An absolutely perfect forecast continues as we roll through the Fourth of July weekend. Temperatures at 3:30 p.m. or so currently range from the mid 60s across southern Iowa, where cloud cover exists, to the mid 70s across northern Iowa.  A few showers or thunderstorms will be possible across the southern two-thirds of the state today with the far northern extent being clear for the most part.

Independence Day looks fabulous across the state thanks to high pressure, aside from some patchy dense fog expected in the morning across the west. Rain should stay away with partly-to-mostly cloudy skies, keeping temperatures below normal (on Iowa 4th of July standards) into the upper 70s to low 80s.

The weather begins to become active right after the Fourth. The Storm Prediction Center currently has much of northern Iowa (mainly north of Highway 20) under an elevated risk of severe weather on Tuesday, with the rest of the state under a marginal risk. A look at the upper-level weather pattern through this week shows a broad trough beginning to develop to the west with generally zonal flow otherwise over the area. A shortwave will move through the area late Tuesday, bringing with it the threat of shower and thunderstorm development, potentially with strong-to-severe storms.

High temperatures on Tuesday will be much warmer than the Fourth of July weekend, returning to the general norms. Highs across the warm sector will range from the upper-80s east to the mid-90s west. With dew points in the low 70s for most locations, plenty of destabilization will occur into the 2500-4500 j/kg CAPE range. One commodity with these type of events is that a strong cap will be in place in the most destabilized spots. With this strong cap, and forcing not expected to be until later in the night across central Iowa, the overall severe weather threat on Tuesday across the southern two-thirds of the state is not expected to be as high as areas farther north.

The current expectation is that storms begin firing in the mid-to-late afternoon across eastern South Dakota, Minnesota, and northern Iowa. Deep layer shear is decent with some modest low-level shear as well. Storms will grow upscale quickly, presenting the threats of large hail to golf ball size, damaging winds to 70 MPH, and even an isolated tornado or two.

There are still some uncertainties with this, and it would be a good idea to check back in later for further updates. More confidence will likely exist in later forecasts.

Another threat for severe weather is in place on Wednesday for mostly areas west of Interstate 35. There is a considerable amount of uncertainty with this as there may be some ongoing convection on the morning of the event, which can affect the later day’s forecast. A surface low pressure system is expected to be hiding out in the central Plains with an associated warm front into the mid-Mississippi Valley. A destabilized environment among modest shear will once again pose a threat for primarily large hail and damaging winds.

Stay tuned to the Iowa Weather Network for further updates!