SAMPLE WEATHERCASTS

Sunday, April 10, 2011

What I'm Watching Heading Into Hurricane Season

Colorado State came out with their forecast for the upcoming hurricane season. They are calling for an above average season with 16 named storms, 9 hurricanes and 5 major hurricanes. Here are a few things we will be watching over the next couple months leading to the start of hurricane season.

La Nina

Hurricanes like warm ocean water and low wind shear. Wind shear is typically low during La Nina, which would lead to an active season. However, La Nina is rapidly weakening (see the map below), so the forecast isn't as clear-cut.




Atlantic Water Temperatures

As I stated above, hurricanes strive in warm ocean water. Sea surface temperatures (SST) have been above normal over the past few months, which points towards an active season.



NAO

The North Atlantic Oscillation (NAO) has an impact on the Trade Winds. We saw a dramatic shift to a positive NAO during January. This increased the Trade Winds and has consequently cooled the Atlantic waters slightly. If we remain in a positive phase, then ocean temperatures could continue to cool.



Conclusion

Colorado State has already decreased it's initial forecast for this upcoming hurricane season. If La Nina continues to weaken and NAO remains mostly positive, then we might see the number of named storms and hurricanes decrease. We will continue to track this and bring you more updates.

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