hurricane Tropical Storm Melissa

[Vorticity0123]

After a lull of about a month in TC activity, a new subtropical storm has developed in the Central Atlantic, and it has been named Melissa. The system is quite large, and seems to have a quite large range of tropical storm winds, but in the last few hours, convection has also built at the center of Melissa, which is a characteristic of a (sub-)tropical cyclone.

Current OSCAT data shows the large radius of tropical storm winds associated with the system (winds of at least three and a half flag suggest tropical storm force winds)

 

Current water vapor imagery shows a tongue of dry air curving toward the center of Melissa, likely impeding in development.

 

 

Shear analysis by CIMSS (not shown here) shows the system is currently in a sharp shear gradient, with values ranging from 20 kt to the east, to 50 kt to the west of the system, providing, along with the dry air, only marginal conditions for development.

 

The NHC is currently forecasting Melissa to get close to hurricane strength, as shear values are expected to drop to values below 10 kt, and SSTS are about 27 degrees Celsius. Thereafter, extratropical transition is about to begin.

 

The storm is forecast to move northward during most of its lifetime, with a recurve toward the northeast afterward. Behind that time, it is yet uncertain if the system will turn back toward Greenland, or continue its recurve toward Spain. The NHC is currently forecasting a backward curve toward Greenland, on which an increasing amount of models seem to agree upon.

 

The track of Melissa as forecast by the NHC.

 

Although the model spread has been reduced in the past 24 hours, there remains a considerable amount of uncertanity about the angle of the recurve.

 

 

An image of the different forecasts of different models, showing the current spread at the medium to long range.

 

It will be interesting to see how the models handle this system now it has been qualified as a subtropical storm, and especially the effects on the forecasted blockade west of Ireland. It is likely that there will be quite some model-hopping in the medium to long term time frame. It is also very nice to see how tropical cyclones could have a significant impact on the weather in Europe, directly or indirectly.

 

To illustrate the model-hopping of the various models on the handling on the storm, some output of the GFS and ECMWF models at T96hr below:

 

GFS:

EC:

 

While the GFS suggests a very pronounced southern part of the complex low pressure area (extreme left, remnants of Melissa), the ECMWF shows a much more pronounced northern part of the system (in this case, the remnants of Melissa would be absorbed). The different handle could easily result in very different outcomes at bigger timeframes.

 

And finally (to get back to the storm itself), a visible image of the subtropical cyclone.

Edited November 18, 2013 by Vorticity0123

[Coast]

 

Subtropical Storm Forms In Northern Atlantic

 

With just about two weeks to go to the end of hurricane season, a subtropical storm has formed in the northern Atlantic.At 11 a.m., subtropical storm Melissa was about 695 miles east-southeast of Bermuda. The storm had maximum sustained winds of 50 mph as it moved toward the northwest at 9 mph.There are no watches or warnings for this storm.

 

The National Hurricane Center forecast calls for Melissa to take a turn to the north on Tuesday followed by a turn to the northeast on Wednesday. Some strengthening is expected over the next day or so.

 

 

 

http://miami.cbslocal.com/2013/11/18/subtropical-storm-forms-in-northern-atlantic/

 

 

Tropical Storm MELISSA: Storm-centered zoom at 117 hours lead

[Sainsbo]

Melissa now has sustained winds of 60mph, and is forecast to reach a peak of 70mph in the next 24 hours, and will likely maintain that strength for a while. With the rate that Melissa has been intensifying, I wouldn't be surprised to see a weak hurricane come from her.

 

Doesn't look very impressive on satellite right now though.

 

[Vorticity0123]

Melissa now has sustained winds of 60mph, and is forecast to reach a peak of 70mph in the next 24 hours, and will likely maintain that strength for a while. With the rate that Melissa has been intensifying, I wouldn't be surprised to see a weak hurricane come from her.

 

Doesn't look very impressive on satellite right now though.

 

 

Agreed, Melissa appears to have lost its beautiful curved structure. And yet, it does seem to me that its current organization reflects more and more a tropical cyclone. This is actually the first time a moderate convective band has wrapped halfway the eastern semicircle, this close to the center.. The system might be in a process in decoupling from the long band to its far east.

 

Indeed, this system seems to have quite a high chance to become the third hurricane of the 2013 hurricane season. The funny fact is, though, that Melissa has a lower MSLP than Humberto had on its maximum intensity, according to satellite estimates from CIMSS.

 

Models have been trending toward a more tropical structure of Melissa in the future, with the GFS now forecasting a symmetric warm core to develop, before extratropical transition begins.

 

Note that on this graph, C is the starting point where the system is at the beginning of the model run, while A is the starting point of the system, when it was firstly recognized by the GFS. 

 

What's also very interesting to note (from the perspective of Europe), is that Melissa is now forecast to remain a seperate entity during the next 5 days. This will definitely have quite some impact on the models in 5 days, thus decreasing the certanity in that timeframe.

 

As from the NHC:

THE INITIAL MOTION ESTIMATE IS 325/08 KT. THERE IS NO SIGNIFICANT

CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING THROUGH 36 H.

NHC MODEL GUIDANCE REMAINS IN EXCELLENT AGREEMENT ON MELISSA MOVING

SLOWLY NORTHWESTWARD AND NORTHWARD OVER THE NEXT 24 HOURS...AND THEN

ACCELERATING NORTHEASTWARD BY 36 H. MELISSA WILL LIKELY REMAIN A

SEPARATE ENTITY THROUGH 120 H AND NOT BE ABSORBED BY AN APPROACHING

FRONTAL SYSTEM UNTIL NEAR OR AFTER THE FORECAST PERIOD. THE

OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND

LIES CLOSE TO THE MULTI-MODEL CONSENSUS TVCA. THE EXTRATROPICAL

TRACK IS BASED ON INPUT FROM THE NOAA OCEAN PREDICTION CENTER.

 

 

Sources:

http://tropic.ssec.wisc.edu/real-time/storm.php?&basin=atlantic&sname=14L&invest=NO&zoom=4&img=1&vars=11111000000000000000000&loop=0

http://en.wikipedia.org/wiki/2013_Atlantic_hurricane_season (for the lowest pressure of Humberto)

http://moe.met.fsu.edu/cyclonephase/gfs/fcst/archive/13111812/20.html

http://www.nhc.noaa.gov/text/refresh/MIATCDAT4+shtml/182053.shtml

Edited November 18, 2013 by Vorticity0123

[Somerset Squall]

Winds are up to 50kts as has been said with an estimated pressure of 987mb, typical of a cat 1 hurricane. When Melissa becomes tropical, which I think it is close to doing, it may be close to hurricane strength, which I think it may well achieve.

[Coast]

 

[Somerset Squall]

Still subtropical at the moment, Melissa seems to be having trouble seperating itself from the upper level low. Chances for Melissa to become a hurricane are lessening IMO.

[Somerset Squall]

Pressure has continued to fall, now at 982mb. Winds are up to 55kts, but Melissa is still classed as subtropical. The only thing holding NHC back from declaring it tropical is the distinct lack of the convection over the LLCC at present, because, at last, Melissa seems to be detaching itself from the troughing to the east.

[Coast]

I think Melissa will have run out of puff before she gets too much further North:

 

Tropical Storm MELISSA: Probability of Cat 1 or above winds to 93 hours lead

[Somerset Squall]

Melissa has become a fully tropical storm, with winds slightly weaker at 50kts. Deep Convection has formed over the centre, and wind radius has contracted to that of a tropical storm. Melissa is racing northeastwards towards cooler water, so weakening then extratropical transition will begin soon.

[Coast]

 

Tropical Storm Melissa is racing east-northeast over the north-central Atlantic Ocean, about 1,000 miles west of the Azores. Melissa began as a "subtropical storm," a sort of hybrid between a tropical and mid-latitude storm system. Over time, it has developed a tighter core of convection (thunderstorms) close to its center, which led to Melissa taking on tropical characteristics late Wednesday morning despite being centered north of 35 degrees North latitude, about the same latitude as Charlotte, N.C.

 

Even so, an approaching cold front over the western Atlantic should catch up to Melissa by Thursday, heralding its inevitable transition to a post-tropical low. Melissa is no direct threat to land, but its large wind field has generated large swells that have affected Bermuda, Hispaniola, Puerto Rico, and the northern Lesser Antilles. High surf and dangerous rip currents should subside along the coasts of those areas as Melissa continues to move farther away and weakens.

 

 

http://www.weather.com/news/weather-hurricanes/tropical-storm-hurricane-melissa-20131119

[ztam]

Could anybody tell me the conditions what this would produce out at sea.. My parents are on the Queen mary 2 cruise ship and have been told they are heading straight for it... I have been trying to track down the ships current location, but unable to fins anything at the moment...

[Somerset Squall]

I would imagine the seas would be fairly rough in the vicinity of the storm, Melissa though is a fairly compact and relatively weak storm at present. I don't really know for sure though Ztam, sorry. If the captain has continued to head towards it then I would gather they don't see it as a significant threat?

 

Melissa itself has weakened to 40kts. The tropical storm is maintaining some deep convection over the LLCC, though this is not expected to last, as sea temps are a decidely chilly 21C beneath the storm currently. This will soon cause extratropical transition (ETT). The Azores may get some rough weather from Melissa over the next day or so. After ETT, Melissa will come up against the large area of high pressure to the west of the UK, and will significantly slow and fill out to sea.

[ztam]

I would imagine the seas would be fairly rough in the vicinity of the storm, Melissa though is a fairly compact and relatively weak storm at present. I don't really know for sure though Ztam, sorry. If the captain has continued to head towards it then I would gather they don't see it as a significant threat?

 

Melissa itself has weakened to 40kts. The tropical storm is maintaining some deep convection over the LLCC, though this is not expected to last, as sea temps are a decidely chilly 21C beneath the storm currently. This will soon cause extratropical transition (ETT). The Azores may get some rough weather from Melissa over the next day or so. After ETT, Melissa will come up against the large area of high pressure to the west of the UK, and will significantly slow and fill out to sea.

Thank you for you reply, Havent heard from them today, but hopefully all ok out at sea...

[Coast]

 I have been trying to track down the ships current location, but unable to find anything at the moment...

 

You can now:

 

http://www.vesselfinder.com/?imo=9241061

 

Got to track on map here:

 

http://www.vesselfinder.com/vessels?name=Queen%20mary%202

 

Currently sailing away East from New York

 

[Somerset Squall]

Melissa has become extratropical. The storm will continue east then slightly south of east as it comes up against blocking. Models indicate the extratropical storm to dissipate in situ thereafter.

[Coast]

 

 

Tropical Storm Melissa became a post-tropical cyclone Thursday, but gale-force winds were still possible over the Azores, U.S. forecasters said. Melissa was about 265 miles north-northwest of the Azores, traveling east-northeast at 28 mph, the National Hurricane Center in Miami said in its 10 p.m. EST advisory. No coastal watches or warnings were in effect but gale-force winds are expected over parts of the western and central Azores. Melissa was expected to experience a decrease in forward speed and turn to the east during the next couple of days. Tropical storm-force winds extended outward from center up to 240 miles.

 

 

 

http://www.upi.com/Top_News/US/2013/11/21/Tropical-Storm-Melissa-weakening-in-the-Atlantic/UPI-20171385034877/#ixzz2lMGvHV7I