Area Forecast Discussion
Issued by NWS Jackson, KY

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833 FXUS63 KJKL 190041 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 841 PM EDT Wed Apr 18 2018 .UPDATE... Issued at 841 PM EDT WED APR 18 2018 Showers and isolated thunderstorms were occurring along a strong cold front over central KY, moving toward the JKL forecast area from the northwest. Clouds have been slow to increase ahead of the front, and have trimmed back sky cover ahead of the cold front this evening. As far as thunder is concerned, forecast soundings suggest weakening instability as the front moves southeast, and trouble breaking a mid level cap, so have continued to hold off on the inclusion of thunder in our forecast area. In terms of wind, gusts to advisory criteria are likely to be limited to areas near and just behind the front, and not affect the region for the entirety of the current wind advisory period. However, the advisory will be left in place as-is to cover the window of time when there is potential for gusts near 40 mph. && .SHORT TERM...(This evening through Thursday night) Issued at 357 PM EDT WED APR 18 2018 The latest surface map features quick-moving low pressure currently centered across western Indiana, with a trailing cold front aligned southwest, just west of the Mississippi River. Aloft, an amplified pattern is dominant across the northern half of the CONUS, with an upper level low spiraling across northern Iowa, and a short wave trough rotating down from southeast Ontario. Eastern Kentucky has been enjoying a nice warm up today out ahead of the approaching cold front, with current temperatures exceeding 80 degrees in several places. Clouds will be on the increase this evening, as the cold front approaches from the west. Shower activity will develop along the boundary and should yield likely rainfall across eastern Kentucky, although QPF will average less than a tenth of an inch. Winds will be strongest along and behind the front, with gusts still looking to approach 40 mph in the western half of the area, with 30 to 35 mph in the east. There will be a lull in the action after midnight from west to east, with even some partial clearing, before a trough axis swings through the Ohio and Tennessee valleys by dawn. Temperatures will turn quite a bit colder behind the front, with upper 30s expected for lows by early Thursday morning. The passing trough will bring another influx of low level clouds and perhaps a few showers across northeastern Kentucky through the morning. Clouds will hang tough through the day, gradually diminishing from southwest to northeast in the afternoon. Highs will be some 25 to 30 degrees colder compared to today, with upper 40s to lower 50s expected. Skies will clear out Thursday night, as high pressure builds in from our northwest. Lows will dip to around the 30 degree mark in the valleys, with areas of frost likely. Will continue to highlight this concern in the HWO. .LONG TERM...(Friday through Wednesday) Issued at 340 PM EDT WED APR 18 2018 An area of surface high pressure is expected to be centered across the Upper Midwest on Friday and upper level ridge will progress east with the surface high Saturday. This will lead to a period of mostly clear skies and dry conditions through the first portion of the long term period. The temperatures will modify through the weekend, but does remain cold enough for Friday night into Saturday morning to lead to frost. Then a southern stream upper level low will progress out of the four corners into the Lower Mississippi River Valley by Sunday afternoon. The model guidance has struggled with continuity and consistency, with regards to the southern stream system. The GFS has leaned the wettest for the late weekend and the other models have leaned wetter toward Monday and Tuesday time frame. This becomes further convoluted as we see phasing potential by early to middle of next week. Given the lower confidence leaned toward the blended guidance which brings slight to chance POPs slowly north late Sunday into Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 841 PM EDT WED APR 18 2018 VFR conditions still prevailed at the start of the period, but changes are on the way this evening. A cold front was over central KY, with a narrow area of showers and isolated thunderstorms along it. The front will move southeast through eastern KY tonight. The thunderstorms area expected to diminish before the front arrives in eastern KY, but showers will likely persist. A period of MVFR is forecast near the front. Many areas could see an improvement back to VFR for a time tonight, before another fall to MVFR which is expected to affect the region overnight and into Thursday morning. Clouds are expected to clear out and allow a return to VFR conditions on Thursday afternoon. Gusty southwest to west winds will continue tonight, with a peak near and just behind the cold front. A few gusts could top 30 kts, but they are not likely to be persistent. An overall lessening of winds is forecast for late tonight and Thursday. && .JKL WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 2 AM EDT Thursday for KYZ044-050>052-058>060- 068-069-079-080-083>085-104-106-108-111-114. && $$ UPDATE...HAL SHORT TERM...GEOGERIAN LONG TERM...DJ AVIATION...HAL is the U.S. government's official web portal to all federal, state and local government web resources and services.