Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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108 FXUS63 KFGF 160814 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 314 AM CDT Mon Sep 16 2024 .KEY MESSAGES... - There is a level 1 out of 5 risk for severe storms over the western Devils Lake region early this morning, with the main hazards being lightning, hail, and localized heavy rain. - There is a level 2 out of 5 risk for severe storms over portions of eastern North Dakota and northwest Minnesota this afternoon and evening. - There are multiple chances for rain this week, with a low probability for severe storms and heavy rain. && .DISCUSSION... Issued at 314 AM CDT Mon Sep 16 2024 ...Synopsis... The pattern remains very active, with a western trough and eastern ridge. With the Northern Plains in southwest flow, periodic shortwaves are expected to track through. However, the overall predictability is much more uncertain beyond about a day or two. ...Severe potential early this morning... There are quite a few areas of storms early this morning. There is scattered activity moving through the arrowhead of Minnesota, another broad area over western South Dakota, and a line of storms just south of Minot. The surface flow is very moist and weak, with a few stations reporting lower visibilities in fog. This seems to be from the Lake of the Woods region down toward Grafton and Grand Forks. Will consider a Special Weather Statement for fog in these areas through sunrise. The line of storms just south of Minot is the closest to the FA, and seems to be associated with the 850mb jet and good 850mb moisture transport. The strongest portion of the 850mb jet is focused into southwest North Dakota, and is much more broad and a bit weaker into this FA. CAMs are not in the best agreement, but some have the activity between Rugby and Minot brushing western portions of the Devils Lake region through sunrise. The HREF shows a few longer UH tracks in this area, so will be keeping a watch on this area over the next few hours. The area of storms over western South Dakota seems to show a better area of rotation, which may be a MCV, which would bear watching for later in the day too as it moves north to northeast. So not sure if there will be a break after sunrise, before more activity fires up again, or the activity will just weaken a bit before strengthening again. Any storms early this morning have been slow moving and will likely drop heavy amounts of rain in a short duration. Will have to keep an eye on where this morning rain falls in case there are more rounds across the same areas this afternoon and tonight. ...Severe potential this afternoon and tonight... High levels of moisture remain over the FA this afternoon and tonight, with precipitable water values rising up to around 2 inches (pretty good for mid September). Will have to see how long and where the morning clouds hang around, to see where the best instability develops by this afternoon. It doesn`t look like there are any surface boundaries that set up this afternoon, but it is hard to say for sure with remnant or dying morning convection around. The 0-6km shear stays on the lower end, but could be increase a bit by 00z Tuesday. The biggest parameter that jumps up again this evening is the low level jet. The 06z model runs are showing it even stronger by 00z Tuesday, potentially as high as 50 to 60 knots, focused into the northern Red River Valley and southeast Manitoba. Precipitable water values remain around 2 inches across northeast North Dakota and northwest Minnesota. The HREF shows longer UH tracks picking up in the mid to late afternoon (across northeast North Dakota and northwest Minnesota) and continuing through about 9 to 10 pm. SPC has updated the Day 1 Severe Weather Outlook to go a slight risk (level 2 out of 5) for this area. So maybe after a mid to late morning lull, convective activity may be on the uptick again by mid to late afternoon into the evening. Hard to time waves beyond this, but the pattern remains active. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1141 PM CDT Sun Sep 15 2024 Look for a chance of showers and thunderstorms overnight and into Monday. The best chances will occur after 10Z at KDVL, then progress east through the remainder of the day. VFR ceilings are expected to prevail at all TAF sites outside of thunderstorm activity. Winds tonight remain light and variable before increasing slightly just before sunrise. Broken to overcast cloud cover prevails in the vicinity of showers and thunderstorms, with SCT clouds elsewhere. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...Godon AVIATION...Lynch