269 FXUS63 KFGF 221219 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 719 AM CDT Sun Jun 22 2025 .KEY MESSAGES... - Level 2 out of 5 risk for severe thunderstorms Sunday afternoon and evening. Primary hazards will be damaging wind gusts to 70 mph, large hail up to 2 inches, and isolated tornadoes. - Heat index values approach or exceed 100 degrees in the southern Red River Valley and portions of west central Minnesota. Heat related impacts are expected. && .UPDATE... Issued at 720 AM CDT Sun Jun 22 2025 Watching thunderstorm development this morning in southeastern North Dakota. A few elevated stronger storms have formed thus far in response to steep mid level lapse rates and an approaching H7 shortwave. These storms will continue to lift north and east through the mid morning and could become severe as temperatures warm and instability increases near the surface. && .DISCUSSION... Issued at 308 AM CDT Sun Jun 22 2025 ...Synopsis... H5 ridging continues to work eastward into the Upper Midwest and Great Lakes region today. Shortwave activity will traverse the western flank of the ridge ahead of a cold front that moves into eastern North Dakota this afternoon. Dew points ahead of the front are in the low to mid 70s, which will combine with afternoon highs in the upper 80s to low 90s to allow heat index values upwards of 100 degrees. The cold front will bring a chance for showers and thunderstorms this afternoon and evening with severe thunderstorms possible. Much cooler temperatures return on Monday, along with lower humidity. Look for minimal rain chances Monday and Tuesday, with increased chances for showers and thunderstorms starting Wednesday afternoon. ...Severe Thunderstorm Risk this Afternoon and Evening... Scattered severe thunderstorms are possible this afternoon and evening along and ahead of a cold front. Development could begin as early as late morning as an H7 shortwave moves along the upper flow from southwest to northeast. The resultant theta-e gradient could provide an axis of development for supercells or hybrid clusters by midday. Soundings support SBCAPE upwards of 4000 J/Kg, along with 25 to 50 knots of low to mid level shear. This, along with a relatively deep effective inflow layer, will support a mention of isolated tornado potential, along with large hail upwards of 2 inches in association with any supercells that develop. As convection goes upscale during the afternoon and evening, high DCAPE of 1300 to 1700 J/Kg will support damaging wind gusts of 70 mph or higher. CAMs do not show great agreement in where initiation takes place; however, there is some consensus on the central Red River Valley and points east. ...Heat Impacts Expected This Weekend... A combination of high dew points in the 70s and afternoon temperatures in the 90s, will provide an environment supportive of heat index values of 100 to 105 degrees. Best chances will be in the southern Red River Valley and portions of west central Minnesota. A heat advisory remains in effect through late this afternoon, with temperatures falling substantially following today`s cold front. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 628 AM CDT Sun Jun 22 2025 IFR conditions prevail at KDVL this morning with MVFR to VFR ceilings elsewhere. Look for isolated to scattered thunderstorms through most of the morning and into the afternoon hours. Storms could become severe starting around mid morning with the threat of damaging wind gusts, hail, and tornadoes. This threat will persist through the late afternoon as a cold front moves across the area. Winds shift to the northwest from west to east, with gusts up to 25 knots following the cold front passage. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Heat Advisory until 7 PM CDT this evening for NDZ052-053. MN...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening for MNZ006-009-016-017-022>024-027-028. Heat Advisory until 7 PM CDT this evening for MNZ029>032-040. && $$ UPDATE...Lynch DISCUSSION...Lynch AVIATION...Lynch