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KEY MESSAGES

- Seasonably cold today, with rain chances ranging from around 60 percent south to 100 percent north.

- Rain may mix with or change over to snow in far northwest North Dakota this morning, with little to no accumulation expected.

- Near to below freezing overnight temperatures possible throughout the week.

- Near to below normal temperatures through the work week, then favored to warm above normal this weekend into early next week.

- Northwest winds may become strong on Thursday.

DISCUSSION

Issued at 505 AM CDT Mon Oct 12 2026

A deep upper trough axis lies over the western CONUS early this morning, with an embedded closed low over eastern Washington and Oregon. Mid level shortwave energy ejecting from the base of the trough will continue to bring periods of rain across western and central North Dakota this morning, diminishing from southwest to northeast this afternoon and evening as the northern stream begins to cut off from the closed low. The most persistent rain is expected in northwest North Dakota, where rain could mix with or change over to snow this morning. Latest HRRR/RAP soundings at Crosby show maximum temperatures aloft remaining above freezing until after sunrise, at which point diurnal heating could begin to offset dynamic and evaporative cooling mechanisms, keeping surface temperatures just above freezing. The most likely outcome is that there will be a few hours of a rain/snow mix across Divide and possibly into parts of Burke and Williams Counties this morning. Grassy surfaces may turn white, but the probability of snow accumulations greater than half an inch are low.

Forecast highs this afternoon range from the upper 30s northwest to around 50 in the southern James River Valley. An overcast sky is expected to prevail through the night. This will likely prevent a hard freeze, but below freezing temperatures are still possible in western and north central parts of the state. Broad surface high pressure settles over the region on Tuesday ahead of a SW-NE mid level trough axis embedded in the northern stream. Deep layer moisture is not expected to be sufficient to support any precipitation with the mid level trough, except perhaps along the South Dakota border where the left exit region of an upper jet could aid forcing for ascent. Consensus guidance would have low stratus clearing Tuesday afternoon and evening, but erosion of stratus is more difficult with the lower sun angle this time of year, and flow aloft remaining cyclonic does not lend confidence to clouds clearing either. Forecast high temperatures in the mid 40s to mid 50s may be slightly too warm if/where an overcast sky prevails. Confidence does begin to increase in clouds clearing Tuesday night, especially in northwest North Dakota where flow aloft will begin to turn anticyclonic. NBM 50th percentile lows are in the mid 20s to mid 30s at most locations. With surface high pressure in place, locations that see a clear sky would likely fall colder than this. But even the 90th percentile, which would be a more likely outcome under an overcast sky, brings Tuesday night lows below freezing across much of western and north central North Dakota.

Ensemble consensus has increased in a transient upper ridge on Wednesday as the cutoff low spins over the Four Corners region and the surface high begins sliding eastward toward the Upper Mississippi River Valley. A sunnier day should allow high temperatures to climb to around 55 to 60, with very light winds. The forecast from Wednesday night through Friday centers around the evolution of the Four Corners cutoff low and a potent shortwave digging into the southern Canadian prairie provinces and US Upper Midwest. Latest cluster analysis gives around a 75-80 percent chance (3 out of 4 clusters) that the cutoff low will eject eastward and interact with the northern shortwave, but only around a 15 percent chance (1 of those 3 clusters) it will do so far enough west to bring more than some very light rain into southern North Dakota Wednesday night into Thursday. NBM precipitation chances have in turn lowered to 15-30 percent, and are only that high from the southwest corner of the state to the James River Valley. Regardless of where the phasing of the 2 systems occurs, all 3 clusters indicate a potential for strong northwest winds on Thursday, with timing of the cold frontal passage favorable for maximizing potential momentum transfer. Each of the 3 clusters shows medium to high chances for 850 mb winds exceeding 40 kts, and low chances for exceeding 50 kts. But there is some longitudinal variability in the axis of strongest winds. If the strongest winds were to line up over southwest North Dakota, fire weather could become a concern.

Regardless of the outcome of the cutoff low, ensemble confidence is high that strong upper ridging will build over the Rockies on Friday and shift eastward on Saturday, leaving a quasi-zonal flow pattern over the Northern Plains in its wake. Cooler and windy conditions may hold on in eastern parts of the region through Friday, but a significant warmup is favored on Saturday, with above normal high temperatures in the 60s and lower 70s lasting into early next week.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 505 AM CDT Mon Oct 12 2026

Rain is expected across northern North Dakota through early this afternoon, ending from west to east from mid afternoon through the evening. Southern North Dakota will see intermittent periods of rain over a similar time frame. MVFR to IFR visibility is possible with heavier showers. Outside of falling rain, fog/mist could also reduce visibility this morning, especially in southwest North Dakota. In northwest North Dakota, rain could mix with or change over to snow this morning. Mostly IFR to LIFR ceilings are expected through the forecast period, perhaps lifting to MVFR in north central North Dakota this morning and in southern North Dakota this afternoon and evening. Winds will turn from northeast around 10-15 kts this morning to northwest around 10 kts this afternoon.

BIS WATCHES/WARNINGS/ADVISORIES

None.