Area Forecast Discussion
Issued by NWS Jackson, KY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KJKL 101854 AAC AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 154 PM EST Sun Dec 10 2017 .UPDATE... Issued at 1139 AM EST SUN DEC 10 2017 Hourly grids have been updated based on observation and satellite trends. The northern third to half of the area should experience a band of mid level clouds working through during the afternoon and sky cover has been adjusted accordingly. Even with the increased cloud cover, forecast max T still appears to be reachable. UPDATE Issued at 637 AM EST SUN DEC 10 2017 The forecast is still on track this morning. Partly cloudy skies and southwest winds at 5 to 10 mph are expected to persist through out the day today. The latest obs were ingested into the forecast grids to establish new trends. No forecast update at this time. && .SHORT TERM...(Today through Monday) Issued at 300 AM EST SUN DEC 10 2017 Low and middle level cloud cover will linger across portions of eastern Kentucky this morning, as an area of low pressure aloft continue to pull off to the east of the area. Partly cloudy skies will be on tap all day today. Temperatures will remain quite cold, with highs forecast to reach the mid to upper 30s for most locations today. A modest warm up is then on tap for tonight and Monday, with tonights lows expected to only fall into the mid to upper 20s for most locations, and highs on Monday ranging from the lower 40s in the far north, to the mid to upper 40s most everywhere else. A ridge of high pressure will keep skies partly cloudy to mostly clear through the first of the week. Winds will start off fairly light this morning, and should increase to 5 to 10 mph out of the southwest by this afternoon. .LONG TERM...(Monday night through Saturday) Issued at 440 AM EST SUN DEC 10 2017 The models continue to be in good agreement with the overall pattern aloft through North America in the extended portion of the forecast. However, the smaller features moving through the longwave pattern are still exhibiting fairly large model spreads - particularly heading into the next weekend. Early on, a compact shortwave will run through the base of the larger Great Lakes trough. This will move through the lower Ohio Valley by Tuesday morning - stronger in the NAM12 and ECMWF than the GFS. Additional energy follows by evening as the core of the main upper low descends into the northern Ohio Valley with decent model consensus. Sharp height fall accompany this energy through Kentucky on Tuesday before relaxing that night and Wednesday as the parent 5h low pivots east into northern New England. The ECMWF takes a trailing shortwave through the region, but dampening it as it moves into Kentucky Thursday morning. Meanwhile the CMC and GFS do not have much reflection of this feature lowering confidence in its potential impact. There is better model support, at least from the GFS and ECMWF, for a resurgence in troughing coming out of the Plains later that day and into Friday. This trough becomes full latitude with ample energy swinging toward the area on Friday, though the ECMWF maintains the core of the trough better than the GFS and more to the south of the area later that day and into Saturday morning. The pattern again relaxes in the wake of this trough for Saturday with heights rebounding throughout the Ohio Valley - though another fast moving wave will be inbound later that night - this time targeting more the northern half of the region. Given the continued model discrepancies and limited support for key features will again favor a general model blend, but with added enhancement for our terrain toward more climatological norms for this type of cold and generally northwest flow pattern. Sensible weather will feature another couple of clipper systems affecting the area during the bulk of the extended with bouts of very cold air moving through, as well. The next one of these passes through the Ohio Valley Monday night into Tuesday morning. Upslope flow will again kick in by midday Tuesday in this clipper`s wake with enough moisture around to generate scattered snow showers of varying strength similar to the system that brought snow to the area yesterday evening. The difference will be likely more wind but also more insolation to help limit the refreeze potential on the roads, though with sunset icy spots will again be possible but the bulk of the snow showers should have moved on to the east by then. Very cold air and still some northwest breezes around that night will make for rather low wind chill values into Wednesday morning. Drier weather does return for Wednesday but another clipper will be approaching by that evening. This one looks to be weaker with less wind and upslope as it passes through the region on Thursday but with more in the way of moisture it could actually yield better chances for snow/rain into that night. Some upslope does eventually develop for Friday with snow showers potentially lingering through the day. A WAA pattern then sets up through the area Friday night into Saturday on the backside of a southeast High. Did make some minor, terrain based, changes to the low temperatures Wednesday and Friday night between clippers with a potential for ridge to valley temperature splits. Again refined the SuperBlend PoPs to reflect the more typical pattern with these northwest flow clipper systems in holding PoPs back over the higher terrain in the east longer and more detailed than provided by the blends. && .AVIATION...
-- Changed Discussion --
(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 135 PM EST SUN DEC 10 2017 A surface high centered to the south and southeast of the area and mid level height rises through about the first 18 hours of the period should lead to vfr through the period. Models do have an increase in low level moisture between 850 mb late tonight so some low stratus or stratocu cannot be completely ruled by the 6Z to 9Z or after, but confidence in this was too low to include at this time due to lack of model blended guidance and mos guidance support. Winds should average out of the southwest nearing 10KT through around 23Z especially on ridges and in more open terrain locations, with locations outside of valleys generally in the 5 to 10KT range also from the southwest through the end of the period.
-- End Changed Discussion --
&& .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...AR LONG TERM...GREIF AVIATION...JP is the U.S. government's official web portal to all federal, state and local government web resources and services.