


Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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415 FXUS63 KFGF 100504 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1204 AM CDT Thu Jul 10 2025 .KEY MESSAGES... - Severe storms are possible, risk level 1 out of 5, in eastern North Dakota tonight, with a small area of 2 out of 5 risk in the Sheyenne Basin. - Severe storms risk level 1 out of 5 will develop Thursday afternoon and night. - Heat risk rises to the moderate category Thursday afternoon, but at this point it looks like heat index values will stay below 100 degrees. && .UPDATE... Issued at 948 PM CDT Wed Jul 9 2025 Severe weather has begun across the Devils Lake Basin. Shear is weak, but instability continues to be impressive (about 5000 J/Kg), and DCAPE remains in excess of 1000 J/Kg. Therefore, thinking brief supercellular characteristics that we have witnessed so far could produce hail a little bigger then a quarter, before the weaker shear causes storms to collapse with more of a wind threat. This threat should continue for another 2 hours or so. Further south, a line of storms is propagating in from Stutsman county down to the SD state line. DCAPE is even higher here, around 1500 J/Kg. 0-3 Km shear is not great, about 25 knots, but sufficient for MCS maintenance as the line arrives in southeastern ND. Wind gusts to 60 mph will be the main threat with these storms. The line should continue to push east, eventually shifting southeast with time following the instability gradient. UPDATE Issued at 746 PM CDT Wed Jul 9 2025 Quick update here as severe thunderstorm watch 500 has been issued from the Devils Lake Basin south to Sargent county. Thinking of convective evolution remains similar to the previous update. The only real change is that convective towers west of the Devils Lake Basin and associated updrafts are persisting, so some cluster of strong/severe storms should push through the Devils Lake Basin over the next several hours. Therefore, the watch encapsulates this area, along with the region further south where the cluster of storms near Bismarck should push into later this evening. UPDATE Issued at 705 PM CDT Wed Jul 9 2025 Thunderstorms have fired west of Bismarck along a dry line. A warm front is situated approximately along our western FA border with BIS. South of this warm front, dew points are in the mid 70s, with an axis of MLCAPE of 4000 to 5000 J/Kg, with the axis still residing to our west in central ND. A lack of forcing and capping has kept things quiet in this FA for now. However, as convection evolves further west, we will see how things hold together as they push into Eastern ND. Shear, while currently 30 knots, will decrease with time as storms approach. In addition, instability decreases as you approach the Red River Valley. All told, while convection will hold together in some form into eastern ND, severity of the storms remains more uncertain. The greatest chance for severe weather seems to be in southeastern ND, where at least marginal shear of 25 knots or so will overlap with the best instability/CAPE along a gradient. As the clusters/lines of storms approach from central ND, they will likely ride this gradient, pushing south and east with time. Another area to watch is between Minot and Devils Lake. Orphaning anvils are evident on satellite. If more persistent convective attempts can survive in this region, there is plentiful instability with marginal shear, a cluster could hold together into the Devils Lake Basin. Plenty to watch evolve over the next several hours. && .DISCUSSION... Issued at 307 PM CDT Wed Jul 9 2025 ...Synopsis... Water vapor loop shows shortwave ridging over the Eastern Plains with a few weak embedded vorts moving through. As expected, best moisture and instability are just to our west so far, but no convection so far except way south in western SD. A stronger shortwave will be moving in for Thursday afternoon and evening and pushing a cold front into the forecast area, but much will depend on how tonight plays out. The cold front will push the rest of the way through the forecast area on Friday as upper troughing digs down into the Northern Plains. A bit of a break with northwesterly flow on Saturday but then it switches back to near zonal and then southwesterly late Sunday and into Monday. Another quick moving trough through the Northern Plains on Tuesday and moving east Wednesday with cooler temps and additional thunderstorm chances. ...Severe chances tonight... While plenty of instability available in central ND with temps in the low 90s and dew points in the 70s, it has remained capped so far. Several of the CAMs have the current convection in western SD spreading northeastward into south central ND, which fits current satellite and radar trends. Still not a lot of upper support for development except some very weak vorts that are moving through. However, instability is very strong at over 4000 J/kg and there is at least some deep layer bulk shear around 30 kts in southeastern ND. Probabilities for strong updraft helicities get above 50 percent in south central ND later this evening, and are still around 30 to 40 percent as the convection starts moving into our far southwestern counties. Can`t rule out some isolated large hail and perhaps some scattered damaging winds. Convection should linger after midnight as the moisture plume moves east, but what little shear there was goes downhill and probabilities of strong updraft helicities drop to around 10 percent. ...Severe potential for Thursday... Much will depend on how the convection tonight plays out and if there are any MCVs or lingering outflow boundaries to help focus redevelopment. There is more upper support with a surface boundary moving through, however, much of the shear is behind the cold front and not with the instability plume that will be over the southern Red River Valley. SPC has lowered the risk down to marginal due to the large uncertainty. Updraft helicity probabilities are not very impressive, but some of the machine learning are still highlighting our CWA for severe potential. ...Heat risk on Thursday... The hot temperatures and moist dew points over central ND currently are expected to shift east and be over our CWA tomorrow. Wet bulb globe temps get into the low 80s, and heat risk is up to moderate with a few spots of high. However, there is still some question of if we will get to the heat index values above 100, especially if there is lingering cloud cover from morning convection. Will hold off on any heat headlines for now, but continue to message hot and sticky conditions. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1204 AM CDT Thur Jul 10 2025 Forecast challenge in the short term is the timing and coverage of thunderstorms. Overnight, thunderstorms will continue to push to the east, impacting KTVF and KFAR. Storms may hold together into KBJI, but there is uncertainty, therefore left any mention out of the TAF. With recent moisture, patchy fog may be an issue Thursday morning, but a lot of uncertainty in the coverage and any impacts to visibility. Any fog would be favored at KGFK and KTVF. The most favored period for fog has 6SM visibility mentioned in the TAF. Finally, storms are possible again Thursday afternoon, however there is a lot of uncertainty with how they evolve. Made no mention of them in this set of TAFs, hopefully the details will become more clear by the next set of TAFs issuance. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Rafferty DISCUSSION...JR AVIATION...Rafferty