Better Hurricane Forecasting-More Time to Get Out

When a hurricane approaches, all the public wants to know is: Where is it going? And, do I need to evacuate?

The National Hurricane Center says better track forecasts will allow them to give you more warning if a hurricane is headed toward your city. Instead of just 24-hours notice, hurricane forecasters say the track forecasts have improved so much, they can now issued a hurricane warning 36-hours in advance of a storm. That gives residents 12 more hours to board up their house, and make preparations for the advance of the storm, including evacuating if need be.  Hurricane watches will be posted along coastlines 48-hours in advance of the storm’s landfall. “With increases in population and infrastructure along vulnerable U.S. coastlines, emergency managers need more lead time in order to make life-saving decisions regarding evacuations,” said Bill Read, director of NOAA’s National Hurricane Center. (Source: NOAA)

Forecast Track: Hurricane Ida, Image: NHC, NOAA

(This is a forecast graphic. Click here for the actual track of Hurricane Ida.)

The image above is a forecast track advisory from Hurricane Ida on Sunday, November 8th when it was between Cuba and Cancun, Mexico. I’ve circled Ida’s position on the map at 12PM on that Sunday. In 24 hours, the storm was expected to still be a hurricane as it approached Southeast Louisiana, Mississippi, Alabama and the panhandle of Florida. The National Hurricane Center was giving the coastlines a 36-hour advance notice that the storm could be a hurricane or extra-tropical hurricane as it approached the coast. Now, this watch will be issued 12-hours earlier.

Will this advanced lead time in the track forecast give TV meteorologists better tools to warn the public? Yes and no. Yes, we will  be able to tell the public “… We are under a hurricane watch this evening. That means National Hurricane Center forecasters believe the hurricane is going to make landfall along our coastline in the next 48 hours.”

But, we still won’t be able to tell the public with complete confidence how strong the storm will be once it approaches. We’ve said this over and over, that despite advances in forecasting the path of the storm, the intensity forecast is still far from perfect.

For example, let’s just take a look at the graphic above, when the storm was 2 days away from hitting the northern Gulf Coast.

Comparing Forecast to Actual Track, Image: NOAA

24 hours after this advisory was issued, Ida had actually weakened to a tropical storm. Thus all the hurricane watches and warnings became tropical storm watches and warnings for the northern Gulf Coast. Ida made landfall in Dauphin Island, Alabama at about 7am on November 10th as a tropical storm with 45 mile per hour winds. A substantial difference from what was forecast just 24 hours earlier.

However, the track forecast was spot on! That’s why the NHC has become more and more confident that they can tell you where the storm is headed.

And, despite the pitfalls I’ve shown you in this blog when it comes to the intensity forecast, more and more hurricane research is aiming to improve that forecast as well.

-Dawn Brown