* Chinese manufacturers, dealers snap up Thai grades - traders
* Unfriendly weather in Thailand tightens supply, drives up prices
* Thai STR20 rises to $1.70/kg, Indonesia's SIR20 at $1.63-$1.65
By Anuradha Raghu and A. Ananthalakshmi
KUALA LUMPUR/SINGAPORE, May 29 (Reuters) - Prices for rubber cargoes in Asia continued to pick up this week as demand streamed in from the world's biggest consumer China, while supply constraints in top grower Thailand aided the rally.
Physical rubber prices have benefited from joint efforts to curb output and boost prices, alongside renewed buying activity from Chinese traders in the recent weeks - which alleviated fears that slowing demand would prolong the supply glut that had caused prices hit their lowest since 2009.
Benchmark TOCOM rubber futures fell early on Friday, but were on course to post a weekly gain of 8 percent, their first in four weeks, on the back of the yen's decline to a 12-1/2 year low against the dollar.
Front-month SICOM rubber, a benchmark in Asia, was trading near a nine-month high of 164.90 U.S. cents per kg, and was on track for its biggest monthly gain since September 2012.
The Thai-grade STR20 was traded at $1.70 per kg for the July shipment, compared with $1.65 last week, with Chinese manufacturers and dealers snapping up cargoes, traders said.
Unfavourable weather in parts of the world's top natural rubber producer, meanwhile, tightened supply.
"Right now there are supply constraints from Thailand, and suddenly demand from China is picking up," said a Thai-based trader.
"The weather is abnormal - some areas are hot and dry, some have heavy rains. This whole situation has led to below-normal supply."
In Malaysia, the SMR20 grade was sold between $1.60 and $1.65 per kg this week, and was offered at higher prices of $1.66-$1.67 on Friday.
The Indonesian SIR20 grade for July shipment was traded in a range of $1.63 to $1.65 per kg on Thursday.
Top tyremaker Bridgestone Corp, typically a large buyer, struck deals at $1.62.
The RSS3 grade was sold at $1.88-1/2 for July shipment, while August cargoes were sold at $1.87-1/2. In Thailand, however, the grade changed hands at $1.90/kg.
"No Chinese buyers were seen this week. It looks like they are buying from Vietnam and Thailand," said a trader in Jakarta.
Despite the jump in prices this week, raw material costs continue to be a concern for Indonesian producers.
The shortage of the raw material has sent costs to 18,000 rupiah ($1.36) per kg this week, from 17,000 rupiah last week, the trader said.
Raw material supply has been soft due to the wintering season, when latex output drops. Output has been particularly tight in Medan, the provincial capital of North Sumatra. ($1 = 13,222.0000 rupiah) (Editing by Subhranshu Sahu)