Tan-Tar-A Snow Report

145 FXUS63 KEAX 220400 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 1100 PM CDT Fri Aug 21 2026 ...06z Aviation Discussion Update... .KEY MESSAGES... * Low confidence forecast tonight with scattered showers and thunderstorms across central into eastern Kansas. Stronger storms would be capable of producing damaging winds and possibly large hail. * Cooler and drier conditions Saturday into Sunday, with periodic storm chances returning as early as Sunday night. && .DISCUSSION... Issued at 241 PM CDT Fri Aug 21 2026 18Z sounding from OAX shows steep mid level lapse rates from 700-500 mb leading to elevated instability. Dry layer below 600 mb leading to reservoir of downdraft CAPE of 1000-1500 J/kg. Cluster of storms that developed in north central Nebraska has somewhat maintained their strength working to the southeast toward the I-80 corridor. Low confidence forecast for tonight as back door cold front associated with low pressure center near the Great Lakes slides south. Instability is largely controlled by the lifting level, but if we are able to get a near surface based storm, there would be enough instability (3000-3500 J/kg) to create the potential for large hail especially with 40-45 knots of effective shear. If storms remain more elevated, the greatest severe threat would be damaging winds owing to the dry air below 600 mb. Models offer a variety of solutions with these storms this evening. It appears the atmosphere is at least weakly capped (cin 50-100 J/kg) across northwest Missouri, with an increasing cap farther south. It is unclear have long the storms would be able to maintain themselves, but some solutions suggest storms trying to build southeast through the evening hours along and west of the Missouri River Valley. Lee troughing across eastern Colorado is expected to become better organized tonight into a weak low pressure center that develops in western Kansas. A weak low level jet extending from central Oklahoma through central KS into western Nebraska is expected to lead to strong theate-e advection and additional thunderstorm development tonight. These storms are expected to move southeast overnight in northwest flow aloft building into central and eastern KS overnight. It appears these storms may primarily remain west of the forecast area, but eastern KS into far western Missouri may get brushed by any activity with the potential of large hail and damaging winds with any storm that is able to sustain itself this far east. Cooler and drier conditions are expected to build south across the region Saturday and continue into Sunday as Canadian high pressure noses into the region. Long standing ridge across the western US has periodic ridge riders that may lead to periodic chances of showers and thunderstorms. The first wave moves through the region Sunday night, with additional storms possible Wednesday morning. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 1054 PM CDT Fri Aug 21 2026 Predominantly VFR conditions are expected to prevail, but have introduced PROB30s for potential shower activity around/after 12z Saturday. Prior to that potential, light and variable winds will prevail across the TAF sites and eventually yield a more prevailing NE direction. Model/CAM guidance continues to keep much of the shower/storm activity west of the terminals, but there is enough of a hint of potential to introduce PROB30 mentions with this iteration. At this time, have kept thunder mentions out with much of the depicted activity rooted quite high and with limited instability. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...BT AVIATION...Curtis