By Phuong Nguyen and Mas Alina Arifin
HANOI/BANDAR LAMPUNG, Indonesia (Reuters) - Heavy rains and strong winds triggered by a typhoon hit Vietnam's key coffee growing region this week, posing a threat to the country's harvest, while the Indonesian market was tepid at the end of the harvest season, traders said on Thursday.
Typhoon Molave, the most intense one to hit Vietnam this year, flooded low-lying areas in a key coffee-growing region and ripped some coffee cherries off the trees.
Meanwhile, the Central Highlands, Vietnam's main coffee belt, is expected to see intermittent rainfall over the next 10 days, which may affect harvesting, as per the National Meteorological and Hydrological Center's forecast.
"No estimation of the storm's impact is available yet but continuous rainfall has prevented beans from turning ripe and ready for harvest," one trader based in the coffee belt said.
"It looks like new beans might not be available until the second half of November."
Another trader based in the region was concerned over the rains in November, which would hamper beans picking and drying process.
Farmers in the Central Highlands sold coffee at 32,400-34,000 dong($1.40-$1.47), compared with last week's 31,100-33,000 dong range.
The London ICE January contract had gained 5.3% over the past week as of Wednesday's close, Refinitiv Eikon data showed.
Traders in Vietnam offered 5% black and broken grade 2 robusta at premiums of $170-$200 per tonne to the January contract, widening from last week's $170-$180 premium range.
Meanwhile, prices of Indonesia's Sumatran robust beans were unchanged from last week, traders said in Lampung province said, as harvest ended.
"It's very quiet this week because harvest has ended by the end of October," a trader said.
One of the traders quoted $170 premium to the January contract, while another offered $270 premium to the November contract, adding that coffee middlemen were still holding on their remaining stocks.
($1 = 23,174 dong)
(Reporting by Phuong Nguyen in Hanoi and Mas Alina Arifin in Bandar Lampung; editing by Uttaresh.V)