414 FXUS63 KJKL 231350 AAB AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 950 AM EDT Fri Apr 23 2021 .UPDATE... Issued at 950 AM EDT FRI APR 23 2021 Zones and grids were updated to get rid of the Frost/Freeze headlines. Only minor refreshes were made based on recent observations with the forecast largely on track at this time. UPDATE Issued at 743 AM EDT FRI APR 23 2021 Forecast remains on track. Radar shows light returns over our southwestern counties early this morning, but it's still likely just virga. There is a small potential that it could make it to the ground and measure, and a 20% POP continues in place. Early morning obs have been blended into the forecast, with minimal changes. && .SHORT TERM...(Today through Saturday) Issued at 445 AM EDT FRI APR 23 2021 Temperatures are starting out below freezing this morning across much of the forecast area, after a night of light winds and mainly clear skies allowed for unseasonably cold weather. Higher clouds are on the increase currently, with mid level clouds upstream over central KY. There are also some light returns aloft on radar there. The clouds and virga are associated with a weak shortwave trough. The trough will weaken and wash out as it passes over today. However, forecast soundings from both the NAM and GFS, as well as GFS MOS, suggest there could be some very light precip in our southwestern counties, and a 20% POP was used there. Broad, weak ridging aloft then passes over this evening with fair weather, before a more significant upper level system approaches from the west. As it moves through on Saturday, it will support surface low pressure moving eastward across the deep south. Overrunning moisture should bring a large area of rain to the north of the low, including the JKL forecast area. .LONG TERM...(Saturday night through Thursday) Issued at 340 AM EDT FRI APR 23 2021 The extended will start off extremely dry and warm, as a large ridge of high pressure remains entrenched over the region. A significant warming trend is anticipated to begin the new work week, with highs climbing into the upper 70s and even lower 80s Tuesday and Wednesday. Highs on Monday will be in the 70s, and the coolest day in the extended, Sunday, should still see max values in the 60s around the area. The warm weather will last through the end of the week, with highs on Thursday forecast to still be in the mid to upper 70s. Our next chance of rain will arrive on Wednesday, as a slow moving area of low pressure moves towards us out of the Great Plains. The straight up NBM data seemed too fast with precip onset, especially when compared to the latest runs of the GFS and ECMWF models, so precip onset was slowed down by several hours on Wednesday to account for the differences. The first showers are expected to move into our western counties early Wednesday morning, and will gradually overspread eastern Kentucky through out the day. A few storms may fire up Wednesday afternoon, as a surface cold front approaches, and warm moist air from the Gulf of Mexico spreads northward. However, until the surface arrives on Thursday, isolated to scattered showers and storms are what we are expecting initially. The front should begin moving across the area on Thursday. As the boundary moves east, more widespread showers and scattered thunderstorms are forecast to occur. The best chances for rain on Thursday should be during the morning and early afternoon hours. Nightly temperatures will vary quite a bit during the period. The coolest nighttime readings will occur Sunday night and Monday night. With clear skies and near calm winds expected each night, we should see at least small ridge valley temperatures differences. Lows Sunday night will be quite a bit below normal, with min readings in the upper 30s to lower 40s expected. Monday nights temperatures should be a bit milder, as light winds and increasing cloud cover are expected. In spite of this, we should still see a decent ridge valley split, with valleys falling into the mid to upper 40s and the ridges only falling into the lower 50s. After that, nightly lows should be above normal, with nightly readings ranging from the upper 50s to lower 60s Tuesday night and Wednesday night. Winds should be out of the south or southwest for most of the period, with a shift to the west expected once the front passes through toward the end of the week. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) ISSUED AT 743 AM EDT FRI APR 23 2021 VFR conditions and winds less than 10 kts will prevail through the period. However, ceilings will be present most of the time, dropping as low as 5-7K ft AGL from late morning into the evening. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...HAL LONG TERM...AR AVIATION...HAL