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
43
44
45
46
47
869 FXUS63 KDLH 232128 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 428 PM CDT Thu May 23 2024 .KEY MESSAGES... - Rain showers and thunderstorms move back into central/north- central MN this evening. A few strong thunderstorms are possible in the western Brainerd Lakes (small hail and brief, gusty winds). - Moderate rain continues spreading across central/north- central MN tonight and the remainder of the Northland on Friday. Can`t rule out some strong thunderstorms (small hail and gusty winds) Friday afternoon in NW WI. - Active weather pattern continues with periodic showers and storms this weekend into next week, though it doesn`t look like anything significant. && .DISCUSSION... Issued at 429 PM CDT Thu May 23 2024 Rest of Today - Tonight: A pleasant day has developed for most of the Northland with mainly sunny skies and light winds. High temperatures top out in the 60s for north-central and NE MN north of a west-east oriented stationary front, and low to mid 70s for the Brainerd Lakes into NW WI. Some cumulus fields have developed around this frontal boundary, but drier air in the low-levels and little to no forcing aloft should prevent shower and thunderstorm development along the front in our area for the remainder of the afternoon/evening. With that said, better forcing aloft associated with a shortwave trough and surface low over the Dakotas has led to thunderstorms developing in the eastern Dakotas. High-res model guidance shows these showers and storms gradually tracking eastward into central and north-central MN very late this afternoon and evening. There is a brief window (6-9 PM) of the potential for a couple strong thunderstorms (small hail and gusty winds) with MUCAPE up to 500 J/kg, effective bulk shear around 35 knots, and steeper mid- and low-level lapse rates. However the later timing of these storms means that they will be on a weakening trend as they approach Cass and Crow Wing Counties, so the better strong to severe storm chances remain to our west. This batch of convection continues to spread over central and north-central MN later this evening into tonight, mainly in the form of moderate showers and a few embedded thunderstorms. These aforementioned areas could pick up a quick 0.25-0.5 inches of rain overnight. Friday: The aforementioned low will be over the ND/MN border by 12Z Friday and track almost due north into Manitoba Friday evening and night. Moisture advection ahead of the low will surge higher PWATs (1-1.25", 80-90th percentile of climatology), but most of the morning precipitation will be in a narrower forced band of showers/storms quickly moving east Friday morning with redevelopment of thunderstorms along/ahead of the cold front across much of the Northland again Friday afternoon into evening before precipitation departs Friday night. There won`t be much instability with the morning round of convection, but a potent 50-60 kt low-level jet in the area means that some of the morning convection could mix down some of the higher winds aloft to the surface (50+ mph at times). Redeveloping convection during the afternoon/evening will also have about 300-600 J/kg of MLCAPE as well as 40 kt of 0-6km bulk shear that should be sufficient to develop some localized organized updrafts, particularly in NW WI where the instability will be highest and low-level lapse rates will be steepest. Strong wind gusts would be the primarily concern with this second round of convection, but small hail will also be possible with the strongest storms. Non-thunderstorm winds will also be breezy out of the east to southeast on Friday ahead of the cold front, with gusts up to 30 mph. Total precipitation amounts from this evening through Friday evening will be 0.5-1 inches over north-central MN, as well as pockets along the North Shore and in NW WI where stronger thunderstorms move overhead. Most of the remainder of the area is poised to see 0.25-0.5 inches of accumulations from the moderate rainfall. Saturday: Surface high pressure passing through the mid-Mississippi River Valley on Saturday should keep southern portions of the Northland dry, but parts of NE MN have a 20-30% chance for light showers and a couple embedded general thunderstorms Saturday afternoon into Saturday night. Additional rainfall amounts of 0.1 inches or less expected. Sunday - Early Next Week: A deeper trough and related developing surface low over the front range of the Rockies on Saturday will push east across Missouri/Iowa Sunday morning and then eject northeast into eastern Wisconsin by late Sunday as the system quickly deepens. Although there is some slight spread in the model low tracks with this system, confidence is high the low will track southeast of our area. However, precipitation bands associated with the northwestern quadrant of the low should lead to 30-50% chances for mainly showers with a few weak storms on Sunday into Monday for the Northland. Highest of these chances will be in NW WI closer to the low. Friday`s low that will be long churning over Manitoba for several days, finally drops back southeast into the Northland on Tuesday, rounding out light shower chances on Tuesday (30-40% chances). Mid - Late Next Week: Ensembles show general agreement on upper-level shortwave ridging moving over the Upper Midwest on Wednesday, possibly lingering into Thursday. This would lead to rain-free conditions during the middle of next week, though the active pattern is poised to return late next week with another round of troughing and associated rainfall moving back into the central U.S. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1254 PM CDT Thu May 23 2024 A few sporadic showers are moving through north-central Minnesota at the moment, and will affect the vicinity of KINL and perhaps HIB to a lesser extent for the first half of the afternoon. Then, showers and storms developing over the eastern Dakotas mid-afternoon will spread into portions of central Minnesota very late this afternoon and evening. Have included VCTS mention at KBRD as it looks as though storms should be weakening in coverage/intensity as they move into the Brainerd Lakes region. Showers and a few embedded storms spread across much of north-central and northeast Minnesota later this evening into tonight, with showers then moving east across the area Friday morning and afternoon along and ahead of a cold front associated with the approaching low pressure system. Winds begin to quickly ramp up out of the east tonight with gusts increasing to 20-30 knots on Friday morning, then shift more southeasterly late Friday morning ahead of the approaching cold front. Expect some LLWS spreading in from west to east late tonight into Friday, as well. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 429 PM CDT Thu May 23 2024 Winds will increase again out of the northeast late this evening into Friday, with the winds being strongest late Friday morning through afternoon when gusts up to around 35 knots are likely (50-60% chance) along the North Shore and up to around or slightly more than 30 knots elsewhere. Therefore, have issued a Gale Warning for Silver Bay to Grand Portage from late Friday morning through the afternoon. Small Craft Advisories are in effect for the remaining nearshore waters of western Lake Superior from tonight through Friday night with winds then subsequently weakening to near or just below the lower Small Craft Advisory thresholds on Saturday and turning southwesterly. Wave heights peak around 7 to 11 feet on daytime Friday and finally subside below 4 feet daytime Saturday as winds and waves diminish. 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...Small Craft Advisory from 3 AM Friday to 4 AM CDT Saturday for LSZ121-143>145-148. Small Craft Advisory from 3 AM to 10 AM CDT Friday for LSZ140>142. Gale Warning from 10 AM to 7 PM CDT Friday for LSZ140>142. Small Craft Advisory from 3 AM Friday to 1 PM CDT Saturday for LSZ146-147-150. && $$ DISCUSSION...Rothstein AVIATION...Rothstein MARINE...Rothstein