textproduct: Bismarck

KEY MESSAGES

- Increasing temperatures and mainly dry conditions expected Thursday, with a slight chance of showers and thunderstorms across the north Thursday afternoon.

- Very hot conditions expected to return Friday through the weekend, with high temperatures and heat index values around 100 degrees.

- Isolated to scattered thunderstorms possible Friday through this weekend. Isolated severe thunderstorms are possible across central and eastern North Dakota on Friday.

- The combination of hot, dry, and breezy conditions could bring near critical fire weather conditions Friday and again on Sunday.

UPDATE

Issued at 1248 AM CDT Thu Jul 23 2026

Limited updates needed at this time. Some mid to high level clouds will move in tonight, with lows in the 50s to lower 60s. Will continue to monitor for any patchy fog developing or lingering smoke. For now the forecast remains on track.

UPDATE Issued at 950 PM CDT Wed Jul 22 2026

Temperature-dewpoint spreads are narrowing along the Canadian border with the approach of sunset, and some 5-6SM visibility reductions are being reported at a few AWOS sensors, likely due to some near-surface smoke being detected as the boundary layer decouples. This will require monitoring, but at this time there's not enough confidence to include either fog or ground- level smoke in the forecast. Only minor changes were made with this update, blending observed trends and recent guidance into the overnight forecast.

UPDATE Issued at 644 PM CDT Wed Jul 22 2026

Southerly winds have developed late this afternoon as surface high pressure moves into central MN and a broad, lee-side low pressure trough deepens in central MT. Shallow low-level cumulus extending from around Watford City to Dickinson and then into south central ND will diminish with sunset, though high clouds emanating from central MT convection may move into southwest ND overnight. Overall a quiet and dry night remains on tap, and only minor changes were made to the forecast with this update.

DISCUSSION

Issued at 230 PM CDT Wed Jul 22 2026

Northwesterly flow is found over the northern Plains, situated as we are between a building upper level ridge to our west and a Hudson Bay low to the northeast. Despite this pattern, dry conditions throughout lower to mid levels will greatly limit the potential for notable precpitation or storms this afternoon and evening, though we can never completely rule out isolated, diurnally driven light showers or weak storms this time of year. Lingering smoke remains evident on satellite imagery across portions of northwestern and central North Dakota this afternoon, with steeper lapse rates allowing for at least some of this smoke to mix down to the surface, though this is expected to begin diminishing as light surface winds turns increasingly to the south-southwest this evening and overnight. Otherwise for today, near normal high temperatures in the lower to mid 80s are expected this afternoon as remain on the cool side of the ridge, while overnight lows are forecast in the mid 50s to lower 60s.

As we head into the later half of the week, the increasing influence of the upper level ridge as it attempts to build in across the Great Plains is going to allow for a warming trend that will again see well above normal high temperatures across western and central North Dakota this weekend. For Thursday, this influence is expected to be somewhat stymied by a weak shortwave riding along the ridge in the afternoon and evening, keeping forecast high temperatures mainly in the upper 80s to mid 90s range. Some limited instability (model values approx 500-1000 J/KG along the International Border) and the favorable positioning of the upper level jet along with this weak wave will be sufficient to get some at least isolated thunderstorms across portions of the northwest and north central North Dakota Thursday afternoon and evening, though severe weather is not anticipated at the time of this forecast.

A more robust convective environment is then anticipated across portions of western and central North Dakota on Friday. With widespread high temperatures peaking into lower 90s to lower 100s, and with dewpoints rising well into the mid to upper 60s across potions of the north central, model MUCAPE values Friday afternoon are beginning to rising into the 2500-3500 J/KG range. Model bulk shear values around this time also begin to peak into into the 35 to 45 knots. There are a few things to consider regarding location and coverage relating to possible convection on Friday. Overall forcing during this period is relatively weak, and the greatest height rises are currently progged to be further south of the best convective environment up in the north central, so it remains uncertain where there will be enough overlap to get things going. That being said, convective temps only in the lower to mid 90s and a developing low level jet in the north central may be sufficient to see some CI in the late afternoon and evening. Another point of contention is potential storm mode. Global models hint at a weak cold front / surface trough moving through the area Friday afternoon, roughly orientated in a SSW to NNE direction between the south central up through the Grand Forks area. With bulk shear vectors roughly at at around 45 degree angle or less to this potential boundary, any storms that develop here may be more of a mixed storm mode. All of that is to say that advertising potential hazards is a little bit of a shamble. My current feeling is the primary hazard with any strong to severe storm is going to be damaging wind, as high DCAPE values around 1000- 1500 J/KG expected, and high lapse rates around 9.0-10.0 C/km will allow some of the stronger winds from the jet to mix down toward the surface, and as the dry, inverted-v signature on model soundings hint at the potential downward acceleration due to evaporative processes. Otherwise, the potential for large hail is also there, especially if any discrete, surface-based storms manages to poke through the residual CIN lingering across the area. The highest hail threat would be associated with any supercells that manage to develop, as hinted by sufficient 0-6KM shear values and the modest clockwise elongation of the hodographs evident across portions of the north central, include the northern James River Valley. As it stands, the SPC has placed portions of central North Dakota into a Marginal (Level 1 of 5) risk for isolated severe thunderstorms for Friday.

Otherwise, the main point of concern Friday heading into the weekend is going to be the very hot temperatures. High temperatures each day are expected to peak into the 100-105 degree range, with such temperatures expected to be fairly widespread on Saturday and Sunday. Overall moisture availability will be a little lower than last week's heat event, which is expected to keep apparent temperatures generally in criteria for a Heat Advisory versus an Extreme Heat Warning during this period. We will need to keep evaluating this period moving forward, especially as some of the CAMs begin to get ingested into the NBM by tomorrow. Another thing to watch heading into the weekend is fire weather. Very dry conditions are expected across portions of the west and central, with minimum relative humidity expected to drop as low as 15 to 20 percent. With strengthening northwest winds expected Friday afternoon, a period of near critical to critical fire weather conditions will be possible, mainly across the southwest.

Looking ahead into next week, the flattening of the ridge across the northern Plains is expected to allow cooler, yet still above normal temperatures through the early half of the week, forecast mainly in the mid 80s to mid 90s. This synoptic pattern is also comparably more conducive to precpitation than this week's, allowing for at least low chances for showers and storms any given day. No strong signal for precpitation or severe weather is advertised by the ensemble for next week.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1248 AM CDT Thu Jul 23 2026

Mainly VFR conditions are expected through the forecast period. The exception is in southwestern ND, around KHEI, where there's about a 50 percent chance that MVFR ceilings in stratus impact the area early Thursday morning. South winds sustained around 10 kt will prevail through Thursday with the area between surface high pressure in the Midwest and broad low pressure in central Montana. Patchy fog or patchy wildfire smoke may bring some visibility reductions tonight into Thursday morning, although confidence is too low to include at this time. There could also be some isolated afternoon and evening showers and thunderstorms on Thursday, with confidence too low to include in the TAFs at this time as well.

BIS WATCHES/WARNINGS/ADVISORIES

None.