The last rainfall reported in Rio Grande do Sul came on Friday with some five mm (millimeters). Parts of Parana and Mato Grosso saw gusty thunderstorms, which gave plantations a good soaking of up to around 60 mm (millimeters).

But the rain proved short-lived as the weekend progressed.

``They haven't had any rain in the South of Brazil since Friday, nothing in Parana or in Rio Grande do Sul...however, it rained a lot in Mato Grosso,'' said Marcio Custodio of Sao Paulo meteorologists Somar.

``We are forecasting all week with no rain in the South of Brazil, apart from Parana, which could have some cloudbursts. But there's no forecast for rain in Rio Grande do Sul,'' Custodio told Reuters.

Parana is Brazil's top soybean-producing state and accounts for around a quarter of the national crop. Mato Grosso and Rio Grande do Sul rank in second and third place, respectively.

According to US-based Weather Services Corp (WSC), a few light showers were reported in the last 24 hours in scattered areas of Brazil's far South, along with Parana's southwestern soy areas. Some more thunderstorms were seen in Mato Grosso.

Agriculture ministry data for Rio Grande do Sul showed very low rainfall for five key soybean towns monitored in the last few days of December and first two days of January.

Somar's Custodio said last week's rains, triggered by a cold front tracking North, now appeared to have departed the main soy areas of the South until at least later next week. Lesser producing states further North could still see rains.

``The cold front is positioned in the southeast, between Sao Paulo and Rio de Janeiro, so it's raining in the coffee belt and in the soy areas of Mato Grosso and Goias,'' he said.

``So all the South of Brazil is dry and should stay that way for at least a part of next week,'' Custodio added.

The WSC was slightly more optimistic for the chances of rain returning to southern Brazil but said the probability of this occurring was unlikely much before Wednesday. For the next 24 to 36 hours, the southern belt would probably remain dry.

``We might start to look at some warming temperatures and at least an increasing chance of showers towards mid-week,'' said WSC's Brian Gonsalves. ``After a couple more dry days, they should see a return to shower activity down there (South).

``Beyond Wednesday, it looks like high pressure will move off the coast and should allow some of that tropical moisture off to the North to make its way South and increase the chance of showers,'' Gonsalves told Reuters.

Parts of Brazil's major soybean areas have suffered from below-average rains since farmers started planting as a drought has affected most of Brazil's South and southeast from September, and even earlier in some key areas such as Parana.

However, uneven weather conditions across the soybean belt have meant that some states are experiencing widely varying situations regarding crops and planting.