Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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711 FXUS63 KFGF 112043 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 343 PM CDT Sat May 11 2024 .KEY MESSAGES... - Near critical fire weather is expected today and again Sunday across much of the region as RH values fall into the 20 to 30 percent range along with wind gusts up to 30 mph. - Isolated thunderstorms are possible late this afternoon and early evening for portions of far northeast ND and northwest Minnesota. A few storms could produce damaging wind gusts to 60 mph. && .DISCUSSION... Issued at 342 PM CDT Sat May 11 2024 The 7 day pattern will feature a tendency towards split flow, with progressive flow across the Northern Plains. Within this flow fast moving mid level shortwaves will bring periodic shower/thunderstorm chances to the region, along with variable high/low temperatures (within a standard deviation of seasonal normals). At this point, there is not a signal in ensemble based machine learning or model climatology for severe thunderstorms or excessive rainfall next week. Regarding showers/storms this afternoon-evening: A mid level wave moving to the north this evening/tonight will push a cold front into the region, and forcing will help lead to widely scattered showers and isolated thunderstorms through the evening mainly in northwest MN (some signal farther west in CAMs). The air mass is very dry, but there is some elevated CAPE forecast to increase with steep lapse rates later this afternoon/early evening. We ultimately may see a lot of activity on radar with minimal precipitation reaching the surface (dry thunderstorm type activity). Inverted-V type soundings and DCAPE near 1000 J/KG in our north may support a few severe wind gusts to 60 mph. Regarding fire weather today and Sunday: Deep mixing and a slower recovery in BL Tds from the west has led to RH values in the upper teens to 25% range across the Red River Valley and locations east. Gusts 25-30 mph have occasionally be reported, but the window for 3hr RFW criteria hasnsn`t be there and near critical is expected through the early evening. For Sunday, the post frontal air mass should bring lower Tds in (along with cooler temps) but adjusting for biases, RH values are likely to once again drop to the 20-25% range. North or northeast winds will tend to favor higher gusts in the Red River VAlley with higher winds aloft decreasing by the afternoon north to south. The result should be near critical fire weather conditions again, with a 40% chance for critical fire weather conditions in the northern Red River Valley. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 151 PM CDT Sat May 11 2024 VFR conditions should prevail across eastern ND and northwest MN. The main aviation impacts from gusty southwest winds decreasing this evening then shifting to the north and increasing behind a front late tonight into Sunday morning. Widely scattered (30% chance) high based (8000-12000 FT AGL) showers and isolated (20%) thunderstorms will be possible after 21Z/4PM this afternoon through the early evening period. The best chances are mainly in northwest MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...DJR AVIATION...DJR