871 FXUS63 KJKL 041309 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 909 AM EDT Sun Apr 4 2021 .UPDATE... Issued at 909 AM EDT SUN APR 4 2021 Temperatures have warmed solidly above freezing everywhere this morning. Consequently, let the Frost Advisory expire on time. The rest of the forecast remains on track. UPDATE Issued at 740 AM EDT SUN APR 4 2021 The forecast remains on track this morning so have mainly just updated the T/Td grids per the latest obs and trends. These updates have been sent to the NDFD and web servers. && .SHORT TERM...(Today through Monday) Issued at 410 AM EDT SUN APR 4 2021 07z sfc analysis shows high pressure edging to the south of the area. This has kept the skies mostly clear overnight along with light winds supporting a rather large ridge to valley temperature difference. Readings vary from near 30 degrees in the most sheltered spots to the mid 40s on the ridges. Dewpoints, meanwhile, are generally around 30 in the valleys to the low 20s on the ridges. Frost is likely prevalent currently and a frost advisory remains in effect for the area through 9 am. The models remain in good agreement aloft through the short term portion of the forecast. They all depict the waning influence of a departing deep eastern trough as flat ridging moves into the region today and tonight. This will weaken the northwest flow and keep any impulses of significance well north of the state, with just some very minor ones drifting by at mid levels through Monday. The models are exhibiting a small spread so have again favored the NBM's blended solution for the grids, though did make some adjustments described below to account for the dry air mix- down each afternoon. Sensible weather will feature fine spring weather following a chilly and frosty start to the day today and perhaps in some of the most sheltered spots on Monday. Ample sunshine, filtered at times through some mid and high clouds, will support temperatures in the upper 60s to mid 70s for highs today and Monday. Afternoon RH values will again fall into the 20th percentile range both days on account of the dry air able to be mixed down. Look for another rather large ridge to valley difference in temperatures tonight allowing for some spots of frost in the most sheltered locations. Again adjusted the NBM's T and Td grids to account for the dry air each afternoon and good radiational cooling conditions tonight. Favored the NBM 10% for dewpoints both afternoons and the 5% MinTs for the deep valleys. PoPs were again zeroed out through the period - in line with all guidance. .LONG TERM...(Monday night through Saturday) Issued at 339 AM EDT SUN APR 4 2021 Surface high pressure will remain in control through at least Tuesday, providing a continuation of the dry weather. Return flow on the back side of the high should allow for milder days both Tuesday and Wednesday. We could approach 80 degrees on Wednesday as the flow becomes more amplified ahead of a cut off low over the central plains. As the ridge axis pushes farther east on Wednesday, diffluent flow will spread east into the region along with some isentropic ascent. This will allow for better rain chances as we get into Wednesday night and Thursday. Instability will increase in the wake of the early precipitation chances Thursday afternoon and evening and could yield a few thunderstorms. The upper level low will continue to slowly meander eastward Friday into Saturday, keeping the threat of a few showers going across the area. The area should see a slight cool down with the expected cloud cover and precipitation potential. Most of the shower activity will likely become diurnally driven as the upper level low pushes closer to the area. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) ISSUED AT 755 AM EDT SUN APR 4 2021 VFR conditions are expected to continue through the period as high pressure dominates. Some AC or flat cumulus near 5k ft AGL cannot be ruled out after 15z, but VFR conditions will prevail. Winds will average 5 kts or less through about 14z, before increasing into the 5 to 10 kts range for the day - diminishing to light after sunset. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF