textproduct: Bismarck

KEY MESSAGES

- Above normal temperatures are forecast through the work week, then much cooler temperatures this weekend. Near record highs possible Thursday and Friday.

- Dry conditions through Thursday, then low to medium chances for showers Friday into Saturday.

- Breezy to windy Friday and Saturday.

UPDATE

Issued at 602 PM CDT Tue Oct 20 2026

Quiet weather continues across the region. No updates are need at this time as temperatures 60s to lower 70s with a weak front bringing a windshift.

DISCUSSION

Issued at 237 PM CDT Tue Oct 20 2026

Weak cold front will continue to push across the state through tonight. As a result cooler temperatures will return tonight, with a steady north wind. Given track of a surface high tonight and clear skies, blended in NBM 10th percentile. Near to slightly below freezing temperatures will be found for some areas, mainly in the northwest closer to the surface high. Humidity values may also increased tonight. Some patchy fog is possible, especially in the north and west where winds are expected to go light from the mentioned surface high. Confidence was not high enough to include in the forecast at this time. Weak ridging builds back in Wednesday, while the surface high moves east. Behind tonight's front could be slightly cooler, yet still above normal, highs for Wednesday in the 60s. As the surface high moves east winds will become easterly to southerly. Given this mixing blended NBM with NBM 90th percentile which brings slightly higher temperatures. Mainly dry and clear conditions are also expected for Wednesday. A steady south wind and southwest flow aloft will bring mild and dry conditions Wednesday night. Look for lows in the 40s. Increased dewpoints from this south wind could also bring some higher RH values Wednesday night. Perhaps more patchy fog is possible then, although the mentioned increased winds and overall dry state of the atmosphere should limit this threat.

Thursday and Friday see southwest flow aloft ahead of a larger upper level wave, and developing surface low. Expect very warm conditions from this pattern both Thursday and Friday. Given ample mixing from southerly flow, continued blending in NBM with NBM90th for high temperatures. This brings highs in the 70s and low 80s each day. Some sites with highs near 80 would approach record highs for this time of year. ECMWF EFI values for MaxT on Friday are elevated showing this potential. Surface low encroaches on the state Friday which could make for some breezier southerly winds. Very warm temperatures could lower RH values enough for some near critical fire weather conditions with these breezy southerly winds. Increasing RH is the limiting factor for this potential thus will continue to monitor. Lifting warm front with this surface low could also bring some isolated showers and perhaps thunderstorms Friday. CSU-MLP showing some low probability for isolated severe storms with this front. Shear looks adequate for severe weather, although instability is limited.

Strong cold front then moves through sometime later Friday or early Saturday. This could bring another isolated to scattered chances for showers and thunderstorms. Much cooler temperatures and breezy to windy conditions will then be found for Saturday. Perhaps some fire weather concerns will linger into Saturday, although cooler temperatures should help limit this. Cooler temperatures then look to remain Saturday nigh with lows in the 20s. Sunday remains cool with less wind. Expect dry conditions as well on Sunday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 602 PM CDT Tue Oct 20 2026

VFR conditions will continue across the region through the period. A weak front will switch winds from southerly to northerly tonight. However, winds will shift back out of the south tomorrow afternoon.

BIS WATCHES/WARNINGS/ADVISORIES

None.