Area Forecast Discussion
Issued by NWS Jackson, KY

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000 FXUS63 KJKL 072018 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 318 PM EST Wed Dec 7 2016 .SHORT TERM...
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(This evening through Thursday night) Issued at 245 PM EST WED DEC 7 2016 Upper low north of Lake Superior will continue to move east across Ontario, with trailing upper trough axis over the plains shifting east. At the surface, cold high pressure will continue to nose east into the Ohio Valley. The upper troughing and surface ridging results in colder air working its way into KY, with lows tonight mostly in the upper 20s and highs on Thursday from the mid 30s to around 40, about 10 degrees cooler than today. Even with the trough shifting east, and the surge of colder air, there will be very little moisture available. The outside chance for a few flurries remains in the forecast for late tonight and early Thursday. Thursday night will be even colder than tonight, with lows in the upper teens to lower 20s. Some clouds will affect the northeastern part of the forecast area as a short wave trough swings by to our northeast. The clouds are not expected until late in the night, so temperatures should still fall off quickly in the northeast Thursday evening. If the clouds move in earlier than expected overnight lows would be warmer than current forecast in the northeast. There is still an outside chance for a few flurries in the northeastern part of the forecast area late Thursday night. .LONG TERM...(Friday through Wednesday) Issued at 318 PM EST WED DEC 7 2016 Models struggle right out the gate trying to capture strength and timing of progressive features in a broad mean trough, or nearly zonal flow pattern across the CONUS. First main shortwave disturbance to deal with will track quickly out of the Pacific NW and through the Plains, bearing down on the Ohio Valley region by sometime Sunday, or possibly Sunday night into Monday. The 12Z ECMWF is roughly 18 to 24 hours slower than the 12Z GFS with this first system. The 12Z Canadian keeps the middle ground, showing similar timing to the ECMWF while at the same time finding a way to support the GFS by picking up on some energy into the area a bit earlier on Sunday proper. The second main shortwave system to affect our area, similar to the first with respect to its track will drop into the region at the end of the extended window. The ECMWF is considerably weaker with this shortwave than the GFS but is similar in timing. For sensible weather, temperatures remain seasonably cold to below normal through the entire period. Models are still having difficulty with the details of Sunday`s system and forecaster confidence is low. This system appears to be trending slower overall. As such that may provide enough time for the column to warm so that the bulk of precipitation falls as rain. However, we still can not rule out a little wintry mix at the onset of precipitation. For our second system at the very end of the extended window, there is reasonable agreement that this next system will be colder. Still way too far out to say for sure, but this system may present our first real chance at some accumulating snowfall. Time will tell.
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&& .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1235 PM EST WED DEC 7 2016 An 30-50 mile wide band of broken to overcast cloud with MVFR ceilings continues to hold fast across southeast Kentucky from Lake Cumberland to Pike County. This should begin to lift and mix out by late afternoon, but MVFR ceilings should persist at LOZ and SJS through mid afternoon. SME should even see some MVFR ceilings for a short time. VFR conditions will prevail from tonight through Thursday. Winds will generally be light and variable through tonight, but become westerly Thursday morning at 5 to 10 knots. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SBH LONG TERM...RAY AVIATION...SBH is the U.S. government's official web portal to all federal, state and local government web resources and services.