DISCUSSION
Issued at 420 PM CDT Thu Jul 4 2024

Active weather continues with an upper level shortwave moving across the area today in combination with a warm humid airmass and and weak surface features to generate some scattered showers/storms. The upper low is over southeast South Dakota as depicted by the nice swirl on IR satellite imagery this afternoon. The convection driven by this upper low is mainly over central and southern MN into WI, with warm air advection driving up over a weak warm front extending from the surface low over southwest MN east along the IA/MN border into southern WI.
A sort of inverted trough extending north into northwest MN, and is associated with the scattered shower and storm activity we are seeing there as well. While we have managed to build CAPE of around 1000 j/kg this afternoon for parts of the area, deep layer shear values are less than 20kts, leaving us with primarily upright storms with little chance for severe storms, though their slow movement may produce locally heavy rainfall, though with the storms not lasting very long, any flooding risk is going to depend on repeat storms over the same areas. This pattern will continue into tonight as the upper low moves slowly east across the area, with it remaining close enough to continue to generate shower and storm chances through Friday.
With this overhead, we have been a little cooler than normal, which should continue on Friday as well.

The upper low moves out in time to give us dry weather late Friday night into Saturday, before another slow moving shortwave swings through the broad upper level trough overhead Saturday evening through Monday. From what is depicted now, we should have another couple days of decent instability without much shear, producing brief heavy downpours and lightning, but any severe risk looks very limited at this point. Again, with the upper low overhead producing more cloud cover, temperatures will be near to below normal.

This active weather pattern continues through much of next week, with what looks like yet another shortwave that dives through the upper level northwest flow, but model agreement on the timing and strength of this feature is quite low, and we are left with some intermittent small chance pops through the rest of the work week. The northwest flow aloft and northwest flow aloft will also help keep us near to below normal for temperatures.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
Issued at 635 PM CDT Thu Jul 4 2024

Low pressure passing through will keep showers and thunderstorms at BRD for several hours this evening, eventually diminishing in coverage and intensity as they move east. Showers and storms are expected to move into HYR later this evening, and persisting overnight with MVFR to IFR ceilings developing as low clouds move in from the south. There is a bit of uncertainty on how long these low ceilings may linger at HYR through Friday morning though, with some models suggesting they may diminish in the mid-morning versus late morning. At DLH, confidence is increasing that storms may not impact the terminal at all with better instability both north and south. Some showers will be possible tonight though, not likely to drop visibility below 6SM. Dry and VFR conditions are most likely at HIB/INL tonight, though there is a very small chance that some showers in the vicinity could affect HIB this evening. As low pressure departs on Friday, lingering instability may prompt some scattered showers and storms to develop, which may affect any terminal (20-40% chance). Some breezy north to northeast winds are expected Friday afternoon, especially at HYR, with some gusts to 15 to 20 kt.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
Issued at 420 PM CDT Thu Jul 4 2024

Northeast winds to slowly increase through this afternoon and evening and gust in the 15 to 20 knot range tonight and early Friday before diminishing again. Waves should build to between 1 and 3 feet. While this may make for a bumpy ride out on the lake, conditions will not be especially hazardous for Small Craft. Winds diminish Friday evening before increasing out of the southwest late Friday night into Saturday. Speeds will remain under 15 knots with waves of less than 2 feet.

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.