Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
142 FXUS63 KFGF 181502 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1002 AM CDT Wed Sep 18 2024 .KEY MESSAGES... - There is a level 1 out of 5 risk for severe storms for most of the FA this afternoon and evening, including the potential for supercells. && .UPDATE... Issued at 1002 AM CDT Wed Sep 18 2024 Band of showers and thunderstorms lifting into the Northern Red River Valley, including some pretty heavy rainfall over the Pembina Gorge. With recent heavy rains in the area, FLASH unit streamflow lighting up, and 3 hour flash flood guidance met, went with a flash flood warning for that area. More showers and thunderstorms moving up from the south, so there is some question as to how much we will destabilize from the surface later today. The HRRR is not very bullish and keeps the back edge of the clearing pretty quiet this afternoon. Some of the other CAMs are a little more active, however, and there is the scenario where we could get some clusters or even some mini supercells to fire as the upper low wraps up over the western Dakotas and sends frontal boundary and lead shortwave into our CWA. Will have to watch closely how conditions evolve as we head into mid-day. UPDATE Issued at 601 AM CDT Wed Sep 18 2024 The most consistent area of showers and storms is currently moving through the Devils Lake region, otherwise the activity elsewhere is pretty isolated. The line near Devils Lake will continue lifting north, while the isolated activity elsewhere will continue through the morning as well. There should still be a break after this current activity fades before stronger activity gets going again this afternoon. The lower visibilities due to fog have generally improved. && .DISCUSSION... Issued at 304 AM CDT Wed Sep 18 2024 ...Synopsis... This will be an abbreviated discussion this morning due to ongoing convection and backing up WFO Bismarck. ...Severe potential this afternoon and evening.. The new SPC Day 1 Convective Outlook is a bit different than it was at this time yesterday. It now covers the far eastern FA with a Level 1 out of 5 risk too, and leaves out the western Devils Lake region down through areas west of the Valley City. There is a Level 2 out of 5 risk for portions of the far southern Red River Valley, which clips portions of Richland/ Wilkin and Otter Tail and all of Grant County. To start, there are always questions with what happens after the morning convection (ie residual boundaries or outflow, cloud trends, etc.). As has been the case for quite a few days in a row now, there is plenty of moisture. Surface dewpoints may get close to 70 degrees this afternoon, with precipitable water values close to 2 inches. That is pretty amazing for mid September! The morning clouds should give way to some sunshine, which will lead to building instability by late morning into the afternoon. Most CAMs seem to indicate a potential hour or two break between the ending morning convection and re- developing late morning and afternoon convection. There was quite a bit of rainfall across the northern FA the other day, so if any storms train across those areas today, they could be susceptible to additional flooding. Pretty hard to nail down where that might be at this point, so will just keep that in mind for now. The low level jet never really goes away today, but does seem to fluctuate in intensity. Don`t see a consistent focus area, but it will definitely keep the moisture feed coming northward. The HREF develops some more consistent UH tracks by mid to late afternoon along the RRV, continuing into the early to mid evening east of the RRV. So it should be another busy day. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 601 AM CDT Wed Sep 18 2024 Other than KDVL, it currently doesn`t look like TSRA will affect any of the other TAF sites early this morning. The lower visibilities around KDVL have also improved, so think the fog threat is done now too. There should be a break until the stronger activity gets going again this afternoon. Tried to put in an idea of when storms may get going again, but confidence in this exact timing is still fairly low. Later shifts can refine if confidence improves. South winds will be fairly gusty today. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JR/Godon/TT DISCUSSION...Godon AVIATION...Godon/TT