Is summer weather over for midwestern, northeastern US?
By Alex Sosnowski, AccuWeather senior meteorologist
August 13, 2017, 3:48:04 PM EDT
You will soon be redirected to the latest forecast information on the return of steamy air to the midwestern and northeastern United States this week: :
The recent spell of September-like temperatures has some people in the midwestern and northeastern United States wondering if summer weather is over for the year.
While heat will remain at bay early this week for parts of these regions, don't write off 90-degree Fahrenheit heat just yet.
Heat to remain at bay early this week
Heat will remain absent to start this week across much of the Northeast and Midwest due to a weather pattern that will stay put.
"Into the third week in August, a jet stream pattern will set up that resembles the Greek letter omega across the northern U.S. and southern Canada," according to AccuWeather Lead Long-Range Meteorologist Paul Pastelok.
The jet stream is a high-speed river of air located at the level in the atmosphere where jets cruise.
The omega block creates somewhat of an atmospheric traffic jam. More cool air will jam into the Northeast. Waves of warm and cool air will flow over the North Central states. The most persistent warmth is likely over the northern High Plains.
"Essentially, this omega block will keep big heat locked up in the Southwest for much of the third week of August," Pastelok said.
Hurricane Gert to stir choppy seas along US East Coast
Locally heavy storms to rattle northeastern US into Saturday evening
2017 US fall forecast: Warmth to linger in Northeast; Conditions ripe for tornado outbreaks from Texas to Tennessee
MAPS: Forecast high temperatures
The sun is still strong enough to cancel out some of the cool air by day with highs in the lower 80s in the Northeast and Midwest.
The nights, however, will tend to be cooler and feel more like September. Temperatures will drop into the 60s fairly often in the Ohio Valley and coastal Northeast. Temperatures can dip into the 50s in the normally cool spots of the Upper Midwest, northern New England and the central Appalachians.
The evolving omega block will also help to steering budding Tropical Storm Gert away from the East Coast.
"Another aspect of the weather pattern will be to create much drier weather over much of the Midwest and Northeast, when compared to the first part of August," according to AccuWeather Meteorologist Dean DeVore.
The dry flow will likely shelter New England and part of the mid-Atlantic from torrential downpours early this week, indirectly associated with an offshore tropical system. Downpours are most likely to concentrate along the southern Atlantic coast.
August may finish warm
Predicting the development and breakdown of omega blocks are challenging. However, if the pattern goes according to schedule, the omega block will break down later in the week and into the last part of August.
"We expect more of a west to east flow with the jet stream with a slight northward bulge over the Great Lakes during the fourth week of August," Pastelok said.
This setup should allow some warmth to build farther north over the North Central states, and some of that warmth should reach the Northeast on occasion.
Which US regions are likely to offer clear skies when the eclipse occurs?
Weekly wrap-up: Franklin slams Mexico as 1st Atlantic hurricane of 2017; Seattle shatters old record with rain-free streak
Keep bugs away this summer with these 5 DIY hacks
During the last part of August, the pattern may evolve enough to allow days with highs in the upper 80s to near 90 from much of the Midwest to the Northeast. This includes areas around the upper Great Lakes and northern New England.
Warmth may linger into September
"Looking farther ahead into September, temperatures are likely to average a few degrees above normal for the month as a whole," Pastelok said.
"However, people need to keep in mind that average temperatures trend downward as the month progresses," he added.
For example, in Chicago and New York City average temperatures drop by about 10 degrees from the beginning to the end of the month. On Sept. 1, the average high is 80 for both cities. On Sept. 30, the average high is near 70 for both cities.
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
More Weather News
Weather News - March 19, 2019, 4:43:43 AM EDT
Showers and cooler conditions have descended upon northern portions of Florida over the past few days as a front slowly churned through the state.
Weather News - March 19, 2019, 4:35:42 AM EDT
The impacts will depend greatly on the track and strength of the storm, which is still yet to develop
Weather News - March 19, 2019, 1:38:04 AM EDT
Flooding will continue in waves and varying degrees of severity over the central United States, including a large part of the Mississippi River watershed, through the spring.
Weather News - March 18, 2019, 1:41:28 PM EDT
Relentless rain, snow and cold hammered the United States during the winter of 2018-2019.
Weather News - March 19, 2019, 4:21:55 AM EDT
Severe Tropical Cyclone Trevor made landfall on the Cape York Peninsula on Tuesday evening and is expected to plow westward into the Gulf of Carpentaria, threatening parts of the Northern Territory later this week.
Weather News - March 19, 2019, 1:31:11 AM EDT
After an extended break from storms, a new storm from the Pacific will eye California and much of the Southwest during the middle to latter part of this week.
Weather News - March 19, 2019, 4:41:33 AM EDT
Tropical depression Chedeng organized across the Philippine Sea and will threaten the southern Philippines with flash flooding and gusty winds early this week.
Weather News - March 18, 2019, 2:06:45 PM EDT
The number of fatalities continues to rise as communities remain isolated by devastating flooding caused by Tropical Cyclone Idai.