textproduct: Grand Forks

KEY MESSAGES

- There is a level 1 out of 5 risk for severe storms today. The main impacts for any storms that become severe will be golf ball sized hail and winds to 60 mph, with a lower risk for a tornado in the Devils Lake Basin.

- Heavy rainfall with any slower moving thunderstorms may lead to localized flooding in poor drainage areas this afternoon into the overnight.

- Windy conditions develop Tuesday with wind gusts to 50 mph across parts of northeast North Dakota and the northern Red River Valley in Minnesota.

..Severe Thunderstorm and Heavy Rain Risk

Ongoing showers and embedded thunderstorms have remain weaker in a much more elevated airmass featuring skinny CAPE profiles but strong effective shear. Current activity developed with the nose of a LLJ and elevated WAA in the 850-700 MB layer and besides heavy rain/lighting it may only feature a marginal hail threat. Expansive cloud cover is also lingering, which may lower our window for surface based thunderstorms during the afternoon and evening.

Surface pattern indicates surface troughing over western ND, with several fronts intersecting near Dickinson. The deepening of this surface low and position/timing of these fronts before sunset will be critical for any potential supercell development to our west that may track into the Devils Lake Basin/eastern ND during the evening hours. Forcing is much more diffuse before the main trough starts shifting east later this evening/overnight, so coverage/initiation carries more uncertain. Still, within the warm sector where clearing develops decent instability profiles may coincide with strongly veered hodographs/strong shear favorable of supercells and a conditional risk for hail around the size of golf balls and a conditions risk for tornado development. Some CAMs (mainly runs of the HRRR) have supported supercell developing to our west and potentially tracking east into our west. The farther east and the later activity lingers/tracks activity will tend to become weaker with more of a marginal hail risk.

Higher PWATs in place raises potential for heavy rain rates with thunderstorm activity once again as with previous days, and any slower moving/training clusters could lead to localized flooding.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 630 PM CDT Mon Sep 7 2026

Variable flight conditions are forecasted throughout the TAF period. To start, south/southeasterly winds will die down after sunset this evening, losing their gusts. A few thunderstorms may push in from the west at KDVL after sunset, therefore maintained a PROB30 at that terminal. Probabilities for thunderstorm activity was too low at all other terminals to include in the TAF. Overnight, a period of MVFR stratus looks to develop at KBJI, sneaking into KTVF as well. Ceilings may flirt with IFR at times, especially around sunrise. There is also some model guidance that brings MVFR back as far west as KGFK and KFAR. While a low probability scenario, it is worth mentioning considering how stubborn cloud cover has been the past several days.

A front passing through overnight into Tuesday morning will bring a shift in wind direction, along with a rapid increase in wind gusts. Gusts in excess of 30 knots are forecasted at KDVL, KGFK and KFAR for at least several hours on Tuesday. The strongest winds will occur during afternoon hours, especially at KGFK and KDVL.

FGF WATCHES/WARNINGS/ADVISORIES

ND...Wind Advisory from 10 AM to 7 PM CDT Tuesday for NDZ006>008- 014>016-024-026>030-054. MN...Wind Advisory from 10 AM to 7 PM CDT Tuesday for MNZ001-004- 007.