Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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473 FXUS63 KFGF 101736 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1236 PM CDT Fri May 10 2024 .KEY MESSAGES... - Scattered thunderstorms are forecast for portions of northwest and west-central Minnesota this afternoon. A few storms may produce wind gusts to 50 mph and small hail. Best chance (50%) for strong storms resides east of US Highway 59. - Gusty northwest winds will develop today. There is a 40% chance sustained winds exceed 30 mph and/or gust to 45 mph to eastern North Dakota and the Red River Valley. These winds along with dry conditions will bring near critical fire weather conditions to these areas. && .UPDATE... Issued at 1236 PM CDT Fri May 10 2024 Starting to get some showers developing over northwestern MN, although satellite shows only a tiny bit of glaciation so no lightning yet but could see some in the next few hours. Mixed layer CAPE is around 250 J/kg and surface based just a bit higher, so instability is pretty minor and effective shear is around 20 kts. Not expecting much other than some brief downpours and gusty winds to 40 mph, but some hail up to peas is not completely out of the question. Cloud cover and showers have kept RH values up a bit higher than what we had going so far on the MN side for fire weather concerns, so even though some spots have been approaching 25 mph in the Red River Valley, the humidity has been high enough to keep the near critical SPS and not upgrade to Red Flag for now. UPDATE Issued at 958 AM CDT Fri May 10 2024 Pulled the low POPs out of the Red River Valley this morning as the shower activity has stayed up around Lake of the Woods and the Red Lakes, and upstream showers in Canada seem like they will take a similar path. Amounts still look light and low impact. Will continue to keep an eye on winds and RH values in the Red River Valley for fire weather concerns. UPDATE Issued at 650 AM CDT Fri May 10 2024 A cold front is moving through the area bringing gusts as high as 40 mph in portions of the northern Red River Valley and northwest Minnesota. This is likely tied to an initial bubble of strong CAA. However, as daytime mixing commences this will spread. In coordination with neighboring offices and MIFC, issued an Special Weather Statement on near critical fire weather conditions within the Red River Valley. && .DISCUSSION... Issued at 430 AM CDT Fri May 10 2024 Synopsis.. Water vapor imagery projects a progressive and potent shortwave trough moving southeast within MB and western ON. This will move into MN today. Cold air aloft embedded within this trough will drive thunderstorm chances today by way of steep lapse rates/weak instability, meager but sufficient moisture, and strong synoptic lift. Some storms may be strong bringing gusty winds and small hail. This trough will also bring gusty winds and dry air over the Dakotas. Behind the quickly departing trough today will be shortwave ridging tonight into Saturday ahead of the next progressive shortwave trough expected to brush our area as it moves through MB into ON. This next trough`s passage will advect warmer air into the region, along with bringing an additional chance for showers and storms to the area, currently favoring northeast ND into MN late Saturday. Additional progressive shortwave troughs are forecast to move through the Northern Plains and Upper Midwest through next week, although predictability in their timing and trajectories remains rather low. Still, additional chances of showers and storms exist through next week. Strong storms in Minnesota today... The path of today`s trough will place our area in a northerly flow regime, with increasing winds with height. As daytime heating commences, convection will start to bubble late morning through the afternoon. This along with a very deeply mixed PBL underneath thunderstorms will contribute to convectively driven wind gusts as high as 50 mph in strongest storms. With such cold temperatures aloft keeping much of the cloud layer sub- freezing as well as generally favorable kinematics, storms will also hold the potential for small hail. Expected hail sizes are generally under the size of quarters, although a few instances of quarter sized hail cannot be ruled out. Overall chance for storms is around 50% mainly east of US Highway 59, which also holds relatively best chances for these stronger storms. Gusty winds today.. Deep mixing today (likely at or above 700 mb) will allow increased winds aloft to mix toward the surface. Overall winds within the deeply mixed PBL today are not overly strong, generally in the 20-30 kt range, although some guidance does mix into a layer where 30-40 kt winds exist. Northwesterly direction of winds will also favor some locally increased winds within the Red River Valley. Available CAMs favor the southern Valley to see best potential in seeing highest winds, with around a 40% chance of meeting wind advisory criteria. Dry air mass moving into the Dakotas along with gusty winds also introduces the potential for fire weather conditions. However, recent rainfall and green up of fine fuels/grasses should mitigate the potential for rapid spread of fires. Still, we are opting to message near critical fire weather conditions based on weather conditions alone. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1236 PM CDT Fri May 10 2024 Cumulus and showers developing mainly over northwestern MN, but all sites VFR and will remain so as convective activity dissipates after sunset. Winds will be the primary aviation concern with many airports gusting above 30 kts from the northwest this afternoon. Should see winds slowly taper off this evening, eventually becoming light and variable overnight. By the end of the period there will be a shift to the southwest at less than 10 kts. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...CJ/JR DISCUSSION...CJ AVIATION...CJ