828 FXUS63 KJKL 150755 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 355 AM EDT Fri Mar 15 2024 .KEY MESSAGES... - Above normal temperatures continue through Saturday just not as warm as it has been. - A cold front brings showers and thunderstorms to the area through this afternoon and early evening in the southeast. Rainfall will generally be a quarter to half of an inch. - A deeper passing system aloft brings a threat of some rain/snow showers on Monday. - Hard freeze conditions Monday night could kill any cold sensitive vegetation that has emerged prematurely due to early season warmth. && .SHORT TERM...(This evening through Friday night) Issued at 511 PM EDT THU MAR 14 2024 Late this afternoon, the axis of an upper level ridge extended from the Caribbean north near the eastern seaboard while another upper level ridge extended across portions of the Pacific into the northwest Conus. In between an upper level trough extended southwest from the Hudson Bay region into the southwest Conus with southwest flow aloft from the Southern Plains into the Lower OH Valley. A closed low was located across the desert southwest with the upper trough while a more progressive shortwave trough extended from Ontario to the Northern Plains while additional weaker shortwaves were moving in the southwest flow toward the OH Valley region. At the surface, a wavy frontal zone extended from the New England coast across the mid Atlantic states into the southern Great Lakes to mid MS Valley vicinity to the Southern Plains to southwest Conus in advance of the upper level trough axis. Earlier convection generally passed north of eastern KY although some isolated showers or storms were moving across the region at this time, generally near or north of the Mountain Parkway as a weak shortwave moves through the OH Valley region. MLCAPE is currently analyzed in the 500 to 1000 J/kg range across the western half or third of the CWA while instability further east is minimal due to dewpoints only in the 40s to around 50. Effective shear is sufficient for some organization to convection. This evening and tonight, shortwaves in southwest flow should continue to progress across the Lower OH Valley region while the axis of the upper level trough shifts gradually southeast to an Ontario to northern Great Lakes to SD line late tonight. This trough axis should progress southeast across the Great Lakes and pass across parts of the OH Valley and into the Northeast. Another more potent shortwave will drop southeast across central portions of Canada and is expected to reach western Ontario to the upper MS Valley by the end of the period. In advance of the shortwave working toward the Great Lakes and OH Valley, the wavy frontal zone should gradually move south and east toward the Commonwealth tonight and cross KY from Friday into Friday evening. the frontal zone and a series of shortwaves will lead to convection at times, though chances peak later tonight through Friday when the combination of moisture and lift peaks. PW reaches the 1 to 1.25 inch range late tonight through Friday afternoon while forcing associated with the front and the passing shortwave peaks during that time. QPF with this system has generally trended down into the quarter to half of an inch range, though as is the nature of convection some locally higher amounts should occur where any stronger thunderstorms pass. Above normal temperatures will persist ahead of the front through Friday and even behind it on Friday night as only a modest cool down is expected. The hourly temperatures and min T for deeper eastern valleys is a bit tricky tonight, but cloud cover should be insufficient for another ridge/valley temperature split tonight with the deeper valleys dropping toward the 50 degree mark and stayed close to the previous forecast with details for that. Coalfield valleys may not drop below the 60 degree mark in some instances. Temperatures for most areas should reach well into the 60s for highs on Friday in the warm sector. Lows on Friday night should as much above normal as tonight, but still above normal nevertheless in the low to mid 40s. .LONG TERM...(Saturday night through Thursday) Issued at 355 AM EDT FRI MAR 15 2024 Surface high pressure will be in place to start the period. Upper- level zonal flow will keep moderate temperatures across the area. Overnight lows Saturday night will be in the low to mid-40s with d anytime highs for Sunday expected to be in the upper-50s to lower- 60s. A dry cold front will cross through the area Sunday afternoon. This will usher colder temperatures back into the area with below average temperatures expected to persist through the early part of next week. The upper-level trough responsible for the cold front is still forecast to pivot toward the CWA and bring the potential for rain/snow mix to the region for Monday afternoon. The areas mostly likely going to see PoP will be along and north of the Mountain Parkway. Models continue to hint at another chance of precipitation on Tuesday as another weak cold front will move through the region Tuesday afternoon. Surface high pressure returns for the middle of next week with temperatures gradually increasing through the week. The active period continues as models bring another system through the region for the end of the period. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 200 AM EDT FRI MAR 15 2024 In general, VFR conditions are expected through much of the overnight, with brief reductions to MVFR and momentary IFR as showers and thunderstorms move through into the day Friday. CIGs will becomes increasingly more prevalent in the MVFR category later in the morning, though, with the potential for IFR, or low- MVFR, conditions along with showers beginning around or shortly after 18Z/Fri. Continued low CIGs follow into the evening for most locations. Winds, outside of storms, will be from the south to southwest at 10 kts or so. With storms, they could exceed 35 kts. The winds then become westerly and northwesterly prevailing by midday Friday as the cold front passes across the area - but with speeds generally remaining below 10 kts sustained. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JP LONG TERM...VORST AVIATION...CMC/GREIF