Soggy spell to squash summertime heat in Southeast

 By Courtney Travis, AccuWeather senior meteorologist

Updated Aug. 2, 2021 4:45 AM EDT

Residents across the southeastern U.S. experienced yet another hot weekend. Thankfully, the most intense heat has begun to wane and AccuWeather forecasters say that trend is set to continue.

To start off the weekend, heat baked portions of the South. On Saturday morning, heat advisories and excessive heat warnings stretched across a dozen states. Temperatures peaked in the middle to upper 90s for most locations from Little Rock, Arkansas, to Tallahassee, Florida, with some areas nearing the century mark in the afternoon.

As the weather pattern changes, residents in the area will be able to say goodbye to the above-normal temperatures.

A cool front began to sag south on Sunday, erasing the heat and bringing in a more refreshing air pattern. However, the clash of warm and cool air also allowed for severe thunderstorms to move across the mid-Atlantic coast.

On Monday, temperatures are likely to be slashed by 10 to 15 degrees across portions of the Southeast, according to AccuWeather Meteorologist Rob Richards.

Temperatures in the lower to upper 80s across the region have been hard to come by for the second half of July. For many, this will be the coolest day since July 19.

Accompanying the cooler conditions will also be the arrival of steadier rainfall.

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"The same front bringing the arrival of cooler air is expected to stall over the region, causing rounds of showers and thunderstorms this week," explained Richards.

While areas from eastern Louisiana to southeastern Virginia could see a downpour any day this week, the most persistent rainfall is forecast from the Florida Panhandle to the Outer Banks of North Carolina. It is in this area that a total of 4-8 inches of rainfall could fall through Friday.

The coverage of heavy rain and thunderstorms is likely to become most widespread during the afternoon and evening hours. Outdoor plans at this time of day may need to be altered, due to wet weather.

Downpours will have the potential to bring ponding on roadways and reduced visibility, leading to hazardous and slowed travel for motorists. After several days of said downpours, the threat for flash flooding will also increase.

"This rain is coming to an area that has already been quite wet so far this summer, so much of the region is especially susceptible to flooding," added Richards.

Since June 1, the city of Pensacola, Florida, has recorded over 21 inches of rain, 138% of normal for through the end of July. Raleigh, North Carolina, has reported just over 12.5 inches of rain during that time, which is 141% of normal.

As the week progresses, the moisture causing the persistent wet weather across the Southeast will shift from one saturated part of the East Coast to another. Showers and thunderstorms are expected to be drawn northward to parts of the Northeast Coast. Locations along the I-95 corridor from Washington D.C. to Boston are likely to get at least one day of downpours later this week.

The Philadelphia area, in just in the month of July, has recorded 6.72 inches of rain, 153% of normal for the month. Additionally, the region is still recovering from an EF3 tornado that ripped through the region this past week.

See Also:

Severe storms to kick off August for NortheastResidents begin cleanup efforts following EF3 tornadoPerseid meteor shower headlines busy month for astronomy

Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.

Wildfire situation in Northwest may worsen this week

 By Courtney Travis, AccuWeather senior meteorologist

Updated Aug. 2, 2021 5:25 AM EDT

The weather pattern is set to change multiple times across the Northwest during the first week of August, bringing some opportunities for rain, but also threatening more bad news for the wildfires in the area.

For many across the Northwest, July was an especially dry month. Portland, Oregon, and Seattle each clocked in with only a trace of rainfall, compared to the normal around a half of an inch for the month.

Portions of the interior Northwest were fortunate enough to get a little bit of rainfall last week, as moisture from the North American Monsoon stretched northward into the region. This included cities like Bend, Oregon; Boise, Idaho, and Jackson, Wyoming, all picking up a couple of tenths of an inch of rainfall before the end of July.

While this is not enough rain to make any noticeable dent in the drought conditions across the region, for some cities, like Bend, Oregon, it was the only rain these locations received all month long.

As the new week begins, the hope for more rain is likely to dwindle.

"An area of high pressure is forecast to shift westward this week, bringing in drier air, and ushering out the monsoonal moisture for locations from Las Vegas to Boise," said AccuWeather Meteorologist Rob Richards.

Any areas that were dampened by the rainfall will have time to dry back out again, increasing the available dry vegetation.

Areas from New Mexico and up through the Rocky Mountains are likely to still get a few thunderstorms, especially in the afternoon and evening hours through Tuesday.

By midweek, the monsoonal moisture will be suppressed southward to just New Mexico and Arizona. However, this does not mean that the rest of the interior West will be bone dry.

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At the same time that the monsoon moisture is pressed south, a storm is forecast to move into the region late Wednesday and through Thursday.

"While it isn't likely that there will be a lot of moisture with this storm, there will still be some potentially dangerous conditions for the region," warned Richards.

Any showers that develop with this storm are likely to be short-lived, once again not giving much in the way of drought relief. In addition, the lack of moisture will bring an increased chance of dry thunderstorms that would produce lightning strikes that could spark new wildfires.

"The windier conditions the come with this new storm could increase the challenge for firefighters in the area," said Richards.

The introduction of stronger, and changeable, winds could have fires growing rapidly and more erratically than in a calmer weather pattern.

While the West, as a whole, has been overrun with wildfires and smoke, the situation has been particularly challenging in the Northwest. As of Monday morning, more than 75 active fires were burning across the northwestern U.S., including the Bootleg Fire in southern Oregon which has already swelled to more than 400,000 acres in size, making it the third-largest in Oregon's history.

The above map shows the more than 75 active wildfires across the northwestern United States on the morning of Sunday, August 1. (Photo/Inciweb)

The weather pattern is likely to change once again over the Pacific Northwest towards the end of the week.

A more impressive storm is forecast to push in from the Pacific as early as Friday, bringing with it a more-impressive wave of moisture to portions of Washington.

"While this wet weather will be good for the fires in British Columbia, gusty winds and a lack of moisture could spell more trouble for the firefighting efforts elsewhere," said AccuWeather Senior Meteorologist Brett Anderson.

The wet weather with this late-week storm may finally bring rain to cities like Seattle and Portland, which have, as of Sunday, gone more than 45 consecutive days without measurable rain.

Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.

This Date in Weather History for August 2,2021

 Weather History

For Monday, August 2,2021

1954 - Severe thunderstorms produced golf ball size hail for thirty minutes in north central Kansas. One drift measured 200 feet long, seventy feet wide and three feet deep. (The Weather Channel)

1975 - Record heat gripped New England. Highs of 104 degrees at Providence, RI, and 107 degrees at Chester and New Bedford, MA, established state records. The heat along the coast of Maine was unprecedented, with afternoon highs of 101 degrees at Bar Harbor and 104 degrees at Jonesboro. (The Weather Channel)

1987 - Hot weather continued in the central U.S. Fifteen cities reported record high temperatures for the date, including Concordia KS with a reading of 106 degrees, and Downtown Kansas City, MO, with a high of 105 degrees. Evening thunderstorms produced severe weather in the Ohio Valley and the north central U.S. Thunder- storms in South Dakota produced wind gusts to 70 mph at Philip, and hail two inches in diameter at Faulkton. (Storm Data) (The National Weather Summary)

1988 - Searing heat continued from the Middle and Upper Mississippi Valley to the Middle and Northern Atlantic Coast States. Twenty- six cities reported record high temperatures for the date. Chicago IL reported a record seven days of 100 degree heat for the year. (The National Weather Summary)

1989 - Low pressure representing the remains of Hurricane Chantal deluged north central Texas with heavy rain. Up to 6.50 inches drenched Stephens County, and Wichita Falls reported 2.22 inches of rain in just one hour. Bismarck, ND, reported a record warm morning low of 75 degrees, and record hot afternoon high of 101 degrees, and evening thunderstorms in North Dakota produced wind gusts to 78 mph at Lakota. Early evening thunderstorms in Florida produced high winds which downed trees at Christmas. (Storm Data) (The National Weather Summary)

Destructive western US monsoon to trigger new concerns

 By Alex Sosnowski, AccuWeather senior meteorologist

Updated Aug. 1, 2021 7:09 AM EDT

Already the 2021 North American monsoon season has gotten off to a tumultuous start. Not only has it been the busiest start to the season in years, the monsoon thunderstorms and their resultant flash flooding have turned deadly across the American Southwest.

AccuWeather forecasters say that although the engine for the monsoon will continue to churn out thunderstorms in the coming days, the activity will shift around in parts of the West. A pattern change could also influence the coverage of storms over the region into the week -- and raise dangers of a different sort.

California, Nevada, Oregon and Washington could all get storm action at times into the week.

Typically during the summer months, a broad area of high pressure develops over the interior West and extends through multiple levels of the atmosphere. This high-pressure area becomes the engine for the monsoon.

The clockwise circulation around this high eventually pulls moisture up from the Gulf of Mexico and sometimes the Gulf of California as well. As that happens, humidity levels tick up, and the extra moisture goes on to fuel daily thunderstorms in the Southwest.

AccuWeather Chief On-Air Meteorologist Bernie Rayno described this season as the most robust since 2015. The surplus of rain this month has helped to knock down the magnitude of the highest levels of drought, especially in New Mexico and Arizona. However, in areas farther to the north and west in California, Nevada, Utah and Oregon, where moisture has been much more limited, the drought has gotten worse.

In some areas, such as in Tucson, Arizona, rainfall this past July ranks high compared to other Julys, or even any month in history. Tucson picked up 8.06 inches of rain for the month, blowing away the wettest month on record, which unleashed 7.93 inches in August 1955.

This year's monsoon has already proven to be dangerous and deadly. There have been multiple incidents of flash floods that have raced through city streets, arroyos and open areas of the Southwest. Dust storms on the leading edge of the monsoon thunderstorms have caused multiple vehicle pileups as well.

Thunderstorm winds flipped over two large rigs near Chiriaco Summit, California, causing one injury, according to the California Highway Patrol.

There are often fluctuations in the areal coverage of moisture from one day and one week to the next. These variances may seem subtle but can lead to stretches of days with thunderstorms every day and just the opposite when thunderstorms can be absent for a long time.

On Friday, satellite images revealed that a surge of moisture was present from western Arizona to much of Utah, much of Nevada, the deserts and Sierra Nevada of California, the Oregon Cascades and south-central Washington.

This image, taken on Friday morning, July 30, 2021, shows a ring of moisture and fuel for thunderstorms was present from western Arizona and southeastern California to parts of Oregon, Idaho and Wyoming. (CIRA at Colorado State/GOES-West)

A pocket of dry air in the atmosphere limited the number of storms in New Mexico, eastern Arizona and southern Colorado at the start of the weekend.

"As some extra energy in the upper atmosphere moves up from the south and southeast, it will trigger storms over a wide area," Zehr explained. The storms could trigger torrential downpours, some of which may be slow-moving, and flash flooding as a result.

At the same time, some of the storms that fire over the Sierra Nevada, Oregon Cascades and parts of south-central and southeastern Washington may bring so little rain that lightning strikes could start new fires -- and gusty winds kicked up could threaten to fan the flames.

Early this week, the upper-level area of high pressure is forecast to shift westward, which will switch up the pattern across the American Southwest.

"The westward shift of the big high-pressure area will tend to weaken the flow of moisture into the West and cause a downturn or pause in thunderstorm activity across California, Nevada and Oregon on Sunday," Zehr said.

Storms are likely to keep firing across the swath from New Mexico and parts of Arizona to Colorado and portions of Utah into the week, but perhaps with less coverage when compared to much of the summer thus far.

The number of storms erupting on a daily basis may continue to dwindle as this week progresses.

However, AccuWeather meteorologists have concerns about one area in particular related to thunderstorm activity coming in from the Pacific this week.

A southward dip in the jet stream is forecast to strengthen over the northeastern Pacific this week. As this dip develops, storm systems with limited moisture are likely to travel into the northwestern U.S. One such storm system may roll ashore in Northern California and Oregon at midweek.

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Even though the jet stream dip and storm system are likely to bring lower temperatures, some cloud cover and perhaps a break in the dry spell for western Washington and coastal Oregon, the features may stir winds and bring just enough moisture to cause thunderstorms to erupt farther inland. In this scenario, the pattern could lead to a new surge in wildfires from both lightning strikes and winds that may further spread ongoing blazes and lead to erratic fire behavior.

Even in the wake of this particular disturbance, a pattern of tricky winds may continue to cause trouble for firefighting efforts later this week throughout the interior Northwest.

As of Sunday morning, August 1, 2021, 87 active large fires had burned 1,771,933 acres across 13 states, mostly in the West, according to the National Interagency Fire Center.

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Soggy spell to squash summertime heat in Southeast

 By Courtney Travis, AccuWeather senior meteorologist

Updated Aug. 1, 2021 6:53 AM EDT

Residents across the southeastern U.S. are experiencing another hot weekend. But the most intense heat is likely to wane this week as wet weather moves in.

To start off the weekend, heat baked portions of the South. On Saturday morning, heat advisories and excessive heat warnings stretched across a dozen states.

Temperatures peaked in the middle to upper 90s for most locations from Little Rock, Arkansas, to Tallahassee, Florida, with some areas nearing the century mark in the afternoon.

As the weather pattern changes, residents in the area will be able to say goodbye to the above-normal temperatures.

A cool front is expected to sag south, erasing the heat and bringing in a more refreshing air pattern. However, the clash of warm and cool air may allow for severe thunderstorms to move across the mid-Atlantic coast on Sunday.

By the time Monday arrives, temperatures are likely to be slashed 10 to 15 degrees across portions of the Southeast, according to AccuWeather Meteorologist Rob Richards.

Temperatures in the lower to upper 80s across the region have been hard to come by for the second half of July. For many, this will be the coolest day since July 19.

Accompanying the cooler conditions will also be the arrival of steadier rainfall.

CLICK HERE FOR THE FREE ACCUWEATHER APP

"The same front bringing the arrival of cooler air is expected to stall over the region, causing rounds of showers and thunderstorms this week," explained Richards.

While areas from eastern Louisiana to southeastern Virginia could see a downpour any day this week, the most persistent rainfall is forecast from the Florida Panhandle to the Outer Banks of North Carolina. It is in this area that a total of 4-8 inches of rainfall could accumulate through Friday.

The coverage of heavy rain and thunderstorms is likely to become most widespread during the afternoon and evening hours. Outdoor plans at this time of day may need to be altered, due to wet weather.

Downpours will have the potential to bring ponding on roadways and reduced visibility, leading to hazardous and slowed travel for motorists. After several days of said downpours, the threat for flash flooding will also increase.

"This rain is coming to an area that has already been quite wet so far this summer, so much of the region is especially susceptible to flooding," added Richards.

Since June 1, the city of Pensacola, Florida, has recorded over 21 inches of rain, 138% of normal for through the end of July. Raleigh, North Carolina, has reported just over 12.5 inches of rain during that time, which is 141% of normal.

As the week progresses, the moisture causing the persistent wet weather across the Southeast will shift from one saturated part of the East Coast to another. Showers and thunderstorms are expected to be drawn northward to parts of the Northeast Coast. Locations along the I-95 corridor from Washington D.C. to Boston are likely to get at least one day of downpours later this week.

The Philadelphia area, in just in the month of July, has recorded 6.72 inches of rain, 153% of normal for the month. Additionally, the region is still recovering from an EF3 tornado that ripped through the region this past week.

See Also:

Severe storms to kick off August for NortheastResidents begin cleanup efforts following EF3 tornadoPerseid meteor shower headlines busy month for astronomy

Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.