Tropical Storm (Eventually Hurricane) Arthur UPDATE

Arthur is now entering warmer water as it moves north today and tonight. Winds are now 60 mph.

Ocean temperatures are between 80 and 85 degrees along the Outer Banks.

The smorgasbord of dynamic and statistical model projections all take this soon-to-be hurricane slightly off shore by the 4th of July.

The winds increase along with significant pressure falls over the next 3 days.

Buoy data near the Outer Banks will start to show spikes in wind speed and pressure drops. Check the buoy data tomorrow and Friday HERE

The heaviest rain should stay off shore on the 4th of July.

First Tropical Storm In The Atlantic: ARTHUR

The first storm has officially formed in the Atlantic 32 days into the season. Tropical Storm Arthur now has winds of 50 mph with slow movement to the northwest. This SITE has a great infrared loop of its evolution.

The circulation is noticeable on the visible satellite Tuesday morning. This image shows its position relative to the east Florida coast and the Bahamas.  VISIBLE SATELLITE LOOP

Tropical storm wind (35+ mph) probabilities through Friday the 4th of July are the highest along the North Carolina coastline.

All of the computer models (spaghetti plot) keep the center of the storm slightly off the Carolina coast over the next 5 days. Google Earth plot is here

The initial model estimates put the eye of the hurricane over the Outer Banks on the 4th of July.

CURRENT NORTH CAROLINA RADAR LOOP

Official National Hurricane Center track as of noon Tuesday July 1st is this:

Hurricane Irene - Soon to be an East Coast Reality

If you read my post from last week, many meteorologists including myself were predicting a dangerous hurricane to develop in the Atlantic with a high chance of it making landfall along the east coast of the United States. The computer were showing this more than 10 days in advance. Predictions that far out are often times "shots in the dark". This time, it was right on the money.

If you are vacationing anywhere from the east coast of Florida to Savannah & Hilton Head especially Myrtle Beach/Wilmington, N.C. and the Outer Banks (my vacation spot from when I was a kid), remember that this storm will pack winds of 120+ mph along with a powerful storm surge.

Residents along the SE coast are used to the threat of tropical systems, not areas from Cape Hatteras to New York City.  Yet the threat of a Hurricane making landfall near New York City is real.  Take a look at just a few of the hurricanes that made landfall around New York City.  Notice that most of the tracks look similar to Hurricane Irene. The first one in the list is an old weather map drawn on the day of the NYC hurricane in 1893

Will Irene be similar? Stay tuned.....

Monster Hurricane IGOR in Atlantic

After a week of not making up its mind, Igor has rapidly intensified into a major Hurricane with winds of 150 miles per hour.  Igor is located in the lower right hand corner of this satellite photo with a close of IGOR and JULIA following.

The reason for this hesitation in strengthening until this past weekend is in large part due to the cooling of the atlantic in the wake of Hurricane Earl and Danielle a week and a half ago.  Below is a NASA animation showing the cooling effect hurricanes have on the water in its wake.




Forecasts have the hurricane intensifying to a category 5 in the next 24 hours with slow weakening affecting Bermuda late Friday.  Notice the curved path of the highest winds staying well offshore.

Globally, IGOR and JULIA have some of the strongest and widespread wind fields.  Check out the global wind speeds.  The southern hemisphere in its winter season features strong systems over Australia and the Southern Ocean.

Hurricane Season's Cranking Up

The official hurricane season forecast back in late May and early June was hinting at a VERY active season for tropical storms and hurricanes.  So far, only 3 named storms and one hurricane.  Will this change?  Will the tropics get more active in the month of August?  All indications are that they will. 

Click here for the National Hurricane Center

Let's head out into the open Atlantic Ocean where the tropical storms often occur.  This year, the amount of dust coming off of the African continent has been above normal.  This has suppressed tropical storm development.  Notice that the organized cloud cover is south of the dust area? Thunderstorms have develops south and are heading west and northwest into warmer ocean waters.

Warm pockets of ocean water are forming in the central atlantic which coincides with the newest tropical depression.  We can expect the ocean to continue warm into August.

Closer to home, the tropics have been very quiet.  No organized storms in the last several weeks.

What is the forecast track on this new tropical system?  Check out the following map.  It looks eerily consistent bringing it closer to home.

Even the National Hurricane Center concurs on this forecast.

If you are vacationing along the east coast, this year and in the next several years could be very active with tropical systems and/or hurricanes impacting the east coast.

Stay tuned for more hurricane updates in the days and weeks ahead.

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.

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.

What is this Loop Current in the Gulf?

image credit: "uscgd8" at flickr

The Loop Current has been making the news since the Gulf Oil Spill occurred a few weeks ago. 
Now that the Oil Spill is drifting east, the Loop Current is now playing a pivotal role in where the oil spill travels.

What is this The Loop Current? is an ocean current that resides between the Yucatan Peninsula and Cuba.  It originates in the Caribbean Sea, flows out into the Gulf of Mexico and loops around southeastward into the Florida Keys and into the Bahamas.  Its a few hundred miles wide and runs more than a 1000 feet deep.

According to the Cooperative Institute for Marine and atmospheric studies, the Loop Current draws its waters from the Yucatan Current, which is ultimately fed by the Caribbean Current, Guiana Current and North Equatorial Current. This provides a vital link between North Atlantic and South Atlantic waters.  Here is a graphic showing the ocean currents around the planet from the 1940s. The animation below shows the currents in action.

Althought this might be the first time you've heard about the Loop Current, you don't have to go far back in
history to find that the Loop Current was involved in another natural disaster.  Remember Hurricane
Katrina?  The Loop Current was directly responsible for its rapid intensification into the historic Category 5
hurricane we all remember. Notice how the track of Katrina and Rita coincides with the Loop Current.

Katrina wasn't the first hurricane to feed off of this moisture/heat rich Loop Current.  Hurricane Rita in 2004 intensified over the loop current as indicated above  Hurricane Camille in 1969, the last hurricane to directly hit New Orleans prior to Katrina interacted with "The Loop". Hurricane Wilma in 2005 and Hurricane Allen in 1981 among others have greatly intensified due to the loop current.


Back to the oil spill.  This same Loop Current that played a direct role in Hurricane Katrina's development
is directly involved with the track of the oil in the next severe weeks.

How can we accurately forecast the movement of the oil spill?  For years, the National Oceanic and
Atmospheric Administration has been doing research on the ocean and its movement. NOAA launches surface buoys to gain valuable data on the oceans and their behavior.  Here is the track of ALL of the buoys from 1978 to 2003.

You can see how the current behave near the loop current and how the current ntersects with the Gulf Stream around Florida and up the eastcoast.  Expect the Loop Current to strengthen hurricanes this season.  More on that later this summer.