292 FXUS63 KEAX 272306 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 606 PM CDT Sat Apr 27 2024 .KEY MESSAGES... - Another round of severe storms possible this afternoon and evening. All severe hazards are possible during the day with a trend to flooding/ flash flooding overnight. - Strong to potentially severe storms linger into Sunday. - Unsettled pattern continues Tuesday through the end of next week. Best potential for additional severe storms is Tuesday afternoon and evening. && .DISCUSSION... Issued at 243 AM CDT Sat Apr 27 2024 Today - Tonight: Satellite and radar imagery early this morning show what is likely an outflow boundary draped from northeastern MO southwestward over the KC area and then into eastern KS. It's possible this could be the cold front but there isn't much of a temperature/dew point difference across it. Regardless, models have not initiated this boundary well and are too far north with it. The boundary will stall close to where it is as of ~08Z. The RAP 305K surface shows this reasonably well. There will be enough forcing along this boundary that showers and storms should increase in coverage across northern MO through the morning hours. During the morning hours, when potential instability is weakest, the threat of severe weather looks to be low. Going into the afternoon and evening hours, as a very warm and humid airmass builds south of the boundary, CAPE values will increase substantially. Models vary on this as well but HREF probabilities show a greater than 90% chance for 2000+ J/kg of SBCAPE. There's even a 20% chance for SBCAPE to be greater than 3000 J/kg over eastern KS and western MO. Additionally, as upper-level flow increases, deep-layer shear will increase so we'll be staring down the barrel of a potentially 3000+ J/kg airmass with 40-50 kts of shear. If a storm can get going in the open warm sector, it will very likely become severe with all hazards possible. This still seems unlikely this far east and is much more likely further west, closer to the dryline. The region will also be in a favorable location of an anticyclonically curved upper jet with strong diffluence noted over the forecast area on streamline plots. In the lower-levels, a strong low-level jet will increase in the evening with intense moisture transport nosing right into eastern KS and western MO. This all points to an increase in coverage/ intensity of convection this evening with rounds of very heavy rainfall and flooding/ flash flooding likely into the overnight hours. Sunday - Sunday Night: Saturday night's convection will bleed into Sunday as the low-level jet shifts eastward through the day and the diffluent upper flow persists. With convection ongoing at the start of this period, and then continuing through the day, we'll struggle to rebuild the instability. CAPE values look to be at least half of what we saw Saturday and likely even less, potentially less than 1000 J/kg. While deep-layer shear will remain impressive, the weaker instability will limit the potential for severe weather. Monday - Monday Night: This period looks to be dry as the main trough that brought multiple rounds of severe weather to the region exits to the east and a drier airmass moves into the area. Mid to Late Next Week: Low-level flow returns to a southerly trajectory Monday night into Tuesday. That will advect moisture back into the area just in time for the next front to interact with it Tuesday. The warmer and more humid airmass will lead to moderate instability with potentially 2000+ J/kg of MLCAPE Tuesday afternoon. With 30-40 kts of deep-layer shear, can't rule out additional chances for strong to severe storms. Unsettled weather will likely continue through the end of the week as the area remains in a humid airmass with multiple shortwave troughs moving through the flow. This will be resolved better (and this forecaster will have more time to look at it) in the coming days. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 604 PM CDT Sat Apr 27 2024 Scattered thunderstorms becoming more widespread across the metro through 04Z. Convection is expected to shift focus farther to the southeast this evening. Potential for strong wind gusts and large hail in the thunderstorms. MVFR stratus develops behind the convection, and lingers through at least mid-day Sunday with breezy south winds continuing. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through Sunday afternoon for MOZ001>008-011>017- 020>025-028>033-037>040-043>046-053-054. Wind Advisory until 7 PM CDT this evening for MOZ011-012-020. KS...Flood Watch through Sunday afternoon for KSZ025-057-060- 102>105. Wind Advisory until 7 PM CDT this evening for KSZ025-102. && $$ DISCUSSION...CDB AVIATION...Collier