Area Forecast Discussion
Issued by NWS Jackson, KY

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278 FXUS63 KJKL 230720 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 320 AM EDT Sun Apr 23 2017 .SHORT TERM...(Today through Monday) Issued at 320 AM EDT SUN APR 23 2017 06z sfc analysis shows a deep southern low passing by just to the south of Kentucky. This low is responsible for the series of waves - consisting of showers now - pushing across southern Kentucky this weekend. Currently there is a lull between these waves, even so sprinkles and drizzle are found across much of the CWA this night. Low clouds blanket the southern half of the area while in the far north they have actually cleared out. Winds are from the north to northeast at 5 to 10 mph locking in the colder air. Temperatures this night are running from near 45 degrees - dewpoints in the upper 30s - north to the lower 50s in the far south - dewpoints around 50. The models remain in good agreement aloft through the short term portion of the forecast. They all depict a developing and closing off low moving into the Tennessee Valley and then continuing south - rolling through the deep south. The models are quite similar with the magnitude, placement, and timing of this low lending a good deal of confidence to their consensus forecast. Accordingly, have favored the CONSShort model blend for most GFE weather elements with special attention to the high resolution components in the short term. Sensible weather will feature a renewed surge of moisture and showers pushing north into the CWA towards dawn and continuing through the bulk of the day. The heaviest showers and higher QPF are anticipated through the areas that remain under a Flash Flood Watch. This may be able to be cleared earlier in the afternoon in the west, but will likely be needed through 4 pm in the eastern part and possibly longer. For now, will hold to the current timing for this headline and pass on to later shifts to watch for a need to extend it later in the east. Otherwise, cloudy, rainy, and cool weather will be the rule today and into the evening for a good portion of the area. The exception may be locations north of Interstate 64 where some sunshine may be seen early this morning and then later filtered through the clouds - but still seasonably cool. On Monday, the sfc low should be far enough east that drier starts to make its way into the area and dry us out from northwest to southeast - allowing temperatures to recover to a bit closer to normal for this time of year. Again started the grids from the CONSShort and ShortBlend guidance set through this part of the forecast. Did not make much adjustment to temperatures or dewpoints given the limited diurnal range over the next 36 hours. However, did again beef up PoPs and QPF, from the blend, across the south given the certainty for measurable rain from yet a couple more surges of shower activity during this time. .LONG TERM...(Monday through Saturday) Issued at 335 PM EDT SAT APR 22 2017 Models are in decent agreement through the extended with mid/upper level flow. In general, the southern Appalachian region will fall under the influence of mean southwesterly flow aloft. That would indicate warmer weather than not, and an occasional shot at showers and thunderstorms should any disturbances in the mean flow get close enough to affect our area. One such disturbance does appear to skirt just close enough to provide a chance of showers Wednesday night into Thursday. Forecast soundings suggest instability is lacking but considering the time of year, will maintain inherited Isold thunder for this time frame. When compared to the ECMWF and Canadian, the GFS is somewhat of an outlier towards the end of the extended window with the potential of a second disturbance. The ECMWF and Canadian swing this second disturbance through the area by late Friday into Saturday, though the ECMWF is much more subtle with this feature. Once again forecast soundings indicate instability is lacking, but considering the synoptic pattern feel it would be prudent to maintain at least a slight chance of thunder. Sensible weather will seem closer to a summer like pattern than spring with temperatures averaging some 5 to 10 degrees above normal. Temperatures warm nicely through the week, with highs climbing into the lower to mid 80s for much of the week. Lows fall generally in the upper 50s to lower 60s each night. Outside of the two disturbances mentioned earlier, any chance for rainfall would be quite low based on soundings as a substantial cap appears to be in place for most of the period. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 200 AM EDT SUN APR 23 2017 Main concern for aviation through the rest of the night will be low cigs in the LIFR or IFR range but with the showers in a lull through dawn, some cigs may briefly bounce up to MVFR. The next surge of showers will push in from south to north during the day Sunday with cigs bouncing between low MVRF and IFR and times of visibility down to MVFR. SYM will have the best shot at remaining VFR through Sunday night as the main influence of the weather system passing by to the south wanes for locations north of a JKL to SJS line. Winds will remain north to northeast through Sunday night with speeds averaging around 5 kts but up to 10 kts at times. && .JKL WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through this afternoon for KYZ079-080-083>088- 110-113-115>118-120. && $$ SHORT TERM...GREIF LONG TERM...RAY AVIATION...GREIF is the U.S. government's official web portal to all federal, state and local government web resources and services.