105 FXUS63 KABR 090509 AFDABRArea Forecast Discussion National Weather Service Aberdeen SD 1209 AM CDT Thu Oct 9 2025
.KEY MESSAGES...
- Southerly winds will increase again on Saturday with gusts up to 40 mph over the forecast area.
- Light rain this weekend, mainly for the James River Valley and eastward. Probability of rainfall of a quarter of an inch or more ranges from 25 to 50 percent.
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.UPDATE... Issued at 858 PM CDT Wed Oct 8 2025
No changes planned to the tonight period forecast.
UPDATE Issued at 634 PM CDT Wed Oct 8 2025
See below for an aviation forecast discussion for the 00Z TAFs.
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.DISCUSSION... Issued at 220 PM CDT Wed Oct 8 2025
Strong southerly wind remains the main forecast concern this afternoon. Low-level jet overhead has been able to mix 40 mile per hour gusts to the surface this afternoon over parts of central South Dakota. We continue to monitor observations, but at the time of this writing (~18Z) there are no plans for a Wind Advisory, as both forecasted and observed winds have fallen short of criteria thus far. Elevated fire weather conditions are only a minor concern today due to the southerly winds advecting increased moisture into the region, but any fires that do manage to start could spread rapidly due to the strong winds. These elevated winds are expected to persist through the afternoon and evening (continuing to gust to 40 miles per hour) before decreasing slightly overnight due to the loss of good mixing into the boundary layer. Winds rebound Thursday, shifting to be mainly over northeastern South Dakota with the progression of low-level jet. Gusts are expected to peak around 30- 35 miles per hour, but some downsloping due to the direction of flow may be possible over the Prairie Coteau, leading to the potential for a localized enhancement of winds. A dry cold front is expected to move through the forecast area Thursday, which will push the low- level jet fully into Minnesota and diminish surface winds by Thursday evening.
An upper-level ridge will continue to be present over the central CONUS for the next couple of days, with an upper-level trough to the west set to replace it in a couple of days. This setup will allow for a bit of a warmup Thursday with the warmer airmass being advected in from the south. This will push temperatures into the mid- 70s, about 10 degrees above normal for this time of year. With the passage of the dry cold front, temperatures will decrease slightly, with dew points following suit. Resulting afternoon highs and overnight lows will be near-normal to just above normal, in the upper 60s and 40s to low 50s respectively through Saturday. Overnight temperatures specifically look to stay warm enough through the weekend to where frost formation will likely not be a concern.
The upper-level trough will support the development of a surface low pressure center that will drag a front across the forecast area this weekend. The main forcing mechanism will be a low-level jet of around 50 knots moving overhead, producing some light rain showers. At this point model soundings do not look very conducive to deep convection, with lapse rates generally around 6-6.5 C/km or lower limiting MUCAPE. As a result, rain rates are expected to be low. The latest NBM runs show a broad 25-50% chance of 0.25" of accumulation over 48 hours ending early Monday morning, with chances increasing as moving from southwest to northeast. Probability of 0.5" peaks at just over 30%, again over northeastern South Dakota into western Minnesota.
Perhaps of greater concern this weekend is the return of strong southerly winds ahead of the front. Pressure gradient will tighten as the low develops to the west, creating the aforementioned low- level jet, subsequently supporting stronger gusts mixing to the surface Saturday and Sunday afternoon. At this time, winds are forecast to remain below Wind Advisory levels (sustained winds of 30 miles per hour or gusts to 45 miles per hour), but it is not out of the question to see gusts reach that high. NBM gives pockets of 10- 20% chances for either sustained winds or wind gusts to reach criteria, mainly over central and north central South Dakota. These southerly winds will be advecting moisture into the the region as well, and dew points will reach 50+ degrees on Saturday over central and north central South Dakota before expanding to cover the entire forecast area Sunday. This added moisture will help keep humidity plenty high enough to where Red Flag conditions will most likely not be much of a concern. Winds are expected to diminish and turn northwesterly with the passage of the front Sunday.
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.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1208 AM CDT Thu Oct 9 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected through the TAF period. Occasionally breezy southerly winds/gusts throughout the forecast area early this morning, with some LLWS for the morning hours, but these will be shifting over to northeast South Dakota and west central Minnesota and increasing during the day, out ahead of a dry cold frontal passage. Behind the fropa, winds will diminish and veer northwesterly.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. &&
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UPDATE...10 DISCUSSION...BC AVIATION...07
NWS ABR Office Area Forecast Discussion