Temperature Changes and a Return of Wet Weather In the Week Ahead

Lightning Fact or Myth?

A change in the weather pattern will bring some relief from the heat, along with wet conditions, to the Plains, Midwest and South. Meanwhile, warmer temperatures are ahead for the Northeast, and portions of the West will continue to experience mild conditions.

These changes are due to a shift in the jet stream this week. A trough, or southward dip in the jet stream, that is bringing the cool and damp weather to portions of New England to start the week will slide eastward, and the upper-level ridge of high pressure that has brought very hot conditions to the Plains, Midwest and South will also begin to push to the east.

This will set the stage for an area of low pressure to bring slightly cooler temperatures to much of the country, along with an increase in rain and thunderstorms.

(MORE: Hottest Temperatures So Far Of 2016 This Weekend)

However, in the West, an upper-level trough will continue to dominate, which will keep temperatures on the mild side for much of the region and showers in the Pacific Northwest.

1.) Warmer Temperatures For The Northeast

Parts of New England and Upstate New York dealt with cool weather conditions at times last week. The start of this week is also featuring cooler than average temperatures.

Highs will be stuck in the 50s and 60s from central New York to Maine on Monday, which is 5 to 15 degrees cooler than average.

Temperatures will begin to moderate on Tuesday across the region. Highs will typically be near to above average later this week. This translates into temperatures climbing into the 70s and 80s.

Lows will also be near average later in the week, with temperatures holding in the 50s and 60s for most locations.

(FORECAST: Philadelphia | New York | Boston | Burlington, Vermont)

Much of the Northeast will enjoy dry conditions in the week ahead. The exception will be northern New England where showers are possible on Monday.

2.) Stormy Weather Returns

After a stretch of dry conditions from the central Plains into portions of the Midwest and South, wet weather is expected to return this week.

Many areas last saw measurable rainfall last weekend or early last week. Drought conditions have already appeared in parts of the South, according to the U.S. drought monitor, and a week of dry and hot conditions has not been good news.

However, this break from the rain has been very welcome in portions of the southern Plains, especially in Texas, where heavy rain led to more flooding.

(MORE: Over 100 inches of Rain Have Soaked Parts of the South Since Spring 2015)

Rain and thunderstorms will return early this week, as an area of low pressure slowly pushes east into the Plains and mid-Mississippi Valley. Moisture will return to the central Plains, Midwest and much of the South ahead of this system. The combination of abundant moisture and the slow movement of this low pressure may lead to flash flooding in spots.

Scattered severe thunderstorms are also likely each day to start the week.

(MORE: Severe Weather, Heavy Rain Returns)

This slow-moving system will keep the risk of wet weather in the forecast for much of this week. By late-week, the chance for showers and thunderstorms will mainly be confined to the South, Ohio Valley and mid-Atlantic.

(FORECAST: Kansas City, Missouri | Louisville, Kentucky | Jackson, Mississippi | Atlanta)

3.) Some Heat Relief Ahead

Slightly cooler temperatures are also expected for much of the central and southern U.S., as the upper-level ridge of high pressure slides east and is replaced by the low pressure system mentioned above. The increase in cloud cover and the chance for showers and thunderstorms will also help to keep temperatures not quite as hot.

Some daily record highs were set over the weekend from the Plains and Midwest into the South.

(FORECAST: Minneapolis | Chicago | St. Louis | Atlanta)

There is relief ahead from the expansive heat, as temperatures will begin to cool slightly, and highs will be closer to average for mid-June in the Plains and mid-Mississippi Valley Monday and Tuesday. Temperatures may soar well above average again Wednesday into Thursday in those areas.

St. Louis will finally see some relief late in the week, with highs in the 90s to near 100 expected through Thursday but dropping to near 90 by Friday.

Parts of the Southeast and Ohio Valley will see much cooler temperatures late in the week.

Atlanta will go from seeing highs in the 90s all week to highs in the mid 80s by the weekend.

4.) Mild West, Wet Northwest

Much of the West experienced very hot conditions early last week, but the heat has been replaced by cooler temperatures, courtesy of an upper-level trough. Temperatures will warm slightly early this week, but another upper-level trough will approach the West Coast mid- to late-week.

(MORE: Extreme Heat in the West Early This Week)

This setup will bring another round of cooler-than-average temperatures heading into midweek and will last through the end of the work week for many. Highs will generally be in the 60s and 70s for the Pacific Northwest, which equates to temperatures 5 to 15 degrees below average.

The Southwest will see temperatures near average for mid-June, which for many spots is 10 to 15 degrees cooler than earlier this week. For example, Phoenix reached 115 degrees last weekend, but through midweek, highs are expected to be near or slightly above 100 degrees.

Portions of the Southwest and Inter-Mountain West, however, will begin to see above-average temperatures once again by the end of the week.

(FORECAST: Seattle | Medford, Oregon | San Francisco | Las Vegas)

This dip in the jet stream will also be accompanied by upper-level disturbances, which will bring the chance for a few showers, mainly to portions of the Pacific Northwest. Rainfall across the region should generally be light.

MORE ON WEATHER.COM: TripAdvisor Best Summer Destinations 2016 (PHOTOS)