Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
Issued by NWS Kansas City/Pleasant Hill, MO
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878 FXUS63 KEAX 081737 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 1237 PM CDT Wed May 8 2024 .KEY MESSAGES... - Rounds of thunderstorms are possible today mainly along and east of a line from Harrisonville to Chillicothe. Very large hail and wind gusts to 60 mph can be expected with the morning storms, while very large hail, strong winds, and a tornado or two are possible this afternoon. - Additional showers/non-severe thunderstorms are expected across northern Missouri on Thursday. - A warming trend is expected through the weekend, with the threat of thunderstorms returning by the end of the weekend. && .DISCUSSION... Issued at 337 AM CDT Wed May 8 2024 Sit and spin upper level low centered across the western Dakotas is expected to fragment today as one of the main shortwaves rounds the base of the trough and pushes east tonight into Thursday. Across eastern Nebraska/eastern Kansas, mid level cloud cover has built overnight with strong isentropic lift near the 300K surface. Area of low pressure has moved into south central Kansas into north central Oklahoma. Warm front with this system has worked into southwestern Missouri as of 08Z, noted with an increase in moisture (dew points of 60+ F) south of the boundary. This boundary is expected to continue to lift north this morning, the increasing low level moisture is expected to reach the edge of the cap. With very steep lapse rates from 700-500 mb and 1-6 km bulk shear values of 40-50 knots overhead, expect storms that develop to be capable of very large hail (>2" in diameter) and possibly a strong wind gust or two owing to the mid level dry air. These storms are expected to move to the eastnortheast around 40 knots, but with very linear hodographs, there is the potential for splitting storms with left movers building into the southern portion of the forecast area (east of I-49 and south of I-70). CAMs suggest convective initiation between 9-12Z this morning. Building low level moisture will favor a loaded gun sounding with increasing instability with the very steep lapse rates remaining from 700-500 mb (in excess of 8 C/km). If the atmosphere is able to become capped for a time frame ahead of an approaching short wave, CAPE values may approach 1500-2000 J/kg with the strong shear remaining. Storms this afternoon could be closer to being surface based, bringing all severe hazards into play. Positioning of the boundary will be critical in terms of figuring out the precise threat area, but the greatest threat appears to be east of a line from Harrisonville MO to Chillicothe and areas east. For forecast highs today, sided close to the mean in areas west and north of the convection, with slightly cooler highs across central Missouri that could see storms throughout the day. As the area of low pressure shifts east this evening, northwest winds develop across the region. Cooler air returns to the region, but expect the chances for showers and perhaps a thunderstorm or two to increase across northern Missouri on Thursday as short wave associated with the northern branch of the jet builds south across the Upper Midwest. The low clouds and precipitation will keep temperatures cool across northern Missouri, while areas farther south warm a bit more closer to normal. Quieter weather is expected on Friday as high pressure builds south across the western Great Plains. As this ridge builds south and eventually east, temperatures should gradually warm through the weekend. Increasing south/westerly winds will lead to moisture building back into the region on Sunday. As a lingering fragment of the upper low builds east from the desert southwest, could see a renewed threat for additional showers and thunderstorms late Sunday into early next week. With weaker wind shear, the threat for severe weather looks to possibly be less than today. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1237 PM CDT Wed May 8 2024 A brf pd of MVFR cigs will cont at MCI and MKC thru 19Z otrw...bkn cigs btn 3-4kft are expected thru 21Z when cigs will sct out. VFR conds are expected thereafter. Winds will be out of the ESE btn 5-10kts thru 21Z wind they will shift to the north. Aft 01Z...winds will become NW while remaining btn 5-10kts. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...BT AVIATION...73