Area Forecast Discussion

KEY MESSAGES

- Highs in the mid 80s to mid 90s today. Windy across western and central North Dakota, with a Wind Advisory in effect. - Isolated to scattered severe thunderstorms are possible over western and parts of north central North Dakota tonight.

- Scattered to numerous severe thunderstorms over much of western and central North Dakota Late Sunday afternoon and Sunday night.

- Except for a brief break on Monday, a more active severe weather pattern looks to continue next week.

DISCUSSION

Issued at 248 PM CDT Sat Jun 6 2026

This afternoon, shallow ridging aloft was moving over eastern North Dakota, while upstream of the forecast area a deep closed low was analyzed over the Pacific Northwest. At the surface, low pressure was located in northeast Wyoming, with southerly low- level flow across North Dakota. A tightening pressure gradient is producing strong southeast winds, and a Wind Advisory is in effect through late this evening for areas south and west of the Missouri River.

Mostly quiet weather is expected for the remainder of the daytime hours, with eyes on a shortwave moving through Montana and convection developing west of the forecast. Latest CAMs runs are in relatively good agreement on the main area of storms extending across northwest North Dakota late this evening and into the overnight hours along a surface trough, with potentially some additional showers and thunderstorms across the southwest where the environment is less favorable. In the northwest, we continue to advertise hail up to the size of ping pong balls and winds up to 70 mph. Forecast parameters are a bit tough, with stronger shear to the west and higher instability to the east, but the narrow area of overlap favored across northwest North Dakota would be supportive of severe thunderstorms if they develop and can survive capping advertised in forecast soundings.

Numerous severe thunderstorms are possible on Sunday (level 3 out of 5) which is an upgrade from the previous shift. Sharp southwest flow aloft will overlap with another surface low and associated fronts from eastern Montana through much of North Dakota. Ahead of the cold front will be a very warm and moist airmass, with forecast dew points in the upper 50s to lower 60s and strong southeast winds across central and eastern North Dakota, which will likely need another Wind Advisory. As the front moves east through the afternoon and evening, a big question is the potential capping inversion and if temperatures will heat up enough to overcome the cap. Right now, forecast high temperatures are in the mid to upper 90s across central North Dakota, slightly lower in the James River Valley, and in the mid to upper 80s across the west behind the front. Convective temperatures are generally from 94 to 97 F, so it will be close. If any initial supercells develop, they would likely be across northern North Dakota, and bulk shear vectors parallel to the front would favor discrete cells. These storms would be where the primary large hail (up to 2 inches) and potential tornado threat would be, although low-level SRH is still somewhat marginal. High-res guidance is pretty split on what develops in the late afternoon, but is coming into more agreement on storms moving into southwest North Dakota in the evening. The mean wind quickly turns southerly along and behind the front which would favor upscale growth and a wind threat. Deterministic guidance is advertising DCAPE over 1000 J/kg and 0-3km shear around 25 knots, so sticking with the 70 mph wind speed in messaging for now although can see this having to be increased if we get more confident in linear mode and the 0-3km shear increases a bit more.

We get a break from precipitation chances on Monday as the upper low lifts to the northeast, with a brief reprieve from the hot and humid airmass from this weekend. Forecast highs on Monday are in the mid 70s to lower 80s, with light surface winds as a weak surface high passes through the region.

Tuesday is the next day to pay attention to for potential severe thunderstorms. Persistent southwest flow combined with a surface low and attendant upper wave is a favorable synoptic setup for convection, and although it's still early, deterministic guidance is advertising a very sufficient environment for severe thunderstorms to develop, with forecast dew points in the 60s across much of the state. CSU machine learning probabilities have jumped up significantly from yesterday, so will be interesting to see how this trends the next few days. NSSL ML probabilities are also modest and highlight most of North Dakota for this period.

As the system from Tuesday continues to move through on Wednesday, severe weather probabilities shift further to the east. NBM precipitation chances keep low to medium probabilities of showers and thunderstorms through Wednesday and into Thursday, although a lack of instability will limit the severe weather potential for the forecast area. Flow aloft turning more northwesterly will also help cooler air filter into the region, with widespread highs in the 60s and 70s by late in the week. Extended outlooks tilt towards below normal temperatures through the middle of the month.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1251 PM CDT Sat Jun 6 2026

Generally VFR conditions expected through the TAF period. The main exception will be the potential for showers and thunderstorms at KXWA and northwest ND this evening, with a PROB30 group for this terminal. Expect gusty and erratic winds near any thunderstorms and IFR-MVFR visibilities with heavy rain associated with any storms. These storms could be severe.

Breezy to strong southeast winds will continue through much of the TAF period, strongest south and west of the Missouri River with sustained winds around 30 mph and gusts up to 45 mph. Southeast winds diminish some tonight but strong southerly winds aloft will necessitate a mention of LLWS at all TAF sites except KXWA. Late in the TAF period, winds start to shift northwesterly across far western North Dakota.

BIS WATCHES / WARNINGS / ADVISORIES

Wind Advisory until midnight CDT /11 PM MDT/ tonight for NDZ017>020-031>033-040>044-059>062.