Area Forecast Discussion
Issued by NWS Jackson, KY

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000 FXUS63 KJKL 190605 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 105 AM EST Sun Nov 19 2017 .UPDATE... Issued at 1245 AM EST SUN NOV 19 2017 Will update the grids and forecast text products to drop the wind advisory for the western tier of counties at 1 am as the winds start to subside from west to east. The rest of the counties will see their advisory run until 4 am and the main zone package update. Did also fine tune the PoPs in the near term and add in the latest obs/trends for the T and Td grids. These have been sent to the NDFD and web servers. The updated ZFP, HWO, and NPW will follow shortly. UPDATE Issued at 1026 PM EST SAT NOV 18 2017 Issued an update to the forecast to input the latest observations and trend them into the night time hours. The line ahead of the front has weakened and evidence of lightning has disappeared and so have remove thunder from the forecast. Also adjusted pops according to the line progressing faster through the area tonight. Will keep a small chance pops through the night behind the front as some low level moisture will be slow to exit. With the colder air rushing in later tonight, some of the higher terrain to change over to snow. A new zfp has been issued with this update. UPDATE Issued at 615 PM EST SAT NOV 18 2017 Issued an update to the forecast to input the latest observations and trend them into the evening. Also fine tuned the timing of showers and thunderstorms into the area, The rest of the forecast remains on track. && .SHORT TERM...(This evening through Sunday night) Issued at 400 PM EST SAT NOV 18 2017 Gusty southerly flow continues this afternoon ahead of an approaching cold front. This cold front is poised to traverse the CWA between 22Z and 3Z, bringing with it a line of showers and thunderstorms. This line is fairly thin over western KY at the moment, though all the latest CAM models continue to be in good agreement that the line with lose strength and spread out as it moves towards eastern Kentucky. A few lingering storms are possible, but should be dissipating. That being said, any storms or heavy showers will have the potential to mix down gusts near 60 mph (severe potential) through the evening. Removed mention of thunder in the grids after 3Z. Otherwise, still expecting gusts between 35 and 50mph through the remainder of the afternoon and into the evening in the prefrontal environment. Once the front passes over, winds will become more westerly and lose magnitude, though will likely remain breezy throughout the remainder of the overnight and during the day Sunday. Westerly flow will also pull in much drier air. Precip is expected to taper off behind the front, especially after 6Z, however some showers and sprinkles could linger in the far east under this flow regime through Sunday morning. The influx of cold air could still cause some snow to mix in with the rain as it tapers off. The only place that this should have any impact will be the highest peaks, generally above 2,500 feet, where a few tenths of an inch of accumulation are expected. Actually lowered snow and QPF amounts from previous forecast since the trend has been to move precip/QPF out of the CWA faster. As we head into the day Sunday, a steep llvl inversion could keep some moisture trapped and lead to continued cloud cover throughout the day. This will interact with the cooler flow into the region, keeping temperatures from reaching 40 degrees in many locations Sunday afternoon. Breezy and cool will be the story for the day. Models show the clouds clearing out into the overnight Sunday night, however based on recent events, wouldn`t be surprised if they stuck around a bit longer. This could tamper with overnight lows. As it is now, if the clouds do clear in the first part of the overnight, as the models predict, temperatures could easily drop off into the mid 20s. Winds will lighten substantially and back to a more SW direction late in the night. This could lead to significant decoupling, with sheltered valleys dropping into the low 20s. Wouldn`t be surprised if this is even lower in some locations, but given the uncertainty about the clouds, did not go to aggressively. Definitely something to keep an eye on in the upcoming forecasts. .LONG TERM...(Monday through Saturday) Issued at 250 PM EST SAT NOV 18 2017 There is good model agreement with the evolution of the overall mean upper air pattern, but there are considerable differences in the details. This is not surprising considering we will be in a fairly progressive pattern through the coming week. The progressive pattern will result in a roller coaster pattern for temperatures from Monday through Saturday. Moisture will remain limited, with the next chance for rain not coming until next Saturday. The week will begin on a cold note, with an upper level trough axis to our east, weak upper ridging over the MS valley, and surface high pressure over the central and southern Appalachians. As the surface high shifts east from Monday into Tuesday and weak upper ridging builds over the area in advance of the next upper trough, we`ll see a quick warm up into Tuesday. That will be short lived as the next trough moves east and drives another cold front across the area Tuesday night. There will be very limited moisture with this front, and no precipitation is expected, but it will bring colder temperatures back to the area for Wednesday and Thanksgiving Day. Another warm up begins late in the week that will last into next weekend. Rain chances will return next Saturday as yet another cold front approaches the area. Looking just beyond the forecast period, indications are for another shot of cold air late next weekend. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 105 AM EST SUN NOV 19 2017 The main concern for aviation will be gusty winds and some MVFR to IFR cigs which will continue over the area through the rest of the night. These cigs will last through tomorrow morning before lifting around or just after 18Z as the last of the low level moisture moves out of the area. Winds will remain gusty through the night from the west at up to 35 knots, initially and then diminishing with time. By morning the west to northwest winds will be down to around 10 to 15 kts continuing fairly steady through the day. && .JKL WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 1 AM EST early this morning for KYZ044- 050>052-058>060-068-069-079-080-083-084-104-106-108-111-114. Wind Advisory until 4 AM EST early this morning for KYZ085>088- 107-109-110-112-113-115>120. && $$ UPDATE...GREIF SHORT TERM...JMW LONG TERM...SBH AVIATION...GREIF is the U.S. government's official web portal to all federal, state and local government web resources and services.