Seasonal rains in Asia's Far East, known locally as the "plum rains," are set to lift northward during the coming week.
Drenching, potentially flooding, rains will set up across the North China Plain to the Korean Peninsula between Sunday and Tuesday, followed by repeated outbursts through the week.
At the same time, steamy heat will build over the Yangtze Basin of central and south-central China as southwestern Japan heats up.
Rainfall in a broad area for the eight days ended Sunday, July 7, 2013, will be 4 to 10 inches (about 10 to 25 cm) with amounts reaching 16 to 20 inches (40 to 50 cm) locally.
In keeping with historical weather patterns, recent days have seen widespread soaking rain with localized flooding across the central China to the southwestern half of Japan. The rains also clipped southern Korea.
Two tropical storms, Leepi and Bebinca, known respectively as Emong and Fabian in the Philippines, likely bolstered the plum rains in both countries.
The coming northward shift in the plum rains will coincide with a northward shift of sub-tropical high pressure over the western Pacific Ocean to a position east of northern Honshu, Japan, next week.
Also, a potential tropical cyclone forming east of the Philippines late this week will help to lift a rain-bearing westerly wind stream significantly northward from its position this week. This moist wind stream, which normally accompanies the plum rains, originates in the southwest monsoon in South Asia. Likewise, onset of the core plum rains begins roughly with the onset of the summer monsoon on the Indian subcontinent.
The plum rains are known as "méiyǔ" in China, the "baiu" or "tsuyu" in Japan and the "jangma" in the Koreas. The heart of the plum rain season stretches from early June to mid-July, with a tendency to shift south to north across the affected area. Start of the core plum rain season begins roughly with the onset of the summer monsoon on the Indian subcontinent.
The plum rains are known as "meiyu" in China, the "baiyu" or "tsuyu" in Japan, and the "jangma" in the Koreas. The heart of the plum rain season stretches from early June to mid-July, with a tendency to shift south to north across the affected area.
In the wake of the mid-June cloudbursts, most of Pakistan to northwestern India last week saw a return to dry, hot weather typical of the weeks leading up to the Monsoon onset. It was as if the Monsoon withdrew to its "normal" position for the latter half of June.
The 38.5 degree C (101 degrees F) reading Tuesday in Ajaccio, Corsica, may have been tops in Europe.
Monsoon Onset was June 13th, 2013, in Delhi, almost two weeks earlier than average. The June 15th onset at Karachi and Islamabad was more like three week ahead of schedule.
In Pakistan, hit-or-miss downpours missed the Sindh capital, Karachi. One did hit Pad Idan, where it left 60 mm of rain Wednesday. This was more than 20 times greater than the normal June rainfall.
It is still possible that this scenario is over wrought as to the intensity and spread of rain in Pakistan and northwestern India. However, it is the hunch of the present forecaster that some very unusual weather is going to unfold in the Subcontinent during the next week!