textproduct: Bismarck

KEY MESSAGES

- Scattered to numerous showers and isolated thunderstorms west and north central today. Locally heavy rainfall is possible, especially in the northwest. - Scattered showers and isolated thunderstorms central this afternoon and this evening. Precipitation ending over central North Dakota late tonight, then mainly dry late Friday and through the weekend. - Temperatures near to slightly below normal through the weekend with highs generally in the 70s. The exception being some 60s northwest and some lower 80s southeast.

DISCUSSION

Issued at 142 AM CDT Fri Aug 14 2026

Latest satellite imagery shows shortwave energy moving into eastern MT and western ND through a broad southwest upper level flow. Moisture is streaming into the area from the central Pacific, combined with strong low level (925-850 MB) moisture transport into northwest ND from the southeast. Strong 850mb FG forcing from northeast MT eastward into southern Manitoba is producing rain showers along the northern tier counties as far east as the Turtle Mountains. With the approaching shortwave, there has been cooling cloud tops over northeast MT into northwest MT, with thunder recently reported at Crosby.

For today, not much has changed as far as the overall forecast. northwest North Dakota is still the focus for heavy precipitation today. The NAEFS SA page is still pinpointing the northwest with unusually high PWATs, but high PWATs also extend a little farther south than 24 hours ago, and even extend into south central ND by around 00Z Saturday. The ECMWF SA Page indicates increased EFI values over far northwest ND. Although the max has shifted a little farther north, high values of 80 to 90 percent have expanded east, and a little farther south (just south of Lake Sakakawea) and the shift of tails of 2 has also shifted farther east into north central ND. Looking at the HREF and REFS, both are indicating the same general area (northwest ND) for highest QPF today, with the HREF increasing max qpf while the SPC REFS backs off a bit. Overall though, the areal extents are very similar. This increases confidence in the northwest being the bullseye for heavy qpf, with the areal extent of significant precipitation (over an inch) extending from the west central into the north central (McKenzie county into western Bottineau county) which wasn't much of a change from 24 hours ago.

There are some indications of more of an eastward extent in the QPF, from southwest into south central ND. However confidence is not as great here. The NBM does show that the 50 percent probability of a quarter inch of QPF (through 06Z SAturday) has expanded farther east across southern ND (From Bowman county 24 hours ago, to the Missouri River from the latest run this morning). The moisture has certainly increased here, however the forcing remain strongest from western into north central ND. Perhaps qpf from southwest into south central ND today may be more hit and miss than points farther west and north.

Overall, messaging has not changed. The confidence in a Flood Watch remains pretty low given the uncertainty for very high precipitation rates with convection. There may still be some issues with localized flooding in the northwest, especially for poor drainage areas and those areas normally prone to flooding.

We did lower forecast high temperatures over a good portion of western ND given the expectation of the cloudy and rainy conditions.

After precipitation ends late tonight or early Saturday over central ND, the remainder of the weekend looks to be dry until perhaps Sunday evening. But for the most part we expect mainly dry conditions with seasonably cool high temperatures in the 70s through the weekend.

We may see a brief warmup on Monday with some 80 degree readings possibly returning, before a northwest flow takes over and we see temperatures mainly in the 70s with hit and miss chances for showers and thunderstorms through the rest of the workweek.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1154 PM CDT Thu Aug 13 2026

Increasing coverage of showers and isolated thunderstorms across western and north central North Dakota will promote lowering ceilings and visibility through the end of the TAF period, with MVFR to IFR ceilings expected at KXWA, KMOT, and KDIK. Have left mentions of thunderstorm activity out of all sites, as confidence in timing and location is very low. Shower activity across the south central is expected to be more limited, thus low VFR ceilings are expected at KBIS and KJMS throughout the TAF period. East winds are expected to be light tonight, before turning southeastern and strengthening Friday morning and afternoon. Gusty winds sustained around 15 knots and gusts up to 25 knots are expected across portions of south central North Dakota Friday afternoon.

BIS WATCHES/WARNINGS/ADVISORIES

None.