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.
The combination of excessive heat and dry thunderstorms in many areas will add to the wildfire threat in the western part of United States and Canada through much of July.
Americans will be hoping for clear skies this Saturday, July 4, as they look to enjoy dazzling fireworks displays, in addition to other popular Fourth of July activities.
A pair of disturbances tracking eastward from the Plains will bring bouts of showers and thunderstorms to the East through the rest of the week.
Tuesday, June 30, will be the longest day of the year by exactly 1 second.
The heat wave that started across Spain and Portugal, will spread across much of Europe this week with some of the hottest conditions of the year.
The last major eruption of Mount Hakone occurred around 2,900 years ago, according to the Global Volcanism Project at the Smithsonian Institution.
Tropical Rains caused flooding. The cloud bursts were generated by the combination of Tropical Cyclone 04B, which made landfall in the eastern state of Orissa the morning of the 29th. In Raipur, 16 inches poured down from evening of the 28th to the morning of the 30th. In Bombay, 10 inches of rain fell in just 9 hours on the 30th; total rainfall from the 28th to the 30th was just over 20 inches.
Flooding rainfall continued. Near Olpe, 4.78 fell in 24 hours, causing major flooding. Dexter was completely cut off by flooding, with roadways in and out of town unpassable. Near Williamsburg, 17.25 inches of rain fell over the past 3 days. As of the 30th, Welda's total rainfall for June was about 20 inches.
The second destructive hurricane in nine days hit the Apalachicola-Tallahassee are; several people were killed, but the area sustained only light damage.