Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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953 FXUS63 KDLH 151128 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 628 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 /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 628 AM CDT Mon Jul 15 2024 Showers and thunderstorms are moving through INL/BRD at this hour, and will continue east through the morning. Thunder chances will be less at HIB/DLH/HYR this morning as current storms move into more stable air. Additional showers and storms are expected to develop this afternoon over northeast Minnesota and move southeast through northwest Wisconsin. Isolated strong to severe storms capable of hail up to half dollar size and wind gusts to 60 mph can`t be ruled out, especially at HYR. Otherwise, expect winds to become west to northwest through this afternoon with gusts from 15 to 20 kt. Showers decrease in coverage and intensity around sunset early this evening, but it is possible a few showers could linger into the evening. && .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 619 AM CDT Mon Jul 15 2024 A Flood Advisory continues across portions of the Rainy River Basin, extending from Lac La Croix to as far west as the Rainy Lake outlet. This advisory has now been extended again through Tuesday afternoon as high water has been slow to move through the system due to the heavy rains in June and more intermittent rainfall in the first half of July. The Vermilion River has now fallen below action stage, and Lake levels on Lac La Croix and Crane Lake have already passed their crests last week, but are still elevated and very slow to fall. Lake Namakan and Kabetogama both reached their crests this weekend, and are also very slow to fall. Rainy Lake also appears to be cresting as the flood wave moves through. Both Rainy Lake and Namakan lake levels are still exceeding the rule curve, however we should see lowering water levels throughout the week even despite the spotty 0.5-1 inch of additional rainfall forecast with storms today (Monday). This additional rainfall may cause brief rises in tributaries and extend the period of high water, but is not expected to significantly change water levels. 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