873 FXUS63 KFGF 161147 AFDFGFArea Forecast Discussion National Weather Service Grand Forks ND 647 AM CDT Tue Sep 16 2025
.KEY MESSAGES...
- Isolated strong or severe storms possible early this evening in parts of west central Minnnesota
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.UPDATE... Issued at 642 AM CDT Tue Sep 16 2025
That shower and t-storm cluster that was near Bismarck indeed moved northeast and just recently dissipated in the New Rockford/Carrington area. High clouds is over south central into eatesrn ND with a clear to partly cloudy in NW/WC MN. Balance of the day to be partly to mostly sunny.
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.DISCUSSION... Issued at 333 AM CDT Tue Sep 16 2025
...Synopsis...
As one upper low sits over central Manitoba ealry this morning, there is one upstream moving south-southeast thru northweset Saskatchewan and another upper low over northwest Wyoming.
The upper low in Wyoming is bringing southwest flow aloft into southern ND early this morning along with a not well forecasted short wave that is south of Bismarck. An area of showers and t-storms continues to move slowly northeast and CAMs and global models not handling it well at all. 07z HRRR is finally catching the area of rain and moves it into the area between Valley City and Devils Lake and then weakens it. But also earlier model runs did the same thing after 1-2 hours. Coord with BIS to spread some pops into that area btwn Valley City and DVL early this morning.
...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.
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.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 642 AM CDT Tue Sep 16 2025
Scattered to broken high clouds over the area today. Winds rather light...but eventually turning to the west or southwest 5 to 9 kts. Risk of isolated t-storm this evening only for areas around Wadena to Elbow Lake, Fergus Falls.
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.FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None.
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UPDATE...Riddle DISCUSSION...Riddle AVIATION...Riddle
NWS FGF Office Area Forecast Discussion