Area Forecast Discussion
Issued by NWS Grand Forks, ND

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172 FXUS63 KFGF 180014 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 714 PM CDT Fri May 17 2024 .KEY MESSAGES... - Isolated to scattered severe thunderstorms are possible this evening. Damaging wind gusts to 70 mph and hail up to 1 to 1.5 inches in diameter are the main concern. - There is a 70 percent chance for wind gusts greater than 40 mph Saturday afternoon and early evening. && .UPDATE...
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Issued at 714 PM CDT Fri May 17 2024 Had a report of 58/59 mph from Devils Lake and Pekin. No hail has been reported yet from this line of storms near Larimore. Environment still looks like it will still be able to support hail growth maybe up to 1 inch instead of 1.5.
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&& .DISCUSSION... Issued at 336 PM CDT Fri May 17 2024 A cold front is going to move through the region this evening. Estimated timing looks to be around 00z for the Devils lake Basin and maybe around 04z for the valley. With scattered to clear skies across the region will allow for optimal heating to help erode away our capped environment. HREF is painting a swath of effective bulk shear between 25 to 35 kts which is normally a little weak but may provide enough shear to sustain any storm development. Given the high LCL and LFC`s generally between 1-3km would allow most of our available CAPE to be utilized in the Hail growth zone resulting in at least 1 inch hail however there are a few analogs that have resulted in higher hail size but im just not confident the environment would sustain anything higher than ping pongs at the largest. The hodographs are fairly straight supporting the idea that today is going to be a more hail and wind threat kind of day and not a tornado type of day. A minor concern or really something to monitor is some ponding to some minor flooding given the potential for some training storms and our already saturated ground moisture especially in the valley. As far as the gusty wind potential on Saturday, there are some pros and cons. For the pros, seeing a pretty unidirectional flow from the surface up to 850mb. Cons are that the winds at 850mb are not all that strong. Seeing something like 30 to 35 knots across the northern half of the FA and 25 to 30 knots across the southern half. The strongest cold advection comes late tonight into early Saturday morning, when the mixing is not the best. For the late morning and afternoon time frame, warm advection begins again. Westerly winds are not the best direction for maximizing gusts. So the thought at this point would be near advisory criteria wind speeds across the northern half of the FA, and slightly lower to the south. May mix in some slightly lower CONSSHORT winds with the slightly higher NBM winds to capture this. As far as precipitation chances, there may still be some ongoing convection Saturday morning. There is a secondary 700mb short wave that rotates through the FA around the parent low that holds over central Saskatchewan. CAMs are showing another potential line of showers/weaker storms following the same track as the ones for tonight (mainly north of I94 in North Dakota and mainly north of highway 2 in Minnesota). This would be mainly for the morning hours, with drying working west to east through the day with the increasing west winds. The remainder of the long term continues to feature cooler temperatures and periodic chances for more rain. The flow remains zonal, with the main differences being the strength and timing of additional waves. Some ensembles show a closed 500mb low possibly holding over the FA Tuesday into Wednesday (which would result in a wetter solution), while others are more progressive (less wet). These details will come into better focus closer over the next few days. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 100 PM CDT Fri May 17 2024 This evening a line of thunderstorms will move through our region creating chaotic wind directions and winds speeds. KDVL will be hit by the storms first then KGFK, KFAR, and KTVF. There`s some uncertainty whether or not thunderstorm will persist long enough to make to KBJI or not but still expecting some rain for KBJI. Winds will become westerly after the front and storms move through the region. Around 12z wind gusts will start to pick up for KDVL with the potential for gust up 30-35kts. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...MM DISCUSSION...Godon/MM AVIATION...MM