112 FXUS63 KEAX 120649 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 149 AM CDT Thu Jun 12 2025 .KEY MESSAGES... - Hot and humid conditions continue this afternoon. Some isolated showers and thunderstorms are possible mainly north of I-70 and east of US-63. - Scattered showers and thunderstorms return Thursday and Friday; heavy rainfall is possible, but no severe weather is anticipated. - Hot and humid conditions with isolated showers and storms continue through the weekend into early next week. && .DISCUSSION... Issued at 202 PM CDT Wed Jun 11 2025 The synoptic pattern is dominated by relatively zonal flow across the northern CONUS and a nearly cut off low across west Texas. Ridging just ahead of this trough keeps much of Wednesday relatively quiet, but the tight corridor between this ridge and the low to the west propels warm air and moisture into the region. This increased relative humidity ushers in hot and muggy conditions. Temperatures this afternoon have easily crested the mid-80s with much of NW MO reaching into the low 90s. Dew points ascend into the mid to upper 60s throughout the region. Heat index values rise into the mid-90s given us our first taste of summer heat. While this heat may not be the most hazardous, it is important to take the heat into account if you will be doing prolonged outdoor activities. Warm air and moisture continue to flow into the region as the low slowly migrates east. Satellite is showing the development of CU across NW MO suggesting destabilization of the atmosphere across that region. CAMs have been routinely showing chances for isolated convection across the region this evening. Guidance has been suggesting some broad scale surface convergence combined with ample 500mb vorticity convection moving over the region later this afternoon. With the lack of a cap thanks to the warm temperatures, there is not really anything stopping the atmosphere from convecting if that CVA is able to create lift to the surface. CU development over SW MO combined with slight surface convergence between STJ and EZZ add confidence to the isolated storm potential. There remains a lack of strong thermal of kinematic boundaries which precludes strong organized convection. Ample instability with a lack of shear or discrete lifting mechanism support weaker air mass thunderstorms; however, it would not be entirely surprising if a couple of these storms get fairly robust with small hail and gusty winds those MUCAPE values near 3000 J/kg and lapse rates approaching 7C/km in the lower part of the vertical profile. The notable lack of shear likely keeps these storms from reaching severe criteria or maintaining themselves much past sunset. Thursday the low continues to progress toward the north and east. The pressure gradient between it and a high over the Gulf creates a small jet streak which boosts the warm air and moisture advection. This also manifests a surface warm front across the I-44 corridor which lifts northward through the afternoon. Scattered showers and thunderstorms proceed northward with this warm front stalling near the I-70 corridor as the center of the cyclone pivots eastward across the Ozarks. Limited forcing from relatively weak thermal boundaries keeps coverage fairly scattered with weak shear and less instability keeping severe potential marginal. However, PWAT values hover between 1.5 and 2 inches bringing the potential for concentrated heavy rainfall. Storm motion vectors parallel to the boundary present the opportunity for training storms which could lead to localized flooding. Again, the primary limiting factor will be the coverage of said storms, but the chance for storms to bring potentially torrential downpours exist. This environment jaunts NE Friday as the center of the low traverses SE MO. Heavy rainfall remains the primary threat as PWAT values remain above 1.5 inches across the state. The good news is storm motions look to be slightly more transient across much of the area lowering the flood threat; however, this is conditional on how previous QPE may lower flash flood guidance lessening the rain amounts needed to potentially flood. CAPE and shear remain rather meager limiting much of the severe potential. This hot, humid, and muggy environment continues for the next several days. Upper level flow turns northwesterly through the weekend bringing "cooler" air into the region. Highs persist in the upper 80s touching 90 degrees over the next several days. Dew points hold fairly steady in the upper 60s to low 70s keeping the sticky conditions around. Ridging begins to dominate the synoptic pattern as a high across the desert SW tries to work its way into the central CONUS. Slight NW flow aloft inhibits this movement and looks to trend temperatures in the upper 80s to 90 degrees. Long term guidance does keep the pattern relatively active with multiple shortwaves traversing the flow with the next substantial wave moving through next Tuesday bringing more rainfall opportunities. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 100 AM CDT Thu Jun 12 2025 Currently VFR conditions with light southerly winds at the terminals. These conditions should continue through the remainder of the morning hours and into the afternoon. A few isolated to scattered showers and storms may be in the area of the KC metro between 20z and 00z this afternoon, so have introduced a PROB30 group for -SHRA during this period. MVFR CIGs may develop by Thursday evening, but confidence was not high enough at this time to commit to it. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Pesel AVIATION...BMW