textproduct: Aberdeen

KEY MESSAGES

- Widespread rain showers and weak thunderstorms move into the area early this morning, continuing into the afternoon. The heaviest precipitation is expected after sunrise over parts of eastern South Dakota and western Minnesota, where some areas may see upwards of an inch of precipitation through this evening. Elsewhere, expect around half an inch of rain in total.

- Strong northwesterly winds will increase behind a cold front this afternoon into evening. Wind gusts will range between 40 to 55 miles per hour this afternoon through tonight. A Wind Advisory has been issued for north central South Dakota.

- Combination of strong winds and humidity below 40 percent will lead to High to Very High fire danger this afternoon across central and north central South Dakota. An increase in humidity will limit fire weather concerns further east.

UPDATE

Issued at 1214 PM CDT Mon Sep 14 2026

Updated discussion for the 18Z TAFs below.

UPDATE Issued at 1011 AM CDT Mon Sep 14 2026

As of 15Z, the center of low pressure is hovering over northwestern ND/MT into Canada with the occluded front extending southward through the western Dakotas and secondary low over southwestern SD with its warm front through NE/KS. Scattered to widespread elevated showers and thunderstorms continue on the WAA side of the system with the bulk of the precip along and east of the Coteau with additional area of precip over south central and through northeastern SD. PWAT values are around 1.5-1.8" (highest eastern CWA) with strong 925/850mb moisture transport from the south and southeast. Overall rain totals have ranged from around a half inch in MBG, .08" in ABR with MBG/ATY around 0.1". As the front tracks eastward, so will the precip with the possibility of additional development through the morning over central SD and afternoon James Valley and eastward. The last of the precip is forecast to exit eastern SD/MN by late afternoon to early evening. Behind the front, winds will increase with gusts of 30-50mph this afternoon and evening, highest over north central SD with tease stronger winds spreading eastward tonight. Other than minor updates to pops, forecast remains on track.

UPDATE Issued at 628 AM CDT Mon Sep 14 2026

See below for an aviation forecast discussion for the 12Z TAFs.

DISCUSSION

Issued at 247 AM CDT Mon Sep 14 2026

Rain showers and weak thunderstorms are moving into the forecast area from the southwest this morning. Expectations over the next couple of hours is that coverage of these showers and storms will continue to expand, covering most if not all of the forecast area by sunrise. These showers and storms are fueled by a 40-50 knot low- level jet moving across the region this morning, strengthening to 55 knots as it progresses eastward after sunrise. In addition to the storm development, this low-level jet is expected to bring strong southerly gusts up to 40 miles per hour to much of northeastern South Dakota and western Minnesota this morning. Still anticipating the highest rainfall totals over eastern South Dakota, and NBM median values through tonight sit around 1"-1.25" over Codington County and the surrounding counties. As mentioned in previous discussions, there is an outside chance of flooding potential given the abnormally high PWAT values advected into the region (around 1.5"-1.75", well above the 90th percentile for mid-September), full saturation through the profile, and a warm cloud layer depth of roughly 11-12k feet. However, antecedent conditions are not very favorable for flooding, and much of eastern South Dakota in particular is under D0-D1 drought. Storm motion is also expected to be fairly quick, although with the low-level jet in play the development of training storms cannot be ruled out. Perhaps the biggest limiting factor though is the lack of CAPE. Generally expecting less than 1000 J/kg of MUCAPE, although it should be noted that values seem to be increasing over the past couple of forecast cycles. Still, not expecting much in the way of strong thunderstorms or severe weather with this development, but will continue to keep a close eye through the morning hours.

After the passage of the cold front, winds will turn northwesterly and increase. The strongest winds, gusting upwards of 35 miles per hour, are expected along and west of the Missouri River, particularly over Corson and Dewey Counties. NBM probability of reaching 45 mile per hour gusts in those two counties sits in the 40- 60% range from around noon Monday through midnight Monday night. Elsewhere, both NBM and HREF probabilities of reaching wind advisory criteria struggle to reach more than 20-30%. However the combination of the strong cold air advection coming in behind, a shallow diurnal inversion at the surface, and the tendency for the NBM in particular to verify near the 90th percentile under this type of setup, there is some slightly increased confidence given to needing an Advisory over Campbell/Walworth/McPherson/Edmunds Counties. Therefore, have expanded the coverage on the previous advisory, running the new additions from 00Z-09Z Tuesday. The potential failure point here would be if the inversion holds, but given the expected temperature drops at 850mb (nearly 10 degrees Celsius in 6 hours), the profile will likely than not be able to maintain some degree of mixing to the surface.

In addition to Advisory level criteria, winds during the afternoon will be the driver behind some elevated fire weather concerns. A brief warmup in temperatures this afternoon out ahead of the front over central and north central South Dakota will push afternoon humidity down below 40 percent over the westernmost column of counties in the Aberdeen CWA. The combination of the wind and low humidity, in addition to fuel status considerations, leads to the Grassland Fire Danger Index reaching Very High in that area. Counties just to the east of the previously mentioned area will reach High Grassland Fire Danger as well.

By mid-week, the upper-level setup will transition to near-zonal flow and a positively tilted trough over the western CONUS. This setup will allow for additional shortwaves into the region, leading to more chances for rain later in the week. Specifically, Wednesday and Friday both sport chances for rain at this time. Model soundings for both of those days do not look particularly favorable for any severe weather potential, although perhaps a touch to early to say for certain on Friday in particular. Also expecting a gradual warming trend with this setup, with median high temperatures reaching near-normal (mid-70s) over the weekend.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1214 PM CDT Mon Sep 14 2026

Terminals KABR,KATY,KPIR,KMBG

Rain has ended at KPIR/KMBG with light to moderate rain continuing at KABR/KATY as the back edge of the precip is just west of the James River. As the front continues to track eastward, the last of the rain should exit far eastern SD/MN by later this afternoon to early this evening. MVFR/IFR cigs per low stratus will decrease west to east behind the front through the late afternoon and evening with ceilings increasing. VFR cigs are then forecast through the rest of the TAF period.

Behind the front per colder air, pressure rises, and stronger winds aloft will mix down with winds increasing west to east across the region with gusts of 30 to 55 mph out of the west/northwest this afternoon through early Tuesday morning. High pressure will filter in, diminishing the winds through Tuesday.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory until 1 AM MDT Tuesday for SDZ003-015. Wind Advisory from 7 PM this evening to 4 AM CDT Tuesday for SDZ004-005-009-010. MN...None.