The atmospheric setting of the tropical western Pacific Ocean is becoming increasingly favorable for spinning up a tropical storm that could threaten southern Japan early next week.
As of Thursday, the makings for an organized tropical system took the form of widespread showers and thunderstorms over the southern Philippines Sea far to the east of the Philippines.
Movement of this broad swath of disturbed weather will be towards the north and northwest and, by later Saturday, a tropical depression, even a named tropical storm, could be under way.
Although the piled-up moisture necessary to form the core of a would-be tropical cyclone has already gathered in the area in question, the upper atmosphere has thus far stayed unfavorable for tropical cyclone development. An expected shift to a more favorable, "less shearing" in the words of tropical storm forecasters, environment is the basis for the tropical cyclone threat for southwestern Japan.
In the event that the upper wind flow becomes favorable to the fullest extent, a typhoon, a tropical cyclone of hurricane strength, would wrap up over waters south of southwestern Japan by next Tuesday.
Less-than-optimal atmospheric conditions could still bring a rain-laden tropical storm or depression landfalling to southwestern Japan early next week.
At this time, the most likely scenario would be the latter, in which torrential, flooding rain would pose the greatest weather threat to life and property.
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Several storms will bring periods of rain and gusty winds to the west coast of the United States next week with the potential for one of these to reach Southern California.
Colder weather, and in some cases, a taste of winter with snow will continue to invade the northeastern United States this weekend.
Dry weather set to dominate the southern United States into November will only worsen the already extreme drought conditions.
The changing of the seasons will bring beneficial rainfall to northern Brazil, a region that has experienced severe drought over the past several years.
Rain will continue to cause travel delays and raise the risk of isolated flooding in parts of the northeastern United States and Atlantic Canada into Saturday evening.
Damaging storms pounded the Pacific Northwest, while two powerful typhoons struck the Philippines within a four-day span.
Tuscaloosa, AL (1884)
No rain from August 28-October 22. Severe drought throughout Southeast.
Temperature reached 104 degrees at San Diego (record for date). Record for date 100 degrees at Los Angeles (downtown). Climax of heat wave of record duration in Southern California.
Ottawa, Canada (1988)
Record October snowstorm brings 21 cm (just over 8 inches).