Tropical Depression SEVEN Forms

(Refer to my last post on where I think the track will go)

The National Hurricane Center is forecasting Tropical Depression SEVEN to move to the west and eventually northwest along the Caribbean. This goes in line with my estimate on where this system could go. The link to that post is above.

If I were to look extremely long range, I would think that there is a fair chance of entering the Gulf of Mexico. However, this could be another 'Ernesto', and we all know how that turned out when the Gulf appeared at risk.

Andrew

Caribbean May Be At Risk Over Invest 92

I believe that model guidance may be incorrect in assumptions that Invest 92 will be a threat to the East Coast and skirt the Virgin Islands to the north, as the steering layer chart above differs from the model guidance.

Steering charts are used for storms within a certain boundary of strength. This one is used for systems with central pressures at or above 1000mb, so we will use this chart to determine where Invest 92 will go. While it is not clearly defined, one can find it in the warm colors below the massive ridge in the Atlantic Ocean.

Looking at this steering chart, the models have good reason to be confused on the track- it is just below the ridge of high pressure. If it were to be influenced by this ridge, as many models are saying, the system would keep straight west and fire off towards the East Coast.
However, as a few models are starting to trend to, there is a tight belt of winds just below the ridge that would take the system southwest, through the Caribbean and possibly towards the USA. I find this to be more possible, as the warmest colors are in the belt of higher winds, and thus would have more influence on where the storm goes. Additionally, this is where the NHC indicates the system is, as shown below on the most recent NHC chart. Invest 92 is the one circled in red.

Andrew

Disturbance Moving Off Africa May Pose Caribbean Threat

A disturbance is moving off Africa this morning that may eventually produce a threat to the Caribbean islands.

This disturbance is located in the middle of the 10 (degree) north line. Its appearance is disorganized, with the main cluster of showers and storms already offshore and mainly debris clouds in tow. Despite the disorganization, I see a potential tropical system on our hands, and here's why.

Because this system is at the 10 degree north line, I find it reasonable that, should movement continue west, climatologically the system would want to enter the Caribbean in a similar way in which Hurricane Ernesto did.

This steering layer wind map represents possible motions for storm systems with central pressures at or above 1000 mb. According to this map, the disturbance would likely continue to move westward and encounter a possible southward motion in the process, However, should this current pattern hold, an eventual westerly-turning-northwest movement would likely result.
Another possibility is that the system is pushed north and is thrown into the massive high pressure system holding an iron grip over mich of the Atlantic. This high pressure system would either result in an East Coast threat or throwing the disturbance out to sea.

But, even if it moves west towards the Caribbean, will it survive the trip?

This map shows shear tendencies over the Atlantic. At the moment, we have generally light shearing over the area where this disturbance would travel should it move west. This would prove beneficial for additional development. There is an area of about 30 knots of shearing on te lower right-hand corner of the image, which i where the system may run into some trouble. However, should it survive that bout, and low shearing holds up over the 10 degree north line, I believe additional development for the disturbance is likely.

Disclaimer: This is long range, and tropical systems are known to be notorious for long range forecasts. This is based off of what I believe may happen, but is not to be taken seriously until the system is a few days away due to the trickiness that comes with tropical forecasting. If it comes down to it, heed warnings from the National Hurricane Center and not from here at The Weather Centre.

Andrew

Invest 92 May Pose Threat to East Coast

Model Guidance suggests that Invest 92, located to the far east of the Barbados, may eventually pose a threat to the East Coast, with several models suggesting the system moving to the north or south of the Leeward Islands in due time.

There is little consensus among the models as time goes on, but a general idea does appear to have the system skirt around the Leeward Islands before curving north and posing a threat to the East Coast. When or if the system does curve north will be a big factor in how much the East Coast is affected.

This is the latest steering map for systems at or above 1000mb. Basically, it can help show you where the system is heading. At the moment, the steering map indicates that Invest 92 will have to skirt around a large ridge in the Atlantic. If we look to the west of the ridge, there is still a fairly tight wind field that could easily pick up the system and throw it out to sea. Seeing as winds appear unsupportive for west or southwesterly movement, I find this solution to be on the table of possibility. Nonetheless, the East Coast and Southeast will have to watch this system closely.

Andrew

July 2012 Was Hottest July on Record

Data released by the NOAA today indicates that July 2012 was the hottest July recorded since record-keeping began in 1895. That means a 117 year old record was broken this past month. The record comes at a time when global warming returns to the debate world.

The average temperature across the nation reached 77.6 degrees (F), a full 3.3 degrees above the 20th century average.

Many are asking is this is a result of global warming. I prefer not to give an opinion on this piece yet, as I would like to see at least 2 years of warmer than normal temperatures to consider such a possibility. While the past 12 months have been the warmest 12 months since record keeping began, one must remember that global warming is warming the entire world and therefore will be slow to occur.

Andrew