textproduct: Aberdeen

KEY MESSAGES

- A Slight Risk for severe thunderstorms (a level 2 out of 5 threat) is in place today. All severe threats, including wind of 60 to 70 miles per hour, hail of 1 inch in diameter, and tornadoes will be possible.

- This is also a Slight Risk for excessive rainfall leading to flash flooding (a level 2 of 4 threat) in place over much of the area today. The greatest chances for excessive rainfall will be over north central and northeast SD as well as western MN. These areas are expected to see at least 1-2" of rain, with the heaviest rain expected in the evening. Areas that see multiple round of storms may see as much as 2-4" of rain in total.

- A slight cooldown is expected Wednesday through at least Thursday, with widespread near-normal to just below normal high temperatures (low to mid 80s). Signs point to a warming trend beginning by the end of the week, and highs may potentially hit triple digits over the weekend.

UPDATE

Issued at 1110 AM CDT Tue Jul 7 2026

Storms are currently less than severe and will continue to move east for the next few hours. Rain reports have ranged from 1 to 3 inches across northern South Dakota. Also received a few reports of small hail. Continue to stay weather aware as frequent lightning still exists in these storms.

UPDATE Issued at 638 AM CDT Tue Jul 7 2026

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

DISCUSSION

Issued at 311 AM CDT Tue Jul 7 2026

As of 07Z this morning, the last of the lingering thunderstorms have moved out of the Aberdeen forecast area, and the early morning hours are expected to be fairly quiet until storms move in again over north central South Dakota after sunrise. Temperatures trend slightly cooler this afternoon, with highs ranging from the mid 80s to mid 90s. Pressure gradient tightens a bit this afternoon, meaning that wind gusts may reach as high as 25-30 knots, particularly along the Missouri River.

Another round of thunderstorms is expected today, and a Slight Risk for severe weather covers the area. A stationary front will settle over the region, providing a source of lift for the storms. The best severe environment will be on the southern side of the front, where a CAPE/shear combo of 2000 J/kg and 30-40 knots will be in place, supporting the potential for hail. Wind will also be a threat, again south of the front with some marginal DCAPE (up to 1000 J/kg) in the area. There is also a bit of a signal for tornado potential along the front. Strong low-level helicity will reach well above 200 m2/s2, and 0-1km shear will increase. With the potential for low LCLs along the boundary, conditions may line up in such a way as to support the tornado threat.

With the stationary front settled in across the region, there is also some concern for flash flooding potential. A southerly to southwesterly low-level jet will move air parcels over the front, and creating the potential for storms to also develop on the north side of the front. Steering winds will be out of the west, generally parallel to the front. Therefore, the setup will potentially be in place for training storms to develop. A number of favorable ingredients are in place, including a long skinny CAPE profile, PWATs upwards of 1.75" (well above the 90th percentile for this time of year), moist low to mid-levels, and a warm cloud layer >10k feet. Cloud layer mean wind and Corfidi upshear vectors looks to both be a bit high, around 25 to 30 knots. These drawbacks could be less of a concern if training storms do indeed develop. With all of that in mind, the flooding threat comes down to two questions: First, will the low-level flow be strong enough to sustain continuous storms, and second, where exactly will the front set up? On the latter point, there has been some increasing signal for the front to become oriented in a more southwest to northeast direction, which would be less favorable flash flooding than the other scenario, a more directly west to east orientation. As of now, the latest high-resolution ensemble guidance places the axis of heaviest rainfall along to just south of the North Dakota and South Dakota border, covering north central and northeastern South Dakota as well as western Minnesota. The 00-06Z time frame appears to have the best chances for the heaviest rainfall, with most areas looking at 1-2 inches in total. The heaviest storms will have the potential to dump as much as 2-4 inches in that 6 hour time period, and up to 5 inches total over the 24 hours ending Wednesday morning.

By Wednesday, the front will complete its journey through the Aberdeen forecast area, and the pattern aloft will shift to become more zonal. As a result, temperatures will cool off slightly through at least Thursday. Highs will be in the low to mid 80s, which is near-normal to roughly 5 degrees below normal for this time of year. Beginning at the end of the week, there is a fair degree of confidence in a warming trend as a broad upper-level ridge takes hold of the western and central CONUS. The latest NBM guidance gives areas west of the James River a 50-70 percent chance for high temperatures to reach triple digit Sunday and Monday as a result of the warmer airmass. Of potential interest, the last time Aberdeen recorded a 100 degree temperature was nearly three years ago, on July 26th, 2023. Probabilities over the weekend of Heat Risk reaching major status reach as high as 70-80% on Sunday and Monday, indicating the potential for widespread heat impacts.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 638 AM CDT Tue Jul 7 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through, at least, the first half of the TAF period. By 06Z Wednesday, sub-VFR cigs could be developing/moving south into the region. More SHRA/TSRA are expected across the region, starting this morning over north central South Dakota (KMBG). As the day wears on, the convective potential spreads further south and east to included the other three terminals. Severe thunderstorms are possible during the late afternoon through late evening timeframe.

ABR WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None.