Freitag, 30. August 2013

Watching a Pair of Tropical Waves

Atlantic Hurricane & Tropical Storm Center


Although the Atlantic Basin remains devoid of tropical systems at this time, that may change in the near future with a strong tropical wave and low pressure area moving off the west coast of Africa. We are also monitoring a weaker tropical wave around 800 miles east of the Lesser Antilles at this time.

Satellite imagery shows a tropical wave around 800 miles east of the Lesser Antilles that is tracking off to the west. This tropical wave has a small area of disorganized showers and thunderstorms associated with it that are not wrapped about the low-level center as most of the thunderstorms are to the north of the center of the weak low pressure area. Further organization and development of this tropical wave seems unlikely as it will move westward into a zone of higher wind shear.

A more robust tropical wave and low pressure center is just emerging off the west coast of Africa into the far eastern Atlantic as of Friday morning. As it track off to the west and northwest, it will bring gusty winds and locally heavy rainfall to the Cape Verde Islands by Saturday and Saturday night. Once the system passes by the islands, it should be passing through a zone that is conducive for tropical development and the system could be a tropical depression or tropical storm by the end of the weekend.

Beyond Sunday, the system may take more of a northwesterly turn into a zone of higher wind shear so there is still a great degree of uncertainty about how developed or intense this potential tropical system could become.

Elsewhere across the Atlantic Basin, we are not expecting any tropical development over the next 24 to 48 hours.

Montag, 26. August 2013

Tropical Storm Fernand

Tropical Storm Fernand Makes Landfall


 Tropical Storm Fernand is located at 19.8 N, -96.9 W with maximum sustained winds of 45 mph, gusting to 60 mph

Tropical Storm Fernand has made landfall just north of Veracruz, Mexico late on Sunday night and is expected to continue to move inland throughout the day on Monday. Now that Fernand has moved inland it is expected to weaken, eventually to be downgraded into a depression sometime later on Monday.

As Fernand moves inland, the main threat from the system will come in the form of heavy rainfall that is expected to bring localized flooding and mudslides in the Mexican state of Veracruz on Monday. Rainfall amounts over the region could reach upwards of 4-8 inches, with a large area receiving at least 2 inches of rain from Fernand.

Outside of the Gulf, activity across the Atlantic Basin remains rather subdued, with dry air and wind shear keeping much from developing. There are a couple of waves. One is moving through the eastern Caribbean and another is out near 35 west.

Montag, 19. August 2013

Atlantic Hurricane & Tropical Storm Center

Atlantic Ocean Mainly Quiet, However, Seveal Weak Features Being Monitored.


The Atlantic Ocean remains relatively quiet. Erin the fifth tropical storm of the season has become a remnant low along its parent tropical wave. This remnant low over the central Atlantic is embedded within a larger area of dry, stable a which caused its demise. A north south cluster of showers and thunderstorms continues to slowly work westward across the Gulf of Mexico. This area of active weather remains disorganized and has no support for development. The area of deep moisture will move into the Texas coast later today and Tuesday bringing beneficial rainfall.

A tropical wave roughly along 85 west has a cluster of persistent thunderstorms near 26 north. This area of thunderstorms is weakly supported by an upper level disturbance. There are no signs of any low level feature and as a result we are not expecting this feature to become any better organized during the next couple of days. But, we will continue to closely monitor this tropical wave.

A tropical wave along 65 west south of 22 north and a tropical wave along 46 west with the remnant low of Erin near 20 north has a larger area of deep moisture. This tropical wave should reach the Lesser Antilles by Thursday night or Friday with more clouds and showers.

The tropical wave that came off the West Coast of Africa yesterday, the 26th tropical wave to move off the coast of Africa this season continues to head westward. The tropical wave is roughly along 25 west longitude with a broad area of low pressure centered near 15 north. Dry stable air and moderate shear will prevent this feature from organizing during the next few days. However, once the feature moves out of this more hostile environment there might be some opportunity for development toward the end of this week or over the upcoming weekend.

More favorable conditions will start to evolve across the entire basin by next week. This could lead to multiple storms. The highest potential for longer range development will be across the eastern Atlantic.

Samstag, 17. August 2013

Erin No Threat to Land

Erin No Threat to Land, Disorganized System Over the Gulf of Mexico.


We continue to monitor an area of low pressure in the southern Gulf of Mexico, Tropical Storm Erin in the far east Atlantic and two weak tropical waves that will affect the eastern Caribbean this weekend.

Visible satellite images early Saturday morning has the circulation 120 miles west-northwest of Campeche Mexico. The low has moved almost due west during the past 6 hours at less than 5 mph. Satellite and Mexican radar images still show no signs of convective showers or thunderstorms wrapping around the low. Southwest shear continues over the system and this is causing a large area of deep convective showers and thunderstorms to be displaced off to the northeast of the surface low.

An upper level trough moving into the northwest Gulf of Mexico will maintain southwesterly shear over this system and over the northern half of the Gulf of Mexico into Sunday. The lower level wind flow will remain out of the east and so the surface low should drift westward the next few days.

If this low is going to develop it probably won't happen until sometime Saturday night or Sunday and it will have to be independent from the activity currently off to the northeast. As the upper level trough starts to lift out to the northeast tonight and Sunday the shear over this system should decrease.

So, if this surface low survives through tonight and thunderstorms wrap around the center it could develop a whole new mid to upper level structure. That would be necessary for it to become a depression or tropical storm. There might be just enough time for this to take place. If this does happen then a depression or tropical storm could threaten south Texas Sunday night and Monday.

Erin has strengthen back into a tropical storm. All of the convection is well north of the center of circulation. So, it will remain a weak tropical storm over the next two days. But the diagnostic computer information shows the system will remain over cool water and in a dry and more stable environment which will weaken Erin back into a depression.

Longer range model output still suggests the large thunderstorm area moving near the west coast of Africa becoming the next tropical wave and perhaps an organized tropical system next week.

Elsewhere across the Atlantic Basin, tropical development is unlikely through the weekend.

Donnerstag, 15. August 2013

Tropical Storm Erin Impacting the Cape Verde Islands

Watching the Caribbean and Gulf

Tropical Storm Erin is passing to the southwest of the Cape Verde Islands and is bringing heavy rain bands and gusty winds to the southernmost Cape Verde Islands. Total rainfall of 2-4 inches will occur through later today across the southernmost Cape Verde Islands as well as wind gusts to around 40 mph that may cause localized power outages. Due to the system moving off quickly to the west-northwest, wind and rain will subside by this evening and early tonight across the southernmost islands of Maio, Santiago, Fogo and Brava.

As the system remains on the west-northwest track, it should gradually strengthen later today as it is moving through a zone of fairly warm water and relatively light wind shear. The system should continue on this general west-northwest track and maintain its tropical storm status through the weekend. However, by later in the weekend, Erin will move into a zone of cooler ocean waters and higher wind shear.

Thus, Erin will struggle to strengthen beyond Saturday and may even begin to weaken by the end of the weekend. As a matter of fact, the shear may become strong enough that some computer forecast models suggest Erin could fall apart early next week. In the meantime, once Tropical Storm Erin pushes west of the Cape Verde Islands later today and tonight, it will continue across the open waters of the eastern and central Atlantic and not will not impact any more land masses in the foreseeable future.

The other order of business is to discuss the broad area of low pressure just east of the Yucatan Peninsula which is causing shower and thunderstorm activity over the northwestern Caribbean and Yucatan at this time. Over the last 6 hours or so, satellite imagery shows that the thunderstorm activity associated with this disturbance has actually weakened somewhat. The center of this low will move northwestward across the Yucatan today and tonight, which should prevent further tropical organization and development.

The low center will then move into the south-central Gulf of Mexico sometime on Friday. At this point, there will be some opportunity for further development as water temperatures are certainly warm enough to support it. However, wind shear will increase over the western half of the Gulf of Mexico tomorrow into the weekend and this will either prevent the low from developing all together or at the very least, prevent it from becoming all that strong.

Mid- and high-level moisture from the disturbance will likely stream northward into the Gulf Coast states even if the low-level center is left further behind across the southern Gulf of Mexico. This moisture being pulled northward could lead to localized heavy rainfall and flash flooding across parts of the Florida Panhandle, southeastern Alabama and southern Georgia through the weekend. If this disturbance were to become a named storm, its name would be Fernand.

Aside from the disturbance near the Yucatan Peninsula and Tropical Depression Five, we are also monitoring a pair of tropical waves approaching the Lesser Antilles. However, these waves have very little shower and thunderstorm activity associated with them and they are passing through an environment that is not all that conducive for tropical development. Thus, we do not expect any further development or organization from these waves over the next few days.


Mittwoch, 14. August 2013

Tropics Heating Up

Atlantic Hurricane & Tropical Storm Center



A large area of disturbed weather over the western Caribbean is moving toward the west-northwest at about 10 knots. The tropical disturbance is centered just northeast of Nicaragua. Currently, there is no clear closed low-level circulation in this area right now. The pressure actually rose a few millibars overnight.

However in the last several hours, an area of thunderstorms started to blossom, so the pressure might fall once again later today. There is still some uncertainty where this tropical system will go once it enters the Gulf Of Mexico on Thursday night. Once this system moves into the Gulf Of Mexico, then it will have the best chance of gaining strength and forming a surface low. Most of the model guidance shows the tropical moisture moves somewhere between the mouth of the Mississippi to the panhandle of Florida.

This is likely to happen on Friday afternoon into Saturday. There is a slight chance that the storm system will move slower into the Gulf of Mexico and head toward central Texas. As of right now this is the outlier, with the most probable outcome will be the system moving towards the Florida Panhandle.

There is a second area of concern that just emerges off the coast of Africa. This area of convection could form into a tropical system by the end of this week. Computer models show this system gaining latitude and entering cooler waters and weakening. If the storm system stays south, it will stay in warmer waters with less dry air. If this is the case it will track closer to the Lesser Antilles. As of right now it it does not appear that this system will be a strong or big tropical system. However, this is still a week and a half away, so we will have plenty of time to monitor this situation.

The rest of the Atlantic Basin remains relatively quiet.

Donnerstag, 8. August 2013

Watching a Few Features Across the Atlantic

There are a few features of interest.



We still have no organized tropical systems to track in the Atlantic basin. There are a few features of interest, but it is unlikely that we see any of them develop further. The general rule across the basin is that high amounts of wind shear and dry air from the Saharan Dust layer continue to dominate the basin and prohibit tropical development. In the longer range, the shear and dust may begin to lessen and allow for more conducive conditions for tropical development.

In the meantime, we do not expect any tropical development in the next 48 hours or so, but we are still keeping our eye on a couple of features. The first is a weak area of low pressure over the southeastern Caribbean Sea. Current satellite imagery shows very little in the way of shower and thunderstorm activity associated with the low pressure center. As this area of low pressure tracks off to the west, it will move through a zone of higher wind shear and thus tropical development is highly unlikely.

Another feature of interest is an upper-level low centered in the central Bahamas. The low will track to the west across Cuba and South Florida through Thursday night and then move westward across the Gulf of Mexico Friday and Saturday. Along the path of this low, there can be locally enhanced rainfall across parts of Cuba, the Bahamas and South Florida over the next day or two.

There is an outside chance that this could transition to a tropical cyclone while crossing the Gulf of Mexico, but it is rare for this to occur. The low should move into northern Mexico and South Texas Sunday night, hopefully causing beneficial rains.

Montag, 5. August 2013

All Quiet Across the Atlantic Basin

The tropical Atlantic Basin remains generally quiet at the present time.



One tropical wave is crossing the Atlantic. It is currently located at about 46 west and is moving westward at about 20 knots, which will take it into the eastern Caribbean by Tuesday afternoon. There are scattered showers with this wave.

Elsewhere across the Atlantic Basin, a large zone of Saharan dust continues to inhibit development across much of the Caribbean Sea. Another zone of dust stretches from the central Atlantic Ocean to the coast of Africa. This large amount of dry air combined with substantial wind shear will help to limit any tropical development over the next 3-5 days.