What Is A Heat Dome? Millions To Face Scorching Temperatures This Weekend
Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content.
Millions of Americans are facing oppressive heat, with forecasters expecting a "heat dome" to develop over parts of the county over the weekend and through next week.
Why It Matters
The National Weather Service (NWS) warns that heat related illnesses increase significantly during extreme heat events.
What To Know
Nearly one-third of the U.S. population is set to face a stretch of extreme heat beginning as early as Friday, according to forecasters at AccuWeather.
The area of extreme heat will stretch from the Rockies to the East Coast, with spikes between five and 15 degrees above historical averages, the outlet said.
It added that some 170 million people will experience temperatures of 90 degrees Fahrenheit or higher.
A forecast map from AccuWeather shows which states are facing the heat this weekend.
A forecast map from AccuWeather shows which states are facing the heat this weekend.
AccuWeather
According to the NWS, the "hottest temperatures of the season so far" are anticipated to begin Friday across the Plains, later expanding across parts of the Great Lakes and Midwest.
Then, the extreme heat will move East and persist across the Ohio Valley and swathes of the East Coast later in the weekend and through much of next week.
An AccuWeather forecast map highlights where the heat wave is expected to spread next week.
An AccuWeather forecast map highlights where the heat wave is expected to spread next week.
AccuWeather
AccuWeather meteorologist Adam Douty told Newsweek that heat dome and heat wave are broadly synonymous. "In terms of impacts, they are the same," he said—though Douty added that heat dome can refer more to the atmospheric set up that leads to a heat wave.
What People Are Saying
AccuWeather meteorologist Adam Douty told Newsweek: "In weather context, a heat dome is created when a strong high-pressure system (in the mid and upper atmosphere) parks itself over an area and doesn't move much.
"The high pressure prevents clouds and [precipitation] from forming, which means more sunshine and even hotter daytime temperatures. And since winds are weak under this dome, it can hang around for days or even weeks."
Ben Noll, a meteorologist for The Washington Post said on X, Wednesday: "A heat dome will form over central states on Friday before expanding and intensifying.
"Heat domes are large and strong heat-trapping lids of high atmospheric pressure.
"This one will last around a week, with numerous temperature records expected to fall."
The National Weather Service Weather Prediction Center (WPC) said on X, Wednesday: "Numerous daily record highs and warm lows are anticipated Sunday into early next week. This level of heat can be dangerous to anyone without effective cooling and/or adequate hydration."
What Happens Next
Douty told Newsweek that this stretch of heat will intensify over the Plains and Midwest through the weekend, shifting to the East by early next week. While temperatures are expected to ease mid-to-late week, highs will still stay above normal in many regions.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Newsweek
3 hours ago
- Newsweek
Flood Warning Issued as River Depth Reaches 90 Feet
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. National Weather Service (NWS) meteorologists extended a flood warning for Iowa residents in Black Hawk County after the Cedar River flooded to 90.7 feet on Friday morning. Why It Matters The extended flood warning in Iowa comes as flood and flash flood warnings have been issued across numerous states amid torrential rainfall. NWS meteorologist Chad Hahn, who works at the Des Moines office, told Newsweek that a 67-year-old rainfall record was broken last month when Des Moines International Airport recorded 10.62 inches of rain throughout the month of July. The previous record, set in 1958, was for 10.51 inches. Behind extreme heat, flooding is the second deadliest weather hazard in the United States. Last year, there were 145 flood-related fatalities in the U.S., according to NWS data. What To Know Rising water levels on the Cedar River prompted the NWS to extend a flood warning for Cedar Falls and surrounding areas that was originally issued last weekend. Communities across Black Hawk County faced heightened risks as the river surpassed its flood stage after it rose to 90.7 feet on Friday morning following more heavy rain that fell mid-week. The NWS in Des Moines issued an extended flood warning for the Cedar River at Cedar Falls, affecting Black Hawk County, effective as of 10:39 a.m. CDT on Friday morning. According to the NWS statement, "Minor flooding is occurring and minor flooding is forecast." At 9:45 a.m. CDT on Friday, the Cedar River's stage was observed at 90.7 feet, exceeding the official flood stage of 89.0 feet. The NWS forecast projected the river would crest at 90.9 feet on Friday evening before gradually receding below flood stage late Sunday evening. Possible flood impacts were noted, including Big Woods Road south of Dunkerton Road and the north parking lot of Island Park should the river rise to 91.0 feet. The rising river levels come as severe weather, particularly flash floods, have inundated the nation this summer, including a devastating flood that killed more than 100 people in Central Texas last month. On Thursday, floods pummeled New York and New Jersey, causing travel chaos and prompting both governors to issue a state of emergency. Meteorologists have noted the excessive amount of moisture in the atmosphere this summer, which is contributing to the heavy rain lashing multiple regions across the U.S. On Friday, parts of Virginia also were under a flash flood warning and flood watch. NWS meteorologist Christopher Grover told Newsweek although rainstorms were normal in that region for this time of year, the rainfall rates were uncommon and were caused by the moisture-laden atmosphere. In Iowa, residents are urged to avoid flooded routes and monitor official bulletins for updated forecasts and safety instructions. The affected area spans from the West Fork Cedar River to the Cedar Falls-Waterloo city limits. Other regional waterways under current or continuing flood warnings included the Shell Rock River at Shell Rock (Bremer, Butler, and Black Hawk Counties) and the Iowa River near Tama Hwy E49 (Tama and Poweshiek Counties). The East Fork Des Moines River near Algona flood warning was canceled for Kossuth and Humboldt Counties. A stock photo of a flooded road. A stock photo of a flooded road. mrolands/Getty What People Are Saying NWS meteorologist Chad Hahn told Newsweek on Friday: "It's been a record year for July rainfall." NWS Des Moines in a flood warning: "Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles." What Happens Next The Cedar River was expected to crest on Friday evening. Water levels will decline throughout the weekend, with the flood warning expiring on Monday morning. Hahn told Newsweek that the forecast for the Des Moines area is in a dry stretch for the next several days, with more rain not expected until the middle of the next week.
Newsweek
8 hours ago
- Newsweek
Wildfire Threat Hits Hawaii as Pacific Hurricane Season Takes Off
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Meteorologists warned of an increased wildfire threat across Hawaii on Friday as strong winds begin to blow across the state, much of which is battling drought. Why It Matters Hawaii entered a period of heightened wildfire risk on Friday as the National Weather Service (NWS) issued a red flag warning for all leeward areas and interior sections of the islands. The warning signaled the potential for extreme fire behavior driven by strong winds and low humidity and comes in the middle of the Pacific hurricane season, which has already seen an active start. Wildfires pose a serious threat to Hawaii's communities, native ecosystems, drinking water, infrastructure, and cultural resources, as evidenced by the destructive Maui fires in 2023, which were fueled by strong winds. What To Know The NWS in Honolulu announced a red flag warning for all Hawaiian Islands, effective through 6 p.m. local time on Friday, due to a combination of dry conditions, strong easterly trade winds, and low relative humidity. The warning covered leeward portions of all islands and interior sections on the Big Island, listing expected wind speeds of 15 to 30 miles per hour with gusts up to 40 mph on Oahu and Kauai, and gusts as high as 50 mph in Maui County and the Big Island. Relative humidity levels were expected to drop as low as 35 to 45 percent in the afternoon, meaning the landscape would be increasingly susceptible to ignition. Residents were urged to avoid outdoor burning, refrain from parking vehicles on dry grass, and delay spark-producing activities until calmer conditions returned. The NWS's red flag warning comes as the National Hurricane Center (NHC) monitors four disturbances, including two tropical storms, Iona and Gil. Iona passed well south of Hawaii earlier this week, and although some of the winds in Hawaii were driven by the tropical systems passing south of Hawaii, AccuWeather lead hurricane expert Alex DaSilva told Newsweek an area of high pressure north of the islands is the primary driver behind the winds, similar to what happened in 2023. "These tropical systems that have gone by, like helped a little bit with some of the winds, but it's a similar two years ago when they had the wildfires in Maui," DaSilva said. "Everybody was really jumping on Hurricane while [Dora] played some role, [the winds] were caused by high pressure north of the island. Unusually strong trade winds really picked up around that high pressure, and that's what led to that event two years ago." DaSilva added that Hawaii is facing a similar setup now, although the trade winds won't be as strong. "We have a similar situation with these storms coming underneath Hawaii and strong high pressure to the north, but it's not nearly as strong as what happened two years ago," he said. "But winds are going to be strong enough through the weekend where there definitely can be some wildfire risk because it's so dry." Wildfires burn over the town of Lahaina as seen in the neighboring Kaanapali Alii resort, on August 08, 2023, in Maui. Wildfires burn over the town of Lahaina as seen in the neighboring Kaanapali Alii resort, on August 08, 2023, in Maui. Gonzalo Marroquin/Getty What People Are Saying NWS Honolulu in a red flag warning: "A combination of strong winds, low relative humidity, and dry fuels can contribute to extreme fire behavior. Any fires that develop will likely spread rapidly. A Red Flag Warning does not predict new fire starts." It added: "Heat from vehicle exhaust systems can ignite dry grass. Park cars on areas that are paved or where vegetation is trimmed and cleared. High winds contribute to wildfire hazard. Delay activities that could throw off sparks until the wind dies down." What Happens Next? Officials and emergency agencies urged Hawaii's residents and visitors to remain vigilant, continue monitoring official weather updates, and take preventive measures seriously. DaSilva said strong winds will persist in Hawaii through the weekend before they start to die down early next week.
Newsweek
9 hours ago
- Newsweek
Map Shows Flash Flood Threat Affecting Millions on Friday
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. National Weather Service (NWS) meteorologists have warned that millions of people across three states are at risk for heavy rain that could lead to flash floods on Friday. Why It Matters On Thursday, torrential rain pummeled the Northeast, prompting the governors of New York and New Jersey to declare states of emergency as flash floods overwhelmed busy roads at peak travel time. Now, although much of the U.S. is expecting some sort of rainfall on Friday, the heaviest downpours are shifting south. What To Know On Thursday night, the NWS posted a map on Facebook showing the main weather threats, which included flash floods, facing the U.S. on Friday. "Scattered thunderstorms and heavy rainfall are expected to bring the potential for flooding across the Carolinas, Southern Plains, and the front-range of the Rockies on Friday," the post said. "Fire weather concerns will persist in the northwestern Great Basin on Friday due to isolated dry thunderstorms. Air quality will continue to be impacted through Saturday in the Midwest due to smoke from the Canadian wildfires." A map from the National Weather Service shows the most likely areas for flash flooding on Friday are in Texas and the Carolinas. A map from the National Weather Service shows the most likely areas for flash flooding on Friday are in Texas and the Carolinas. National Weather Service According to the map, all of South Carolina, much of North Carolina and east-central Texas had the highest risk of seeing rainfall heavy enough to cause flash floods. Meanwhile, rain and thunderstorms are expected across the Pacific Northwest, central U.S., South and Northeast. Despite the forecast, the only flash flood warning in place on Friday morning around 10:30 a.m. Eastern time was for the Tulsa, Oklahoma, forecast region. Bob Oravec, the lead forecaster at the NWS Weather Prediction Center, told Newsweek that heavy rain could begin in the Carolinas in the early afternoon, with thunderstorms peaking between 6 to 8 p.m. In Texas, the storms are expected to begin later in the night and peak around 3 or 4 a.m. Saturday. "The risk has definitely pressed southward from where it was yesterday," Oravec said. "Right now, there's really not much on the radar, but as the afternoon goes on there's a frontal boundary that's lying across central southern North Carolina into northern South Carolina that will be the focusing mechanism for the thunderstorms this afternoon." What People Are Saying A National Weather Service forecast issued on Friday said: "A front extending from the southern Mid-Atlantic southwestward to the Southern Plains will move southward to northern Florida westward across the Gulf Coast and then northwestward across Texas to the Southern High Plains by Sunday. "The front will trigger showers and thunderstorms, accompanied by heavy rain, over parts of the southern Mid-Atlantic. ... The associated heavy rain will primarily create localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas being the most vulnerable." The forecast continued: "Additionally, showers and thunderstorms with heavy rain will develop along and near the boundary over parts of the Southern Plains and Southern High Plains. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over two areas of the Southern Plains and Southern High Plains through Saturday morning. The associated heavy rain will primarily create localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas being the most vulnerable." What Happens Next Rain is expected to continue across the U.S. throughout the weekend. Residents in the high-risk areas should monitor local weather guidance as the storms arrive.
