Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
Issued by NWS Kansas City/Pleasant Hill, MO
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413 FXUS63 KEAX 090818 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 318 AM CDT Sun Jun 9 2024 .KEY MESSAGES... - A complex of showers and thunderstorms moves through the area overnight. Much of the activity will remain south of Interstate 70. Primary threats are for heavy rainfall leading to potential flash flooding. Isolated strong to severe storms with damaging winds and hail cannot be ruled out in the short term. - Cooler conditions expected Sunday with a drier pattern anticipated through the first half of the work week. && .DISCUSSION... Issued at 318 AM CDT Sun Jun 9 2024 Thunderstorms developing along a CAPE boundary draped across southwest MO. The low level jet looks like it has not migrated as far north as initially anticipated which has resulted in the line of storms developing a little further south. The good news about this is that this area did not receive as much rain from the showers and thunderstorms that moved over the area Friday into Saturday. However, RFC flash flood guidance still resides around 1.5 to 2 inches per hour and 2 to 3 inches per 3 hours. With PWAT values ranging from 1.5 to over 2 inches, those rain rates are plausible as storms are expected to be highly efficient rain producers. With storm motions being from west to east parallel to the orientation of the front, this sets up a situation where storms will train over areas for several hours. A Flash Flood Warning has already been issued for Linn County KS as a radar estimated 2-4 inches of rain has fallen resulting in exceedance of the earlier mentioned flash flood guidance. Over the course of the night, more stratiform precipitation is expected to move in from the west. The CAPE gradient which the thunderstorms current reside, sags southward. More robust convection across central KS is expected to follow this gradient and likely pass south of the area. A few strong storms may clip the souther portions of the coverage area bringing brief moments of torrential rainfall. As the MCV tightens up, stratiform precipitation is expected to expand northward potentially enveloping the KC metro and some areas north of I-70. Rain rates with this broad precipitation are expected to be less; however, an isolated patch of heavy rainfall cannot be ruled out. While flooding concerns are relatively decreased compared to 24 hours ago, the potential for pooling and ponding in urban areas remains. Please exercise caution if traveling as flooded roads may be difficult to see at night. This system is expected to move out the area during the post sunrise hours with some lingering showers possible through mid morning. Northwest flow and midlevel high pressure then start dominating the forecast regime. This results in cooler and drier conditions. Saturday brought a little taste of summer with dew points around 70 degrees. Fortunately, Sunday looks to be more pleasant with dew point sinking back into the mid to upper 50s. Highs range in the upper 70s to low 80s. The upper level pattern continues this northwesterly pattern for the early part of the week. Interestingly, part of the reason in the pattern stagnation is due to a cutoff low pressure that stalls off the southern CA coast. This shifts westerly flow across the northern Rockies which is then turned toward the southeast due to a stout low across the NE CONUS. Model guidance has been hinting at a small embedded shortwave creating a leeward cyclone Tuesday; however, there remains much uncertainty on the track and intensity of this cyclone. At the moment, it is looking like the system and associated rainfall will miss the area. The cut off low looks to reintegrate into the overall upper level pattern toward the end of the week setting up for a return of showers and thunderstorms for the upcoming weekend. Reopened southerly flow to the Gulf increases plausibility for strong thunderstorm, but it is too far out to speculate at this time. Extended guidance is pointing toward a pattern shift as the summer solstice approaches. Namely, an expansive high pressure building across the central and southern CONUS resulting in hotter and drier conditions. However, models have not given up on embedded shortwaves and leeward cyclones bringing further rainfall chances; keeping the dog days of summer at bay for the time being. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1217 AM CDT Sun Jun 9 2024 VFR conditions prevail through most of the period. Rain showers are anticipated within the first few hours of the TAF period, with model guidance keeping the most intense rain south of the sites. Ceilings associated with rain showers do have the potential to briefly lower to MVFR thresholds, but uncertainty remains with this possibility. Skies are expected to clear starting around 15Z Sunday morning. Clearing is expected to start earlier for STJ. Winds will be out of the northeast around 5-10 knots, becoming slightly more northeasterly as the TAF period progresses. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Pesel AVIATION...Hayes