More Time to Batten Down
On May 15, 2009, the National Hurricane Center (NHC) began issuing tropical storm warnings earlier than ever before. According to NHC experts, advancements in track forecasts make it possible to provide greater lead time.
Residents and managers along coastlines will get a heads up 12 hours earlier than in previous years. Within 48 hours of possible tropical storm conditions, NHC will issue a tropical storm watch. Warnings will be issued when those conditions are expected within 36 hours.
The same goes for hurricane watches and warnings, which will generally be timed to provide 48 and 36 hours notice, respectively, before the onset of tropical storm force winds. That additional time will allow people to better prepare for storms and head for safe shelter.
Hurricane Scale Un-Weighted
This hurricane season, the NWS will decouple the Saffir-Simpson Hurricane wind scale from predictions of storm surge and flooding. According to NWS, the scale was changed because storm surge is dependent on a combination of factors, the variability of which can translate into surge values and associated flooding significantly outside the ranges suggested in the original scale. Those factors include the storm's intensity, size, motion, and barometric pressure, as well as the depth of the near-shore waters and local topographical features.
Storm surge forecasts will still be included in hurricane advisories and statements but will be expressed as height above ground level, as initiated in late 2009. According to the NWS, this gives residents a better understanding of the potential for flooding at their location.
KIMBRA CUTLIP is a freelance writer and former assistant editor for Weatherwise.