Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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254 FXUS63 KFGF 180447 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1147 PM CDT Fri May 17 2024 .KEY MESSAGES... - Isolated to scattered severe thunderstorms are possible this evening. Damaging wind gusts to 60 mph are the main concern. - There is a 70 percent chance for wind gusts greater than 40 mph Saturday afternoon in eastern North Dakota. && .UPDATE... Issued at 1143 PM CDT Fri May 17 2024 Rest of the severe t-storm watch 255 will expire at midnight. Still have the area of rain and thunderstorms from Jamestown region into northwest MN. Overall intensities continue a decline but still getting pockets of wind gusts 45-50 mph at times in SE ND with a storm moving out of Edgeley. Overall the next few hours will see pockets of gust winds 40+ mph but chances for severe wind gusts are low, not zero, but low. && .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 /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1143 PM CDT Fri May 17 2024 VFR conditions will persist throughout the day tomorrow. Winds will gradually shift to the west after the line of storm moves through. Some of the model guidance has KTVF or KBJI dropping into IFR conditions around sunrise. Most of the consensus was to maintain VFR conditions so that is what I prevailed. For KGFK, KDVL, KFAR, and KTVF expect winds gusting up to around 30 knots in the afternoon. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ MESOSCALE...Riddle UPDATE...MM DISCUSSION...Godon/MM AVIATION...MM