976 FXUS63 KABR 111415 AAB AFDABRArea Forecast Discussion...UPDATED National Weather Service Aberdeen SD 915 AM CDT Thu Sep 11 2025
.KEY MESSAGES...
- There is a Marginal Risk (level 1 out of 5) of severe weather over portions of north central SD this evening and again on Friday. Additional strong to potentially severe storms will be possible this weekend.
- High temperatures will run 10 to 20 degrees above normal today through Saturday.
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.UPDATE... Issued at 914 AM CDT Thu Sep 11 2025
At this time, no changes are planned to the today period.
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.SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/... Issued at 445 AM CDT Thu Sep 11 2025
Hi-res models are not impressed by the marginal risk in place today and Friday, mainly for north central SD. Southerly flow below upper ridging will help draw in some moisture, enhancing CAPE. Surface low pressure is expected to move off the Rockies and into the western Dakotas this evening. Shortwave energy moving through the upper ridge will add some lift. The low meanders over western SD on Friday, nosing into central SD by late afternoon. Bulk shear remains marginal at 25 to 30 kts. There`s some weak capping with H7 temps of +12C, but until the low and its associated frontal boundaries lean farther east on Friday, forcing is minimal. This may be why most hi- res and ensembles are struggling to place any pops over the forecast area.
Southeast winds will be breezy today and Friday with gusts to 35 mph today. The good mixing under the ridge will push highs into the upper 80s to lower 90s today and Friday from the James Valley west, well above normal for mid September.
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.LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/... Issued at 445 AM CDT Thu Sep 11 2025
Friday evening, the area is under a southwestern upper level flow pattern with a trough sitting off to our west on the western side of the Rockies. The trough moves east through the day Sunday and looks to be across the area by the end of the day Monday. There is fairly good agreement among deterministic models of this outcome. The next upper level disturbance comes in during the mid week. There is less agreement here than the weekend trough. The EC shows a low tracking across ND Tuesday while the Canadian brings it across ND Tuesday evening and the GFS brings a much weaker low across SD on Thursday.
Shower/storm chances start late Friday night/early Saturday morning as that weekend trough starts to move in. There is a chance that some storms could become severe. There is a marginal risk (level 1 out of 5) for severe storms over north central SD. The main threat with these storms looks to be wind gusts of 60+ mph, although there is a chance of some hail an inch in diameter. 40-60% PoPs continue through the day Saturday staying mainly west of the James River. 40- 50% PoPs spread east Sunday before diminishing Sunday night. The next significant round of PoPs moves in Tuesday afternoon and evening and the NBM keeps chances through the end of the period due to the uncertainty among the models on that mid-week low. Temperatures during the period get closer to average for this time of year as we move into mid-week. Winds are expected to be relatively calm which could lead to several days of morning fog.
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.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 621 AM CDT Thu Sep 11 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected through tonight. Southeast winds will increase this morning with gusts to 30 kt.
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.ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. &&
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UPDATE...10 SHORT TERM...20 LONG TERM...13 AVIATION...20
NWS ABR Office Area Forecast Discussion