Hurricane/Tropical Storm

I originally posted this on 6/11/2013.  I thought you might like seeing it again in view of tropical storm Erika.  Just remember: your friendly local media wants to make sure you always have something to worry about.

Here we are again.  It's hurricane season.  The Atlantic hurricane season lasts from June 1st to November 30th.  This season, 2013, is forecasted  to produce 18 tropical storms with 9 becoming hurricanes, of which 4 will be major hurricanes.  A typical year will have 12 tropical storms with 7 becoming hurricanes.  There is a 72% chance that a major hurricane will strike on the U.S. coastland this year.  For the east coast and Florida it is 48% and for the gulf coast it is 47%.

This year the tropical Atlantic unexpectedly warmed over the last several months  and the chances of El Nino phenomenon are unlikely.  El Nino is associated with strong vertical shear creating conditions less conducive to storm development.  Seventy-eight percent of storms form from August to October.   The last three Atlantic seasons have had 19 storms each season.  In fact over the last 10 seasons only one season was forecast to have an average number of storms.  All the rest have been average to above average or normal to above normal  and above average or above normal.

Forecasts come from meteorologists Philip Klotzbach and William Gray at Colorado State University's Tropical Meteorology Project. Gray's team was the first organization to issue forecasts back in 1984.  This is the team's 30th season of hurricane forecasts.  The Weather Channel and the National Oceanic and Atmospheric Administration also issue forecasts.   These annual projections are intended to provide a best estimate of activity to be experienced during the season, not an exact measure.  Insurance companies, emergency managers, and news media use the forecasts to prepare Americans for the season's likely threat.

The source of most of the forecasts delivered  on your TV news and smartphones is supercomputers in Reston and Orlando.  An infusion of Hurricane Sandy related dollars this year will help the weather service upgrade two supercomputers that are used in virtually all U.S. weather predictions.

The behavior of the atmosphere is governed by physical laws which can be expressed as mathematical equations.  The best hurricane forecasting models are "global" models that solve the equations at every point on the globe.  Models that solve these equations are called a "dynamical" models.  The four best hurricane forecast models are ECMWF (European Center for Medium Range Weather Forecasts), GFDL (NWS Geophysical Fluid Dynamics Laboratory), GFS (Global Forecast System), UKMET (United Kingdom Met Office).  These models take several hours to run on the world's most sophisticated computers.  Even so they have there limitations due to accuracy and availability of data and our incomplete understanding of  the atmosphere.  There are other less sophisticated models than can be run in a shorter period of time.

At the end of the day after all the hype and the TV teasers and the new tracks etc., etc. it has been said that a good forecast is one that is communicated well and leads to good decisions by public officials and the general populace.

You must decide what supplies you will need (food, water, medicine) and procure them.  You must decide what is necessary to prepare the outside of your home  and whether and when to shutter.  There are many checklists available from various sources.  Most TV stations put out an annual hurricane guide which is available at the supermarket.  I got one from my local Community Center.  Some decisions will be made for you, such as when or whether to go to work or send the kids to school..  There may be a curfew.

So, hurricane season presents us with some challenges.  Keep informed.   Get prepared early.  Be that person who having prepared and strengthened himself can be a help to others.  One other thing,  don't watch too much about the storm on the television.  It'll make you crazy.