"Light rain that fell at the start of the week, was quickly followed by a deluge over the week-end.
"If the dry weather that we have experienced in 2012 is partly to be blamed for the crop shortfall, the heavy rainfall that we are witnessing now is unlikely to give way to record crops in the near future."
The island's tea production this year has lagged behind last year's output owing to drought, which along with crop shortfalls in other key origins had helped prop up prices in certain months.
But John Keells said the heavy rain itself could retard crops.
"The overcast (conditions) and high rain fall in the plantation districts, particularly in the 'High Grown Sector', will hinder growth which in turn will have an impact on crop intakes."
The tea crop had recovered somewhat in September after rains resumed, reducing the crop shortfall to some extent.
"On account of better weather for growth in September, Sri Lanka’s crop for the month of 26.8 milliok kilos is 2.8 million kilos above the corresponding month of 2011," the brokers said.
"It is the highest crop achieved for a September with the previous best of 26.3 million kilos in 2008."John Keells brokers also said the rains will relieve the suffering caused by drought which had reduced irrigation water and hydro-power generation.
"Every storm cloud has a silver lining and one area which has benefited immensely from these down pours have been the rise in the water levels of the hydro power reservoirs in the central hills and depleted irrigation tanks in the North Western, North Central and Eastern provinces.
"It is reported that with the recent heavy rains some of them have already reached spill level which will boost hydro power generation and supply much needed water for agricultural and drinking purposes in the dry zone which has been reeling under the impact of the severe drought."