textproduct: Grand Forks

KEY MESSAGES

- There is a level 1 out of 5 risk for isolated to scattered severe storms Saturday night in parts of southeast North Dakota and over most areas Sunday late afternoon and night.

UPDATE

Issued at 347 AM CDT Sat Aug 29 2026

A cluster of showers and t-storms developed just north of Fargo around midnight and have been developing slowly east/southeast with time and will continue to do so. The area is on the nose of a 35 kt 850 mb jet and moisture advection. Strongest jet is farther south into the storms moving into SW Minnesota. Overall this activity will be in MN lakes country thru mid morning, with west development possible into the city of Fargo. Storms are elevated in nature and not quite strong enough to generate hail so far as individual storm cores/updrafts have been short lived. PWS station near Perley MN had 2.02 inches of rain 1230 am to 330 am. Pockets of 1-2 inches in this area thru north central Clay county and into parts of northern Otter Tail county likely as well. But lack of heavy rainfall rates lasting for a long time at any one spot and also rain is over non-urban areas so flooding concerns are limited.

UPDATE Issued at 954 PM CDT Fri Aug 28 2026

In a bit of a lull with only a few scattered rain showers, but expecting convective activity to ramp up later tonight as the shortwave along the MT/ND border moves east and the low level jet ramps up. Many of the CAMs keep the strongest thunderstorm cells to our south over SD/central MN, but several of the solutions break out some pretty strong activity near the I-94 corridor. Can't rule out some elevated storms producing large hail as we head into the overnight. As for heavy rain, there has been some shift further north with the western end of the heaviest precipitation band, more in the central Red River Valley. However, west central MN continues to show the best chances for 2 to 4 inches, with a few CAMs showing pockets of 5 inches. At this point have nothing to add to the current messaging for marginal severe and heavy rainfall potential.

..Synopsis

Relatively low amplitude longwave ridging will allow a series of shortwaves to permeate east along the top of the ridge through early next week bringing above average moisture to the region for the 6-10 day period. With these shortwaves will come a minor risk of flash flooding and low end severe chances (mainly wind/hail) each day through Sunday. Beyond these threats the rains will certainly be welcome and beneficial to easing the worsening drought though is likely too little, too late for many crops unfortunately and may even put a short stop to the ongoing wheat/sugar beet harvest. Dry/hot Ridging does briefly return for the middle of next week before we transition to prevailing SW flow aloft indicating another wet period though uncertainty remains on any amounts or associated hazards (flooding/severe).

- Today

Machine learning remains pessimistic overall about the chances for any severe weather tonight with hail being the only thing really sticking out. Overall buoyancy is pushing 2000-2500 MUCAPE with 40kts of eff shear. Overall the marginal risk for a couple quarter sized stones is warranted but the threat seems to be more of a heavy rain one. The saturated profiles aloft could be an artifact of convective contamination on the CAMS but assuming they are not that type of profile does not fit the conceptual model for efficient hail growth. Conversely the elevated nature of parcels given inflow layers around 800-850mb and long straight hodos should favor hail growth. Its really a tossup between if hail occurs or it goes the way of efficient warm cloud layers producing a predominant heavy rain threat. Should hail occur analogs support hail of golf ball to baseball but would think the max size would trend toward the lower bound of that range.

That said the pattern does overall resemble the Maddox Frontal Pattern with the ridge to the western and a shortwave paralleling the stalled 850-700mb front. Sustained overnight southerly moisture return along with general WAA across the front combined with cloud layer (850-300mb) shear of ~40kts atop deep moisture convergence should favor repeated training storms in southeast North Dakota and west central Minnesota overnight. Some CAMS are outputting areas of 2-4" with many areas likely to see at least quarter inch tonight easy the drought south of HWY 200. The confidence in these higher totals manifesting is currently too low to issue a Flood Watch but it remains something to be monitored tonight (10pm to 8am).

- Saturday

Another shortwave is forecast to crest the flattening ridge on Saturday with a developing surface low on the MT/ND border. This will bring more strong southerly moisture return to north central North Dakota and a marginal risk for severe weather to the western 2/3rds of the state. A few strong storms may make into the Sheyenne river valley but most stay west of the Red River Valley. HREF PMM is showing areas of 1-2" with this activity but it mostly remains west of our forecast area unfortunately. Could still see a few areas in north central North Dakota with amounts exceeding a quarter to half inch but those will be the lucky few rather than the norm for our forecast area.

- Sunday

More storms are yet again expected Sunday afternoon/evening as yet another shortwave moves east through Montana initiating storms along the state border around 5-7pm working east as an line as eff shear of 40-50kts and MUCAPE of 2500-3000 looks to favor linear modes with time. Right now the ceiling looks to be a strong MCS perhaps with hail initially west of Bismarck and winds up to 70mph out here. Should the low levels be favorable some mesovortex type tornados cant be ruled but will have to monitor that threat more over the next 24 hours as CAMS become available.

- Next Week

Near zonal to southwesterly flow aloft continues into next week. Temps look to be above average with several chances for precipitation as weak shortwaves come through. Timing and intensity of any storms still uncertain with such weak forcing and unknown instability.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 710 AM CDT Sat Aug 29 2026

For most of the day into tonight a broken coverage sky in majority altocu. Kept cloud bases in the mostly 5000-8000 ft agl and higher thru the period with a southeast wind 5-10 kts. It is anticipated that the morning t-storms will hold in that area from south of Fargo to Fergus Falls.

FGF WATCHES/WARNINGS/ADVISORIES

ND...None. MN...None.