Friday, August 31, 2012

Isaac Postmortem

Isaac proved to be one of those systems that caused headaches everywhere it moved through, from Haiti with reported deaths there, to South Florida with heavy rain, and finally the Gulf States with devastating floods.

No matter how weak a storm is, as it was when it passed over us, there is always the potential for trouble. When the center of Isaac slid just South of Key West, it brought some gusty winds, rain, and minor flooding, but no major problems. It wasn't until the following day, when it was over the Gulf of Mexico, that South Florida felt its presence.

A feeder band parked itself right along the East coast with tropical storm force winds and heavy rain, leading to widespread flooding in northeastern Broward and Palm Beach.  Trees came down, electrical lines snapped, roofs leaked, and some neighborhoods had water rise up to their front doors. All of these problems happened, not from a direct hit but from a glancing blow form one of its feeder bands.

This is why it worries me when folks say, "Ah, its just a storm", or " A Cat 1 is nothing to be scared about", or "We're out of the cone, so no worries here". With this mentality,  they fail to prepare and then suffer the consequences.

A storm or hurricane is not a dot on a map. That is just the center of circulation or where NHC tracks the system from.  The clouds, winds, rain and surge can be felt hundreds of miles away. Case and point: Isaac.  Even though, much of South Florida was outside the cone of concern, there were advisories up and down both coasts. This is why its so important to prepare and to worry about each system, no matter how small or insignificant you may think it is...it can always surprise.

Storms are like people and come in all shapes and sizes.


  • Andrew: When is slammed South Florida in 1992, was a small and compact system with little rain, but a violent storm surge, powerful winds, and isolated tornadoes.
  • Katrina: Its path over South Florida in 2005 saw Cat 1 winds, but loaded with rain, dumping as much as 16 inches over parts of Miami Dade causing flooding.
  • Isaac: While only a tropical storm, it was a huge system in size. It did not make landfall across South Florida, but a back-side feeder band lead to all sorts of flooding problems due to heavy rain.


This is why we should always monitor tropical systems no matter how big or small or whether we're in the cone or not. If its close by, keep your eyes on it, and prepare accordingly. Preparation is key.

I always tell my friends that if an earthquake were to happen right now, I could not give them any warning. If I could give you a few minutes notice that a tornado was coming, I would be on  my A game... unlike any of these phenomena, a hurricane will never take you by surprise. Sometimes I will be on TV ad nauseam warning you of its presence, letting you know its coming.

I hope we don't see any more activity this season, but if we do.... prepare and you will be fine. Whats the worse that can happen? You got ready and nothing hit?  Then think of it as a fire drill, in this case, a hurricane drill.

Stay safe.


Friday, August 24, 2012

What next for Isaac?

UPDATE: As of LATE Friday morning, Isaac is a little stronger but remains disheveled. Even though there is plenty of rain with this system, most of it is to the south over the Caribbean Sea. Wind speeds have picked up somewhat, but the northern end of Isaac is being interrupted by the high terrain of Hispaniola. How much more strengthening Isaac will undergo remains to be seen.



Overnight recon detected a center that was being stretched out. Imagine if you will the core of a paper-towel roll, stand it up right, and that would be the center of a well organized storm. Good inflow at the bottom, and just like an exhaust, good outflow at the top.  In this case however, tilt the roll almost at a 45 degree angle and this is Isaac's center. It is elongated, stretched out, and with little organization.

About the only thing in its favor is the available fuel from the warm waters of the Caribbean Sea. Even with that NHC says it does not expect for Isaac to get that much stronger in the short term.

For the next day or two, it will aim for Haiti, Jamaica, and Cuba, and then.... this is where it gets interesting. Most models point it towards the Keys, but any slight deviation or change in forward speed, and those models could change. As a matter of fact, if the system keeps slowing down, it could give it a chance to grow stronger and nudge more in our direction.  DON'T LET DOWN YOUR GUARD.

From NHC earlier:

  • THE LONG TERM INITIAL MOTION ESTIMATE IS A HIGHLY UNCERTAIN AS THE INITIAL POSITION ESTIMATE IS BASED ON A BLEND OF RECENT FIXES AND CONTINUITY. 
  • THE TRACK MODEL GUIDANCE CONTINUES TO BE IN GENERALLY GOOD AGREEMENT ON THE RESUMPTION OF A WEST-NORTHWESTWARD AND THEN NORTHWESTWARD MOTION IN THE NEXT 24 HOURS AS THE SUBTROPICAL RIDGE NORTH OF ISAAC WEAKENS. 
  • THIS GENERAL MOTION SHOULD CONTINUE THROUGH DAY 4...WHEN A TURN MORE TOWARD THE NORTH IS SHOWN AS A SHORTWAVE TROUGH AMPLIFIES OVER THE MISSISSIPPI VALLEY. 
  • LATE IN THE PERIOD THE TRACK MODEL GUIDANCE IS IN BETTER AGREEMENT ON THIS SCENARIO...AS THE ECMWF HAS TRENDED EASTWARD TOWARD THE REST OF THE MODELS THIS CYCLE. 
  • THE NEW NHC FORECAST HAS BEEN ADJUSTED ABOUT A DEGREE SOUTHWARD IN THE FIRST 12 HOURS DUE TO THE INITIAL POSITION AND MOTION...AND IS THEN BLENDED BACK TOWARD THE PREVIOUS TRACK BY 48 HOURS. AFTER THAT TIME...THE NHC FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS ONE...AND IS BETWEEN THE ECMWF ON THE LEFT AND THE GFS AND TVCA CONSENSUS ON THE RIGHT. 


IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK DUE TO UNCERTAINTIES IN THE INITIAL LOCATION AND THE TRACK FORECAST...AND THE FACT THAT ISAAC HAS A LARGE AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH IT. 





Keep monitoring.

Wednesday, August 22, 2012

Isaac Aims for Hispaniola

Isaac will swing South of Puerto Rico this Thursday, but its sights are set on Dominican Republic and Haiti.



During the overnight hours, Isaac appeared to have gotten its act together. There is much more banding,  strong storms are developing along the center, and shear is relaxing . However, that center is hard to find.

There is plenty of information to convey from NHC, so here goes:



  • AN AIR FORCE RECONNAISSANCE AIRCRAFT INVESTIGATING ISAAC THIS MORNING HAS FOUND A POORLY DEFINED INNER CORE WITH A LARGE AREA OF LIGHT WINDS AROUND A CENTER...WHICH IS SIMILAR TO WHAT AN EARLIER NOAA RESEARCH MISSION INDICATED.
  •  RADAR DATA FROM GUADELOUPE AND SAN JUAN ALSO INDICATE A POORLY DEFINED INNER CORE CONVECTIVE PATTERN.




The bottom line is that Isaac remains as a Storm, but is expected to strengthen as it nears Hispaniola.



The cone suggests Isaac could be over us sometime late in the weekend, or early next week.

Here is what we can expect today, according to NHC:

  • TROPICAL STORM CONDITIONS ARE EXPECTED OVER PUERTO RICO AND THE U.S. AND BRITISH VIRGIN ISLANDS ON THURSDAY.  



By Friday:

  • HURRICANE CONDITIONS ARE EXPECTED OVER PORTIONS OF THE DOMINICAN REPUBLIC BY EARLY FRIDAY...AND OVER PORTIONS OF HAITI ON FRIDAY.  


  • TROPICAL STORM CONDITIONS ARE POSSIBLE OVER THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS BY LATE FRIDAY.

Impacts:

  • MAXIMUM RAIN AMOUNTS OF 6 INCHES ARE POSSIBLE OVER PUERTO RICO AND THE VIRGIN ISLANDS.  
  • TOTAL RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES...WITH MAXIMUM AMOUNTS OF 20 INCHES...ARE POSSIBLE OVER HISPANIOLA.  THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.




In the long haul:
Everything depends on where Isaac makes landfall. If it strikes Hispaniola, the high terrain there should slow it down and weaken it.  The down side to that is that it will dump allot of rain across Dom. Republic and Haiti causing dangerous floods along with land and mudslides.

It should emerge as Tropical storm and move into Cuba over the weekend.
Everyone in the area highlighted on day 5, should monitor this system carefully.


Tuesday, August 21, 2012

Tropical Storm Isaac

This Wednesday starts with little change for T.S. Isaac. Its still in the Atlantic Ocean, a few hundred miles East of the Leeward Islands.  Overnight there were a few t-storm flareups around the center of circulation and some spiral banding began to appear giving it a more typical hurricane-like look.

Isaac is still fighting off some drier air to the north as well as some light to moderate shear just ahead of it. This combo should keep it as a tropical storm over the next 24 hours.





High pressure will continue to push it due west through the end of the week, then by the weekend most models indicate a turn to the north/northwest. This turn puts South Florida in the cone of concern.




While the track is coming more into focus, the question of how strong it will be, is still a mystery. If Isaac tracks over the Islands, specially Hispaniola, high terrain here (the highest in all of the Caribbean. Pico Duarte in Dom. Rep. is over 10,000 feet high) could shred it apart. This may sound good, but that process could dump allot of rain over Dominican Republic and Haiti leading to flooding, land and mudslides.

If Isaac misses the islands and stays over the warm waters of the Caribbean, there is plenty of hot water here that it could use as fuel for growth.

This what NHC is saying:

THE INTENSITY FORECAST
IS COMPLICATED BY HOW MUCH THE CORE OF THE SYSTEM INTERACTS WITH
THE MOUNTAINOUS LAND MASSES OF HISPANIOLA AND EASTERN CUBA.  THE
OFFICIAL WIND SPEED FORECAST IS FAIRLY CLOSE TO THE STATISTICAL-
DYNAMICAL GUIDANCE FOR THE FIRST 48 HOURS AND THEN TRIES TO TAKE
INTO ACCOUNT THE LAND INTERACTION.  NEEDLESS TO SAY...THERE IS
CONSIDERABLE UNCERTAINTY IN THE INTENSITY OF ISAAC IN THE 3 TO 5
DAY TIME FRAME.



Because of this UNCERTAINTY, everyone throughout the Caribbean and South Florida should continue to monitor the track of Isaac. Another recon mission is set for today to get a better handle on Isaac and where it may eventually end up.

Tropical Depression 9

As of Tuesday morning we are now tracking a brand new depression just east of the Lesser Antilles.

Tropical Depression 9, is a good looking system. There is good spiral banding around the storm. Plenty of t-storm activity is spotted around the center of circulation, and there is only limited shear to its north.

This shear should subside over the next 24-48 hours.





High pressure to the north is keeping this system on a W/NW track, but by the weekend some models suggest that strong winds will veer out of the Southeastern USA. This will force the Bermuda high to move east, away from Florida, and force TD 9 to slow down.  This slow-down will allow TD 9 to grow stronger, it could be a Cat 2 by then.

As the high moves away, it opens a door in the atmosphere for the storm to take, and unfortunately, some of the models place the storm CLOSE TO FLORIDA sometime next week.



Watches and warning are already in effect for most of the Lesser Antilles and Puerto Rico, as well as parts of the Dominican Republic. Many more will be added over the next day or so.

This is what NHC is expecting over these areas:


WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE WARNING
AREA BY WEDNESDAY AFTERNOON...MAKING OUTSIDE PREPARATIONS DIFFICULT
OR DANGEROUS.

RAINFALL...TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES ARE POSSIBLE
OVER THE NORTHERN WINDWARD ISLANDS AND THE LEEWARD ISLANDS.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
WINDWARD ISLANDS AND THE LEEWARD ISLANDS DURING THE NEXT COUPLE OF
DAYS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE FOR
MORE INFORMATION.


NHC is sending out a recon plane this afternoon to get a better handle on the situation.

For South Florida, now is the time to prepare. Make sure you have all your supplies. Pick up a FREE channel 7 Map & Guide at your local Publix and follow all the tips and suggestions offered there to help you weather the storm.

Monday, August 20, 2012

Tropics, back in Action

It has been a little hectic at the Ferro household, with summer vacation coming to an end, and getting the kids back to school... my free time has been hard to come by.  Thankfully the tropics have been rather quiet, but low and behold as the kids get settled in, something has popped up in the Atlantic that may have its sights set on South Florida.




NHC is keeping tabs on 4 areas. One near Mexico in the Gulf, aiming for that country. Gordon is in the Eastern Atlantic apparently aiming for Portugal as a depression or a weak low down the road.  A tropical wave near the Cape Verde Islands, and a good looking tropical low a few hundred miles east of the Lesser Antilles. This last one is the one we should watch. If it does develop, it will be called "Isaac".




Most models forecast this feature to impact the Leeward Islands, track over Hispaniola, and Cuba, and then be near Florida or the Bahamas in about 7 days.

Here is what it has going for it:

  • It will travel over the Caribbean Sea where Sea Surface temps are very warm and should provide enough fuel for growth.


Working against it:

  • If it directly impacts the islands, it will be traversing over some of the highest terrain in the region. Some peaks in Haiti are over 8,000 feet tall. This in essence should shred the storm.
  • If El Nino, is gaining strength, then upper winds should be counterproductive for this system to get stronger.


Lets watch this carefully.

I will be posting another update regarding the wave next to the Cape Verde Islands as it gets its act together .  Long range models place this one too near the Leewards Islands.  The Peak of Hurricane season is next month. Keep your fingers crossed.

Friday, August 10, 2012

Cape Verde Season is here

The tropics are heating up. We are following five areas from Mexico through the Far Eastern Atlantic.

They are:

  • Ernesto over Mexico
  • Tropical Wave over Cuba
  • Remnants of Florence in Mid Atlantic
  • Tropical Depression 7 in Eastern Atlantic
  • Low pressure by the Cape Verde Islands.


Speaking of Cape Verde, with all this recent activity developing near that area, we can safely say Cape Verde Season is underway. This short season within a season runs from roughly August through the end of September. Lets give you a quick rundown of all the activity.

Ernesto: After making two landfalls over Mexico, one over the Yucatan as a hurricane and the other as a storm across Central Mexico, it has now dissipated. It continues to dump plenty of rain over the region. The remnants of Ernesto may emerge into the Eastern Pacific and have another shot at regeneration.



Tropical Wave over Cuba:  The area of clouds and rain near us is made up of two features. There is an upper low over Cuba and a tropical wave stretching from the Caribbean Sea north through the Bahamas. The low will drag the moisture from the wave here, and if it doesn't fall apart, we could be soggy from today through Sunday.



This is what the local NWS office is saying:

THUNDERSTORMS: SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN TO

SPREAD ACROSS THE ENTIRE SOUTH FLORIDA PENINSULA LATER TODAY. THE
MAIN IMPACTS WILL BE FREQUENT LIGHTNING, LOCALLY HEAVY DOWNPOURS,
AND GUSTY WINDS.

WIND: THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS
OF 40 TO 50 MPH.

FLOODING: AS DEEPER MOISTURE MOVES INTO THE AREA, LOCALIZED
FLOODING MAY OCCUR WITHIN HEAVIER SHOWERS AND THUNDERSTORMS,
ESPECIALLY IN URBAN AREAS.


You can keep track of the rain here:




Next is Florence, once a proud tropical storm, it weakened so much a few days ago that NHC no longer issued advisories on it. But since then, its been trying to come back firing up t-storms every so often. It has been hovering around a 10% chance for regeneration but as of this writing, NHC has it down to zero. Right now it is just a small area of clouds to the north of Puerto Rico.



Tropical Depression 7 could be an Ernesto Redux.  It appears to be gaining strength and could become Tropical Storm Gordon soon. It will threaten the Lesser Antilles, and be near the Yucatan in about 5-7 days. All our friends throughout the Caribbean should monitor TD 7 closely.



Finally, there is an area of low pressure next to the Cape Verde Islands. NHC is giving this feature a 50% chance that it could become the next system to track. Most model runs however, keep whatever develops in the open waters of the Atlantic and only a worry for shipping lanes.





Plenty to follow.

Sunday, August 5, 2012

Down to two

If you are a viewer of WSVN, you have probably heard me say many times in the past that tropical waves and disturbances are very difficult to forecast. They can grow quickly or fall apart just as fast. Case and point , the disturbance that we had approaching us from the Bahamas. It dumped plenty of rain on Friday, was forecasted to move over us and provide more tropical downpours, and at one time even NHC had given it a chance for development. Well.... it fell apart providing us with a rather nice Saturday.



It is no longer a big rain threat for us this Sunday  It is but merely a wrinkle in the atmosphere across Northern Florida. The local weather office is still hinting at enough leftover moisture for a few afternoon storms.

This is what they say:

.UPDATE...
THE DEEPEST MOISTURE AND LOW LEVEL CONVERGENCE REMAIN TO OUR
NORTH, WE STILL EXPECT SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS THIS AFTERNOON, AIDED PARTIALLY BY SEA BREEZES.
LATEST GUIDANCE STILL INDICATES THE MOST CONCENTRATED ACTIVITY
OVER INTERIOR PORTIONS OF THE REGION, PEAKING BETWEEN 19Z-22Z.


In the Tropics: 
It appears El Nino is kicking in. What is happening now is what usually takes place  during an El Nino episode. Strong upper winds keep systems in check, as is the case of Ernesto, or they tend to curve storms out into the middle of the Atlantic, as is happening with Florence.

Ernesto is now a worry for parts of Central America and the Yucatan.

It should remain as a storm aiming for Belize. Even though winds are not that strong, it is still a rain maker.

Large amounts of rain could lead to land and mudslides specially over high terrain.

Ernesto could still become a hurricane if it survives landfall and then moves over the warm waters of the Gulf of Mexico.





Tropical Storm Florence will be a nuisance for the shipping lanes.

It is losing steam and the forecast calls for it to be a depression in about 5 days. If it survives, it could brush by Bermuda in the long run.






Saturday, August 4, 2012

Jamaica, Grand Cayman Info

I have many friends with roots in the Caribbean and they are all worried about family members in Jamaica and Grand Cayman. Ernesto continues to look better organized and could soon be a hurricane.

As Tropical Storm Ernesto makes its way through the Caribbean Sea and with the possibility of further strengthening... the islands are already taking precautions.



Ernesto will first come close to Jamaica.

This is the latest from the Jamaican Meteorological Office:



  • The centre of Tropical Storm Ernesto was located about 760 kilometres (470 miles) east-southeast of Morant Point, Jamaica or 410 kilometres (255 miles) south of Santo Domingo, Dominican Republic.
  • Ernesto continues to move towards the west near 30 km/h (18 mph) and this general motion is expected to continue during the next 48 hours. This will bring the centre of the tropical storm near 200 kilometres (125 miles) south of Jamaica by late Sunday morning.
  • Maximum sustained winds are now near 95 km/h (60 mph), with higher gusts, and some strengthening is possible during the next 48 hours. Ernesto could become a hurricane by tomorrow. Tropical storm force winds now extend outward up to 220 km (140 miles) mainly north and east of the centre of Ernesto.
  • Based on current projections, southern parts of Jamaica are likely to be within the range of tropical storm force winds (over 63 km/h or 40 mph) and heavy rainfall, exceeding 100 millimetres (4 inches) on Sunday and early Monday. 
  • All small craft operators, including fishers from the cays and banks, should by now have completed all the necessary safety precautions and are advised to remain in safe harbour until all warning messages have been discontinued and wind and sea conditions have returned to normal.



This is the latest from the Cayman Islands:
  • The Cayman Islands (especially Grand Cayman) is now in the 'Alert' phase - 72 hours before possibly being affected by Ernesto.
  • Based on its current path, the 'Watch' stage (48-hours before) begins Sunday afternoon, Ernesto is expected to be south-east of Jamaica by Sunday morning; west of that island by Monday morning; and about 150 miles south-west of Grand Cayman by Tuesday morning.
  • Government workers spent Friday afternoon securing the main government administration building, while others (such as PWD shuttering crews and the hurricane shelter staff) have been put on alert.
  • "The civil service should ensure the continuity of government's operations," said a government official. He noted that a decision will be made by Sunday afternoon if offices will open for business or not.


As more information becomes available, I'll pass it along.


Friday, August 3, 2012

Its getting active!

The weather office is busy following three areas in the Tropics, from activity near Florida, and the Caribbean, to the far Eastern Atlantic. Lets take them one at a time.

1) Disturbance near Florida.





NHC is looking at an area of clouds and rain near the Bahamas for possible development. They are giving it a small chance for growth but even if it doesn't develop, it will bring heavy rain to South Florida over the weekend.


Models are split on where it may end up with some taking it into the Gulf and others, into the Atlantic. Conditions remain unfavorable for growth.

With so much moisture around us, we can expect pockets of heavy rain from the Bahamas through South Florida, through the weekend and possibly into Monday.





2)  The second area is Tropical Storm Ernesto which is looking a little better on Saturday.

By Monday, conditions in the atmosphere will improve allowing it to get stronger.

It could become a hurricane by then, close  to the Cayman Islands.

Caribbean waters are very warm and this could allow Ernesto to intensify.






The long range cone pushes Ernesto into the Gulf of Mexico by the middle of next week.

Everyone from Jamaica, the Caymans, Western Cuba, and the Yucatan Peninsula should be on the lookout as rapid intensification could turn Ernesto into a very dangerous system.

If it impacts the Yucatan, heavy rain could lead to land and mud slides. We'll be following it carefully over the next few days.




3) Finally, there is a new Tropical Storm by the name of Florence, in the Far Eastern Atlantic. Its a few hundred miles Southwest of the Cape Verde Islands and will continue to move west over the next few days.  You can barely make out the red dot on the far right of the image.  It should stay as a Tropical Storm  this weekend, but strong upper winds should weaken it by Monday.




Originally, most models kept it over the open waters, but the latest cone has it aiming for the Lesser Antilles in about 8-10 days.




Stay tuned for the very latest.

Wednesday, August 1, 2012

Caribbean Worry

Invest 99 was updated to Tropical Depression #5, Wednesday afternoon. It is located around 500 miles East of the Windward islands with 35 mph winds. Very little has changed since then.



What we are looking for on Thursday is to see if the depression can get its act together. The last 24 hours have not been kind to it as strong upper winds are keeping it in check. After a flare up of thunderstorm activity on Wednesday, most of that has fallen apart. This could just be a flux in organization.



The official forecast cone takes the low through the Windward Islands on Friday, possibly as Tropical Storm Ernesto by then. After that, the intensity forecast gets a little dicey.

  • The models suggest little strengthening due to moderate shear over the region. It should stay as a storm until next Monday when the models  project it to become a hurricane.
  • However, as it travels through the warm waters of the Caribbean Sea, they could provide the fuel it needs to grow stronger. 
  • With all this uncertainty, a recon plane is scheduled for Thursday to check out the depression and get much needed first hand data.


This is the latest info from NHC:

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* BARBADOS...ST. VINCENT AND THE GRENADINES...AND DOMINICA
* ST. LUCIA
* MARTINIQUE AND GUADELOUPE

INTERESTS ELSEWHERE IN THE LESSER ANTILLES SHOULD MONITOR THE
PROGRESS OF THIS SYSTEM.

The impact on the Lesser Antilles will be in the form of squally weather with periods of rain and gusty winds.



What South Florida needs to watch out for is the long range models. While the consensus is for the system to stay in the Caribbean, a few models are now trending a possible turn north putting us closer to its path.  We should just keep an eye on it over the next few days as we get a better idea as to where it may end up.

Invest 99 looking better

Invest 99 is getting its act together in the middle of the Atlantic Ocean.  It is now sitting about 1000 miles east of the Southernmost Windward Islands. As of Wednesday morning, there are more showers and t-storms around its center of circulation.



NHC is giving it a 60% chance of becoming a depression or tropical storm over the next 48 hours . Upper air conditions are favorable for that to happen since there are no wind currents to stop it or cut it down.

Most models push this low west, impacting the Windward Islands in a few days. By then it could be "Ernesto".



Everyone in the Caribbean should monitor this system closely.