textproduct: Bismarck

KEY MESSAGES

- High-impact storm system producing very strong winds and blizzard conditions across much of the state this morning. Conditions will gradually improve from northwest to southeast throughout the day.

- Much colder today and tonight, with highs mostly in the single digits above zero and lows below zero across northern and eastern North Dakota.

- Another system will bring low (south) to high (north) chances for mixed precipitation across the state Friday morning, followed by mild but windy conditions for Friday afternoon.

- After a cooler Saturday, temperatures are favored to warm back to near or above average leading up to Christmas.

DISCUSSION

Issued at 633 AM CST Thu Dec 18 2025

984 mb MSLP low was analyzed near Bemidji, MN at 6 AM CST. Intense pressure rises/cold air advection coupled with very tight surface pressure gradient trailing the low through western and central North Dakota have produced widespread wind gusts in the 65 to 75 mph range, with occasional gusts around 80 to 90 mph late last night. Snow has also accompanied the strong winds. An earlier expansion of the Blizzard Warning in southwest North Dakota was made on account of a stationary snow band embedded in gusts commonly as high as 70 to 80 mph, paired with HREF guidance showing high conditional probabilities for at least 3 hours of near-blizzard to blizzard conditions. Since then, the system as a whole has gained forward momentum, resulting in improving conditions in our far western areas. We will wait to make any further adjustments to the Blizzard Warning until after sunrise so we can more easily confirm the state of conditions. For most areas east of Highway 85, snow continues to fall with widespread blizzard conditions north of Highway 200, and isolated to scattered blizzard conditions in rural areas to the south. Latest high-resolution/rapid-refresh guidance suggests falling snow will quickly end from northwest to southeast through this morning. The strong winds are also forecast to gradually diminish through the day, but could remain strong enough to prolong impactful blowing snow (but perhaps not blizzard conditions) for several hours beyond the end of snowfall. In addition to the winds, snow, and blowing snow, temperatures will be much colder today than the previous couple days. Widespread wind chills in the 20s below are expected through the morning, with lower to mid 30s below across the north where a Cold Weather Advisory remains in effect. Highs this afternoon across northern and central North Dakota will be limited to the single digits, and may struggle to climb above zero in the Turtle Mountains. Lows tonight are forecast to fall below zero north and east of the Missouri River, with teens below far north central. However, we do anticipate temperatures beginning to rise overnight as warmer Pacific air approaches.

Yet another clipper system is forecast to cross the region on Friday. This one will not be nearly as dynamic as the current one, but could still produce some impactful weather. From early Friday morning through the early afternoon, a band of mixed precipitation is forecast to cross the state from west to east, with probabilities for measurable precipitation increasing from south to north. The precipitation is likely to begin as snow at any given location, but could quickly transition to freezing rain (possibly with sleet mixed in along the transition zone) as warm air advection aloft outpaces that at the surface. There appears to be at least medium chances for a glaze of ice along and north of I-94 Friday morning. This potential hazard will need to be investigated and addressed further after the conclusion of the ongoing blizzard. Precpitation should exit to the east Friday afternoon, but we are looking at another round of gusty winds. The most aggressive guidance would suggest momentum transfer potential as high as 55 mph mixing down to the surface across the northern half of the state Friday afternoon and evening. This too will need to be more closely examined once we are past the ongoing high-impact weather. It will at least be much warmer on Friday with highs above freezing in the western half of the state, including as high as the mid 40s in the southwest.

The cold front attendant to Friday's clipper will drag a lower-grade Arctic air mass across the region on Saturday, bring highs back below average for most areas (except the southwest). Ensembles tend to favor an active pattern for next week, but with more of a zonal flow as opposed to northwest, and there are signs of a possible central CONUS ridge building by midweek. Only a couple periods of low precipitation chances are in our current forecast through Christmas Day on account of the inherently lower predictability of the favored pattern. There is a typical amount of temperature spread in the NBM for the medium to long forecast time range, but the distributions are generally skewed near to above normal, and there is a clear signal for colder temperatures to the northeast and warmer to the southwest.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 633 AM CST Thu Dec 18 2025

Strong storm system will continue to impact western and central North Dakota this morning, with conditions gradually improving from northwest to southeast from late morning through the afternoon. Expect periods of IFR to LIFR visibility in falling and blowing snow, MVFR to IFR ceilings, and northwest winds this morning around 25-35 kts, gusting to 45-55 kts. VFR conditions and lighter winds are expected later this afternoon and evening. Then later tonight, winds will turn southerly and increase to 10-20 kts. An area of mixed precipitation, primarily snow changing over to freezing rain, may be entering western North Dakota by the end of the forecast period.

BIS WATCHES/WARNINGS/ADVISORIES

Blizzard Warning until noon CST /11 AM MST/ today for NDZ001>003-009>011-017-018-021-031>033-040-041-043. Cold Weather Advisory until noon CST today for NDZ001>003- 009>011. Blizzard Warning until 6 PM CST this evening for NDZ004-005- 012-013-022-023-025-037. Cold Weather Advisory until 3 PM CST this afternoon for NDZ004- 005-012-013. High Wind Warning until noon CST /11 AM MST/ today for NDZ009- 017-018-031>033-040-041-043-044. High Wind Warning until 3 PM CST /2 PM MST/ this afternoon for NDZ019>021-034>036-042-045>048-050-051. Winter Weather Advisory until noon CST /11 AM MST/ today for NDZ019-020-034-042-044-045. Winter Weather Advisory until 6 PM CST this evening for NDZ035- 036-046>048-050-051.