FXUS63 KEAX 190354 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 1054 PM CDT Wed Sep 18 2024 ...Updated 06z Aviation... .KEY MESSAGES... - Well above normal temperatures continue through Friday. - Isolated strong to marginally severe storms will be possible tomorrow afternoon/evening. - Several rounds of showers and thunderstorms are possible this weekend into Monday. Locally moderate to heavy rainfall will be possible. - Much cooler temperatures are expected for early to middle of next week. && .DISCUSSION... Issued at 228 PM CDT Wed Sep 18 2024 Water vapor imagery overlaid with 500 mb heights shows a well defined closed low spinning over northeastern Montana with troughing extending southward into the central High Plains. Meanwhile, an anticyclone resides over northern Mexico with ridging and warm 850 mb temperature anomalies extending northward into the south central Plains. At the surface, a north south oriented cold front is draped across central Nebraska into western Kansas. This helped generate some showers and storms over Kansas this morning, but these dissipated well before encroaching on our region. Current conditions across the region are quite warm, with 3 pm temperatures in the mid 80s to as warm as 90 degrees with breezy southerly winds. The aforementioned closed low over NE MT continues to slowly move northeastward into southern Manitoba by late tonight, with a relatively strong south southwesterly low level jet projected to develop late tonight into early tomorrow morning across central and eastern Kansas into southeastern Nebraska, nosing its way into NW Missouri by mid tomorrow morning. This will likely develop some isolated to scattered convection overnight across eastern Kansas, moving eastward into our area (far eastern KS, western MO, NW MO) tomorrow morning and early afternoon. Mid level ridging strengthens tomorrow afternoon, with higher mid level heights overspreading the region. This will help send afternoon highs into the low to mid 90s for most locations. Additionally, increased moisture advection and pooling out ahead of the cold front should send dew points into the upper 60s to lower 70s. This will yield max afternoon heat indices in the mid 90s to potentially as warm as 100 degrees. This will also yield a corridor or moderate instability (2000 to 3000 J/kg of MU CAPE) tomorrow afternoon and evening. This will be paired with up to 30 knots of deep layer shear, and could yield some strong to marginally severe thunderstorms along and ahead of the surface cold front tomorrow afternoon and evening. On Friday, the northern trough continues its pivot northward into Canada. However, a new closed low and associated trough comes ashore into Southern California, with ridging remaining firmly entrenched over our region. Hot temperatures should continue, with highs in the low to mid 90s once again for most locations. The good news is that dew points should be much lower behind the weak cold front, so conditions for Friday afternoon should not be quite as uncomfortable. The western trough is progged to move across the Southern Rockies and into the Southern Plains by Saturday afternoon and evening. This will increase moisture return, and with increased forcing for ascent from the approaching trough, chances for showers and thunderstorms return to the forecast for Saturday. Chances increase even further Saturday night into Sunday as the trough and associated surface low makes its final approach into the area. With increased west southwest flow overspreading the region on Sunday, wind shear should increase to 40+ knots. This may allow for some strong to severe storms, and SPC has discussed the possibility of introducing 15 percent severe probabilities to portions of our area for Sunday. Relatively high PWATs will allow for the potential for locally moderate to heavy rainfall, and WPC has much of the region highlighted within a marginal risk for excessive rainfall for Saturday and Sunday. Total rainfall accumulations have trended down just a little bit, with 1 to 2" of rain forecast for much of the area for the weekend. Precip chances should largely come to an end from west to east on Monday as the cold front pushes through the area. Much cooler temperatures are also anticipated, with highs in the 70s forecast for Monday through Wednesday of next week. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 1051 PM CDT Wed Sep 18 2024 Most of the overnight hours will remain quiet, but will be watching showers west of the area moving through that could reach the terminals during the morning hours of Thursday. CAMs have been more consistent with activity, so have placed -SHRA in the metro TAFs this morning. Those should move out, and then will be waiting for redevelopment in the late afternoon. There is some potential for storms over the terminals, but storms could quickly move eastward. Overall, cloud bases look to be VFR. If a heavy rainshower moves over the terminal, this may result in brief MVFR or IFR conditions. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Williams AVIATION...Krull