Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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
160 FXUS63 KDLH 170851 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 351 AM CDT Tue Sep 17 2024 .KEY MESSAGES... - Warm and muggy again today and tomorrow with some isolated storms possible - Severe storms possible Thursday afternoon and evening as a cold front moves in from the west. - More seasonable temperatures look to return Sunday into next week. && .DISCUSSION... Issued at 344 AM CDT Tue Sep 17 2024 Current Conditions/Today: A stalled out boundary draped along the International Border is bringing some showers and thunderstorms across the north. Further south a weakening low level jet has spurred some light rain moving across north central MN. We will continue to carry some PoPs (20- 30%) through the day. High res guidance has been very little help as it tends to struggle with weakly forced environments. However, looking at some of the isentropic charts reveals prominent moisture pooling and lift through the Brainerd Lakes Region and towards the Borderlands. Another humid day will be on tap with dewpoints in the 60s. We will manage to build out some instability this afternoon (1000 J/kg). Shear remains weak but a few storms can`t be ruled out. Tonight/Tomorrow: Overnight and Wednesday follows a similar pattern. An upper level trough over the Great Basin propagates towards the Northern Rockies. Meanwhile, out east a semi Rex Block weakens. Leaving us with another strong low level jet moving moisture into the region and allowing weak forcing for ascent. Additional chances (20-30%) for showers and storms will populate across the MN side of the CWA. Thursday/Severe Threat: On Thursday a cold front associated with a vertically stacked low treks east across the region. Timing of the arrival and departure is still a bit in flux. The latest update has the arrival slightly sooner then the previous package. This would have the front moving through MN in the afternoon and NW WI in the evening hours. A small corridor of favorable severe parameters sets up across our region with this FROPA. Moderate instability with MLCAPES in excess of 1500 J/kg will combine with bulk shear values greater than 40 kts to promote upscale storm growth. Cells may initially be discrete before congealing into a line through their life cycle. Mid level lapse rates of 8C/km will aide in hail growth. There is also some indication of low level curvature in the hodographs allowing for a small window of tornadoes. Currently SPC has our severe weather outlook as a slight (2 out of 5). Friday into early next week/Cooling trend: The system will exit through Friday with temperatures cooling slightly into the mid 70s. We will see another cold front work in from the west on the weekend bringing more rain chances and some isolated storms. Behind this front temps quickly fall back to seasonal norms on Sunday and maintain themselves into early next week. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1228 AM CDT Tue Sep 17 2024 A few waves of thunderstorms are riding along the International Border this early this morning impacting INL. The sector of storms near INL at TAF issuance are slowly exiting the terminal with the next wave still over the Red River Valley. There is some uncertainty as to whether the subsequent wave can hold together and impact the terminal. The rest of Tuesday will be a challenge as high res guidance suggests minimal storm coverage through the day. However, given the favorable southerly flow and weak lift we have opted to put some VCTS in the afternoon hours despite the lack of a signal in the high res models. Additionally, we removed the threat of low level wind shear across the region as the strength of the low level winds is more confined to southern MN. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 344 AM CDT Tue Sep 17 2024 Light southeast winds across the Lake with speeds of 5 to 10 kts. A few isolated thunderstorms will be possible in the afternoon. Overall, winds continue to remain light through with some intermittent thunderstorms. On Thursday there will be a chance for severe storms in the afternoon and evening. Winds and waves currently don`t look to increase until later this weekend. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...None. && $$ DISCUSSION...Britt AVIATION...Britt MARINE...Britt