Atlantic Sat Image

Atlantic Sat Image
Clouds over Atlantic

Thursday, May 30, 2013

Barbara could become Andrea?

Mother Nature is giving us a glimpse at a would-be tropical rarity.  We could see a storm born in the Pacific, cross over Mexico, and then emerge in the Gulf.

I'm talking about what once was Hurricane Barbara which made landfall on Wednesday as a Category 1 system on the Southern Pacific Coast of Mexico.

It has been battering the region with copious amounts of rainfall leading to localized flooding with land and mudslides.

Barbara is presently falling apart as it aims to reach the Gulf of Mexico. It was downgraded to a depression earlier Thursday morning. But what next?

NHC says:

  • Global models insist the system will fall apart soon, BUT, a remnant low is forecast to develop within 12 hours in the Bay of Campeche, in the Southwestern Gulf of Mexico.
  • Satellite imagery suggests that new thunderstorms are popping up within this weak low
  • If the system survives its trek over land, and emerges in the Gulf, the advisories will be changed from a "Pacific" storm to an "Atlantic Basin" storm.
  • If Barbara falls apart completely, but then re-organizes, it will be re-named "Andrea", the first name on the list of Hurricanes for the Atlantic Season. NHC says that to be considered the same tropical cyclone, an identifiable center of circulation must be tracked continuously and the cyclone must have been of at least tropical storm strength in both basins . 

Has this cross-over happened before?
Yes, but not often.

Northeast Pacific Tropical Storm Alma (May 2008) became a remnant low in the Atlantic where it merged with another tropical wave which generated Atlantic Tropical Storm Arthur.

Northeast Pacific Hurricane Cosme became Atlantic Tropical Storm Allison (June 1989).

A Northeast Pacific Tropical Storm (September-October 1949) became an Atlantic Hurricane (Storm #10) and made landfall in TX.

A Northeast Pacific Tropical Storm (October 1923) became an Atlantic Hurricane (Storm #6) and made landfall in LA.

There have been others that did the opposite, moving from the Atlantic into the Pacific.

Atlantic Hurricane Iris (October 2001) become a remnant low over Central America and regenerated in the Northeast Pacific as Tropical Storm Manuel.

Atlantic Hurricane Cesar (July 1996) became Northeast Pacific Hurricane Douglas.

Atlantic Tropical Storm Bret (August 1993) became Hurricane Greg in the Northeast Pacific.

Atlantic Hurricane Joan (October 1988) became Northeast Pacific Hurricane Miriam.

Atlantic Hurricane Greta (September 1978) became Northeast Pacific Hurricane Olivia.

Atlantic Hurricane Fifi (September 1974) became Northeast Pacific Tropical Storm Orlene.

Atlantic Hurricane Irene (September 1971) became Northeast Pacific Tropical Storm Olivia.

Atlantic Hurricane Hattie (October-November 1961) after dissipating over Guatemala contributed to the formation of Northeast Pacific Tropical Storm Simone which crossed the isthmus of Teuhantepec and merged with other disturbed weather which later formed Atlantic Tropical Storm Inga.

The above historical information is courtesy of NOAA's hurricane research division.

Saturday, May 25, 2013

Memorial Day Weekend

Memorial Day weekend has become the unofficial start of summer, but its true meaning is to remember the service men and women who gave their lives for our nation. So as you are enjoying the freedoms they died for.... say a little prayer for them this Monday. 

Meanwhile, I know many of you are headed for the beach, but you'll have to be careful. The wind will be picking up, thus increasing the risk of rip currents. Make sure you swim at guarded beaches only. 

Our Holiday weekend will be dominated by high pressure through Monday. This high is pushing along a weak cold front (believe it or not!) that should get rid of the excessive heat we had on Friday when the temp in Miami tied a record of 94°, set back in 1989. 

As the high builds, the winds will pick up. Not so bad on Saturday, but by Sunday and Memorial Day, it will be downright windy. This will increase the threat of rip currents. 

You may notice the red flags going up at lifeguard stands this weekend alerting you of this water danger.

These "Out of Season" fronts are a rarity for us in South Florida, so get out end enjoy but do so safely. Do not drink and drive or operate a boat and above all have fun. 

Thursday, May 23, 2013

2013 NHC Forecast

And so it begins. With the release of NOAA's seasonal outlook, I officially ramp up the Tropical Blog for 2013.

This is what NOAA says we can expect for the 6-month season, which gets underway June 1.

  • Named Systems: 13 to 20
  • Hurricanes: 7 to 11 
  • Major Storms: 3 to 6 (Category 3, 4 or 5; winds of 111 mph or more).

A typical year sees 12 , 6, and 3. 

Remember, no outlook or forecast can tell you where a system could make landfall, or how many for that matter. These numbers are here just to give you an idea of how active a season may be, but truly, there could be 40 out there and if none make landfall... big deal.  BUT, it just takes one to make landfall to cause major headaches for everyone.

South Florida has been spared a direct hit in recent years. The last time we had a significant strike was back in 2005 with hurricanes Katrina and Wilma.   

The accompanying graph illustrates the frequency in which South Florida sees a direct hurricane impact, and its between 6 and 7 years.  

It appears we may be due, so now is the time to get your plan ready in case mother nature throws one our way.


 So why this above average outlook?   NOAA cites three key features.

Hot ocean temps: 

The main ingredient for hurricane formation is hot water 80° or higher. Recent satellite images suggest many areas in the Atlantic are there already. This is just more fuel for storm formation.

 El Niño - La Niña:

These two features will from time to time influence our hurricane season, but NHC says this year neither will be a factor.

El Niño is a warming of the Equatorial waters of the Pacific Ocean that can disrupt atmospheric currents worldwide. While la Niña is a cooling of the Pacific waters.

Stuck in a rut:

This leaves the third feature which is the pattern we've been stuck in since 1995.  

For almost 20 years, plenty of moisture moving in from the Eastern Atlantic has been able to feed small disturbances with enough fuel to grow into storms.  This pattern remains firmly entrenched.

Some other important features for this year: 
  • Storm warnings will continue to be issued by NHC even though the system may have become extra tropical.
  • A new super computer will be added to NHC's arsenal over the next few months to help deliver more accurate forecasts.
  • Doppler radar will be placed in hurricane hunters to allow them to see in more detail the inner structure of a storm.

All these improvements will help us deliver better forecasts. 

Please allow me this shameless plug.  WSVN's hurricane preparedness special, "Surviving a Storm", will air Friday May 31st, at 8pm.