768 FXUS63 KBIS 291807 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 107 PM CDT Mon Jun 29 2026 .KEY MESSAGES... - Isolated to scattered severe thunderstorms are possible this afternoon and evening, especially in central to eastern portions of the state. Main hazards will be hail up to 2 inches in diameter and wind gusts up to 70 mph, with an isolated tornado threat. - A gradual warming trend is expected through Friday with above average highs favored. A cooling trend back to near average highs is then favored for the holiday weekend. - Scattered showers and thunderstorms are possible as early as Thursday lasting through the holiday weekend. && .DISCUSSION... Issued at 104 PM CDT Mon Jun 29 2026 An impressive upper level trough sat over Montana and Wyoming early this afternoon with a jet rounding the base into the northern high plains. A surface low is centered over the central to eastern Dakotas, which will lift northeast as the upper jet continues to eject out over the plains through the evening. A lower level moisture gradient is a highlight of today's setup with 17Z surface dew points sitting at around 70 degrees in the warm sector, mainly near and east of a line that cuts north- south through the state (roughly going through Bismarck and just east of Minot). West of this line low level moisture is notably lower with a few non-severe thunderstorms rolling through this morning. Scattered convection is expected to redevelop this afternoon under the influence of the ejecting upper jet/trough. This incoming jet aloft will provide strong shear in the 50-60kt range with the wwarm sector's rich moisture bringing a conditional opportinity for adequate instability for severe weather. Early morning convection made the instability potential somewhat uncertain, though satellite trends at 17Z show pockets of clearing which should allow for an increasing trend in surface based instability. Supercells with the threat of very large hail and damaging wind gusts will be the primary threat, at least initially until some clustering and upscale growth likely occurs. A tornado threat will also accompany thunderstorms, especially towards the eastern portions of the state. The intensity of the overall wind shear cannot be understated and will allow for any storm that can tap into richer low level moisture to produce hail exceeding 2 inches in diameter or wind gusts exceeding 70 mph. As mentioned before the coverage may partially depend on how well earlier stratus can clear, with lingering clouds preventing full destabilization. Several rounds of severe convection will be possible as the upper level trough swings through late this evening. The thunderstorm threat will likely linger longest across the far north before exiting around or just after midnight. On Tuesday the upper low will be well over the southern Canadian plains with drier westerly flow across North Dakota. Windy west winds of 20-30 mph with gusts up to 45 mph will be common with highs from the mid 70s northwest to mid 80s far southeast. Flow on Wednesday remains westerly, though less windy than Tuesday. There is rising confidence among deterministic and machine learning guidance in convection and severe weather potential returning as early as Thursday, though where the strongest storms set up in the state is still dependant on uncertain moisture return. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1242 PM CDT Mon Jun 29 2026 Scattered showers and thunderstorms are expected today through the evening, with severe thunderstorms possible across central and eastern North Dakota. Thunderstorm threat should taper off from south to north through the evening. IFR stratus should gradually lift somewhat at KJMS through the afternoon but this may be a slow process. Otherwise, IFR ceilings/visibility and erratic winds possible with any thunderstorm, with severe weather possible near and east of a KMOT-KBIS line. Surface winds turn west/southwest through the evening then increase after 09Z. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Edwards AVIATION...Edwards