. Afternoon highs will likely be in the 40s. Sfc high pressure builds east across KY Tue night, which should allow temps to drop into the mid 20s to lower 30s. There is some uncertainty on upper level sky cover trends, especially heading into Wednesday, as another low pressure system gets organized over the southern Plains. This system could bring another round of precipitation Wednesday into Thursday, but confidence on the details/evolution remains very low at this time. && .AVIATION /18Z TAFS THROUGH 00Z SUNDAY/... Issued at 1240 PM EST Fri Nov 22 2024 A large area of low stratus will gradually fill in this afternoon, with MVFR ceilings expected through much of the current forecast period. As this area of clouds fills in, occasional improvements to VFR CIGs are possible, but MVFR probabilities increase from 20Z into the evening hours. Winds will remain gusty out of the W/NW this afternoon. There is the possibility for occasional VIS reductions at LEX and RGA this afternoon with patchy drizzle moving toward the area. Tonight into tomorrow morning, MVFR CIGs are generally expected to predominate, though occasional VFR CIGs are possible at SDF. Winds will gradually ease overnight, and remain relatively light into Saturday morning. An improvement in ceilings is likely Saturday afternoon, but this is expected to occur near the end of the current forecast period. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...CSG LONG TERM...EBW AVIATION...CSG