MyFoxHurricane.com blog

“Bonnie” heading for south Florida

Posted by Paul Dellegatto under Daily updates

Tropical storm “Bonnie” has been dealing with vertical shear and dry air. The environment surrounding the tropical storm is not expected to be conducive for significant intensification until she moves into the central Gulf in about 36 to 48 hours. Satellite imagery continues to show some deep convection, however most of the thunderstorm development is being pushed to the northeast and away from the center of circulation.

The track forecast reasoning remains straight forward. “Bonnie” will be steered around the periphery of an upper level low in the Gulf and a subtropical ridge over the southeastern United States. The weather will start deteriorating over south Florida on Friday and showers and thunderstorms will develop over central Florida later in the day. There is some potential for development as the storm moves into the central Gulf of Mexico. Seas will build around the spill site to between ten and fifteen feet.

Tropical Depression Three may soon be “Bonnie”

Posted by Sheena Parveen under Daily updates

Tropical Depression Three formed early Thursday, now having developed a more defined center.  Enhanced satellite imagery shows shower and thunderstorm activity near the center, with well defined cloud bands on the outer edges.  It is moving near the Bahamas where a tropical storm warning is in effect.  This system is forecast to strengthen over the next 6-12 hours, possibly becoming Tropical Storm Bonnie.

A ridge of high pressure to the NE of this tropical depression will steer it in a West/Northwest track over the next few days.   Computer models below all agree on this scenario.

The system is encountering some wind shear, and is forecast to possibly encounter more as it moves into the Gulf of Mexico, that being the reason for struggling development.

The good news for us is that Tropical Depression Three looks likely to stay to our South.  Increased cloud cover and some moisture with the passing of this system will keep temperatures slightly cooler Friday and this weekend.  A tropical storm watch has been issued for the East coast of Florida from North of Golden Beach to Jupiter Inlet, including Lake Okeechobee.  By Sunday, a shift to the NW may put it anywhere from Texas to Louisiana at tropical storm strength if wind shear interaction continues. 

Another tropical wave lies off the Mexican coast, still fairly unorganized, but will be moving on land soon to the West/Northwest. 

97L not giving up, the NHC to investigate.

Posted by Dave Osterberg under Daily updates

Once again there has been a flare-up in the convection associated with 97L.  Over the past few days it has undergone lots of shearing and dry air intrusion, but it still keeps fighting back.  As of 8AM the Hurricane Center has put chances at high for development (70%). Given this, they will send a plane out to investigate 97L. If they find low level circulation, this could be upgraded to a depression, or possibly a storm. It will be interesting to see what happens with this. The computer models still push it all to the WNW. At this trajectory, the bulk of the system will pass to our south, but at the same time tons of tropical moisture will be pushed into our area. So our rain chances will go from next to nothing to likely in a short period of time in Central Florida. It will be interesting to see what happens when this system reaches the Gulf. The waters are warm, and the loop current may be in play. Hopefully the wind shear will stay high enough so if it develops, it can stay weak.  One thing is for certain, and that is rough seas and squally weather will be on tap for at least South Florida as we head into the weekend.

97L A little less organized this morning

Posted by Dave Osterberg under Daily updates

Dry air and wind shear did a number on 97L overnight, with a lot of the deep convection falling apart. An upper low to the west with some dry air as well keeping the organization at bay. Over the next couple of days, some strengtheing may occur, so the Hurricane Center has kep the chance high at 60%.  Hurricane Hunters were going to go out to investigate, but that flight has been postponed until tomorrow.  There is no doubt a lot of tropical moisture in this area, and as you can see by the computer models, it is forecast to drift WNW and toward the state. If the current situation holds, Central and South Florida will have some clouds and showers  over the weekend. If it gets further developed, then the situation changes. But the longer it takes to organize, the less time it has before moving across Florida.

“Bonnie” on the way??

Posted by Paul Dellegatto under Daily updates, MyFoxHurricane.com website

The vigorous tropical wave located near Hispaniola continues to look better organized on satellite this afternoon. While we are not seeing any dramatic drop in atmospheric pressure, environmental conditions continue to favor development. An upper level low, clearly seen on water vapor imagery, is actually aiding in thunderstorm development. Based on current trends it seems likely that a tropical depression or storm will be developing north of Hispinola or near the south east Bahamas during the next 24 to 48 hours.

The forecast track is becoming more clear cut as a subtropical ridge will stay north of the system for the next few days. Slow intensification is likely, but there is an area of dry air aloft over the Bahamas and Florida that could hinder development as the depression/storm approaches the United States. We will have to watch this area closely. Any impacts to Florida would not be until later this week with the potential of a storm in the Gulf by the end of the weekend.

97L dumping heavy rain on Puerto Rico.

Posted by Dave Osterberg under Daily updates

Although very disorganized, the system designated as 97L has been dumping lot of rain on Puerto Rico as it slowly heads toward the WNW and near Hispaniola. The Dominican Republic and Haiti are next in line for heavy rains over the next few days.  After that where does it go? Well in the short term, moderate to high wind shear is keeping it at bay, and not allowing it to organize. But as the upper level low moves away to the NW, the wind shear will likely relax and some development may occur. A couple of days ago, none of the computer models were developing this, but now a few have come on board.  I will say at this point we should take these with a grain of salt, until we see some consistency.  Our first concern should be the residents of Hispaniola because Haiti is still recovering from that terrible earthquake, and the last thing they need is heavy rains on top of that. Stay tuned.

Watching Invest 97L

Posted by Jim Weber under Daily updates

We have been watching 2 tropical waves, the first and weaker of the two is in the central Caribbean and has show no signs of organization and mostly void of convection. The second is near Puerto Rico and has a large area of disorganized storms. This was designated as Invest 97L this morning.

It has been producing heavy rains across which has prompted flash flood warnings. Already just during the morning hours today over 3 inches of rain has been observed on the north east side of Puerto Rico. Heavy rains will continue well into tomorrow. These rains will begin to spread over the Dominican Republic tonight and flooding is a large concern.

The water vapor imagery gives a good indicator to what is going on with this system.  A upper level low is positioned to the northwest of the disturbance which is creating southwesterly shear over the system. Shear analysis in this region show winds of 20 to 30 knots which is keeping any development at bay. There is also a swath of dry air located from just west of the disturbance over to Florida. This dry air is being drawn in from the west.

Models agree on a general track to the west over the next several days and no models show much if any development of this system thru this week. This region is expected to spread heavy rains over the Dominican Republic and move towards Cuba and the Bahamas later in the week.

The WRF Shear forecast run this morning shows the area of stonger wind shear just to the north of this system. The medium blue color is shear of 20 knots and the darker blue is 30 knots.

By Wednesday this area of shear is actually forecast to intensify up to about 40 knots (green shade). Unless the shear lessens around this system it will have a very difficult time of producing much more than heavy rains.

2 Tropical waves to watch

Posted by Dave Osterberg under Daily updates

It seems as thought overall the tropics want to become active. As we head into early August, we will likely see and uptick in orgainzed storms. But this morning, we have two areas of interest, both with 20% chances of development. There is one near Jamaica, which may be lacking tons of convection, but pressure are beginning to fall in this area. The wave is moving to the west and development, if any would be slow to occur. The more interesting tropical wave is the one northeast of Puerto Rico. There is a lot of convection with this one, but no real circulation to speak of. It is moving WNW and by the end of the week some of the moisture with this could impact South Florida.  It is intersting to note, that the computer models aren’t developing either of these, but that doesn’t mean we will stop watching them.

Wind shear becoming more favorable. . .

Posted by Sheena Parveen under Daily updates

As La Nina continues to develop in the tropical Pacific Ocean, wind shear over the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea will slowly become more favorable for tropical cyclone development.  Lower wind shear is forecast as we move deeper into the hurricane season.

La Nina is cooler-than-average waters in the tropical Pacific.  A good example of the water temperatures is below:

Through the Atlantic Ocean, we see a few areas of disturbed weather.  One tropical wave to the East of the Lesser Antilles is showing shower activity, but organization is poor.  Through the next few days it will  be encountering unfavorable upper level winds.  In the tropical Atlantic there area a few spots where shower and thunderstorm activity is present, but no organized cyclonic flow is present at this time.

The tropical wave over the Leeward Islands is continuing to look unorganized.   This area of disturbed weather could develop further, but very slowly as atmospheric conditions aren’t ideal at this time.  One other weak tropical wave is located in the Central Caribbean.  This one is also very unorganized, producing widespread shower and thunderstorm activity.  Both waves are moving West around 10 mph.

Wind shear remains moderate to high North of the Caribbean Sea, and circled in orange is the tropical wave East of the Lesser Antilles.  As this wave moves West, it will encounter some wind shear, so development of this system is not likely in the next couple days.  In the central Atlantic, a large area of high pressure is keeping the atmosphere quiet.

La Nina on its way; tropics quiet for now. . .

Posted by Sheena Parveen under Daily updates

La Nina (cooler than average Pacific water temperatures) is developing in the tropical Pacific Ocean, and is expected to occur through July into August.  For us, this means a more active hurricane season.  Cooler water temperatures in the Pacific affect how much wind shear is present through the Atlantic, Caribbean, and Gulf of Mexico.  So, these cooler temperatures mean lower wind shear, and lower wind shear means tropical systems will have a better chance to develop and strengthen. 

Currently in the Caribbean Sea, there is a very weak area of low pressure over Cuba, as well as some shower and thunderstorm activity.  Nothing organized though.

Out in the tropical Atlantic Ocean, there is very little activity. 

There are areas of moderate wind shear through parts of the Caribbean and Atlantic Ocean, and due to the lack of any significant tropical waves at this time, all is quiet. . . for now.  High pressure is also providing a more stable atmosphere with drier air through most of the Northern and Central Atlantic Ocean.