628 FXUS63 KEAX 150829 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 329 AM CDT Fri Aug 15 2025 .KEY MESSAGES... - Hazardous heat is expected over the next few days. Temperatures reach the low to mid 90s today with heat index values ranging from 100-105F. Temperatures climb into the mid 90s Saturday with much of the area seeing heat index values around 105F. - Pockets of cloud cover and isolated storms could affect the potential for hazardous heat in some areas. - Pattern shift expected Tues and Wed next week bringing rain chances and cooler temperatures. && .DISCUSSION... Issued at 328 AM CDT Fri Aug 15 2025 A large high pressure over the central CONUS continues to dominate the weather pattern. Southerly flow along the ridge axis amplified by diurnal heating and the low level jet continues to advect warm air and moisture northward. This axis is expected to slide a little eastward through the night channeling warm humid air into the region. Highs today jump up another 5-10 degrees with most places reaching the mid to upper 90s. Heat index values crest to 100-105 degrees. Diurnal heating taps into the midlevel flow mixing it to the surface gusting winds through the afternoon to around 15-25 MPH. Some uncertainties remain in today's temperature forecast as the spread between the 25th and 75th percentile lean slightly below or above typically hazardous heat criteria. A weakening MCS over western Nebraska is moving a cloud shield towards the east and is likely to envelope far northern MO this morning. Model guidance hints that this cloud shield gradually breaks up as it moves further east and the sun rises; however, the presence of clouds does present some uncertainty in hazardous heat north of I-70. CAMs present further uncertainty as 500mb shortwaves and a receding LLJ may initiate some showers and storms near sunrise across southern IA. This could reinforce portions of the cloud shield hampering temperature expectations. That said, HREF does suggest the potential for southerly winds to over perform base guidance boosting the flow of warm air into the region today. If winds lean toward the higher end of the forecast range, it is feasible for high temperatures to push the upper 90s, especially with small boosts from diurnal heating. A heat advisory has been issued for Friday afternoon for the entire region. Adjustments may be needed to the advisory area depending on the progression of clouds and potential showers overnight. Confidence is higher in hazardous heat Saturday as the ridge builds a bit northward. High temperatures reach the upper 90s with heat index values pushing 105 area wide. A boost of diurnal heating during the afternoon opens up opportunities for isolated convection Saturday afternoon. Overnight lows along the MO/KS state line bottom out in the mid to upper 70s bringing little relief from the heat, especially in the urban areas. A similar pattern is expected for Sunday. A separate Heat Advisory is in effect for 1 PM to 7 PM Saturday with the potential for this advisory to be extended through Sunday depending on forecast confidence. Forecast models continue to paint a complex picture for the next few days. Deterministic models paint a fairly broad reaching ridge depicting a fairly straightforward pattern for prolonged hazardous heat. However, CAM guidance is a taking into account more nuanced shortwave, LLJ, and diurnal interactions introducing the possibility for storms, mainly outside of the forecast area, of which remnant cloud cover could hampering later temperature expectations. Effects on hazardous heat expectations are expected to be relatively local to sub-regional in nature depending on the scope of any clouds and/or potential showers. The primary result of these uncertainties is heat advisories being more day to day than a blanket from X to Y time frame. A wholesale shift is expected this coming Tuesday into Wednesday when a cooler air masses is progged to descend from interior Canada enveloping the region as the antecedent high breaks down. This is likely to bring cooler conditions as well as the opportunity for showers and storms. Temperatures look to reset back toward seasonal normals in the upper 80s. Several uncertainties remain with the precipitation outlook which will become more refined with further forecast iterations. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 1033 PM CDT Thu Aug 14 2025 VFR conditions are expected (>95%) through the forecast with only high-level clouds streaming overhead. Winds increase some late morning into the afternoon with gusts of 20-25kts, then decrease near sunset. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening for MOZ001>008-011>017-020>025-028>033-037>040- 043>046-053-054. Heat Advisory from 1 PM to 7 PM CDT Saturday for MOZ001>008- 011>017-020>025-028>033-037>040-043>046-053-054. KS...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening for KSZ025-057-060-102>105. Heat Advisory from 1 PM to 7 PM CDT Saturday for KSZ025-057- 060-102>105. && $$ DISCUSSION...Pesel AVIATION...CDB