Based on the future movement of Typhoon Jelawat and Tropical Storm Ewinar, cold air may plunge into part of the northern U.S. days later.
You could call it the typhoon teleconnection, or the Tokyo, Chicago-New York connection, or something of that sort.
AccuWeather.com meteorologists have observed for years that whether tropical cyclones in the Western Pacific curve away from Asia or plow inland over China determines whether or not cold air aims for portions of the Midwest and Northeast approximately 10 to 14 days later.
According to Expert Senior Meteorologist Bob Smerbeck, "When a typhoon or strong tropical storm curves to the northeast along the coast of Asia, the way the jet stream gets jumbled up in the process usually allows a batch of chilly air to plunge southward from Canada to the swath from the northern Rockies to the northeastern U.S."
The jet stream is a zone of high speed winds at high levels of the atmosphere that often marks the path weather systems will take. The jet stream typically marks the boundary between cool air to its north and warm air to its south.
In short, the way a tropical cyclone curves northeast of Japan amplifies the jet stream over the Pacific Ocean and North America.
Exactly how strongly the tropical system curves will determine the wavelength and position of jet stream ridges and troughs over the Pacific Ocean and North America. (A ridge is a northward bulge of warm in the jet stream; a trough is a southward dip of chilly air.)
"In the case of Typhoon Sanba, which curved away from southeastern China around Sept. 14, 2012, but slammed Korea before heading north of Japan around Sept. 16, we had big ridge set up in the western and eastern Pacific with a trough in the middle of the Pacific and a trough over the Upper Midwest and Northeast U.S. during the latter part of September," Smerbeck said.
The situation in the Western Pacific now is a bit more complex in that we have two tropical cyclones, so we may not have a textbook case of how the push of cold air behaves a couple of weeks later.
We do believe that as Jelawat curves northeastward across Japan and Ewinar curves east of Japan this weekend, a push of cold air will begin to drive southward next week over western Canada," Smerbeck said, "From there, the cold push may get hung up over the North Central states or could drive more into the Great Lakes and Northeast next weekend into week two of October."
When tropical cyclones plow northwestward into mainland China and diminish, there is no direct connection in the weather a couple of weeks later for the northern U.S. Neither Jelawat nor Ewinar are forecast to reach westward into mainland China.
A powerful 7.6 magnitude earthquake struck near the Peru-Brazil border region shortly before 6 p.m. local time Tuesday evening, the U.S. Geological Survey said. A second 7.6 earthquake occurred about five minutes later.
While Atlanta has received above-average rainfall so far this month, dry and calm conditions are forecast for the area this week.
Compared to Thanksgiving Day in 2014, this Thanksgiving will be substantially warmer in the Northeast.
Hurricane Sandra, located hundreds of miles southwest of Mexico, is becoming better organized and will likely track northward through the rest of the week.
A few days of drier weather is expected across southern India before downpours return this weekend.
An expanding area of snow, rain, wind and cold will hamper Thanksgiving travel in the West, while most areas east of the Rockies can expect no major weather-related problems during the early to middle part of this week.
Wilkes-Barre/ Scranton (1971)
Heavy snowfall in the Wilkes-Barre/Scranton area. It started to snow the night before, and by about noon Thanksgiving Day 11/25/71, 20.5 inches of snow was reported on the ground at the Avoca, PA airport. Some of the surrounding areas had even more snow. Dallas, PA, had 27 inches and parts of the Poconos had as much as 30 inches. Barn roofs collapsed, power lines were downed, and tree branches were broken. The majority of the snow fell within 12 hours.
A dozen tornadoes across these states.
Astoria, Or (1998)
5.56 inches of rain fell, setting a new all-time record. the previous rainfall record was 4.53 inches from January 9, 1966.