Maps across the nation are ablaze with warnings, illustrating the relentless eastward march of a massive heat dome that's blanketing a significant portion of the United States. Heat advisories and warnings, depicted in stark shades of red and orange, are sprawling across multiple states, highlighting the dangerous temperatures impacting millions. The National Weather Service's online maps, along with those from private weather companies, vividly show the extent of the extreme heat, clearly marking areas under excessive heat warnings where temperatures are expected to pose significant health risks. The visual representation on these maps is crucial for understanding the scope of the crisis. One can readily see the concentration of advisories in the central and eastern parts of the country, expanding from the already-baked Midwest and into regions not typically associated with such intense heat. The maps also frequently provide specific temperature forecasts, often exceeding 100°F (38°C) in many affected areas, and in some cases, reaching far higher. Isotherms – lines connecting points of equal temperature – further highlight the dramatic temperature gradients across the affected regions, providing a clear visual of the heat's intensity and spread. Beyond the simple temperature readings, many maps integrate additional data layers, such as heat index values, which combine temperature and humidity to reflect the perceived air temperature, providing a more accurate picture of the actual risk to human health. These more comprehensive maps often include shaded regions indicating different levels of heat risk, making it easier for individuals to understand the severity of the conditions in their area and take appropriate precautions. The inclusion of relevant information like hydration tips, safety guidelines, and links to cooling centers further underscores the urgency of the situation portrayed on these vital tools. In essence, these maps are not just meteorological data visualizations, but critical public service announcements, crucial for effective communication during a major heat wave.
The that has baked much of the central United States this week is shifting east ahead of the weekend, forecasters said. More than 100 million Americans are under heat alerts that will remain in effect through Tuesday night.
The extreme heat arrives along the East Coast on Friday and will stick around through the weekend and the first half of next week. Parts of the Midwest, including the Corn Belt, have felt the high temperatures for multiple days.
Temperatures on Friday are forecast to be 10 to 15 degrees above average for this time of year, with feels-like temperatures over 100 degrees expected in multiple areas.
Some parts of the Mississippi Valley will continue to see high temperatures over 90 degrees and feels-like temperatures over 100 degrees for at least a few more days, even as the heat dome moves over parts of the Northeast.
A happens when hot air is trapped over an area due to a persistent high-pressure system, William Gallus, a professor of atmospheric science at Iowa State University, said.
Heat domes can last for days to weeks and can stretch over multiple states.
Heat-related illnesses increase significantly during extreme heat and high humidity events.
With extreme heat in the Corn Belt, a region including parts of the Plains and Central Mississippi Valley, a phenomenon known as has made the humidity worse, experts said.
"There are pores on the bottom side of the leaves," Iowa state climatologist Justin Glisan told TheNews national correspondent Lana Zak. "And that's where oxygen is released, but also water vapor."
The process can add up to 10 degrees to the feels-like temperature, Glisan said, because just 1 acre of corn can release as much as 4,000 gallons of water into the air per day. Iowa has around 13 million acres of corn.
