FXUS63 KJKL 201932 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 332 PM EDT Mon Apr 20 2026 .KEY MESSAGES... - Frost or light freeze conditions are expected across most of eastern Kentucky late tonight into early Tuesday morning. - Below normal temperature will last through early Tuesday, followed by warmer weather to last into the weekend. - The next expectation of area wide rain is not until the weekend. && .UPDATE... Issued at 200 PM EDT MON APR 20 2026 Very dry air is spreading southward across eastern Kentucky this afternoon. Given concerns for an extensive light freeze in sheltered valleys, the Frost Advisory has been upgraded to Freeze Warning in the highly dissected terrain east of the Pottsville Escarpment. The Frost Advisory was expanded to include Laurel and Whitley Counties as well. UPDATE Issued at 1050 AM EDT MON APR 20 2026 Secondary cold front is settling across eastern Kentucky late this morning with a period of mid-level cloud cover and even a few sprinkles over far eastern counties. The lingering sprinkles should depart into southwest Virginia within the next 30 minutes. Thereafter, remaining cloud cover should shift southeast and clear the JKL CWA by 2 PM. In the wake of the front, anticipate a dry northwesterly breeze at 5 to 10 mph through the afternoon. Afternoon high temperatures are forecast to range from mid 50s northern foothills to mid 60s in deeper valleys near the KY-TN border while dew points drop back into the 10s and 20s. && .SHORT TERM...(Today through Tuesday) Issued at 745 AM EDT MON APR 20 2026 An impulse is dropping into the base of a longwave trough departing to our east this morning. An associated weak cold front is dropping south through the JKL forecast area, accompanied by clouds. There are some weak returns on radar, but it looks like it's virga. Have included only a mention of sprinkles in the forecast for this morning. The clouds and any sprinkles should be on the decline as they exit to the south and southeast today. Skies will be clear tonight as surface high pressure passes by to our northeast. Low level flow will turn out of the south tonight and begin warm air advection. However, most locations should decouple this evening, which will allow for cold temperatures. Will expect valleys to bottom out around 30 east of I-75 by dawn on Tuesday, and a Frost Advisory was issued for those counties. Warm air advection tonight will result in a steep inversion by Tuesday morning. With nothing more than high/thin clouds expected during the day Tuesday, insolation should result in a significant warm-up as we mix upward through the inversion. .LONG TERM...(Wednesday through Monday) Issued at 332 PM EDT MON APR 20 2026 Upper level ridging will dominate the beginning of the long term period. On Wednesday, a cold front will meander south from the Great Lakes region, but will become diffuse as it is abandoned by its upper level support. Weak moisture return ahead of the front could potentially support isolated showers and perhaps a rumble of thunder in the northernmost portion of the forecast area (generally north of the Mountain Parkway). However, PoPs remain relatively low at this time (20-40%), with better precipitation chances generally expected closer to the front. Elsewhere, warm temperatures and limited moisture return will allow RH values to approach critical levels. This, in combination with breezy conditions, will allow for elevated fire weather concerns. By Thursday, continued high pressure will allow for temperatures to soar into the 80s, once again leaving afternoon RH values near critical levels. However, a weakening pressure gradient will limit afternoon wind gusts (likely reaching a maximum of 10-15 mph), helping to mitigate fire weatherconcerns somewhat. This weekend, a series of shortwaves moving through a longwave trough over the western half of the US will gradually break down upper level ridging, allowing for a wetter pattern to set in. By Friday, southwesterly flow ahead of a sharp cold front over the central United States will usher in a period of more earnest moisture return, leading to gradual dewpoint increases. This front will enter Kentucky on Saturday, finally allowing for widespread and appreciable rainfall. As of now, the best chance for showers and thunderstorms seems to be from Friday night through Saturday. However, models diverge with respect to the synoptic pattern this weekend, particularly with respect to the amplitude of pre- existing upper level ridging and when this ridge will breakdown. The structural evolution of these upper level features will be critical for precipitation timing and QPF this weekend. This QPF uncertainty is reflected in LREF guidance, which maintains a ~0.50 discrepancy between 25th and 75th percentile accumulations this weekend. Regardless, confidence is high (80-90%) in receiving at least a quarter of an inch of rain across the forecast area this weekend. Looking ahead, quasi-zonal flow should allow for a more active weather pattern early next week. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 200 PM EDT MON APR 20 2026 VFR conditions are forecast through the period. Winds will be light and variable through tonight. && .JKL WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 11 PM this evening to 9 AM EDT Tuesday for KYZ044-050-051-058>060-069-080-085. Freeze Warning from 11 PM this evening to 9 AM EDT Tuesday for KYZ052-086>088-104-106>120. && $$ UPDATE...GEERTSON SHORT TERM...HAL LONG TERM...FAGAN/GEERTSON AVIATION...GEERTSON