158 FXUS63 KBIS 220220 AFDBISArea Forecast Discussion National Weather Service Bismarck ND 920 PM CDT Sun Sep 21 2025
.KEY MESSAGES...
- Patchy fog late tonight into Monday morning.
- Above average temperatures through the week.
- Dry conditions through the week.
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.UPDATE... Issued at 920 PM CDT Sun Sep 21 2025
Quiet weather continues here this evening. Most of the hi-res models no longer produce low visibilities due to fog, so the forecast will continue to say `patchy fog`.
UPDATE Issued at 610 PM CDT Sun Sep 21 2025
Quiet weather this evening, so limited adjustments are needed. We are still expecting fog to form again overnight.
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.DISCUSSION... Issued at 207 PM CDT Sun Sep 21 2025
Current surface analysis places low along the Saskatchewan/Alberta border with trough dropping down into central/eastern Montana. Upper level analysis places ridge stretching from the Four Corners region northward into eastern Montana, while a compact low spins over northern Minnesota. Over our area, quiet weather continues with a modest southerly wind ahead of the aforementioned trough. Skies are mostly clear, but some afternoon fair weather cumulus have developed over eastern parts of our area in the modest cyclonic flow on the backside of the aforementioned upper low.
Quiet weather is expected tonight, but winds will start to shift towards the northwest very late tonight as the aforementioned surface trough pushes east. Ahead of this, winds will be quite light with clear skies and ample low level moisture so expect patchy fog to once again be a possibility, lingering into Monday morning.
On Monday, trough meanders east before stalling out over central North Dakota. Winds will become northwest behind this feature, possibly becoming a bit breezy over the far west. Otherwise, a quiet day is on tap with skies remaining mainly clear.
Through the remainder of the week, we end up in perpetually dry pattern with temperatures continuing to be above average, mainly in the 70s to lower 80s, with NBM continuing to show high confidence in the temperature forecast.
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.AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 920 PM CDT Sun Sep 21 2025
VFR CIGs until patchy fog develops tonight. Confidence remains low for now. So for now we left mention out of the TAFs. Light and variable winds through the period.
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.BIS WATCHES/WARNINGS/ADVISORIES... None.
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UPDATE...Smith DISCUSSION...JJS AVIATION...Smith
NWS BIS Office Area Forecast Discussion