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Category: Tropical

Danny Now a Hurricane

| 10:20 am August 20, 2015

danny 9 avn_lalo-animated

Danny was upgraded to hurricane status on the 10 a.m. advisory from the NHC.

Here are the Fast Facts:
———————————————–
LOCATION…12.5N 44.8W
ABOUT 1090 MI…1755 KM E OF THE WINDWARD ISLANDS
MAXIMUM SUSTAINED WINDS…75 MPH…120 KM/H
PRESENT MOVEMENT…WNW OR 295 DEGREES AT 12 MPH…19 KM/H
MINIMUM CENTRAL PRESSURE…992 MB…29.30 INCHES

The system is very small, which makes it vulnerable to unfavorable environmental conditions. It is expected to remain in an area of low shear, which is favorable for intensification, so it might strengthen even further. The current forecast calls for a peak intensity of 85 mph.

There is lots of dry air to the north, so the double edged sword is that intensification might act to pull in some of this drier air to the cyclone, which would weaken it.

Here is the official 5-day forecast track for Danny:

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There is good agreement between two major global models that the system will impact the northern Lesser Antilles, including the Leeward Islands, Virgin Islands and Puerto Rico. On this track, it would impact Hispaniola as well. That mountainous island tends to knock the stuffing out of tropical cyclones, and a small one would be especially vulnerable.

In fact, the cyclone is forecast to degenerate into a tropical wave by the two global models.

A change in track to the north or south could change this way of thinking.

It is too early to know if Danny can hold together and impact the Gulf of Mexico, but of course, any storm in the Caribbean gets our attention here in the region. We will have plenty of time to watch it, as it is at least 7-8 days from being a threat to the Gulf or South Florida.

Hello, Danny ! !

| 3:56 pm August 18, 2015

It has taken a number of days, but Danny has finally made an appearance on the tropical stage! The National Hurricane Center (NHC) named the storm this afternoon. Danny has continued to improve in overall look and strength since the last advisory including the development of interlocking curved convective bands and the formation of an upper level anticyclonic outflow pattern. Here’s a look at Danny from the GOES East satellite.

vis Danny

The European satellite actually has a slightly better look at Danny, so here is that view.

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Danny was about 1,450 miles east of the Leeward Islands moving westward or 280 degrees at 12 mph with maximum sustained wind estimated to be near 40 mph. Danny should continue of a heading just slightly north of west for the next couple of days before turning slight more westerly. Here is the track forecast graphic from NHC.

203240W_sm

Danny is forecast to continue to strengthen and should become a hurricane in about two days, roughly around noon on August 20th. Using the historical hurricane data from NOAA, I noted that nine (9) storms have gone within 10 miles of the present location of Danny. One (1) struck Mexico, one (1) made landfall on the South Carolina coast just north of Savannah, and the other seven (7) all recurved out to sea and remained in the Atlantic.

Historical data doesn’t tell us where THIS storm is going, but at least it gives us some ideas on what past weather patterns have done. The historical data goes all the way back to 1892.

By the way, the center of Danny was located about 3065 miles southeast of Birmingham. Using the present speed, it will take Danny over 256 hours (over 10 days) to get here if it moved on a steady track northwest and didn’t make any pit stops!

-Brian-

Tropical Depression Four Forms

| 10:50 am August 18, 2015

td four tue 10 aavn-animated

Tropical Depression Four has formed in the Atlantic a little more than 1,600 miles east of the Lesser Antilles.

The depression is moving just north of west at 13 mph.

Top winds are 35 mph according to satellite estimates and the central pressure is estimated at 1009 mb.

The system will likely become Tropical Storm Danny tonight or early Wednesday. It should become a hurricane by Friday.

But the system will weaken as it approaches the islands over the weekend. It may well get into the eastern Caribbean, but it will encounter more unfavorable conditions and could weaken further.

By late in the weekend, the Bermuda high should start to weaken and a trough will develop over the East Coast. I don’t think this trough will be strong enough to recurve Danny if the tropical cyclone holds together. It could deflect Danny into South Florida. Or it could build back in time to keep Danny steaming on a westward course across the Caribbean. We will wait and see!

Tropical Action

| 9:10 am August 17, 2015

It has been very, very quiet across the Atlantic basin this season, which is expected during an El Nino year. But, we have a wave in the far eastern Atlantic with a good chance of becoming a tropical depression or storm over the next five days…

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The wave will move to the west/northwest…

AL96_current-2

And, most tropical models ramp this up into Tropical Storm Danny by late week…

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Way too early to determine if this will impact the U.S. or any land mass.?

Invest 96L To Be TD#4/Danny?

| 4:27 pm August 16, 2015

avn-animated 96L

The tropical wave in the far eastern Atlantic approaching 30W longitude has a surface low associated with it now and it is increasingly looking like it will become tropical depression number four in the next couple of days. The NHC now puts the probability of that happening in the next 48 hours at 50 percent and the probability in the next 5 days at 60 mph.

Wind shear is low in the vicinity of the system, which enhances the potential for development. It will be moving over warm sea water, running between 27.5-28C, which is above the 26.5C threshold. It is ensconced in high humidity air for now, which should not serve as a serious impediment.

The SHIPS model shows that the disturbance could become a depression anytime, a tropical storm by Monday morning and a hurricane by 60 hours, which is early Wednesday morning.

The morning run of the GFS was not very bullish on the storm becoming very strong, running it into some more substantial shear as it moves into the middle of the Atlantic between the Caribbean and the Cape Verdes. It also turns the system out to the northeast before it reaches the islands.

Interestingly, the GFS develops a couple of additional tropical cyclones behind this one, with the next one reaching the islands around the first of the month. With a ridge developed back to the north of it, that system could get into the Caribbean.

The next named storm will be Danny. The next will be Erika. The 2015 Atlantic Hurricane Season is not dead just yet.

Tropical Storm Claudette Forms

| 12:10 pm July 13, 2015

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The low pressure system off the Mid-Atlantic Coast has become organized enough to be named Tropical Storm Claudette. Top winds are 50 mph. Further strengthening is not expected. In fact, it will weaken before it brushes Nova Scotia Tuesday night and makes landfall in Newfoundland on Wednesday morning.

The storm is no threat to the U.S.