Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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537 FXUS63 KDLH 150839 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 339 AM CDT Mon Jul 15 2024 .KEY MESSAGES... - A couple rounds of showers and storms today. There`s a ~5% chance that a few storms could be strong to severe, possibly containing damaging winds and large hail. - Temperatures cool off a bit mid-week and rain chances decrease. - Temperatures warm back into the low 80s for highs over the weekend with a little rain possible. && .DISCUSSION... Issued at 339 AM CDT Mon Jul 15 2024 We have some mixed weather conditions out there this morning. A potent trough roughly over the ND/MN border is producing showers and thunderstorms, the anvils of which are bringing higher clouds mainly to north-central MN at this time. Further east and south, where skies are clear to partly cloudy, some fog has developed. Expect cloud cover to increase this morning as the upper level trough approaches from the west. There is a small (and decreasing) threat for a few strong to severe storms this morning (<5% chance) for southern parts of Cass/Crow Wing counties along with general chances for showers and storms across the region (~40-75% chance). The most likely scenario is that storms will continue to track along a CAPE gradient that is roughly situated along the I-94 corridor, keeping most (if not all) of the severe weather threat this morning south of the Northland. The storms that will affect the Northland this morning should all be elevated, and as such, threats for large hail or damaging winds are certainly minimized (but not zero). Some of the stronger storms could produce wind gusts to around 50 mph and small hail around the Brainerd Lakes. Storms will continue to weaken as they move east during the morning as they run into more stable air, and as such, the main threats will be the usual thunder/lightning and occasionally heavy rain. As the upper level trough slowly pushes through this afternoon, the CAPE gradient will slowly move east along with it. With increasing daytime instability, additional storms are likely to fire across northeast MN first around mid-day to early afternoon, then move into northwest WI through the afternoon. The most unstable air associated with warm air advection will remain to our south, but just enough may inch northward to keep a ~5% chance for damaging winds (to 60 mph) and large hail (up to 1" to 1.25") especially in northwest WI. Hodographs are largely unfavorable for tornadoes, but there might be the smallest sliver of a chance (~1%) for a brief spinup with some low-level veering under the warm air advection regime this afternoon, again mainly over northwest WI. The afternoon threat for any strong/severe storms is expected to be short-lived, and storms should exit the region to the southeast by sunset. We will have PWATs hovering around 1.25" today. This is in the higher end of climatology, but less than 90th percentile. Most places can expect to see up to half an inch of rain, but locally higher amounts up to 1"-2" can`t be ruled out in the more persistent thunderstorms. This could lead to some brief ponding of water, but the progressive nature of these storms is expected to keep any flooding threats very minimal. After the main trough passes through this afternoon, the showers and storms could largely clear out with northwesterly flow, weak cold air advection, and drier air moving in. A few models suggest the possibility for a few lingering light showers into tonight, but confidence isn`t high enough to include a mention in the forecast at this time. Going into Tuesday, we start a noticeable cool down in temperatures as more relatively colder air moves in from the northwest. In addition, another upper level trough may bring some showers and possibly a few non-severe thunderstorms to parts of the region, especially along the Canadian border. Wednesday is looking like the coolest day of the week with high pressure settling roughly over the ND/MN border. Highs in the upper 60s and low 70s will allow us to give air conditioners a bit of a break! A southwesterly flow pattern will gradually set up later in the week into next weekend, which should warm temperatures up again. Rain chances don`t look impressive, but there are some hints for some sort of weak system over the weekend that could bring a little rain. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1245 AM CDT Mon Jul 15 2024 Fog will be possible over the next several hours, mainly at HYR and possibly DLH/HIB. A bit of haze from smoke aloft could also briefly affect INL/HIB over the next several hours. MVFR visibilities are possible. Then, an upper level trough and weak surface cool front will bring showers and thunderstorms from west to east through the morning. The best thunder chances will be at BRD (about 60% chance) and about 30-40% chance elsewhere. MVFR to briefly IFR visibilities will be possible as showers and storms pass through this morning. Redeveloping storms are expected to develop around mid- afternoon in northeast Minnesota, then spreading into Wisconsin during the afternoon. There is a ~5% chance that some of these storms could be strong to severe containing strong winds and hail. Aside from storm chances, west winds will strengthen this morning, becoming northwesterly around 10 kt and gusting to 20 kt this afternoon before weakening during the evening again. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 339 AM CDT Mon Jul 15 2024 Wind directions will be a bit variable this morning with speeds less than 10 kt, then becoming mostly westerly by the afternoon with gusts to around 15 kt. There will be rain and thunderstorm chances today (50-80%). Isolated strong to severe storms can`t be ruled out, which could produce strong winds or hail up to quarter size (<5% chance). West to northwest winds persist through Tuesday with gusts not expected to exceed 15 kt for the most part. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .HYDROLOGY... Issued at 648 AM CDT Fri Jul 12 2024 A Flood Advisory continues across portions of the Rainy River Basin, extending as far east as Lac La Croix and as far west as the Rainy Lake outlet. This advisory has now been extended through Monday afternoon. Lingering high water from rains in June continue across the Rainy River Basin. The Vermilion River continues to fall. Lake levels on Lac La Croix and Crane Lake have crested, but are still elevated and slow to fall. Lake Namakan looks like it is now cresting as of Friday morning. All this high water continues to lead to slowing rises on downstream lakes, notably Kabetogama (Kab) lake where minor flooding continues, and on Rainy Lake where levels are still exceeding the rule curve. Kab and Rainy Lake crests should occur this weekend. This could bring Nam/Kab just under 1120 feet with a peak level somewhat similar to the high water during the summer of 2014. This is still 2 feet or more below the high water levels of Spring 2022 - we are nowhere close to that level of flooding and extreme rises to that point are currently not expected. As is usual for this basin, water will move slowly and recessions will happen at glacial speeds with some flavor of high water possibly continuing through the month. However, peak should happen soon, based on latest observations. Additional rainfall may cause brief rises in tributaries and extend the period of high water in core lakes depending on where and how much rain falls with several rounds of showers and thunderstorms late tonight through Monday. Boaters should expect high water, potentially hidden underwater hazards (including submerged docks), and strong currents in constricted areas. Some of the storms this weekend could be strong to severe, which could lead to erratic gusts out of thunderstorms and impact wave heights, as well. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...None. && $$ DISCUSSION...JDS AVIATION...JDS MARINE...JDS HYDROLOGY...Rothstein