NOAA is calling for between 12 to 18 named storms, between 6 to 10 of them to become hurricanes, and 3 to 6 major hurricanes. There are several different reasons they expect such an active season. The first is the Atlantic multidecadal Oscillation (AMO) which we have been in since 1995.  This pattern brings an increase in the activity of Atlantic basin hurricanes.

The second is sea surface temperatures in the Atlantic and Caribbean continue to run above average particularly in the Main Development Region (MDR) which is between 9°N-21.5°N.

This graphic depicts the SST anomalies over the Atlantic basin. While much of the Gulf of Mexico has been below average much of the Caribbean has been 0.5°C above climatology. This holds true for much of the Atlantic especially in the MDR.

The third is the weakening La Niña. Signs are that we will move into a ENSO neutral pattern. La Niña typically helps to keep the waters in the MDR cooler, but with this dissipating then the expectation would be to continue to see warmer sea surface temperatures continue.

Finally, the outlook takes into account long range dynamical models, including the NOAA Climate Forecast System (CFS), the European Centre for Medium Range Weather Forecasting (ECMWF), the United Kingdom Meteorology (UKMET) office, and the EUROpean Seasonal to Inter-annual Prediction (EUROSIP) ensemble. All of these models suggest an above normal season.

The season offically begins on June 1st, so now is the time to begin to review your families plan for the hurricane season and prepare. Keep in mind all of these numbers which forecast an above normal season tell us nothing about exactly where these eventual storms will go. Only time will tell so we must be prepared each season. It is a mistake to assume that last season was an active year and we did not have any hurricanes hit “my house” so this year will be the same. It only takes one hurricane to make a direct hit on you to make it a really bad year for your family.

Stay safe and be sure to keep up to day with myfoxhurricane.com

Water temps in this region are running in the mid 70s but as this disturbance tracks more northward it will move into cooler waters.

Models are in fair agreement that this disturbance will track northwest into cooler waters and then begin to drop south again. Wind shear will remain high and unfavorable and this is not climatologically a time of year to expect to see a tropical disturbance form. Especially with high shear and only marginally warm waters. Invest 91L does not appear to have much of a chance to do much and in case you are wondering, just because you see a disturbance in April does not suggest anything about the activity of the upcoming season.

A hurricane strike at any particular point on the coastline is a fairly rare event. Human nature being what it is, we want to know how the weather will be where we are. If a hurricane does not strike your town or even anywhere in the United States, one might consider the season to be inactive. The seasonal forecasts produced at CSU are for the entire Atlantic basin, which includes the Caribbean Sea and the Gulf of Mexico. Last year the hurricane season was very active with 19 named storms, 9 hurricane and 5 major hurricanes. However, no major hurricane hit the Unites States for the third year in a row, which ties a record for the number of years without a U.S. major hurricane strike.

I was visiting St. Lucia in the Caribbean last week. They were hit late in the season by Hurricane Tomas. It was the second strongest hurricane to hit the island nation. I still saw evidence of damage with land slides. I drove by an area where several people had been killed by Tomas due to land slides. I suppose they thought they were safe since they were higher in elevation that the storm surge. The side of a mountain gave way with the torrential rains, though, and their house slid down the mountain. The local residents were still talking about the “active” hurricane season of 2010. Ironically in Florida, I have heard many people say that they thought 2010 was not very active (because Florida was not hit).

The bottom line is that hurricanes are a potential threat to all residents along the Atlantic, Gulf and Caribbean Sea coastlines during the summer and fall. Everyone should have a written plan as to wht they will do if a hurricane threatens. Now, when the weather is quiet is a good time to think about planning without any pressure.

Dr. Gray and Dr. Klotzbach have researched factors which lead to active hurricane seasons and these factors can be used as predictors. They are still noticing above normal water temperatures in the hurricane development region of the tropical Atlantic. In addition, other factors indicate that wind shear should be less than normal, which would allow hurricanes to concentrate more heat and energy near their core. One factor which is not certain relates to the El Niño Southern Oscillation (ENSO). We were in La Niña conditions in 2010 which is favorable for hurricane development. The La Niña has been weakening in 2011. Dr. Gray and Dr. Klotzbach believe that we will be in neutral conditions which are neither El Niño or La Niña.

In addition to using specific predictors, the CSU team looks at year in the past with similar spring weather conditions. The closest analog years were 1955, 1996, 1999, 2006 and 2008. They were all active hurricane seasons. The long term trend of above normal topical cyclone activity in the Atlantic basin in 1995 appears likely to continue into 2011. In fact, these cycles usually last 25 to 30 years. Ironically, the western Pacific Ocean had the least number of tropical cyclones ever recorded last year. The variation in the number of hurricane in the Atlantic basin is greater than in any other hurricane basin.

The 5 major hurricanes were Danielle, Earl, Igor, Julia, and Karl. Karl became the first major hurricane in the bay of Campeche and also was the most damaging hurricane this season with over $4 billion in damages and 16 deaths.

Despite it being a very active season the US did not have any major impacts. In fact the last landfall of a major hurricane in the United States was Hurricane Wilma which made landfall on Cape Romano Oct 24, 2005. Records show 3 times we have had a stretch of 5 years without a major hurricane in the US. The last time was 1910-1914. It is interesting to note that we have never had a 6 year period without a major hurricane in the US. If history holds this is bad news for the US for the 2011 hurricane season.

We came close to using the entire set of names this season with only 2 left over before having to move to the Greek alphabet.

The following is a list of the names for the 2011 Hurricane season which begins June 1, 2011.

Computer models aren’t doing anything too impressive with this system.  It should be held back from moving too far North as it encounters a cold front approaching from the NW by next week.

The GFS model picks up on this system, but by next week, once it encounters this cold front, it shows the system being pushed back to Central America, then dissipating. 

Another tropical wave in the eastern Atlantic is producing a lot of thunderstorms but has no circulation and is undergoing shear.

A closer image of Invest 93L shown below indicates that the heaviest convection was located south of Puerto Rico and the Virgin Islands. However, if it moves northward heavy rains could overspread Puerto Rico and the Virgin Islands tonight and Wednesday.

 Most models shown below indicate that the system should head north and probably not directly affect Haiti, although the Dominican Republic could be affected. A few models are indicating more of a westward motion in the western Caribbean.

The GFS model valid at Thursday at 8:00 AM does not intensify Invest 93L to a depression. The model does show a large lumbering extratropical low in the western Atlantic which could bring large swells all along the eastern seaboard later in the week.

The GFS model valid Sunday at 8:00 PM still shows Invest 93L as a tropical wave, but the GFS model takes the system westward into the western Caribbean.

The circular center of Tomas can be seen in the image below but what is left of his convection remains in a small area to the north and east of the center of circulation.

The GFS model valid Tuesday at 8PM shows a large extratropical cyclone to the northwest of Tomas. The extratropical low will eventually absorb Tomas into its circulation.

It will continue to the NE, then dissipate over cooler Atlantic waters.

Computer models are also taking it to the NE.

The GFS model valid Monday at 7:00 PM shown below shows a strengthening extratropical cyclone off of the New England coast. Several models indicate that the non-tropical will absorb Tomas into its circulation by  Wednesday. A few models continue to take Tomas eastward into the Atlantic. At any rate, Tomas should not have any more affect on the Caribbean Islands and will not affect the United States.

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