textproduct: Grand Forks

KEY MESSAGES

- Frost chance exists Monday night/early Tuesday for northwest MN and possibly northeast ND.

- Next rain chance is Wednesday night/early Thursday and Saturday.

UPDATE

Issued at 359 AM CDT Mon Sep 21 2026

Broad 500 mb low moving slowly south-southeast into northern Nebraska this morning. Clouds and leftover sprinkles, very light rain showers perist in north central ND around Minot and does extend east toward Rugby and near Devils Lake where sprinkles are in grids thru 6 am. Overall though today will see this upper low move farther away and an upper level ridge begin to build from western Montana into Saskatchewan and Manitoba. This will aid in pushing the upper level system farther south and eventually allow the clouds to clear out over the area today into tonight. Surface high will be well east of our area and we will have no fresh supply of cool air. But sufficiently dry airmass and winds under 5 kts should lead to at least a chance for frost for NW Minnesota, and possibly even parts of northeast ND. The 20-30 percent probabilities of temps below 36F exist in areas east and west of the RRV overnight in northeast ND and northwest MN. The biggest signal of frost is in northeast MN.

..Next precipitation chances Wednesday night and Thursday

Shortwave trough moving into the western Dakotas Wednesday will progress quickly into the Great Lakes by Thursday. Instability is pretty weak at less than 500 J/kg, so severe is not expected although some thunderstorm activity is not completely out of the question. Main impacts look to be rain, with 40 to 60 percent probabilities of over a quarter of an inch in portions of our western and southern counties.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1148 PM CDT Sun Sep 20 2026

The main question overnight is if fog will form. There remains uncertainty on its coverage and exact location. Model guidance shows slightly higher probabilities for fog at KGFK and KBJI compared to elsewhere. With BR already introduced in previous TAF issuance's at these two terminals, maintained its inclusion in this set. However, predictability remains too low to introduce BR or FG at any other terminals at this time. Otherwise, conditions will remain VFR for Monday, with easterly wind of up to 10 knots during the afternoon. Winds will drop off after sunset Monday evening, becoming light and variable to end the TAF period.

FGF WATCHES/WARNINGS/ADVISORIES

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