Why the Increase in Hurricanes this year?

If you are making a trip to the east coast from Myrtle Beach to the Outer Banks to Hilton Head down to Miami, pay attention to the tropical forecast this summer and fall as tropical storms will be a plenty.

Click here for the FULL HURRICANE OUTLOOK

Why is season going to be so active?  Here is a technical/sciency peek into how the experts come up with their HURRICANE FORECASTS:

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The first factor is whether an EL NINO or LA NINA is present.  Remember that EL NINO/LA NINAs are changes in sea surface temperatures in the Pacific Ocean.  These changes alter the position and direction of the jet stream in the atmosphere either BREAKING APART tropical systems of allowing them to BUILD INTO HURRICANES.

Last year, EL NINO BROKE APART THE STORMS.

This year without EL NINO, and with LA NINA rapidly developing, the sheer is weak so the environment is very strong for TROPICAL STORM DEVELOPMENT. Storms are steered right into the Caribbean.

The next factor is the temperature of the Atlantic Ocean.  For the last several months, the Atlantic SEA SURFACE TEMPERATURES have been at levels not seen in decades.  Remember last winter's cold spells?  That same arctic pattern responsible for our winter cold drove the Bermuda High south allowing the ocean to heat up to near record levels.  The red shades on the map below show the warmer than normal water in the central Atlantic. 

One other factor that will be present in hurricane forecasts for years to come has to do with a decadal cycle of high and low hurricane frequency.  The ATLANTIC MULTIDECADAL OSCILLATION or the AMO is a cyclical pattern of sea surface temperature completing a cold/warm/back to cold cycle every 70 years or so.  Since 1995, we have been in a warm cycle.  Here is the cycles since 1860.

There are also US LANDFALL HURRICANE TRENDS that correlate to the AMO. Check these out below.  The left image is a reflection of the current WARM CYCLE.  We can expect more US landfall hurricanes in a WARM AMO cycle which will more than likely continue for the next 20 years.

Factor in a turbulent and strong LOOP CURRENT shown here...

which has a history of rapidly intensifying hurricanes like Katrina and Rita in 2005...

 and you get this year's ABOVE NORMAL HURRICANE SEASON.

Hurricane Season Outlook 2010 - National Hurricane Center

National Hurricane Center - Hurricane Outlook Press Release

As indicated earlier this year, the National Hurricane Center as well as other experts have been hinted at an above normal hurricane season which starts June 1st.

Here are the bullet points of the NHC's seasonal outlook with some analysis:

Across the entire Atlantic Basin for the six-month season, which begins June 1, NOAA is projecting a 70 percent probability of the following ranges:

    * 14 to 23 Named Storms (top winds of 39 mph or higher), including:
    * 8 to 14 Hurricanes (top winds of 74 mph or higher), of which:
    * 3 to 7 could be Major Hurricanes (Category 3, 4 or 5; winds of at least 111 mph)

The outlook ranges exceed the seasonal average of 11 named storms, six hurricanes and two major hurricanes.

The factors that support the outlook are:

    *  Upper atmospheric winds conducive for storms. Wind shear, which can tear apart storms, will be weaker since El Niño in the eastern Pacific has dissipated. Strong wind shear helped suppress storm development during the 2009 hurricane season.

    * Warm Atlantic Ocean water. Sea surface temperatures are expected to remain above average where storms often develop and move across the Atlantic. Record warm temperatures – up to four degrees Fahrenheit above average – are now present in this region.

    * High activity era continues. Since 1995, the tropical multi-decadal signal has brought favorable ocean and atmospheric conditions in sync, leading to more active hurricane seasons. Eight of the last 15 seasons rank in the top ten for the most named storms with 2005 in first place with 28 named storms.

“The main uncertainty in this outlook is how much above normal the season will be. Whether or not we approach the high end of the predicted ranges depends partly on whether or not La Niña develops this summer,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center

“If this outlook holds true, this season could be one of the more active on record,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator.

Click here for the ENTIRE OUTLOOK.

Muckelhead Photo from Cleveland

This was a photo taken outside the WJW FOX 8 studios in May of 2009. That "shadow" looking thing on the ground is actually a pile of Muckelheads.

Now imagine that the pile is thousands of these...(image credit: flickr "kuddlyteddybear2004")

Our First Tropical Storm Already?

...Its a good possibility. 

Last week, a pocket of tropical moisture began to develop into an organized area of low pressure.  Although not unusual to have tropical systems this time of year, to have one develop in this area of the Atlantic Ocean is somewhat rare due to the relatively cool ocean water temperatures.

The moisture in the Atlantic was incredible this past weekend.  Notice the warmer colors in the middle of this image showing tropical moisture.

Here is the satellite picture showing the system.

Lots of dry air pushing into the backend of this system which could weaken it later this week.

Computer model projections keep it stationery.

While this "tropical pocket of moisture" probably won't gather enough steam to turn into a full fledged tropical storm, we are expecting a very active tropical storm season with several landfalling hurricanes or tropical storms along the US coast.  More on tha tlater.