textproduct: Grand Forks

KEY MESSAGES

- There is a level 1 out of 5 risk for severe thunderstorms Monday afternoon and evening.

UPDATE

Issued at 329 AM CDT Sat Aug 22 2026

Near term/short term impacts are minimal with passing mid level CU, seasonal temperatures in the 70s to near 80. Forecast concern over the next 4 days continues to be on the potential for a few severe thunderstorms late Monday and potentially Tuesday. Monday signal in more reliable AI systems has backed off compared to 24hr ago, and this is primarily driven by less favorable timing of forcing/instability in relation to our our CWA. The trend is for a slower frontal arrival (more guidance keeps this west) and delay in better forcing from the shortwave trough. Deep layer/effective shear will be maximized in our area though during the afternoon/evening and as the front does approach elevated storms could support a hail threat.

The mid/upper low shows more variance in track through Tuesday, with at least some ensemble guidance showing a closed mid level low and center of cold pool dropping over our northeast and eastern CWA and under that scenario there would be at least a conditional risk for weak tornadoes. The vast majority of ensemble guidance shows a weaker low center (more of an open wave) and a track farther north and east with only a minimal chance for showers/weak thunderstorms in our northeast.

..Synopsis

NW flow continues to become more amplified the next few days with increasing ridging across the Rockies and high plains. Troughing off the Pacific coast looks to move ashore Saturday and flatten the ridge bringing increasing precipitation chances Monday and Tuesday. Ridging then returns for the mid and late week. Could see some strong to severe storms on Monday/Tuesday though there are still a some unknowns so wont speculate into the potential too much. Overall seasonal weather with highs in the mid 70s to mid 80s each day and peak daily heat indices generally 80-85 making a it a comfortable stretch of late summer weather.

- Today

A shortwave is quickly traversing the northwest flow aloft with cold air advection behind yesterdays wave helping to steepen mid level lapse rates. Overall pretty skinny instability but reminiscent of a springtime northwest flow with a deepening CU field and the expectation for afternoon showers/thunderstorms once we reach the convective temp in the low to mid 80s this afternoon. Not likley to see high rainfall totals but a few locations in northwest Minnesota could squeak out a quick tenth. Severe weather is not expected with only 20-25kts of eff shear and 1000 j/kg of ML CAPE but some small hail is not out of the question.

- Rain/Severe Chances Early Next Week

Similar to yesterday AI ensembles agree strongly on the track of the wave through the canadian provinces on Monday afternoon/Tuesday morning with the Euro still the more progressive solution but the GFS is catching up as expected. Overall the expectation is for lee troughing east of the rockies with MUCAPE in excess of 2000 j/kg to support at least a wind and hail threat on Monday afternoon/evening across parts of the Dakotas. This does appear to evolve into a closed 500mb wave with closed isotherms as well within the low meeting the definition of a cold core low supporting a localized tornado threat in Saskatchewan and Manitoba Monday but given the track this appears to stay well north of our area.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1220 PM CDT Sat Aug 22 2026

VFR conditions prevail through the TAF period at all TAF sites. North winds are expected most of the day, generally at 7-12 knots. A few gusts to near 20 knots are possible at KFAR, KGFK, and KBJI. Heading into the evening, winds become light and variable. Skies remain clear to partly cloudy today, with only a few cumulus possible this afternoon during peak heating.

FGF WATCHES/WARNINGS/ADVISORIES

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