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KEY MESSAGES

- Hot and windy today, with critical fire weather conditions in western North Dakota and high temperatures and heat index values around 100 in south central North Dakota.

- Smoke from distant wildfires could reduce visibility today through Monday.

- Low to medium chances for showers and thunderstorms tonight through Monday. A few storms could be strong to severe in central and eastern parts of the state.

- Much cooler but still windy on Monday, with near-critical to critical fire weather conditions south and west of the Missouri River.

- Highs only in the 70s on Tuesday, then warming back up to the 80s and 90s through the end of the work week.

UPDATE

Issued at 1242 PM CDT Sun Aug 2 2026

Limited updates needed early this afternoon. Surface front is progressing across western ND bringing areas of smoke and a shift to west northwest winds breezy at times. This front is also bringing dry air, further contributing to near critical to critical fire weather conditions today. Meanwhile ahead of this front warm dry and breezy conditions are found in central and eastern areas with slightly higher dewpoints bringing increased heat index values. Overall the forecast is remaining on track, although the mentioned front may have slightly higher winds than previous forecast. Limited changes were needed this update.

UPDATE Issued at 955 AM CDT Sun Aug 2 2026

No major updates needed at this time. Some wildfire smoke is starting to enter into northwestern ND, with more abundant smoke further upstream showing up on the Geocolor RGB Satellite product. Otherwise temperatures are starting to warm up, with the highest heat index values still expected in the ongoing Heat Advisory area. Critical fire weather conditions are also expected in the west today, where the current Red Flag Warning is. Overall the forecast remains on track with little updates needed at this time.

DISCUSSION

Issued at 539 AM CDT Sun Aug 2 2026

Positively-tilted upper level ridge extends from the Desert Southwest through the Northern Plains early this morning. A "cold" front/surface trough is moving from central into eastern Montana, attendant to a Canadian surface cyclone whose parent upper low is crossing the Canadian Rockies. Low level jet induced warm air advection has generated some isolated sprinkles or light rain showers in northern parts of the state early this morning, and this activity may continue into the early afternoon while sliding eastward. The front will enter western North Dakota later this morning and reach central North Dakota this afternoon before it begins to stall as the Canadian low occludes. The thermal ridge axis should mostly align with the frontal interface, which gives high confidence in the hottest temperatures at or slightly above 100 degrees in south central North Dakota this afternoon. Heat indices should be similar to air temperatures in this part of the state as dewpoints fall into the 50s or perhaps 40s. A Heat Advisory has been issued for Morton, Grant, Sioux, Burleigh, and Emmons Counties from noon to 8 PM CDT. High temperatures will be cooler with increasing distance from the Heat Advisory, mostly in the 90s but with mid to upper 80s far northwest. Windy conditions are anticipated both ahead of and behind the front, but may actually be lighter along the frontal interface. Already seeing breezy southerly winds early this morning, which should increase to 20-30 mph with gusts near 40 mph in central North Dakota this afternoon. Behind the cold front, northwest winds are expected to increase to around 20 mph with gusts to 30 mph through early afternoon, but then decrease later in the afternoon as mean boundary layer winds become lighter. The combination of windy conditions and very low humidity will produce near-critical to critical fire weather conditions in the western half of the state today. See the fire section below for details.

The occluded Canadian low will spin across Saskatchewan late tonight, pushing mid level height falls into the Northern Plains and turning flow aloft southwesterly. Underneath, the surface front is forecast to stall from northeast to south central North Dakota. The increase in synoptic scale forcing, including an increasing low level jet on the leeward side of the surface trough, could initiate scattered showers and thunderstorms over parts of the state late tonight into Monday morning. While MUCAPE could increase above 1000 J/kg and effective bulk shear for the most-unstable elevated parcels could increase above 40 kts, most CAM guidance is pessimistic that the maximum CAPE/shear parameter space will be realized. A few UH tracks do begin to show up in the Devils Lake Basin and James River Valley by around 6 AM CDT Monday morning, but this is not universal among all CAMs. We will continue to advertise a strong to marginal severe storm risk tonight into Monday morning, with baseline severe hazards of quarter size hail and wind gusts near 60 mph.

During the day Monday, a separate shortwave ejecting from the American side of the Northern Rockies will join forces with the Canadian occluded low and push a secondary but much stronger cold front into the Northern Plains. High temperatures could still reach the 80s in south central and eastern North Dakota, but the northwest corner of the state may struggle to rise above 70! Windy conditions will also continue on Monday, out of the north to northwest around 25 to 30 mph with gusts to near 40 mph. Despite the cooler temperatures, humidity will still fall low enough to prolong fire weather concerns south and west of the Missouri River. Please refer to the fire section below for further details. The other concern for Monday is the eastward progression of the lead surface trough and trailing shortwave, which will determine whether mid to late-day thunderstorms develop in our forecast area. CAMs show a mixture of potential outcomes, ranging from no storms after the morning (e.g., the 06Z HRRR) to scattered strong to severe storms in the eastern half of the state late Monday afternoon and evening (e.g., the 06Z NAMnest). It is difficult to put too much weight into any specific outcome given the potential for the midday environment to be modified by morning convection. We will therefore tie the severe risk on Monday in with that of tonight/Monday morning for messaging purposes.

Forecast confidence is high that surface high pressure will build into the region on Tuesday under an upper level longwave trough. This should bring below normal temperatures to all, with highs on Tuesday in the 70s and lows around 45 to 50 both Monday and Tuesday nights. A quick warm up remains favored thereafter, with near normal highs in the 80s on Wednesday increasing to above normal in the 90s along and south and west of the Missouri River by Friday. But there is still uncertainty in the evolution of the synoptic pattern and how much the Hudson Bay low may keep the western CONUS upper ridge from building eastward. This uncertainty is reflected in larger temperature spreads by the end of the work week, and also keeps precipitation chances after Monday very low for the time being.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1242 PM CDT Sun Aug 2 2026

VFR conditions are generally expected for the forecast period. Cold front will move from west to east today, changing a breezy south wind to a breezy west north west wind. Behind this front will be areas of smoke, with visibilities mainly VFR to perhaps briefly MVFR at times. This smoke could continue tonight through much of Monday morning. Smoke is then expected to diminish from northwest to southeast Monday afternoon and evening. Mainly dry conditions are expected today. Tonight into Monday could see some showers and thunderstorms, although confidence was not high enough to include in the TAFs at this time. Although confidence was not high enough to include at this time, low level wind shear may return to eastern portions of the state tonight into Monday morning, including in the KJMS area.

FIRE WEATHER

Issued at 539 AM CDT Sun Aug 2 2026

Ahead of a cold front moving into western North Dakota later this morning, southerly winds should steadily increase through the day, reaching sustained speeds around 20 to 30 mph with gusts near 40 mph in central North Dakota this afternoon. Wind speeds along the frontal boundary are not projected to be quite as strong, but there could be a rapid shift in direction from south to northwest. Gusty winds are expected behind the front in western North Dakota late this morning into the afternoon. But by late afternoon, wind speeds along and behind the front are forecast to weaken, following those above the surface. This wind forecast adds complexity to the fire weather forecast for today. The RH forecast is more straightforward, with minimum forecast values around 10-15 percent in western North Dakota south of the Missouri River, increasing to only 20-25 percent along the eastern peripheries of the Missouri River Valley. A Red Flag Warning has been issued for the aforementioned 10-15 percent RH area, as well as Williams County. Near-critical fire weather conditions are expected across the rest of the western half of the state. Outside of the warning, the area that has the highest chance for approaching critical fire weather conditions is in Burleigh and Emmons Counties where there could be just enough overlap of stronger southerly winds with lower RH. The area between the Red Flag Warning and Burleigh/Emmons Counties is not expected to have strong enough winds for long enough of a duration. But there will still be the shift in direction there, and high temperatures are expected to reach around 100 degrees.

Temperatures will be much cooler on Monday compared to today. But with dewpoints falling as low as the mid 30s, RH could still fall as low as 20 percent in southwest North Dakota. It will also be windier on Monday, with north to northwest winds around 25 to 30 mph and gusts up to 40 mph. The NBM has been very consistent over the past several days in bringing 6-8 hours of critical fire weather conditions to Slope and Bowman Counties on Monday. Given that information paired with humidity tonight only rising to around 45 percent and northerly winds not falling under 10 mph, the decision was made to extend the Red Flag Warning into Monday evening for just Slope and Bowman Counties. Fire weather conditions will be at least near-critical for other areas south and west of the Missouri River on Monday. The most recent NBM guidance took a significant jump in a more concerning direction, painting +3 hours of critical conditions as far north as Lake Sakakawea and as far east as Lake Oahe. But given this is the first occurrence of critical conditions forecast to be this widespread on Monday, would like to see better consistency before pivoting the forecast and messaging (although time is running short). This was the main factor in deciding not to issue a Fire Weather Watch for a larger area on Monday at this time, and instead opting for the higher confidence Red Flag Warning in the far southwest.

BIS WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for NDZ009-017-018-031>033-041-044. Heat Advisory until 8 PM CDT /7 PM MDT/ this evening for NDZ035-042-046-059>062. Red Flag Warning until 8 PM MDT Monday for NDZ040-043.