369 FXUS63 KABR 131532 AAB AFDABRArea Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1032 AM CDT Sat Sep 13 2025
.KEY MESSAGES...
- There is a Marginal Risk (level 1 out of 5) of severe weather over central South Dakota through Sunday morning, before expanding to eastern South Dakota and western Minnesota Sunday afternoon into Sunday night. Hail up to an inch in diameter and wind gusts up to 60 mph are the primary threats.
- There is a slight risk (level 2 out of 4) for excessive heavy rainfall over portions of north central South Dakota through tonight, and over central South Dakota (mainly west of the Missouri River) Sunday into Sunday night. The main concern will be rain falling over the same location/training storms.
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.UPDATE... Issued at 1027 AM CDT Sat Sep 13 2025
Continuing to see the heaviest showers across north central SD this morning, producing heavy rainfall at times over the same areas. Elsewhere, general showers further south and east over the CWA and had earlier this morning expanded PoPs to better match radar trends. Fog across the eastern CWA still remains mainly around the Summit region and have mention of this through the remainder of the morning. SPS was issued earlier this morning to highlight dense fog. Expansive cloud cover across a good portion of the CWA, but there should be gradual erosion through the day. High temperatures may be in jeopardy for some locations (due to lingering cloud cover) and will continue to monitor.
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.DISCUSSION... Issued at 413 AM CDT Sat Sep 13 2025
Warm, muggy air remains in place this morning with temperatures at 08Z in the 60s, with low 70s south of PIR. Patchy to areas of fog remain over and east of the Sisseton Hills/Prairie Coteau this morning. At 09Z the visibility at ATY was less than 2 miles, with area webcams showing lower visibility north and east.
The current surface weather map shows the area of low pressure along the south central SD/north central NE border near VTN. There is a marginal risk for severe storms across central South Dakota through the day Sunday, and across the forecast area Sunday night. If strong storms develop, the main concern would be damaging wind gusts up to around 60 mph and large hail up to around an inch in diameter.
Showers and storms continue north of the low mainly north of a line form Mission Ridge to Onida. We will continue to monitor this area of precipitation as it moves over some locations that already received heavy rain in excess of 3" across western Corson County. The HRRR has done a fairly good job this morning with the areal coverage of the showers and storms, and will be integrated into the ongoing forecast. The overall trend is for the more steady precipitation to shift into ND by daybreak, with more spotty showers and a few storms lingering over central SD through the daytime hours today. Again, the focus for excessive rainfall will likely be over portions of north central SD, and mainly Corson and Dewey Counties which are highlighted in the WPC excessive rainfall forecast for today/tonight.
The surface low will slide a bit east, mainly around Redfield and south by 03Z Sunday and drift north overnight as a reinforcing low over southwestern NE moves into south central SD Sunday afternoon. There are some differences in how storms later this evening and overnight will evolve, with the most likely scenario being strong to potentially severe storms again over central SD and generally west of the MO River. Timing/location/intensity of these storms vary significantly but there are some common themes. By 03Z Sunday the main area of concern looks to be south of PIR before expanding and spreading north again through the night. We will be watching for embedded stronger storms and training of storms that could lead to flooding tonight into Sunday morning. The threat over central South Dakota through the day Sunday will expand to eastern South Dakota and western MN Sunday afternoon into Sunday night.
By 12Z Monday the surface low will be over far northern SD, but mainly across ND, with a trough lingering across eastern SD through at least 00Z Wednesday. There are some small differences on the timing of the eastern exit of the trough. The overall trend will be lower/near normal temperatures by Wednesday afternoon through the rest of the period. After mainly dry weather late Monday afternoon and Monday night, a 40-50% chance of showers and storms will return for later Tuesday through Wednesday.
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.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 639 AM CDT Sat Sep 13 2025
Terminals KABR,KATY,KPIR,KMBG
IFR to LIFR ceilings continue at ATY with MVFR to VFR fog through around 15Z. The main concern is thunderstorm activity over central SD. The storms south of MBG have a history of producing wind gusts of 30-40kts. Have increased winds at MBG. Timing of additional storms remains difficult over central SD, with the highest chances again tonight when -shra or PROB30 thunderstorms have been included.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. &&
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UPDATE...TMT DISCUSSION...06 AVIATION...06
NWS ABR Office Area Forecast Discussion