Heat advisories issued ahead of hot stretch of weather

MONDAY MORNING UPDATE:

A heat advisory has been issued for much of the Eyewitness News viewing area until Friday evening.

This is a downgrade from an excessive heat watch, but still indicates that a combination of heat and humidity can lead to heat-related illness.

Our normal high this time of the year is 84 degrees, but the atmosphere has different plans given a large ridge of high-pressure building across the eastern U.S.

After seeing our first 90 temperature of the year on Father's Day - 93 to be exact - that trend will continue through the rest of the week and even into the weekend.

Despite temperatures rising later in the week, a slight drop in humidity should allow heat indices (what it feels like) to actually fall a tad.

The highest heat indices will likely be earlier in the week when dewpoints (moisture content of the air) are highest. During the afternoons, it will 'feel' like it's around 100.

And here's the thing - it's not even officially summer yet. The summer solstice will occur later this week on Thursday afternoon though. With a time of 4:50 p.m. on June 20, this will be the earliest start to summer since 1796.

Rain chances, although low overall, will be greatest over the next couple of days when our humidity is at it's highest.

That being said, there's very little upper-level support underneath the ridge for sustained/long-lived showers or thunderstorms. However, outflow boundaries (rain-cooled air falling out from a thunderstorm) can go on to produce new showers or storms - so they can be sort of random, but still widely scattered in nature.

It's possible, given the high heat and humidity, that a cell or two could turn briefly strong with gusty winds, hail and brief torrential rainfall, but that risk looks very isolated.

If you don't see rain on Monday, you'll probably hope to see some on Tuesday - but rain chances appear to be even lesser there.

Some of the guidance suggests a few thundershowers forming over the mountains before drifting northwest into parts of the lowlands later in the day. Expect a fair amount of cumulus clouds to develop regardless, so our model output of 95 could be a little high.

Many lawns and plants will be very thirsty as this week goes on, especially if you miss out on a downpour/thunderstorm in the coming days - but could something in the tropics change that?

While it's way too early to determine that, it's at least something to keep an eye on. The National Hurricane Center has a 70% chance of formation in the Bay of Campeche in the Gulf of Mexico, and a 30% chance of formation north of the Bahamas in the coming days.

With a large ridge north of these potential systems, they will have a propensity to move in a general westward fashion.

Even if we don't see moisture directly from the tropics, these potential tropical entities may be able to eventually break this large ridge of high-pressure down after briefly reinforcing it, but that remains to be seen.

And yes, this is early in the season for the tropics to wake up. With unusually warm waters across the Atlantic, along with weakening wind-shear thanks to La Nina gradually developing this summer, the upcoming season looks very busy.

SATURDAY UPDATE:

Temperatures each day should reach the low to mid 90s with a heat index (feels-like temperature) topping out near or above 100.

Heat-related illnesses increase significantly in these expected temperatures.

Outdoor activities should be limited in the afternoon and individuals will need to make sure to stay hydrated.

The prolonged nature of this heat wave (likely to last into next weekend) has a cumulative effect that increases heat-related impacts.

This will likely be the longest heat wave since at least 2020 in our area.