FXUS63 KJKL 290025 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 825 PM EDT Thu Mar 28 2024 .KEY MESSAGES... - Temperatures will remain seasonably cool through Friday morning, with one more night of near or sub-freezing temperatures and frost returning for most valley areas late tonight. - A warming trend then ensues Friday afternoon and continues through early next week. - PoPs start to creep back in from the northwest this weekend and continue to ramp up through early next week. && .UPDATE... Issued at 750 PM EDT THU MAR 28 2024 23Z sfc analysis shows high pressure just to the southwest of eastern Kentucky and this is keeping the skies mostly clear and the air mass dry. Lingering west winds of 5 to 10 mph will be settling shortly following sunset. Currently, temperatures are running in the low to mid 50s in the more open areas, and on ridges, while the sheltered valleys have fallen into the middle 40s. At the same time, dewpoints are running in the upper 20s to lower 30s, most places. Expect the terrain based temperature disparity to build through the night with many of those valleys reaching near or below freezing by dawn and frost a strong possibility. Along the rivers and lakes patchy fog will likely develop, as well. For the frost and sub freezing potential an SPS will be issued shortly highlighting these concerns. Did also fine tune the sky cover and add in the current obs and trends for the T/Td grids with this update. These minor adjustments have been sent to the NDFD and web servers. && .SHORT TERM...(This evening through Friday night) Issued at 304 PM EDT THU MAR 28 2024 Present surface analysis has high pressure firmly established over the area. This has allowed for mostly clear skies across the area. Upper-level northwesterly flow will limit afternoon highs a little bit but highs are still forecast to climb into the upper-50s to low- 60s. Dry air associated with the surface high, will keep dewpoints on the lower side leading to RHs in the in the low-20s to low-30s through the afternoon. Fortunately, light winds and recent rainfall will keep fire weather concerns on the lower side. Upper-level flow continues to remain out of the northwest through the overnight. A little shortwave working through the circulation, responsible for the northwesterly flow, will interact with mid-level moisture to increase clouds across the northeastern portions of the CWA. This may limit how far temperatures fall across the Big Sandy Basin. On the flip side, clearer skies will allow for temperatures to fall across the southwestern portions of the CWA. Opted to lower Monticello a few more degrees than guidance for this very reason. Overall, overnight lows are forecast to dip into the upper-20s in the valleys and low-30s for the ridges. Those temperatures will allow for areas of frost, especially in the more sheltered valleys. Friday will continue to keep surface high pressure in place and temperatures will climb into the upper-60s to low-70s in a few places. However, to the west, a shortwave trough is forecast to develop off the lee of the Rockies and bring a change in the weather pattern. As that surface low approaches, the associated warm front will lift through the region late Friday night into Saturday morning. This will usher in the regime of WAA and moist southwesterly flow. Along the front, shower chances will increase in coverage starting early Saturday morning and persisting into the long-term forecast period. .LONG TERM...(Saturday through Thursday) Issued at 456 PM EDT THU MAR 28 2024 The period will start with large surface high pressure centered off the southeast coast providing us with a continue warm southwest low level flow with increasing moisture. Aloft, rather zonal flow will be over the central and eastern CONUS, with a weak shortwave rippling through it and supporting a surface low crossing the Great Lakes. The cold front trailing from this low is expected to reach KY Saturday night and stall. The proximity of the front could be enough for a few showers Saturday and Saturday night, especially in our northern counties, but GFS forecast soundings show a cap and thunder has been left out of the forecast at that time frame this go around. By the time the front stalls nearby Saturday night, a deep upper low will be dropping SSE into the southwest CONUS at the heart of a large trough. This promotes a lee low over the high plains, increasing flow off the gulf, strengthening the frontal boundary and letting it creep back northward. Our potential for showers/thunderstorms will continue in this scenario, enhanced periodically by impulses aloft. The western trough eventually heads east along with the surface low. The passage of the low to our north will send the boundary through KY as a cold front, with the GFS and ECMWF deterministic runs coming into better agreement for cold fropa on Tuesday evening. Our highest POP and most significant precip is expected with the approach and passage of the cold front. GFS forecast soundings show an instability/shear combo supportive of severe wx, and SPC has the area in a slight risk. However, it is still many days out, and models will need to be watched for changes. Much cooler air arrives Wednesday behind the front, with dry weather by Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 825 PM EDT THU MAR 28 2024 VFR conditions will prevail through the TAF period as surface high pressure slowly passes through the area. Sustained west to northwest winds of 5 to 10 knots with a few gusts up to 15 knots will be noted through sunset before slackening to light and variable. Winds begin to increase again around 14Z Friday from the west with sustained speeds of 5 to 10 knots and gusts upwards of 20 knots by late afternoon. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...VORST LONG TERM...HAL AVIATION...VORST/GREIF