Just a quick update. Hurricane Hunters late this morning found Invest 97L to be Tropical Storm Matthew with 60 mph winds. See NHC track below. On the forecast track it is expected to pass near or over Jamaica Monday as a Cat 2 Hurricane. This AMs forecast still holds and I await its turn to the NW and N on Saturday. Where and when the turn occurs will be the key to whether or not we see any associated weather.
Good morning. Since Monday a few things have changed with Invest 97L. Most significantly it has moved about 3 degrees north and is currently centered around 12 degrees N latitude. This is probably good new for us in South Florida. The NHC expects it to become a Tropical Depression or Tropical Storm Matthew later today. It is presently about 150 miles east of Barbados and should enter the Caribbean Sea later today. If you look at the water vapor loops of the Western Atlantic this morning, http://www.ssd.noaa.gov/goes/east/tatl/flash-wv.html , you will notice several features. First an upper level low north of Hispaniola, an upper level low in the central Atlantic moving SW, A trough just to our east starting from a small upper level low south of Cuba and a frontal boundary pushing SE across the lower SE US. The southern extension of the trough to our east to south of Cuba along with the more northern position of Invest 97L makes a move to our N and east more likely. It is currently moving W to WNW at 15-20 mph and is building a dome of high pressure over it which is mitigating the affects of significant shear to its north and west. It should move around the periphery of high pressure centered just east of Bermuda (see below) and hopefully pass far enough east of us for us to avoid significant weather. Due to the complexity of the weather around it, it is still too early to write it off though things look encouraging this am. I will be writing more as things develop and will post some of the latest computer models later this am after they become available. Until later, Matt. Above are the latest models from 8 this am, note some still bring the system S and west of South Florida. We'll need to keep a close eye on it. The key will be how far west it is when the NW to N turn starts to occur. This should be Friday night or Saturday depending on forward speed.
Good morning.
I am writing about a broad area of low pressure in the southern Central Atlantic which the NHC has labeled Invest 97L. It is currently located near 9 degrees N and 43 degrees W and is moving west at 15-20 mph. The NHC is giving it a 90% chance of tropical development in the next 5 d and it is forecast to enter the southern Caribbean Sea on Wednesday. It exited Africa a few days ago at around 9 degrees. In 5-7 days a frontal trough is forecast to stall over central Florida which if the system is far enough north would tend to turn it to the north. The NHC is currently forecasting it to turn sharply north in few day and pass to our east due to this front. It is currently quite far south and may even brush the north coast of South America, Venezuela, which would be very unusual. If it stays too far to the south it may not perceive the pressure weakness to its north in which case a course toward Central America or the Yucatan would be more likely. The pressure patterns around this system are quite complex. High pressure over Cuba, an upper level low over the Big Bend area of Florida and an approaching frontal system from the Mississippi Valley. Shear in the Caribbean is currently quite high as well. Its too early to say much about this system at this time but we'll probably know more in a couple of days when it enters the Caribbean. I've attached some of the current models. I'll let you know as things develop but I wouldn't be surprised at all if it takes the more southerly route. Matt. Good morning.
The tropics show activity however fortunately none of the present systems appear to pose any threat to the US. (see satellite image below). 2 below, the wave I spoke about in my last update is coming off the coast of Africa now. The NHC is forecasting it to move WNW and eventually turn north into the mid Atlantic trough. Karl is expected to do the same. So far so good. I'll write if things should change. Matt. Good morning.
Just a quick update to let you know that for now things look good. Newly formed TS Ian in the Central Atlantic is moving north and should not be a threat to the US. A disturbance over the northern Bahamas (1) should drift over the Florida Peninsula today, development is not expected. A wave just off the coast of Africa (2) is expected to move WNW into the mid Atlantic trough and should not be a threat as well. There is a wave which we'll need to watch over Africa, (see below), which should emerge in a couple of days. I'll let you know as things develop, or not. Until later, Matt. Good morning.
Hermine made landfall in the Big Bend area of Florida late last night as a Cat 1 Hurricane with 80 mph winds. It is currently a tropical storm over Southern Georgia. It is forecast to move through the Carolinas today and tomorrow and then stall off the NE coast early next week as an extra-tropical storm. This could become a huge rainmaker for New Jersey, Long Island and coastal New England with significant beach erosion. (see forecast track below). The low pressure area which I talked about in my last forecast is presently in the mid Atlantic centered around 15 degrees N latitude. It is surrounded by dry air and moderate shear. NHC is only giving it a 20% chance of becoming a tropical depression over the next 5 days as it enters the northern Caribbean Sea. I'll continue to keep an eye on it but hopefully it will not be a threat to South Florida. Elsewhere in the tropics TS Gaston is approaching the Azores and as is weakening and is expected to degenerate to a remnant low tomorrow. Have a great Labor Day weekend. Until next time, Matt. Good morning.
TD #9 continues to move west slowly and is expected to turn to the NW and eventually N and NE. The NHC has not revised its track since yesterday and yesterday's chart still holds. (see 8-29-16 forecast track/diagram). Pressures are dropping (29.62" last advisory) and the system is expected to become a tropical storm today. We should continue to see enhanced shower activity through Thursday due to higher atmospheric moisture associated with this system. Of note is that the tropical wave which I wrote about yesterday moved off the African coast last night. Yesterday it moved SW and exited the coast at around 12 degrees N latitude. (see yesterday's post) I'll be watching it. Until next time, Matt. Good morning.
At 8 pm yesterday Invest 99-L was upgraded to TD #9. At that time it was at it's closed approach to the Keys and was 60 mile S of Key West as it passed through the Florida Straits. It is currently located at 23.5 N & 83.9 W, see below, 155 miles WSW of Key West. Due to NW shear from an upper level low off the coast of N FL, GA and SC most of the weather associated with the system remains to the south and east of the center. This also left us with a mostly sunny and dry weekend other than a few passing showers. Rainfall total at my house for the weekend was just over 1/2 an inch. About normal for late August. The NHC models are in good agreement for the system to make landfall in the Big Bend area of Florida on Thursday. We will probably see enhanced shower activity through Thursday due to increased moisture in the area associated with this system. No significant winds are expected in South Florida. North Florida may see a tropical storm, though it is currently very poorly organized and shear is anticipated to persist making it unlikely to become a strong system. A couple of points of interest if you go to this link ( http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html ) now you will see Hurricane Gaston spinning in the mid Atlantic. It is a major Hurricane now with peak winds of 115 mph, ( Note you usually do not initially see a well defined eye on satellite imagery until winds get to around 100 mph.) The second point is that the area which we will need to watch is a tropical wave coming off of Africa. Another pearl is that waves coming off between 10 and 12 degrees N are the ones that tend to pose the greatest threats to South Florida, and the US for that matter. This one is currently between 13-14 degrees. We'll see how things develop. Have a great week, Matt. Good morning.
In reviewing the data on Invest 99-L this am the remarkable thing is that there is nothing there. It's circulation center is over the SE Bahamas w/o any associated weather near it. It is moving WNW @ 10 mph and should pass through the Florida Straits this weekend. Most of the associated moisture is to its south and east. Development of this system is extremely unlikely and the NHC has reduced it probability of development to 20% in 2 days and 60% in 5 days. I do not think we will experience any weather directly from this system. The old frontal boundary stalled across central Florida is the feature that has been causing our showers the past couple of days. It should persist and they may be enhanced by the moisture associated with this system as it passes to our south. It is possible that it may develop after it gets into the Gulf of Mexico, but no preparations appear to be necessary for South Florida at this time. I will probably not write again until Monday, if it still exists, unless things should change. Have a great weekend, Matt. Good evening.
Since yesterday not much has changed with Invest 99-L which may be good news. It remains very poorly organized and its circulation center (currently near the Turks and Caicos) is exposed NW of most of its associated weather which is over and south of Hispaniola. It is presently experiencing 20-30 knots of shear which is causing this. The NHC has reduced its probability of development in the next 48 hours to 40%, and at 5 d to 70%. In 5 days it will be past us. In its current state it would take some time to get its act together. This makes the likelihood of a South Florida Hurricane low and it may not even make it to Tropical Storm status until it is past us. It is also possible that it may not even develop at all. It frankly looks very weak right now. (see below). By late tomorrow the shear above it will begin to subside and so slow development is possible. It is currently moving westward at 15-20 mph and at this speed should be in our vicinity Saturday night-Sunday. High pressure over the NW Gulf should continue to move it W to WNW. The NHC models as expected have begun to shift to the south (see below) and my track through the Florida Straits has not changed since yesterday. I'll write again tomorrow but the prospects of a significant storm for S Florida appears to be much less. My best to all, Matt. |
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