687 FXUS63 KABR 270803 AFDABRArea Forecast Discussion National Weather Service Aberdeen SD 303 AM CDT Sat Sep 27 2025
.KEY MESSAGES...
- Above normal temperatures (10-15 degrees above normal) plus dry and windy conditions will return for the end of the weekend into the first half of next week.
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.SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/... Issued at 300 AM CDT Sat Sep 27 2025
A dry cold front is passing through the area early this morning, but gusty northwesterly winds behind have been reaching 20-30 miles per hour. These stronger winds remain fairly transient, sticking around only for an hour or two as a surface high pressure center continues to slide east into the CWA. Cold air advection aloft will help keep highs closer to normal today, reaching the low to mid 70s across the forecast area.
An upper-level ridge will build in tonight and Sunday, allowing for an abnormally warm air mass to return to the forecast area. Of note are 500mb heights and 850mb temperatures, both of which are modeled to be well above the 90th percentile for late September, at ~5280m and 20 degrees Celsius respectively. This setup will support highs north of 80 degrees across the forecast area, 10-15 degrees above normal for late September. As the ridge-supported surface high pressure center moves further east Sunday, a tightening pressure gradient on the backside will support the return of southerly winds of 15 to 20 knots, gusting up to 30 knots. The main impact areas are over central into parts of north central South Dakota, but nearly all of the CWA is forecast to have a few hours of 25 knot gusts or greater Sunday afternoon. At this time, the NBM does not give any significant probabilities for a Wind Advisory (sustained winds of 30 miles per hour or gusts to 45 miles per hour) to be issued on Sunday.
Smoke is also a minor concern in the short-term forecast. Current air quality remains at Moderate levels, meaning impacts are likely only to those sensitive to smoke. Still, additional smoke will move into the area today, mainly expected over central South Dakota. Most of the smoke will remain aloft, but enough could still make it to the surface to impact those sensitive to smoke. At this point, not anticipating any visibility reductions due to haze, and air quality is expected to remain within the Moderate threshold.
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.LONG TERM /SUNDAY EVENING THROUGH FRIDAY/... Issued at 300 AM CDT Sat Sep 27 2025
No major changes for the forecast next week. Mild temperatures and the winds are the main `concern`. A broad ridge overhead to start the week is going to be very slowly supplanted by an upper trough developing over the Pacific Northwest, but that may take till next weekend before transiting far enough east that we start to get into the better chances for moisture. Thus...until then its a mainly dry pattern with a series of southwest flow shortwaves. The first plume of elevated moisture from the southwest monsoon comes in late Monday/Tuesday with the current upper low lifting northeast and becoming an open wave. BUFKIT profiles feature moist adiabatic lapse rates above 700mb/10kft. The next few waves after that are weaker and related to plumes of moisture coming in from the Pacific.
As for temperatures, 850mb temperatures are expected to stay above normal at approximately a standard deviation above climo if not higher. Thus, all next week temperatures will be running about 15 to 20 degrees above normal for highs and 15 to 25 degrees above normal for lows thanks to persistent winds. In fact, we are very close to record warm low temperatures for the week.
Winds will also be rather persistent. 1/2km winds are up around 30- 40kts Sunday night, Monday night and Tuesday night as the boundary layer decouples. There will also be a 10mb gradient from northwest to southeast across the state. The only thing about the winds is the mixing efficiency with south/southeast low level flow and warm advection. As such, see no reason to deviate from NBM. Winds will subside Wednesday with a surface trough passage.
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.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1143 PM CDT Fri Sep 26 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected over the next 24 hours. Mainly elevated smoke remains over western SD, and will continue to sink south overnight into Friday morning. Most EPA sensors are in the low end moderate range (yellow) over the area, but visibility restrictions at the surface have not been noted. The mention of smoke remains out of the TAFs at this time due to the limited impacts and no reduction in visibility.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. &&
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SHORT TERM...BC LONG TERM...07 AVIATION...06
NWS ABR Office Area Forecast Discussion