Comment Large parts of the Lower 48 are set to bake this week after a punishing, prolonged heat wave set records across the Pacific Northwest, east and south. Few areas will be spared as the heat spreads to different areas each day, scorching the Northern Rockies on Monday, the central states on Tuesday and Wednesday and the Northeast on Thursday. There will be no escaping the heat in Texas, which has already had a historically hot summer. Temperatures there are forecast to remain above normal — with highs mostly in the triple digits — through the week. The heat wave originated in the Pacific Northwest, where it set records for longevity in Seattle and Portland. Combined with a historically severe drought, the heat has fueled dangerous conditions for wildfires to spread in Northern California, where the recently ignited McKinney wildfire is devouring the landscape. The fire, located in the Klamath National Forest, has burned 51,468 acres and is completely out of control. 2 dead in McKinney fire, now California’s largest wildfire this year As the heat wave moves eastward, it will bring triple-digit heat to 43 million Americans. Heat warnings have already been issued in the Plains states, and it’s possible that extreme heat warnings will be issued in some cities in the coming days.
Records are falling in Northwest and Northern California amid escalating fire danger Relief is finally arriving in the Pacific Northwest after a week of intense heat, though another day of triple-digit highs is forecast for eastern parts of Washington and Oregon. Seattle set a record for its longest stretch at or above 90 degrees. The previous record was a tie between two fortnights in 2015 and 1981. It reached 94 degrees on Tuesday, 91 on Wednesday, 94 on Thursday and Friday and 95 on Saturday and Sunday. Record tied 5th straight day with a high of 90°+ in Seattle today. Average high temperature for the 5-day streak 93.8° (94.91.94.95.95). Average High Temperatures Over Remaining 5-Day Streak.95.0° 8/7-11/198191.6° 7/1-5/2015 Hottest 6-Day Stretch in Seattle, 6/24-29/2021, m. The. high 94.8°. #wawx — NWS Seattle (@NWSSeattle) July 31, 2022 Portland also experienced a record-breaking stretch of extreme heat, with a full week of consecutive days at or above 95 degrees ending Sunday. The previous record was a tie between six days in 1941 and another in 1981. The city’s average July high is 81.8 degrees, and yet three days between July 25 and the end of the month hit the century mark. NEW DISK FOR PDX. Today marks the 7th straight day of 95+ temperatures. From 345 p.m. the airport was at 97 degrees. Will it reach 100? #orwx #pdxtst — NWS Portland (@NWSPortland) July 31, 2022 In Medford, Ore., the temperature reached 114 degrees on Friday, just one degree off the all-time high. Tri-Cities Airport near Kennewick, Wash., hit a high of 110 degrees on Thursday, 112 on Friday and 109 on Saturday. Warm weather across the West has fueled wildfires in Oregon and Washington, but the McKinney fire in Northern California is the region’s most serious. It has burned an area about twice the size of Disney World, as high temperatures have helped dry out the landscape and the ground is littered with dry fuels available for burning. Many small fires have been spotted this weekend. Crews have been dispatched and are addressing them, but we need your help. We don’t have the resources to deal with careless fires caused by people. Never leave a fire unattended and not where permitted. pic.twitter.com/ab1CDlUoCj — Forest Service NW (@ForestServiceNW) July 31, 2022 How dry is this area of California? The ERC, or energy release element, is 97 percent. This is a number related to how much fuel per unit area is available for burning. Values above 80 percent reflect a trend toward dangerous fires. at 97 percent, explosive forest fire growth is possible. Warmer temperatures, amplified by the effects of human-induced climate change, are contributing to larger and more extreme wildfires. Eighteen of California’s 20 largest wildfires have occurred in the past two decades.
Extreme heat dripping east short term As the Pacific Northwest heat wave weakens, the responsible high-pressure area — or heat dome — will sink southeast and be absorbed by another heat dome extending from the Four Corners in Florida. The combined heat domes will bend northeast at times over the next few days. Heat warnings have already been lifted for the Plains, Ozarks and Corn Belt, covering St. Louis, Kansas City, Omaha, Des Moines, Sioux Falls and the Twin Cities. The core of the heat will settle into the central states on Tuesday and Wednesday and could extend into the Northeast on Thursday. Here are the hot spots of the day:
Numerous record highs between 90 and 105 degrees are forecast across the eastern Pacific Northwest and Northern Rockies from eastern Oregon to central Montana, including Billings, Helena, Great Falls and Missoula. Triple digit highs are forecast for much of the belt from Texas (off the coast) to western Nebraska. While predicted highs are only in the mid-90s in Missouri, heat indices are forecast to reach 100 to 110, including St. Louis.
Highs of at least 100 degrees are expected from Texas (away from the coast) to South Dakota, with heat indices as high as 105 to 110. Highs in the 90s are forecast for much of the South and Midwest, with a huge swath seeing heat indices of 100 to 105, including Dallas, Oklahoma City, Wichita, Omaha, Des Moines, Kansas City, St. Louis and Little Rock. Heat indices flirting with 100 could extend as far north as Minneapolis.
The heat is concentrated from Texas to Illinois, with widespread forecast highs in the 90s to 105 and heat indexes in the 100s to 110s. The heat index could reach 100 as far away as Chicago and Detroit.
The heat is spreading to the northeast. Boston and Hartford, Conn., both are expected to reach 96 degrees on Thursday, and Albany, New York could soar to 98. That would tie a record set in 1955. Highs in the mid-90s are forecast from DC to New York , with heat indices 5 to 10 degrees higher. Most of the Southeast will be in the low to mid 90s, but oppressive humidity will push heat indexes into the upper 90s or even near 100. Across the Plains, upper 90s or lower 100s are possible. Dallas, Austin and San Antonio will see highs of 103 or 104 degrees.
Plains to continue baking in a larger range A look at the extended range, moreover, suggests this dome of heat could languish for a week or more, possibly into mid-August, as it consolidates over the plains. See how hot it can get:
Upper 90s to low 100s spread from Texas as far north as the Canadian border, peaking around 102 degrees in Rapid City, SD, which would tie the 1964 record.
Some cooler air sinks into the northern plains, but highs in the 90s and low 100s stretch from Texas to Iowa.
