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KEY MESSAGES

- Areas of dense fog are possible in northwest North Dakota tonight through mid Friday morning.

- Slightly cooler Friday and Saturday, then hot again for most areas on Sunday.

- Temperatures are favored to fall closer to normal next week, with forecast highs mostly in the 80s.

UPDATE

Issued at 104 AM CDT Fri Jul 17 2026

The Severe Thunderstorm Watch was allowed to expire on time. Radar shows the remnants of the last thunderstorm in Wells County have vanished, but there are now a couple of showers popping up from near Mott to Lake Tschida. The forecast will soon be updated to reflect this.

Fog is developing in northwest North Dakota. Visibility has already fallen below 1/4 mile at Crosby and is around 1/2 mile from Estevan to Bowbells. Rapid refresh guidance shows confidence in dense fog expanding throughout northwest North Dakota by early Friday morning. A Dense Fog Advisory may eventually be needed, but for now the dense fog is limited enough in scope to handle with a Special Weather Statement for the time being.

UPDATE Issued at 1032 PM CDT Thu Jul 16 2026

For the forecast area, the Severe Thunderstorm Watch continues for Wells and Foster counties, though has been canceled behind the front for Rolette and Pierce counties. While the storms are appearing to become more disorganized in nature, there are still occasional photos of funnel clouds and possibly tornadoes coming in. Therefore, continue to stay tuned for any further warnings over the next couple hours.

UPDATE Issued at 657 PM CDT Thu Jul 16 2026

A severe thunderstorm watch has been issued until midnight for Rolette, Pierce, Wells, and Foster counties.

Currently, isolated thunderstorms are developing along a frontal boundary draped from eastern Bottineau down through western Sioux County. With a lack of shear, storms in the south are having a more difficult time sustaining themselves. However, near the Canadian border, storms development is starting to intensify near the triple point where a lot higher shear is present. The primary threats are wind and hail with brief heavy rain. However, a tornado cannot be ruled out. Storms will likely move to the east of the CWA within the next couple to few hours, which may allow the aforementioned counties to be canceled earlier than the current expiration time.

DISCUSSION

Issued at 230 PM CDT Thu Jul 16 2026

Increasingly zonal flow is found over the northern Plains this afternoon as low amplitude shortwave moving across Canada flattens the upper level ridge that has been prevalent over much of the CONUS over the past week. At the surface, a center of low pressure has been steady lofted toward northeast North Dakota by the passage of the previously mentioned shortwave, dragging an inverted surface trough / cold front across the forecast area this afternoon. An interrogating of BUFKIT model soundings across portions of central North Dakota reveals a somewhat robust convective environment developing through the early evening, with model MUCAPE values approaching 3000 to 3500 J/KG overlapping with 0-6KM shear values around 30 to 35 knots over portions of the north central and the north east. The biggest obstacle to CI would be a fairly robust low level capping inversion over much of the forecast area, with 850mb temps roughly 5 degrees higher than the surface. That being said, with forecast surface temperatures expected to approach convective temperatures by the early evening, it wouldn't be overly surprising to see this cap erode enough to allow for some isolated thunderstorms to develop. With orientation of BULK shear vectors generally perpendicular to the inverted trough/cold front, discrete storms can generally be anticipated, while sufficient shear and with at least somewhat curved hodographs could promote a transient supercell or two. The primary hazard associated with any severe storm would be large hail up to 2 inches in diameter, though high DCAPE values approaching 1500 J/KG would also suggest strong winds up to 70 MPH are also possible. The overall potential for tornadoes remains low, with near surface SRH and shear values remain well below expected norms. That being said, conditions across north central North Dakota are analogous to previous events where we've had had high-based hybrid tornadoes, where a developing landspout along a surface boundary becomes anchored to a supercell (with research suggesting these types of hybrid tornadoes occur when you have an overlap of very high cape values exceeding 3000 J/KG, strong deep layer sheer around 30 to 40 knots, low near surface SRH, and developing supercells along a cold front). With that in mind, we will need to keep a close eye on any supercells that do end up developing this evening. Also of note is the above normal PWATs over much of central and eastern North Dakota today, around 1.5 to 1.75 inches, which means that heavy rainfall can also be anticipated with any storm that does develop. With a discrete storm mode, this heavy rainfall is expected to be fairly brief, and thus flash flood concerns remains low at this time. For today, the SPC has placed portions of north central North Dakota and the northern James River Valley into a Marginal (level 1 of 5) risk for isolated severe thunderstorms.

Above normal high temperatures in the mid 90s to lower 100s continue along the south half of the state today, while conditions across the normal remain slightly cooler with highs from the lower 80s to lower 90s. Along with dewpoints generally in the upper 60s to lower 70s, apparent temperatures across portions of the southwest and south central are expected to be around 100F this afternoon into early this evening. A Heat Advisory remains in effect along and south of Highway 200 through 10 PM CDT tonight. With low temperatures forecast mainly in the lower 60s to lower 70s, better overnight recovery is expected across western and central North Dakota than we have seen all week, which is help alleviate further heat concerns moving into the start of the weekend. Otherwise for tonight, patchy fog will be possible across portions of the far northwest through Friday morning as a near surface temperature inversion develops, and as northeasterly winds become very light overnight.

Northwesterly flow is then generally expected across western and central North Dakota as we head into the weekend, promoting a slight cooling trend that will promote highs from the lower to mid 80s along the International Border, up to the mid 90s and lower 100s. This synoptic pattern is also more conducive for precipitation, with at least low chances for showers and a few storms expected late Friday into Saturday morning across the far west. A more robust Canadian trough is then expected Saturday night into Sunday, turning flow aloft more zonal and promoting low to medium chances for precpitation across much of western and central North Dakota. Overall QPF is expected to be fairly limited due to the transient nature of these showers and storms, though high PWATs through the weekend would allow for brief period of moderate to heavy rainfall when and where thunderstorms develop. CSU machine learning has begun to highlight portions of the forecast on Sunday, which is expected to be associated with storms in the afternoon. We will monitor forecast trends through the weekend.

A return to northwesterly flow as we head into early next week will again allow the cooling trend to continue, bringing highs back down toward near normal by the midweek. With this synoptic pattern, low chances for showers and thunderstorms can be expected somewhere in North Dakota just about any given day, though the ensemble does not advertise a strong precpitation or severe signal at this time.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 104 AM CDT Fri Jul 17 2026

Periods of MVFR to LIFR ceilings are possible across much of western and central North Dakota tonight into Friday morning. Highest confidence in low ceilings is in western and north central North Dakota. Dense fog could also spread across northwest North Dakota later tonight into Friday morning. After the fog and low clouds clear, VFR conditions are expected from Friday afternoon through the remainder of the forecast period. Winds will primarily be northerly to easterly around 5-10 kts, with some higher afternoon gusts at KJMS.

BIS WATCHES/WARNINGS/ADVISORIES

None.