Area Forecast Discussion
Issued by NWS Jackson, KY

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000 FXUS63 KJKL 280600 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 200 AM EDT Tue Mar 28 2017 .UPDATE...
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Issued at 145 AM EDT TUE MAR 28 2017 Updated the near term grids to reflect the departure of the bulk of the rain earlier in the night - though still allowing for a passing shower or two through dawn as the actual cold front moves across the area. Otherwise, have tweaked the T and Td grids per the latest obs and trends. These have been sent to the NDFD and web servers. UPDATE Issued at 1159 PM EDT MON MAR 27 2017 Have eliminated the thunder in the far east as the leading edge has moved into West Virginia and Virginia. Also freshened up the POP trends as the southern cold pool showers gradually move east and dissipate. Updates have been sent. UPDATE Issued at 1112 PM EDT MON MAR 27 2017 The severe threat is over, as the last of the storms will exit far eastern Kentucky before midnight, with just some cold pool showers following on its heels, as well as another area of showers affecting locations along and south of the Hal Rogers Parkway and Highway 80 corridors. These showers will exit southeastern Kentucky in the next few hours. There will be lull in the activity following this, until the surface cold front and short wave trough axis nears before dawn. Have allowed for an uptick in showers once again that will carry into Tuesday, before finally diminishing by Tuesday night. Patchy fog will also be seen overnight, especially in areas that saw locally heavy rainfall. Temperatures will not move much from current readings in the mid to upper 50s. UPDATE Issued at 843 PM EDT MON MAR 27 2017 Ongoing complex of strong to severe thunderstorms is gradually winding down as it heads east well ahead of the parent forcing. There are still pockets of severe wind gusts following a persistent lead supercell in the central portion of the forecast area. Expect a continuing gradual decline of this activity through 10 pm, with a lull in the action until a short wave trough axis approaches from the west overnight. This will likely bring an uptick in convection once again, but mainly just showers. Freshened up the POP timing based on the radar trends.
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&& .SHORT TERM...(This evening through Tuesday night) Issued at 440 PM EDT MON MAR 27 2017 A shortwave trough is expected to dampen as it moves into the OH and TN Valley regions through tonight and then across the Appalachians on Tuesday morning and then the Eastern Seaboard by the end of the period. At the same time, a surface low will track near or north of the OH River through this evening and tonight and then into the mid Atlantic states through the end of the period. Height rises and mid and upper level ridging area expected behind the shortwave with surface high pressure nosing into the OH Valley on Tuesday night. Isolated to at times scattered convection continues to move across parts of central and eastern KY in advance of more organized convection over western and west central Ky and western and middle TN. This earlier convection has produced some hail across the region and marginally severe hail and some wind would appear to be a threat over the next couple of hours. MLCAPE of 500 to 1000 J/KG over the far south and MUCAPE of 500 to 1000 J/KG across the area combined with 35 to 40KT of 0-6km shear would support this although much of the area has been worked over and the southwest part of the area should be the first to destabilize again per RAP and model forecasts though much of the western part of the CWA is expected to reach ML or MUCAPE near 1000 J/KG for a time in the west. Satellite trends would also support another window for heating in the south. The far southwest counties remain in a Severe Thunderstorm Watch through 3Z. Trends will continue to be monitored for Severe thunderstorm chances further east, but much of this area has received convection this evening or in the case of the VA border counties has lower sfc dewpoints due to downsloping effects. Some of the convective allowing models bring the convection into east KY around 23Z to 01Z but weaken the eastern line segment as this will near sunset and boundary layer should begin to stabilize. The models generally take the westernmost line east or southeast with the recent HRRR runs favoring southeast while some previous runs brought some of that convection more toward Lake Cumberland. However, pending strength of cold pool, the first more northern line segment of convection may not weaken as quickly as models project as it moves in. Wind appears to be the primary threat with any of this convection with bowing line segments and possibly marginal hail from the strongest updrafts. Locally heavy rain will also be possible if storms could train in an area. Chances for thunderstorms will begin to diminish overnight with shower chances also decreasing late as well as the surface low tracks into the mid OH Valley and the cold front works into the area and the axis of the 500 mb trough approaches. Chances for convection will decrease through the day on Tuesday as the trough and low pressure system exit to the east and northeast and mid and upper level as well as sfc high pressure begin to build in. Low level moisture is expected to linger well into Tuesday night, but if the low clouds thin, radiational fog will be possible and subsidence could bring some stratus build down late Tuesday night. .LONG TERM...(Wednesday through Monday) Issued at 310 PM EDT MON MAR 27 2017 The extended period should once again feature good chances for showers and thunderstorms from late Thursday morning through early Friday evening. The trigger for this activity will likely be a slow moving area of low pressure that is progged to move across the Tennessee and lower Ohio Valley regions. The slow forward motion of the system should keep rain in eastern Kentucky through Saturday morning. Thunderstorm chances should come to an end around 0Z Saturday, as the best upper level support and overall lift should be east of the area as the low pressure system moves off to our east. The rain should begin quickly tapering off around dawn Saturday morning, with the rain being completely out of the area before noon on Saturday. The weather should remain dry from Saturday afternoon through late Sunday night, as an area of high pressure settles over the region. Our next round of rain could move into eastern Kentucky very early Monday morning, but due a lot of uncertainty still exists that far out in the period. Temperatures will continue to run well above normal, with daily highs ranging from the mid to around 70 on most days. Thursday looks to be by far the warmest day, with forecast highs on that day in the 70s. Nightly lows should generally be in the 40s and 50s. && .AVIATION...
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(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 200 AM EDT TUE MAR 28 2017 Although a passing shower will still be possible through dawn, ceilings will gradually lower through the night - likely down to IFR levels, as winds shift from the southwest to west northwest behind a cold front moving through. Look for ceilings to marginally improve later today.
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&& .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JP LONG TERM...AR AVIATION...GREIF is the U.S. government's official web portal to all federal, state and local government web resources and services.