textproduct: Bismarck

KEY MESSAGES

- Scattered severe thunderstorms are expected tonight primarily over northwest North Dakota. The main expected hazards include hail to the size of golf balls and damaging winds to 70 mph.

- Low to medium chances for showers and thunderstorms Friday through Friday night, with a risk for isolated severe thunderstorms. Low shower and thunderstorm chances remain in the forecast at times through the holiday weekend, with chances increasing Sunday night.

- Highs mainly in the 80s expected through Independence Day, with 90s on Sunday.

UPDATE

Issued at 1217 AM CDT Fri Jul 3 2026

** Mesoscale Discussion **

Storm intensity has gradually been waning in western ND in the last 60 minutes, as expected, but several clusters of storms persist as of 04z in west central/northwestern ND and eastern MT. MLCIN is gradually increasing and resulting in convection gradually becoming more elevated versus boundary-layer-based. Nonetheless, steep midlevel lapse rates and a sufficiently-deep moist layer are contributing to 1500-2000 J/kg of MUCAPE amid sufficient effective-layer shear for organized convection. We do expect storm intensity to continue to gradually wane in the absence of stronger large-scale forcing and as MLCIN continues its diurnal increase. However, the terminus of an ~30 kt low- level jet is focused in west central/northwest ND and will aid in some maintenance of convection, and the overall MUCAPE/shear combination will favor a marginal severe-storm risk continuing in parts of west central, northwest, and north central ND for the next 1-3 hours. CAMs support continued gradual weakening and lessening of the risk overnight, though, just as we expect at this time.

CJS

UPDATE Issued at 932 PM CDT Thu Jul 2 2026

** Mesoscale Discussion **

Scattered strong-severe thunderstorms including several supercells have evolved over western ND in the past hour. These storms are in an environment characterized by around 2000 J/kg and 40-45 kt of effective-layer shear. Hodographs in southwest ND favor splitting supercells with both left-moving and right- moving supercells allowed to persist. Hodographs further north in northwest and west central ND have a bit more curvature in their lowest 1 km, suggesting right-moving supercells may be a bit more favored in that area. Regardless, the well-established mesocyclones are expected to persist the next 1-2 hours even as MLCIN gradually increases. Surface dewpoints have increased into the lower 60s F, though, which is higher than RAP-based/SPC objective mesoanalysis. That may offset increases in MLCIN and allow some of the supercells to persist even a bit longer than they otherwise would alone.

Upstream in southern Saskatchewan, a linear convective complex has been organizing. Forward-propagating MCS motion vectors do suggest this may eventually move into northwest and north central ND in the next few hours, with an attendant severe- storm risk, much like recent HRRR simulations have shown.

UPDATE Issued at 538 PM CDT Thu Jul 2 2026

** Mesoscale Discussion **

The severe-storm risk is gradually increasing over parts of western ND, though some uncertainty remains in its evolution. Large hail up to golf ball size and damaging wind gusts up to 70 mph are the main concerns with severe storms this evening.

As of 2230z, visible satellite imagery shows persistent attempts at convective initiation near Glendive and Wibaux Montana. The background environment features weak forcing for ascent with neutral to slight height rise tendencies aloft, and generally-weak surface convergence. That said, there is broad surface confluence apparent in east central MT, which may be enough to allow the convective initiation to become sustained in that area. While the Beach AWOS suggests the low-level moisture immediately along the ND/MT border may be shallow, the observed temperatures in the mid 80s F are sufficient for MLCIN to be minimized per modifications to the 18z KBIS RAOB and recent modified RAP soundings in southwestern ND. If this convection can be sustained in the next 30-60 minutes, overcoming any residual (even if slight) warm nose aloft, we would expect it to become supercellular and move into southwestern ND, particularly into Golden Valley and Billings Counties in the next 1-2 hours. This is a conditional scenario, but the CAPE-shear setting and steep low- and midlevel lapse rates would be favorable for large hail and damaging winds if this comes to fruition. It's possible that even if a storm becomes sustained, that it would take it time and further-eastward reach into southwestern ND by a county or two in order to intercept somewhat richer low- level moisture and intensify further. That is identified by dewpoints in the upper 50s to lower 60s F in the Dickinson and surrounding areas.

Otherwise, some CAMs have signaled the storms in northwestern SD could move into southwestern ND, but this would likely depend on or be a result of left-split supercells given mean winds and supercell-motion vectors. Forecast hodographs do favor splitting supercells in northwestern SD, but only the left-moving vectors favor propagation of this particular activity into southwestern ND. This may provide an isolated severe-storm risk in parts of Bowman, Adams, and surrounding counties in the next 1-3 hours, as well.

Finally, there are storms gradually intensifying in southern Saskatchewan and northeastern MT with a more well-defined impulse and related ascent aloft. These storms may impact parts of northwestern ND with an associated severe-storm risk by mid to late evening, and will be monitored closely in the coming hours to identify their associated trends.

DISCUSSION

Issued at 106 PM CDT Thu Jul 2 2026

Ongoing convection along the I-94 corridor from Bismarck to Jamestown will probably fester through the afternoon. WOFS is not impressed with the severe potential here, and neither are we, although an isolated marginal severe hailstone can not be ruled out. Bulk shear has increased here in the past hour and there is a large increasing gradient in hail cape from Jamestown to Bismarck. I think the main concern is now shifting more to the west. Near full sun and increasing shear and instability is expected across western ND this afternoon, but there is still disagreement in the CAMS as to when convection will develop with some developing convection early-mid afternoon and others holding off until closer to 00Z Friday. The Wofs is showing convection developing in the far west around 21-22 UTC. Storm mode would support supercells over western ND this afternoon and all hazards would be in play then. LCL heights are pretty high though so the threat in the far southwest to west central looks lower than in the northwest late afternoon into early evening. There is also a small max in the far south central early this evening, but overall the tornado threat remains on the lower side. Also large to very large hail would be a threat with supercells that can maintain their updrafts. A transition to a linear system may still occur later tonight although the signal for this has not been consistent and it has backed off from yesterday. SPC has pulled the enhanced area out of the James River Valley. Yesterday, convection firing out west or along the east to west boundary over central/southern ND transitioned into one or more linear convective systems that tracked into southeast ND. That's not really showing up today. Although a smaller linear or bowing segment from any convection that fires over western ND can not be ruled out. There has been some consistency in convection later this evening/overnight either developing over or moving into northwest ND (from Montana or Saskatchewan) and tracking into the north central. We will continue to monitor, but overall very perplexing with little agreement in the CAMS. Also do not want to downplay the severe potential if/when convection does develop. Although the bulk shear does not appear to be as strong, and there are some limiting factors such as the upper level ridging mentioned in a prior discussion, the potential for severe storms does remain and if you do have plans that take you outdoors, remain weather aware and be ready to take shelter if threatening weather approaches.

Friday may be another day similar to today, with little agreement in CAMS and possibly some morning convection to throw another wrench into things. However, overall, the threat seems a bit lower with instability, and especially bulk shear not as high as today. However, we will need to monitor. Convection does look to taper to isolated to scattered in nature as we go through the Holiday weekend. Temperatures will be on the rise though, especially on Sunday with high temperatures into the 90s across the area, and perhaps getting into the upper 90s southwest. Beyond the weekend, we see a quasi-zonal flow along the northern tier states with occasional impulses bringing chances for showers and thunderstorms. Temperatures remain near or a little above climatological normals (lower 80s) for this time of year.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 116 AM CDT Fri Jul 3 2026

Scattered thunderstorms continue over western and parts of central North Dakota, which may spread east overnight. Some storms may be severe over northwest North Dakota very early this morning, with large hail and +50 kt wind gusts. Any storm will be capable of heavy downpours briefly reducing visibility to at least IFR levels. Additional thunderstorm development possible Friday and Friday evening. Mostly VFR conditions are expected to prevail outside of thunderstorms, although there is a low to medium chance for MVFR ceilings developing in north central North Dakota this morning. Winds will primarily be light.

BIS WATCHES/WARNINGS/ADVISORIES

None.