471 FXUS63 KFGF 090451 AFDFGFArea Forecast Discussion National Weather Service Grand Forks ND 1151 PM CDT Mon Sep 8 2025
.KEY MESSAGES...
- After a bit of a break, thunderstorm chances return on Thursday and continue off and on through the weekend.
&&
.UPDATE... Issued at 1151 PM CDT Mon Sep 8 2025
Got a spotter report of fog east of Detroit Lakes and visibility has dropped down to a half or even quarter of a mile at Baudette. Web cams show coverage is extremely patchy currently. Will include a mention in the grids but hold off on any headlines for now as uncertain how mid and high clouds moving in from the west will affect visibility. Still some lingering showers and thunderstorms just southwest of our CWA as well as in west central MN, so kept some low POPs going for much of the night.
UPDATE Issued at 950 PM CDT Mon Sep 8 2025
Still getting some showers and thunderstorms mainly in the southern CWA although a few stray showers have approached Benson county from central ND. Should continue to see at least isolated to widely scattered activity as the shortwave moves through and elevated CAPE continues. Low level jet is feeding storms more to the east, and shear has been on a downward trend the past few hours. The threat of severe has diminished and the marginal risk has been removed. Adjusted POPs for current radar trends, but lightning and brief downpours will remain the main impacts.
UPDATE Issued at 657 PM CDT Mon Sep 8 2025
Still getting showers and a few weak thunderstorms developing over the southern Red River Valley into western MN as shortwave moves through. Not a lot of ML CAPE to work with but elevated CAPE is around 2500 J/kg and effective shear around 30 kts so can`t completely rule out some cells strong enough for elevated hail in the next few hours. Risk still looks marginal so messaging 1 out of 5 seems reasonable. Made some minor tweaks to POPs for timing and placement as we head into the overnight, but no major changes to our messaging.
&&
.DISCUSSION... Issued at 328 PM CDT Mon Sep 8 2025
...Synopsis...
Showers and thunderstorms are possible this afternoon, evening, and early overnight hours. H5 shortwave continues southeastward along the downstream side of an approaching ridge. This ridge is expected to move very slowly to the east, displaying characteristics of a standing wave or weak blocking pattern. This is due to deep, H5 troughs on either side of the ridge, with slow movement to the east. Warmer temperatures build into the ridge today through Friday, allowing afternoon highs to climb well into the 70s to low 80s each afternoon. Mid 80s become possible heading into Friday and Saturday before the ridge pushes to the east, giving way to southwest H5 flow. The oncoming flow pattern shows support for showers and thunderstorms as early as Thursday afternoon, with additional precip chances each day through Sunday. While it remains too early to gather exact details, strong storms could be possible late this week and into the weekend due to multiple shortwave passages.
...Isolated Severe Thunderstorms Possible Today...
A weak shortwave is moving across the region this afternoon and evening. A relatively strong 850mb jet is currently moving eastward into west central Minnesota, providing moisture ahead of the shortwave and allowing MUCAPE to climb upwards of 2000 J/Kg. Lapse rates this evening will be high enough to allow a mention of at least a few stronger storms; however, this conditional threat will be somewhat short-lived as the low level jet continues eastward. The primary hazard this evening will be hail up to 1 inch in diameter, with the potential for smaller hail persisting into the early overnight period.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1151 PM CDT Mon Sep 8 2025
Visibility starting to drop at KGFK and KBJI, and could see some LIFR conditions later on towards morning. Will keep vis above 1/2 mile, but will monitor and make amendments as needed as fog formation will be very patchy. Other TAF sites have vis dropping but not quite as much. Light and variable winds but mid and high clouds will also have an impact on fog formation. Fog should burn off by mid to late morning. Winds will pick up out of the north by the end of the period but remain under 12 kts.
&&
.FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None.
&&
$$
UPDATE...JR DISCUSSION...Lynch AVIATION...JR
NWS FGF Office Area Forecast Discussion