Eastern US Winter Pattern and South America Winter

Alexandre Aguiar

Dear Friends

It is our first week in Stormtrack and it is a honor to be part of the group. We hope to offer some views from the Southern Hemisphere and learn a lot with you. Many times we will slide in the English writing, but we are sure you gonna get the message. As this is winter time to the vast majority of the users here, I would like to write about something we blogged in our website early in January, when NYC was under 72F.

Everyone was astonished by the record warm in the Eastern US. Cherry trees were beginning to blossom. It looked like spring. Well, we wrote to our Brazilian audience that for some years we have been observing a season to season relationship between temperature pattern in Southern Brazil and Eastern US.

In 2006, winter arrived earlier to us here in the Southern Hemisphere with a very cold May that presented July conditions. Remember the record lake-effect snowstorm in October 2006 in New York state ? And the recent snow and ice storm in the Midwest late in November ?

Well, in July 2006 – our coldest month of the year here in Southern Brazil – we had abnormally record-breaking warm for the first three weeks. Just like in the Northeast United States, flowers could be seen two months earlier than expect. The warm weather accelerated crops germinations in the countryside.

In the last week of July a very powerful cold blast brought very cold temperatures and severe frosts. As the plants germinated earlier in the croplands, winter cultures suffered major losses. The lowest temperature of the year in regional scale were observed on July 30th and July 31st.

In August, two major cold waves impacted us and September was incredibly cold. On August 21st and 22nd it was bitterly cold to our standards and the higher elevations (above 3.000 feeet) experience 15F. On September 4th we observed the most widespread snow event in Southern Brazil for September so far in history. Losses mounted in the fruits industry.

Here is a graphic depicting daily temperature anomalies in Rio Grande do Sul state (Southern Brazil) from June 22nd (beginning of the winter) and September 21st. (end of the winter).


What I am trying to say is that we had winter, than spring than a very cold winter during the climatic winter from May to September 2006. Of corse it is not equal, but in recent years patterns were very similar season to season. Let's see if this trend continues in the next weeks. So far it has been very similar. Will Punxsutawney Phil see his shadow ? If the pattern sustains, he will.

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