Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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552 FXUS63 KJKL 031158 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 758 AM EDT Wed Jul 3 2024 .KEY MESSAGES... - Sultry weather continues today through Friday. Afternoon heat indices may reach near 100 in some locations. - A potential for showers and thunderstorms arrives tonight and lasts at least into Friday night as a frontal boundary stalls in the area. - A cold front finally pushes through as we move into the weekend, with dry and somewhat cooler and less humid weather arriving. && .UPDATE... Issued at 758 AM EDT WED JUL 3 2024 Have blended early morning obs into the forecast without any substantive changes. && .SHORT TERM...(Today through Thursday) Issued at 603 AM EDT WED JUL 3 2024 Upper level high pressure centered over the Deep South is ridging northeast over the Appalachians and New England early this morning. Shortwave troughs rippling through the prevailing westerlies aloft north of the high will suppress the ridging southward during the short term period, and somewhat stronger westerly flow aloft will drop south over KY. The evolution of the upper level pattern will allow a cold front to move as far south as the Ohio River tonight before it becomes largely parallel to the upper level flow and stalls. Showers/thunderstorms near the front may make it into the forecast area tonight, with the greatest probability being in our northern counties. The highest probability of showers/thunderstorms will be during the day Thursday over the northern portion of the forecast area as heating/destabilization occurs and a weak wave ripples through the upper level flow above the nearby surface frontal boundary. Deep layer moisture will increase over the area as the ridging aloft is suppressed and mid-upper level blow-off from earlier convection advects over us. Models show precipitable water nearing or exceeding 2 inches arriving from the north northwest tonight and Thursday. Thunderstorms in this environment would be efficient rainers and should they train, could cause localized hydro problems. .LONG TERM...(Thursday night through Tuesday) Issued at 255 AM EDT WED JUL 3 2024 The forecast period will begin with mean upper-level zonal flow but a digging shortwave moving through upper-Mississippi valley will eject into the Great Lakes. At the surface, a stationary boundary is draped across the CWA keeping chances of PoP across the area to start the period but to the west, the aforementioned shortwave will bring a renewed chance of PoP as a surface cold front approaches the area. Along and ahead of the front, showers and thunderstorms are likely through the day Friday into Saturday before the front exits Saturday evening. Severe chances look to be largely limited with FROPA as widespread cloud cover will inhibit instability and shear is fairly weak ahead of the boundary. However, can`t rule out an isolated severe thunderstorm with FROPA during the day Friday. Also, there`s forecast 90-99th percentile above climatological precipitable water values, 2.10" to 2.30", through FROPA is expected. Which, if these showers and storms are efficient, heavy rainfall leading to possible hydro issues could be possible before the front exits on Saturday. High pressure builds in for Sunday into Monday before another double- barreled surface low sets up for next week. The first is another shortwave developing in the upper-Mississippi Valley and ejecting into the Great Lakes with a cold front crossing through the Commonwealth. The second feature is a weak surface low riding along a low-level jet streak. The second feature will bring increasing showers and thunderstorms to the region Monday afternoon before the first system drags a cold front through the region on Tuesday. Showers and thunderstorms are forecast to persist through the day Tuesday and linger through the remainder of the forecast period. Overall, the period will highlighted with periods of showers and thunderstorms that`ll bring much needed rain to the area. Also, temperatures will return to more seasonal ranges as daytime highs in the mid-80s to low-90s and overnight lows ranging from the upper-50s to upper-60s. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) ISSUED AT 758 AM EDT WED JUL 3 2024 Very limited valley fog is currently dissipating. Outside of this, VFR conditions are expected today and will last at least until this this evening. A few thunderstorms (with sub-VFR conditions) can`t be ruled out tonight, with the greatest probability being north of I-64. Winds will mainly be from the south to southwest at around 10 kts or less during the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...HAL LONG TERM...VORST AVIATION...HAL