textproduct: Grand Forks

KEY MESSAGES

- Isolated strong or severe storms possible early this evening in parts of west central Minnnesota

..Potential isolated severe storms this evening

With upper low and surface low in cenetral Manitoba at the surface south winds will turn a bit more westerly today, with south-southweste winds holding from eastern SD into northeast MN. This weak boundary will be in place with consensus from near Ely MN back toward Elbow Lake MN and into northeast SD. MUCAPE near and south of the boundary will reach 1500-2000 j/kg range in a band from Duluth to Brainerd to Elbow Lake. Thus idea of a narrow axis of isolated thunderstorms forming in that zone seems reasonable. NAMnest is more aggressive than most though. So pops in this area are not high yet as confidence in storm formation remains more in the 30 percent range. SPC has this zone mentioned from NE MN into SD in marginal risk, and this covers far southeast fcst area. Timing wise if storms form it would be after 6 pm. 0-6 km bulk shear isnt that great but enough for a few supercells with shear around 25 kts. Hazard would be potenteial for 1 inch hail and 60 mph winds.

There is some support from NSSL machine learning for a high enough risk of severe storms in that zone to at least mention.

For the rest of the week, precipitation chances will depend on position, development of upper low as models move the Wyoming low into South Dakota. Very slow moving so a prolongued period of shower and t-storm chances start Wednesday and persist into the weekend, though how far north rain gets is uncertain. Model blends and WPC both have rainfall amounts for the 12z Wed to 12z Sun period of around 2 inches or more in far SE ND, parts of west central MN. But this rain will fall in waves, but these high amounts will be over a long period. But something to monitor for any flooding potential if one period seems to be more robust.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1118 PM CDT Mon Sep 15 2025

Winds have continued to diminish this evening. VFR conditions will prevail through the overnight period and for most of the TAF period tomorrow. Scattered cumulus is expected to develop tomorrow afternoon with ceilings between 1500-3000 ft, so there is the potential for MVFR conditions to arise if density is high enough. No other aviation impacts are expected.

FGF WATCHES/WARNINGS/ADVISORIES

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