148 FXUS63 KABR 081950 AFDABRArea Forecast Discussion National Weather Service Aberdeen SD 250 PM CDT Mon Sep 8 2025
.KEY MESSAGES...
- Mainly elevated smoke will remain across the area into Tuesday. Some of this smoke will near the surface with visibility reductions possible mainly west of the Missouri River tonight.
- There is a 20% chance of showers and a few thunderstorms over portions of northeastern South Dakota late this afternoon into this evening. Severe weather is not expected at this time.
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.DISCUSSION... Issued at 250 PM CDT Mon Sep 8 2025
A look at the current surface map showed a low pressure center over western ND with a trough over much of the area. A milky sky was observed due to wildfire smoke, with reductions in visibility reported from AWOS/ASOS over far eastern MT and far western ND this afternoon. The surface low will be stretched across central South Dakota and western Minnesota this evening, before exiting across southeastern South Dakota Tuesday afternoon.
Isolated showers have been common over Corson County and portions of south central ND during the morning and early afternoon hours, with the line extending northeast to storms near Bemidji, MN and southwest to the Black Hills. The showers in our area have continued to struggle, and remain limited in coverage and intensity. We`ll continue to monitor the trends, as the boundary moves into an area over eastern SD and western MN that is more unstable. Lapse rates around the entire area will be around 8 C/km, shear is a bit more limited, and CAPE values increase to around 2k J/kg (or higher with the NAM).
The main concern will be around 00-04Z if the cap of warmer air above the surface is able to be eroded. We`ll also be looking for additional light shower and potential thunderstorm development across central SD this evening that may shift to northeastern SD by daybreak Tuesday. Low chances of precipitation (generally less than 30%) remain in the forecast for these 2 areas this evening and overnight into Tuesday morning.
Another elongated are of low pressure will organize to our west on Wednesday, with the pressure gradient increasing over the Dakotas. Winds Wednesday afternoon gust out of the southeast 25 to near 35 mph over central South Dakota. The surface low will finally edge east and move across at least central/NE by 00Z Saturday. Expect 30-60% chances of showers and storms over central SD Friday night to slowly expand across the rest of the forecast area Saturday and Sunday. While timing and placement of the surface low looks reasonable through 06Z Saturday, enough variability begins to move in later Saturday and Sunday to result in a lower confidence forecast. These differences show up in the ensemble clusters for 500mb as well, with the ridge that will be overhead Wednesday either hold on a bit longer with a weaker trough sliding in from the west (as shown by around 35% of solutions) to the ridge shifting east across MN and the Upper Great Lakes (65% of solutions).
High temperatures through Friday will be in the 80s, with just a few upper 70s across far northeastern SD and west central MN both Tuesday and Wednesday. Lows will remain in the 50s to low 60s through the upcoming weekend.
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.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1231 PM CDT Mon Sep 8 2025
Terminals KABR,KATY,KPIR,KMBG
Fog over eastern SD and smoke over western SD will be a concern. However, mainly VFR conditions are expected to continue for the next 24 hours for most locations. MVFR visibility due to smoke has the highest chance of occurring at PIR 06-16Z Monday. Morning fog has the highest chance of occurring at ABR and PIR, but forecast solutions remain inconsistent on coverage and and intensity. As a result, fog was not included in the forecast at this time.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. &&
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DISCUSSION...06 AVIATION...06
NWS ABR Office Area Forecast Discussion