458 FXUS63 KPAH 171928 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 228 PM CDT Sat Aug 17 2019 .SHORT TERM...(Tonight through Monday night) Issued at 228 PM CDT Sat Aug 17 2019 A broad area of southwest low-level winds will keep hot and humid weather intact through the short term. Heat indices will peak between 100 and 105 each afternoon. Diurnal thunderstorms should be mainly isolated given the lack of forcing. A 500 mb high will strengthen somewhat over the southern Plains and lower Mississippi Valley, keeping the cold front at bay. In the immediate near term, a few thunderstorms will persist through late afternoon along an outflow boundary that extends from kowb west toward kpah. The boundary is becoming difficult to locate in visible satellite imagery, and it should dissipate by evening. The next chance of storms will be on Sunday, mainly from midday through the afternoon. Some of the cams models develop a convective complex over the Plains tonight, then bring it eastward into southern IL and southeast MO around midday Sunday. These models indicate the system will be decaying, and they dissipate the convection as it reaches the lower Ohio Valley in the afternoon. The 12z arw and nmm are two examples of this scenario. Given the time of day, it is likely isolated new storms would develop along any outflow boundaries from the decaying mcs. Any convection on Monday would be tied to diurnal heating since the 500 mb high will be strengthening over our region. A slight chance of storms will be mentioned in the forecast. Afternoon highs will be in the lower to mid 90s. Dew points will average in the lower to mid 70s, which is not quite as high as our most recent oppressive heat event. .LONG TERM...(Tuesday through Saturday) Issued at 228 PM CDT Sat Aug 17 2019 Tuesday will be an oppressively hot and humid day, with heat indices in the triple digits area wide, and near Advisory levels in the south. We're sandwiched between a weak boundary to the east, and high pressure to the north. Some isolated pm storm chances will be about the only relief from the heat that day and night. On Wednesday, it'll start out just as sticky, but clouds and an incoming front and its passage will be a game changer as we transition to a different airmass. Northwest flow energy will drive a cold front across the region during the day, and pops will spike along/with the front's entry/passage. The front makes its way to the south and east Wednesday night and Thursday, as we transition to northerlies that will begin to draw down our dew points and yield a little cool off in temperatures as well. The week is poised to end in this much more comfortable airmass, with dew points falling into the mid 60s and temperatures likewise making the 80s/60s for highs/lows to close out the week and begin the weekend. Storm chances Thursday thru Saturday similarly wane, but do not disappear necessarily altogether. We maintain a small chance for heat of the day potential, mainly along our southern counties, closer to the by then stalled frontal boundary. && .AVIATION... Issued at 1220 PM CDT Sat Aug 17 2019 An outflow boundary from this morning's thunderstorms over central Illinois has moved into the Ohio Valley as of 17z. Scattered storms along this boundary will affect the kevv/kowb area this afternoon. Winds will be locally gusty near storms. The southern end of the boundary may reach the kpah area before it dissipates. No activity is expected along this part of the boundary as it dissipates. Skies will be mainly clear tonight with light south winds. Some ground fog is possible around sunrise in the fog-prone low areas such as kcgi. Skies will be mainly sunny on Sunday morning, aside from some high cirrus clouds. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ SHORT TERM...MY LONG TERM...DH AVIATION...MY