528 FXUS63 KABR 061951 AFDABRArea Forecast Discussion National Weather Service Aberdeen SD 251 PM CDT Sat Sep 6 2025
.KEY MESSAGES...
- Low temperatures Sunday morning will be within around 5 degree of record low values.
- High temperatures Sunday will be around 10 degrees below normal.
- Patchy frost is expected late tonight into early Sunday morning, mainly east of the Missouri River, as temperatures drop into the 30s.
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.DISCUSSION... Issued at 251 PM CDT Sat Sep 6 2025
East of the MO River, a ribbon of moisture around 800mb and daytime heating has resulted in another day of flat fair weather cumulus clouds. This ribbon of moisture will be diminishing during during the late afternoon and evening hours. A few forecast models have indicated the potential for fog over portions of our eastern counties around daybreak Sunday morning. However, the fog potential looks limited at this time. If fog or lower ceilings were to develop it would result in warmer overnight temperatures and potentially negate some of the frost. The elongated area of high pressure set up from Manitoba through ND and the east half of SD will be focused over our area by 06Z and drift across IA and southern MN shortly after daybreak Sunday.
A Frost Advisory has been issued for most of our counties east of the MO River for late tonight into early Sunday morning. The low temperature forecast is to be in the 30s. Record lows for September 7th are mainly in the low to mid 30s, and 29 degrees at Aberdeen. If winds go calm, a few of these records could be in jeopardy. Aberdeen is the least likely to be broken at this point, as our current forecast is for a low near 35. A PNS has been issued to highlight the current forecast low and record lows for the 7th.
Southerly winds will return during the day Sunday, between the exiting surface high and trough over eastern WY and far southwestern SD by Sunday afternoon. Gusts of 20 to near 30 mph can be expected over central South Dakota, along with increasing temperatures. Lows Monday morning will be in the 50s, or 15 to 20 degrees higher than what is forecast for Sunday morning. Winds just above the surface (low level jet) will be 30-35kts overnight into early Sunday morning. A 20% chance of showers and thunderstorms will return to far eastern SD and western MN as early as Monday into Monday evening as the surface trough to our west pushes a low over at least central SD Monday into Monday night before sinking to our south.
Taking a look at the overall pattern, the 500mb ridge flatting out over our area Sunday night and Monday will rebound for the middle of the work week, in response to the next 500mb low moving onshore over the west coast. A 20-30% chance of showers and storms will return to central SD Wednesday, and expand across the rest of the area off and on during the rest of the forecast period. Overall precipitation amounts look to be at or below seasonal normal values for this period.
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.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1228 PM CDT Sat Sep 6 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected to continue over the next 24 hours. Less than 20% of model guidance does show fog near/south of ATY around daybreak Sunday. We will leave this out of the forecast for now, but monitor the latest trends for a possible addition to later TAF issuances.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...Frost Advisory from 3 AM to 9 AM CDT Sunday for SDZ004>011- 016>023-034-036-037.
MN...None. &&
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DISCUSSION...06 AVIATION...06
NWS ABR Office Area Forecast Discussion