WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Potential Trouble in Tropical Atlantic; Karl Brushes Bermuda; Megi Eyes Taiwan

By: Jeff Masters and Bob Henson 5:23 PM GMT on September 24, 2016

A tropical wave located a few hundred miles south-southwest of the Cabo Verde Islands on Saturday morning was poorly organized, with only a limited amount of heavy thunderstorm activity and spin. This wave was under low to moderate wind shear of 5 - 15 knots and was over warm ocean waters near 29°C (84°F), but was too close to the equator (near 9°N) to be able to leverage the Earth’s spin and acquire enough spin of its own to develop into a tropical depression. However, the tropical wave may move far enough from the equator to be able to develop by Monday or Tuesday, when it will be approaching the Lesser Antilles Islands. Working against development, at least in the next five days, will be the fast forward speed of the system. The storm will be driven west at 20 - 25 mph by the trade winds associated with an unusually strong Bermuda-Azores High; tropical waves moving at 20 mph or faster usually have trouble achieving the vertical alignment needed to intensify. However, the storm does not have as much dry air to contend with compared to other storms we have seen this year, and it would not be a surprise to see this system be close to tropical depression or tropical storm status when it begins moving into the Lesser Antilles Islands on Tuesday night or Wednesday morning. Once the storm enters the eastern Caribbean, long-range model runs suggest that the system might be very close to the coast of South America, which would interfere with development.


Figure 1. Satellite image of the tropical wave (left) located southwest of the Cabo Verde Islands at 1445Z (10:45 am EDT) Saturday, September 24, 2016. Image credit: NASA/MSFC Earth Science Office.

There was increased model support for development of this tropical wave in the Saturday morning runs of the models compared to their Friday runs. Our top three models for predicting hurricane genesis—the GFS, UKMET and European models—all predicted in their 00Z Saturday runs that this tropical wave would develop into a tropical depression or tropical storm between Monday and Thursday. About 80% of the 20 forecasts from the members of the 00Z Saturday GFS ensemble showed development into a tropical storm, with 40% predicting a hurricane. The European model ensemble was less aggressive developing the storm, probably because of a predicted track too close to the coast of South America—about 30% of its 50 ensemble members predicted a tropical storm in the Caribbean. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave this system 2-day and 5-day development odds of 10% and 50%, respectively. The Hurricane Hunters are scheduled to make their first flight into the storm on Tuesday afternoon.





Figure 2. Forecasts out to ten days from the 00Z Saturday European model ensemble (top) and GFS model ensemble (bottom) had a number of their 70 members predicting a hurricane for late in the week in the Caribbean (light blue dots). The operational versions of the models, run at higher resolution (red lines), also showed the storm becoming a hurricane by ten days into the future.


Figure 3. Enhanced infrared image of Tropical Storm Karl as of 1545Z (11:45 am EDT) Saturday, September 24, 2016. Image credit: NOAA/NESDIS.

Karl brushes Bermuda
Tropical Storm Warnings were lifted for Bermuda on Saturday morning after Tropical Storm Karl brought a night of heavy rains and squalls to the island. At 11 am EDT, Karl was located about 125 miles east-northeast of Bermuda, packing top sustained winds of 65 mph and moving northeast at 18 mph. Earlier on Saturday morning, a Hurricane Hunter flight measured top flight-level winds of 63 knots (73 mph) and detected peak near-surface winds of 47 knots (54 mph) with the SFMR instrument (stepped frequency microwave radiometer).

Karl’s core of showers and thunderstorms, already east of Bermuda, reintensified late Saturday morning after some fragmentation earlier in the day. Strong upper-level winds associated with a large upper-level low in the North Atlantic were accelerating Karl to the northeast. Karl could become the fifth hurricane of the 2016 Atlantic season on Saturday night or Sunday morning before it evolves into a powerful post-tropical storm in the North Atlantic, eventually getting swept up into the massive upper low east of the Canadian Maritimes.

Karl’s recurving path brough the storm’s weaker left-hand side to within about 50 miles of Bermuda. Sustained winds topped out at a mere 29 mph Saturday morning at Bermuda International Airport, with gusts reaching 43 mph. Heavy rainbands doused the island, though, as the airport racked up more than 4” from Friday afternoon to Saturday morning.

Lisa is a tropical storm again
After decaying to tropical depression status late Friday, Tropical Storm Lisa got a new lease on life Saturday morning, regaining its tropical storm strength thanks to a burst of convection that developed atop its low-level center. Those storms have now weakened and blown eastward in strong wind shear of 30-40 knots, leaving the center again exposed (see satellite loop at bottom], so Lisa's resurgence will be brief. The NHC outlook brings Lisa's peak winds back below the tropical storm threshold by late Saturday afternoon, and Lisa should be a post-tropical low by Sunday or Monday.

Invest 94E off the Pacific coast of Mexico may develop
In the Eastern Pacific, satellite loops on Saturday morning showed that an area of low pressure located about 900 miles southwest of the southern tip of the Baja California Peninsula on Saturday morning (Invest 94E) was well-organized with plenty of heavy thunderstorm activity. One of our top three models for predicting hurricane genesis—the GFS model—predicted in its 00Z Saturday run that 94E would develop into a tropical storm or tropical depression over the weekend, and remain offshore of Mexico’s Baja Peninsula though the next five days. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave this system 2-day and 5-day development odds of 80% and 90%, respectively.


Figure 4. Enhanced satellite image of Typhoon Megi as of 1641Z (12:41 pm EDT) Saturday, September 24, 2016.

Typhoon Megi taking aim on Taiwan
The last thing Taiwan needs is another approaching typhoon, but that’s exactly what is on the table with intensifying Typhoon Megi. With sustained winds at 65 mph as of 12Z (8:00 am EDT) Saturday, Megi was already a large and well-structured typhoon, with excellent outflow at upper levels helping to nourish its growth. Located about 900 miles east-southeast of Taipei, Megi was heading west-northwest at about 16 mph.

Models are in unusually close agreement on Megi’s continuing a remarkably straight west-northwest course, which would bring it to the vicinity of Taiwan by late Tuesday local time. That will give Megi plenty of time to strengthen, with unusually warm sea-surface temperatures of 29-30°C (84-86°F), a moist atmosphere (relative humidities around 70-75%) and low wind shear of 5 - 15 knots expected along Megi’s path over the next couple of days. The Joint Typhoon Warning Center projects that Megi will approach Taiwan as a Category 3 typhoon, with peak winds of 120 mph. There is a distinct possibility that Megi could strengthen more than predicted. The 00Z Saturday runs of the GFS, European, and UKMET models all bring Megi across southern or central Taiwan. The island has already dealt with the close approaches of Super Typhoon Meranti just to its southwest (which killed two residents and left nearly a million without power) and Typhoon Malakas just to its northeast. Only a few weeks earlier, Typhoon Nepartak hit Taiwan on July 7 as a Category 4 super typhoon with top sustained winds of 150 mph. Taiwan averages 3 to 4 typhoon strikes per year, according to the Central Weather Bureau.

On its predicted course, Megi would make a second landfall along the coast of southeast China, not far south of where Meranti claimed at least 29 lives and caused at least $2.6 billion in damage.

We’ll be back with our next update by early Sunday afternoon.

Jeff Masters and Bob Henson


Figure 5. WU depiction of Joint Typhoon Warning Center track forecast for Tropical Storm Megi issued on Saturday morning, September 24, 2016.



Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

1001. SLU
Quoting 999. snowboy:



That corresponds to what I'm seeing on earth.nullschool.net


Yes is seems that a broad circulation has formed which explains the rolling motion already seen on visible imagery.
GFS Time.
1003. ProPoly
Quoting 995. washingtonian115:

HurricaneTracker App ‏@hurrtrackerapp 16m
Beyond 5 days, models are all over the place (this is normal)! It’s why you can’t trust them. Solutions range from Mexico to east of the US


It's also October and 5 days is at or beyond the predictive barrier for what a trough will be. That determines when this turns.
1004. Thrawst
Quoting 973. CybrTeddy:

Farewell Karl, the Cape Verde Hurricane that never was.




Did you expect anything else? ;)
1005. beell
Quoting 997. Barefootontherocks:

Wonder if "I'm not Lisa" might exert a slight northerly pull on 97L? They are interacting moisture-wise.
Today 9:15 a.m. cdt...

image credit: NOAA


They seem to be too far apart-over 1200 nm to affect path. But they are communicating through a skinny thread of a convergence/confluence line through the dust. Probably telling each other goodbye.
1006. SLU
000
NOUS42 KNHC 251518
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1115 AM EDT SUN 25 SEPTEMBER 2016
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 26/1100Z TO 27/1100Z SEPTEMBER 2016
TCPOD NUMBER.....19-122

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: PROBABLE LOW-LEVEL INVEST OF A
SYSTEM IN THE CENTRAL ATLANTIC NEAR 12.0N 54.5W FOR 27/1800Z.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.

$$
SEF
06z GFS ensembles still consistent on 97L going over Cuba, and into the Bahamas.
Quoting 1006. SLU:

000
NOUS42 KNHC 251518
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1115 AM EDT SUN 25 SEPTEMBER 2016
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 26/1100Z TO 27/1100Z SEPTEMBER 2016
TCPOD NUMBER.....19-122

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: PROBABLE LOW-LEVEL INVEST OF A
SYSTEM IN THE CENTRAL ATLANTIC NEAR 12.0N 54.5W FOR 27/1800Z.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.

$$
SEF
Think the center will pass between Grenada and st Vincent just south of Barbados
1009. CW7859
I know this is off topic, and nrtiwlnvragn mentioned it earlier but I wanted to expand on it. South Florida suffered a tragedy early this morning. Miami Marlins star pitcher Jose Fernandez died in a boating accident with 2 others this morning off Miami Beach. A boat he was a passenger in hit an unlit jetty, 2 people were ejected from the boat and one was found underneath the wreckage.

Jose was a Cuban born pitcher and a figure of hope for the Cuban community, and the Miami Marlins. Jose and Stanton were to be the pillars of the franchise going into the future. His family, fellow players and all of Miami have suffered a tragic loss today.

He leaves behind a pregnant girlfriend with a child that will never know a father. Thoughts and prayers go out to his family, friends and unborn child, and to the other 2 people that perished with him. RIP Jose, you will be missed.

97L has a very broad circulation, however it's low enough and generating enough convection in the NW quad to really help fight that dry air. It's hard for me to imagine a storm this far south going anywhere but Central America, but that's just in my opinion.

Quoting 1009. CW7859:

I know this is off topic, and nrtiwlnvragn mentioned it earlier but I wanted to expand on it. South Florida suffered a tragedy early this morning. Miami Marlins star pitcher Jose Fernandez died in a boating accident with 2 others this morning off Miami Beach. A boat he was a passenger in hit an unlit jetty, 2 people were ejected from the boat and one was found underneath the wreckage.

Jose was a Cuban born pitcher and a figure of hope for the Cuban community, and the Miami Marlins. Jose and Stanton were to be the pillars of the franchise going into the future. His family, fellow players and all of Miami have suffered a tragic loss today.

He leaves behind a pregnant girlfriend with a child that will never know a father. Thoughts and prayers go out to his family, friends and unborn child, and to the other 2 people that perished with him. RIP Jose, you will be missed.


Very sad RIP Jose
HurricaneTracker App @hurrtrackerapp 13m
Think Puerto Rico is “safe” at the moment and the Western Gulf. Could change, but this is what we see at this moment in time. #97L #Matthew
1013. CW7859
Quoting 1005. beell:



They seem to be too far apart-over 1200 nm to affect path. But they are communicating through a skinny thread of a convergence/confluence line through the dust. Probably telling each other goodbye.


I prefer to think Lisa and Matthew are holding hands while traversing the Atlantic together :)
1014. SLU
Quoting 1008. bupsin101:

Think the center will pass between Grenada and st Vincent just south of Barbados


Safe bet.
1015. SLU
The GFS has consistently shown that the circulation would be strong enough to make 97L a TD by 12Z Tuesday.

At the moment, invest 97L seems to be moving almost due west at about 280. Its circulation is broad, slowly organizing, but far too south. If this thing organizes enough before the islands I go with the easternmost solutions, but at the moment it seems the southernmost solutions are gaining the game. That could change, of course.
Quoting 1015. SLU:

The GFS has consistently shown that the circulation would be strong enough to make 97L a TD by 12Z Tuesday.


Looks a tad stronger in this run
1019. aquak9
"Lisa leh-ft yew....
Yeaers uh-goe..."
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1134 AM EDT SUN SEP 25 2016


Excerpts:

ENSEMBLES CONTINUE TO TREND TOWARD A MORE SLOWLY MOVING AND CLOSED
OFF UPPER LOW IN THE EAST THAT DIPS THROUGH THE CENTRAL
APPALACHIANS AND OUT THROUGH SOUTHERN NEW ENGLAND. THE SPREAD IN
SOLUTIONS RANGE FROM A MUCH WEAKER UPPER LOW LIFTING OUT QUICKLY
THROUGH NEW ENGLAND THU/FRI TO A COMPLETELY CLOSED OFF AND
ISOLATED UPPER LOW MAKING A CYCLONIC LOOP OVER THE SOUTHERN
APPALACHIANS. THE ECMWF/UKMET HAVE BEEN MOST AGGRESSIVE IN RECENT
RUNS IN A FARTHER SW AND ISOLATED CUTOFF LOW WHILE THE GFS HAS
BEEN MORE IN LINE WITH THE ENSEMBLES. THE CANADIAN AND ITS
ENSEMBLES WAS LATE TO COME IN LINE WITH THE GEFS AND ECMWF
ENSEMBLES BUT LIES CLOSE TO THE GFS IN ITS 00Z RUN. THOUGH THE
POSSIBILITY REMAINS FOR AN ECMWF/UKMET SOLUTION (THERE ARE ABOUT A
HALF DOZEN ECMWF ENSEMBLE MEMBERS THAT ARE TO THE SW OF THE ECMWF)
IT IS CONSIDERED A LOW PROBABILITY SOLUTION. JUST FOUR CYCLES AGO
THE ECMWF SHOWED NO SUCH CLOSED LOW AT ALL IN THE NORTHEAST FOR
LATER THIS WEEK. THE GFS HAS HAD BETTER CONTINUITY WITH THIS
SYSTEM (THOUGH FAR FROM PERFECT) THUS FAR BUT THAT DOES NOT
NECESSARILY MEAN IT WILL VERIFY BETTER IN FIVE DAYS. THE
AGREEABLE ENSEMBLE MEANS PROVIDE A GOOD POSITIONING FOR FUTURE
CHANGES TOWARD EITHER A DEEPER/MORE OR WEAKER/LESS CLOSED OFF
SOLUTION.

IN ADDITION, THE POTENTIAL DEVELOPMENT OF WHAT IS CURRENTLY AL97 (WELL EAST OF THE LESSER ANTILLES) IS STILL UNCERTAIN LATER THIS WEEK, THOUGH ITS POSITION BY NEXT SUNDAY PER THE ENSEMBLES WOULD LIKELY BE SOUTH OF THE GREATER ANTILLES.
1021. SLU
Quoting 1018. bupsin101:

Looks a tad stronger in this run


Yes it is. Now that there is an actual system the models should start to lock into a better solution.
I think GFS will be a little stronger earlier and will shift more west this run then this mornings run.
Quoting 1023. WeatherkidJoe2323:

I think GFS will be a little stronger earlier and will shift more west this run then this mornings run,
I am still amazed at the disagreement between the Operation and it's Ensembles.
Quoting 1024. Climate175:

I am still amazed at the disagreement between the Operation and it's ensembles.


It's still far out in time when they spread, I would trust ensembles on track but the Euro and GFS members differ, I think once this is past 50W the operationals and ensembles will come together with a clearer idea with more agreement.
HurricaneTracker App @hurrtrackerapp 2m
12Z GFS depicts #97L may become a depression before the islands. Not likely to be a strong system before the islands.
Sinking air doesn't look like it will be an issue for 97L:
1030. Gearsts
Quoting 1029. HurricaneFan:

Sinking air doesn't look like it will be an issue for 97L:



In fact this is one of the main reasons it has major Hurricane potential, so much rising motion, lack of sinking air, high tchp and low shear. I know why the models are so bullish
1033. JLPR2
HWRF develops it quickly into a strong system before reaching the islands, therefore it starts moving more WNW towards Guadeloupe and then turns west. But its west turn is due to interaction with a low or tropical storm to its south east which must likely wont happen, so yep. Might as well throw it out the window.

1034. Gearsts
hmm
12z GFS looking more like the ECMWF regarding the Ohio Valley and Northeast US pattern; slower moving low pressure and a cutoff forming. We'll see what it shows for 97L.
rip jose about ten yrs ago here at jetty park i was fishing on the pier and a boat crashed up on the rocks. the crew were sleeping coming in from the bahamas. the boat was on auto pilot.
HurricaneTracker App @hurrtrackerapp 45s
Here are the long term players. Cutoff low over the SE US may help to erode the W side of ridge over the W Atlantic, allowing a N turn…#97L
Afternoon all . Diffluent flow aloft is causing some seriously impressive looking wx over the NW Bahamas ..... lots of thunder and lightning over the western half of New Providence atm .... I'm hoping the power supply will remain uninterrupted, but...well, we'll see ...

So far no rain at my house.
Quoting 1032. Climate175:


The timing of the front and the strength will be interesting..
1043. CW7859
@ #1037 & 1034, at hour 132 it's down to 997mb and the trough over the SE is eating into the HP, seems to have pushed it east of the Bahamas already.

HurricaneTracker App @hurrtrackerapp 3m
If this verifies, it would be tough for #97L to track beyond 80/85W. Would mean a likely track east of FL. Still can change 7+ days out.
1045. JLPR2
Quoting 1042. Prouss:

Wow!



Exactly what I though, Jeez...
1046. Patrap




1047. Gearsts
The troll award for the day goes to...
Quoting 1042. Prouss:

Wow!



Agree.
Quoting 1047. Gearsts:

The troll award for the day goes to...
I hope your not referring to me, I am just posting all the interesting information from HurricaneTrackerApp.
1050. Gearsts
And the one who plus the comment.
1051. Xulonn
I know that cyclogenesis can take place on the ITCZ - a zone of rising tropical moisture. 97L is right on the ITCZ as can be seen on the Nullschool wind map.

So what is the relationship between the ITCZ and tropical cyclone development and strengthening. It seems that strong and big hurricanes break away from the ITCZ, and once they get started and are over warm ocean waters - barring dry air intrusion or shear ripping them apart - they create their own updrafts and don't need the rising air of the ITCZ for a "boost'".

Edit: I see that my comment posted immediately - does the blog comment lag problem seem to be under control?
1052. Grothar
Just a few GFS ensemble members







1053. Gearsts
Moving NW?
1054. Patrap
The ignore feature is wonderful.

🌞 🌎 🌚
Quoting 1044. Climate175:

HurricaneTracker App @hurrtrackerapp 3m
If this verifies, it would be tough for #97L to track beyond 80/85W. Would mean a likely track east of FL. Still can change 7+ days out.



We will have to wait and watch. The strength of any ridge or trough is hard to determine beyond 5 days.
Quoting 1030. Gearsts:



Don't you know all the things that have to work out right...in order to create it.
Awesome and beastly. I wish to admire from afar.
Quoting 1049. Climate175:

I hope your not referring to me, I am just posting all the interesting information from HurricaneTrackerApp.


No, it's related to an off topic comment.
1058. Gearsts
Quoting 1054. Patrap:

The ignore feature is wonderful.

🌞 🌎 🌚
Don't know how to use it.
1059. Xulonn
. Delete duplicate
1061. Grothar
GFS NOAA

1062. Gearsts
Moving north!
1063. JRRP7
Quoting 1053. Gearsts:

Moving NW?


a bit shift to the right
Quoting 1049. Climate175:

I hope your not referring to me, I am just posting all the interesting information from HurricaneTrackerApp.


I think he means 1040
Quoting 1053. Gearsts:

Moving NW?



Yup will probably miss U.S. on this run
1067. Gearsts
KoritheMan will hate this run on the gfs ;)
Quoting 1013. CW7859:



I prefer to think Lisa and Matthew are holding hands while traversing the Atlantic together :)
Not to worry. They are connected forever... "As the Water Vapor of the World Turns," they will meet again.
Wkcayman might or might not like the 12z gfs
Quoting 1066. wunderweatherman123:



Yup will probably miss U.S. on this run


dont be so sure, moving NNW now through 192
I wish people wouldn't post the ensembles when the newest run of the model is coming out as it confuses people.
The GFS just pulled a 180 on the Northeast/Ohio Valley pattern. 6z (top) vs. 12z (bottom).



1073. Patrap
The blog lag was du to rogue characters updating those Asian,Caribbean, summaries.


The issue is resolved.

🌎🌞


Look how much stronger the trough is on this run compared to the last few runs.
Quoting 1072. MAweatherboy1:

The GFS just pulled a 180 on the Northeast/Ohio Valley pattern. 6z (top) vs. 12z (bottom).






guess that will be the big question. if its there, OTS after hitting Cuba, if not then into the gulf
OTS on the GFS... because of a huge trough
ridge looks like it is building back in at 204 though as the system is moving across Cuba. OTS on this run is not a guarantee
Quoting 1077. wunderweatherman123:

OTS on the GFS... because of a huge trough


at 204 that trough is moving away and there is a ridge to the north
could this be other hurricane sandy like track?
1082. ProPoly
Quoting 1081. thetwilightzone:

could this be other hurricane sandy like track?


Trough at 8 days is speculative.
1083. JRRP7
CMC similar with GFS
at last

EP, 18, 2016092512, , BEST, 0, 152N, 1197W, 30, 1006, LO


seems like we been tracking 94E for weeks now
system might just move north though until it gets pulled NE by the next through
Sad story. Brings back memories of the Indians players killed in the boat crash roughly 20 years ago. Thoughts to the families.

Quoting 1009. CW7859:

I know this is off topic, and nrtiwlnvragn mentioned it earlier but I wanted to expand on it. South Florida suffered a tragedy early this morning. Miami Marlins star pitcher Jose Fernandez died in a boating accident with 2 others this morning off Miami Beach. A boat he was a passenger in hit an unlit jetty, 2 people were ejected from the boat and one was found underneath the wreckage.

Jose was a Cuban born pitcher and a figure of hope for the Cuban community, and the Miami Marlins. Jose and Stanton were to be the pillars of the franchise going into the future. His family, fellow players and all of Miami have suffered a tragic loss today.

He leaves behind a pregnant girlfriend with a child that will never know a father. Thoughts and prayers go out to his family, friends and unborn child, and to the other 2 people that perished with him. RIP Jose, you will be missed.


OTS for sure at 228 hours
what dos the GFS models show for shear for the area that 97L is going in
GFS 12z is starting to smell of Westward re curve into east coast of Florida
Yep, CMC agrees.
Quoting 1086. Hurricanes101:

system might just move north though until it gets pulled NE by the next through
Way too far out
Not too sure about buying the run for 12 GFS

We will have to see if this continues as a trend in the next few runs

A lot of variables
How fast storm moves
How strong the storm gets
The placement and intensity of the Atlantic high
The movements and intensity of the trofs
Among many other variables

I remember a few days ago GFS had shown this type of Northerly movement kinda out the Caribbean and into N Atlantic for a few runs then it quickly shifted back to what most of the runs shown track through the whole Caribbean and into GOM

This may be a similar case anyway as I said let's see what the next few runs indicate
1094. Grothar
Models and ensembles remind me of the guy who went to a psychiatrist and said, "Doc, I'm confused. One day I'm a teepee and the next day I'm a wigwam." The doctor answered, "the problem is you're two tents."
12Z UKMET maintains low rider.......





NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 72 HOURS
FORECAST POSITION AT T+ 72 : 12.8N 55.9W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 28.09.2016 72 12.8N 55.9W 1008 31
0000UTC 29.09.2016 84 13.2N 58.6W 1004 41
1200UTC 29.09.2016 96 12.7N 61.4W 1001 48
0000UTC 30.09.2016 108 12.3N 63.5W 991 58
1200UTC 30.09.2016 120 11.7N 64.5W 983 66
0000UTC 01.10.2016 132 11.7N 65.7W 985 61
1200UTC 01.10.2016 144 11.3N 66.5W 990 54
cmc identical to the gfs
Quoting 1090. isothunder67:

GFS 12z is starting to smell of Westward re curve into east coast of Florida



yea I am a big confused about how the GFS has it moving north into the high
Something tells me the later runs will have this totally missing the U.S.That has been the pattern these past few years and we saw that with Joaquin and Cristobal.They were both looking like threats to the U.S but a trough came and turned them away.
Quoting 1052. Grothar:

Just a few GFS ensemble members










Are we gonna get screwed with this one ? SE Florida
If this trend continues it will be interesting, been seeing a more Eastern shift now for a couple days. Nothing is set in stone and it can easily shift back to the west but looking good for the gulf coast.
1101. ackee
All I know once this system get in central carribbean it could go any where the track by The GfS storm like flora Hazel and Thoms comes to mind many area would have been affected here
1102. Grothar
Quoting 1099. toddbizz:



Are we gonna get screwed with this one ? SE Florida


No one knows. They are just different GFS ensemble members. They change from run to run.
Quoting 1090. isothunder67:

GFS 12z is starting to smell of Westward re curve into east coast of Florida



TWC talked about the that scenario this morning and now the has a major eastward shift.
Quoting 1100. masiello3:

If this trend continues it will be interesting, been seeing a more Eastern shift now for a couple days. Nothing is set in stone and it can easily shift back to the west but looking good for the gulf coast.


nice call, looking good for the Gulf Coast on a system that is over a week out that has not developed yet. Watch for trends, not run to run changes.
Also new run of the CMC is further S and W of previous run so far
Well that's a little more comforting for us here in Cayman than what the GFS was seeing last night.
Quoting 973. CybrTeddy:

Farewell Karl, the Cape Verde Hurricane that never was.


It was a somewhat boring tropical cyclone; It last for 11 days exactly, it weaken to a TD and never reach hurricane status.
models will get march better once the recon starts flying in too 97L in tell then we got too make do with what we got
12Z GFS does not make sense to me. Has the system moving north and then northeast into the high. There does not seem to be any steering present that would cause that movement.
1111. JRRP7
Quoting 1095. nrtiwlnvragn:

12Z UKMET maintains low rider.......





NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 72 HOURS
FORECAST POSITION AT T+ 72 : 12.8N 55.9W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 28.09.2016 72 12.8N 55.9W 1008 31
0000UTC 29.09.2016 84 13.2N 58.6W 1004 41
1200UTC 29.09.2016 96 12.7N 61.4W 1001 48
0000UTC 30.09.2016 108 12.3N 63.5W 991 58
1200UTC 30.09.2016 120 11.7N 64.5W 983 66
0000UTC 01.10.2016 132 11.7N 65.7W 985 61
1200UTC 01.10.2016 144 11.3N 66.5W 990 54


yea but at the end looks like will move NW

this is 00z run


am I wrong or does this set up have the storm moving back west towards FL-SC?
OTS. looks like the U.S. will escape another one. on this run...
Watched Levi's new video. Favors a southerly track entering the Caribbean with a strengthening hurricane heading into the central Carribean. He would not speculate track after that.
All these posts about missing the US and Baha is like Hello......
Looking like a Joaquin scenario all over again.
NVM, has it hugging the coast all the way up.
Quoting 1113. wunderweatherman123:

OTS. looks like the U.S. will escape another one. on this run...


the run makes no sense though. It is moving the system right into the base of the ridge with no influence of a trough.
Quoting 1100. masiello3:

If this trend continues it will be interesting, been seeing a more Eastern shift now for a couple days. Nothing is set in stone and it can easily shift back to the west but looking good for the gulf coast.


This is exactly what the GFS a few days ago for a few runs then it shifted back S and W maybe this is same thing and we could see it shift back on next run or run after
Quoting 1106. wunderkidcayman:

Also new run of the CMC is further S and W of previous run so far


Your buying the CMC but not the GFS?
we now wait for the 18z
Quoting 1037. Climate175:
HurricaneTracker App @hurrtrackerapp 45s
Here are the long term players. Cutoff low over the SE US may help to erode the W side of ridge over the W Atlantic, allowing a N turn…#97L
If that happens we could be looking at a east coast scraper- a potential nightmare
models keep shifting but at this moment, looks like OTS is the likely scenario. Note I said AT THIS MOMENT. Huge trough forecasted. wasn't there before
Quoting 1120. Bucsboltsfan:



Your buying the CMC but not the GFS?


I don't buy the GFS because it basically ignores the ridge. It has the system moving north and then NNE-NE right into the base of the ridge.
1125. Patrap
1126. aquak9
Quoting 1115. nrtiwlnvragn:
All these posts about missing the US and Baha is like Hello......


- - Is it me you're looking for? (Lionel Ritchie)
i think the 12z GFS is a out liner whats wait for the 18z and see if what we saw on the 12z is true or not
What can be certain is that we'll have a strengthening hurricane in the Caribbean next week, after that its just a bunch of speculation. The models can easily shift back west just as easily as they can shift more to the east. Environmental conditions are very tricky to predict and the stuff they show 7-10 days out is still well over the Pacific and a lot can change before it gets here.
This is as far as we should look out in time for track, to many variables and position of those variables will mean everything.

Quoting 1037. Climate175:

HurricaneTracker App @hurrtrackerapp 45s
Here are the long term players. Cutoff low over the SE US may help to erode the W side of ridge over the W Atlantic, allowing a N turn…#97L


That could be bad mmmkay
Quoting 1123. wunderweatherman123:

models keep shifting but at this moment, looks like OTS is the likely scenario. Note I said AT THIS MOMENT. Huge trough forecasted. wasn't there before


OTS is not the likely scenario it all so all ready hit land in many area so you guys can not call it a fish storm
1135. ackee
It will be interesting to see what the euro does once this system enter the carribbean we should have good idea what will happen
Quoting 1115. nrtiwlnvragn:

All these posts about missing the US and Baha is like Hello......


Haiti and Cuba would experience a horrible tragedy if the 12z GFS scenario occurred.
1137. Patrap


Quoting 934. Grothar:






Hmmmm, my Dad was a kid on the Narragansett bay in 1938, and I grew up hearing his stories, and seeing the "high water marks" around town when we visited my grandparents. Am guessing the map of that storm looked similar.

From up here in Vermont I am happy to see this is in fantasy land, as there are still plenty of folks around who remember the damage from '38 around here.
97L honestly has just about everything going for it to be a very strong hurricane. Very high oceanic heat content + SST's in the Caribbean, lack of dry air, positive MJO, low wind shear, and even a CCKW to aid in its development. If everything verifies like the models have been suggesting, I wouldn't be surprised to see this storm become the one to end the record-long Cat. 5 drought in the Atlantic...
I mean if you want more precision, wait for HH to get data from 97L, then incorporate it into models. Biggest question is that trough. How far it digs is key. It will be there but we don't know how strong
1141. Patrap
1142. aquak9
(... everybody.... is... ) -- not "are"
all so any one noted how cold things really starting too get looks like whats ever is lift of summer in joy it has it looks like the N states will be in for a cold snap


1144. JRRP7
1145. Patrap
Levi just said pattern over north America that far out is hard to predict. Throw in a hurricane in the caribbean and models have no clue what to do. Extreme low level of confidence after Day 5
Quoting 1132. thetwilightzone:



OTS is not the likely scenario it all so all ready hit land in many area so you guys can not call it a fish storm

I always wondered the minute a scenario that is the best case..ppl always assume that it is the scenario that is gunna happen...like I am just being honest but some people need to chill and just wait and stop being so stubborn on this.
Quoting 1143. thetwilightzone:

all so any one noted how cold things really starting too get looks like whats ever is lift of summer in joy it has it looks like the N states will be in for a cold snap





We have a possibility of this setup being similar to when Hurricane Wilma hit Florida.
The west side of Hurricane Wilma brought in the first cold front of the season to Florida. The front is also what turned Wilma to the NE and brought in the cool air to Florida after the storm passed.

It's still way too early to say, but it is one of many possibilities.
1149. ackee
Euro Saw It First All Other Model Seeing Some Turn Hati Jamaica and Cuba where that turn happen in the central carribbean will be key 4 days of model going back and forth
Quoting 1124. Hurricanes101:



I don't buy the GFS because it basically ignores the ridge. It has the system moving north and then NNE-NE right into the base of the ridge.

Single images of surface pressure can be very misleading, especially with a deep/well developed system. If you watch over time, that surface high is moving off to the east. In addition, in the mid-levels (around 500-700mb, there is a trough moving in from the west just to the northwest of the cyclone with the mid-level ridge further east of the cyclone; this causes the cyclone to move to the north. This site does a good job explaining we should look at the environmental mean flow vs. a single level: http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/pub ref/References/GUIDE/chap4/se100.htm.
The 12z GFS run is interesting - still a lot of uncertainty though. If it's 50-100 miles further southwest it could end up being pulled up the east coast of the US. Either way it's going to deliver some heavy rains to parts of the Lesser Antilles and Jamiaca - everything else is still too far out to know for sure yet.
https://youtu.be/uke3bLLqCk0


Levis link Tropical Tidbits....summary....someone's gonna get hit and we need to standby for Development once it passes the Lesser Antilles....
what will wind shear be like for the Caribbean, what do model show for the Caribbean, for WIND SHEAR in order too have a strong hurricane we need low wind shear


and what right this wind shear map can not be trusted has we found out with Karl it showed it had 5 too 10 kt of shear over it too where it should have showed it sould of had 30 too 40kt of shear all so once Karl got up to Bermuda it showed it was in 30 to 40kt of shear too where the storm look like it was in 5 too 10 kt of shear




so do you guys no where there a better wind shear map ? has the map above needs too be discontinued has it is not all ways 100% right and that wind shear map was way off on Karl
I didn't know who the baseball guy was until today.24 is young though but this is not the time/place to discuss this.
Quoting 1124. Hurricanes101:



I don't buy the GFS because it basically ignores the ridge. It has the system moving north and then NNE-NE right into the base of the ridge.


CMC is a hypster's dream model. It consistently over develops tropical farts into majors. Obviously, the sooner and stronger a model develops something in the north atlantic, the sooner the model will bias it north due to coriolis effect. This is so far out in time, with a lot of variables in play. We have almost one week before we know if it will even be a threat to the continental US.
Quoting 1097. Hurricanes101:



yea I am a big confused about how the GFS has it moving north into the high


I'm wondering myself anyway I'm calling it a dud run unless we could get some consistency with the runs from here on out (I doubt that however)



Quoting 1100. masiello3:

If this trend continues it will be interesting, been seeing a more Eastern shift now for a couple days. Nothing is set in stone and it can easily shift back to the west but looking good for the gulf coast.


I doubt it will GFS done this same thing a few days ago for a few runs then shifted back S and W and continued to be consistent with that till now

Quoting 1107. Supposetobefishin:

Well that's a little more comforting for us here in Cayman than what the GFS was seeing last night.


Don't relax just yet this could easily change back on the next run

Quoting 1109. thetwilightzone:

models will get march better once the recon starts flying in too 97L in tell then we got too make do with what we got


Yes indeed first flight expected Tues 27 at 18Z

Quoting 1110. Hurricanes101:

12Z GFS does not make sense to me. Has the system moving north and then northeast into the high. There does not seem to be any steering present that would cause that movement.


I'm not buying this 12Z run

Quoting 1111. JRRP7:


yea but at the end looks like will move NW

this is 00z run


Where do you see any NW movement in the latest run

Quoting 1120. Bucsboltsfan:



Your buying the CMC but not the GFS?


I didn't say or suggest any such thing I'm just simply noting that the 00Z vs 12Z run and that it is further S and W of the previous run so far that's all

Quoting 1124. Hurricanes101:



I don't buy the GFS because it basically ignores the ridge. It has the system moving north and then NNE-NE right into the base of the ridge.


I don't think this will trend nor do I think it will happen

1157. SLU
Quoting 1098. washingtonian115:

Something tells me the later runs will have this totally missing the U.S.That has been the pattern these past few years and we saw that with Joaquin and Cristobal.They were both looking like threats to the U.S but a trough came and turned them away.


Maybe that unexpected trough HAARPens to be the east coast hurricane deflector? :) ;)

1158. JRRP7
Seeing the potential set up, this is my greatest fear. But still way too far out in time. Bears watching and by this Friday we should know if a GOM threat, east coast threat or OTS.

Quoting 1112. masiello3:



am I wrong or does this set up have the storm moving back west towards FL-SC?
Here's the blocking pattern that was setup during Hurricane Wilma. The front dropped down across the GOM and it eventually merged with Wilma over Florida.
The CMC a few days ago showed 97L going out to sea and a low developing by Panama lifting north and blowing up south of Cuba, headed for the Gulf. Anything is possible with these long computer runs and conditions will change rapidly. Anything now more than 3 days out is only entertainment.
I got that same feeling about 97L as I did Hermine, I feel we have a Hurricane heading our way, I am thinking somewhere along the gulf coast
Quoting 1113. wunderweatherman123:

OTS. looks like the U.S. will escape another one. on this run...


Even to say "looks like" is an reckless error at the 240 hour mark on any model run. That should be regarded simply as 'potential' 10 days out. This will play out very different than any of these models show past 124 hours. You have until next Sat before you know if the US is at risk and then with 500 miles worth of forecast track error.
Quoting 1146. wunderweatherman123:

Levi just said pattern over north America that far out is hard to predict. Throw in a hurricane in the caribbean and models have no clue what to do. Extreme low level of confidence after Day 5


Yes a lot of factors, very important that the turn north models show is beyond 7 days. I believe the west Caribbean and eastern gulf is the most likely path, just hope not though.
1168. ackee
97L looking best it has so for convection increasing I give this thing about Tuesday or Wednesday when we should have better idea which are be impacted
1169. SLU
Far more realistic run from the HWRF




Yesterday the GFS had the system going into Mexico. Today it has the system moving north through the Bahamas and into the north Atlantic.

There hasn't been any consistency from run to run. We need at least a couple days of consistent runs to build confidence.

I wouldn't trust the current run at all.
Big difference in the 12z GFS is the position of the cut-off low predicted to develop over the Mid-Atlantic and Ohio Valley. 06z GFS shows the cut-off low dissipating, whereas the 12z GFS shows the low sticking around over VA/NC and causing 97L to recurve. While this is a clear trend to the 00z ECMWF, I'll point out that the 00z EPS disagreed with the ECMWF and showed the low dissipating and being replaced by solid ridging. Highly, highly uncertain forecast setting up. The idea here is that we need to wait and see. Right now the only thing I have some confidence in is 97L developing into a tropical depression by Tuesday.
1172. Patrap
Its the same song and dance.



HH flights,plus G4 sniffs and the global hawk drone as well.....will so!ute out a good track downstream in time.



Have a nice cold Fresca and enjoy your Sunday.








Ok we keep things the way they are no shifts out of the Caribbean yet for now we keeps eyes on the models over next few days see if it's trending (which I doubt but we will see) keep eyes on the system we wait till recon flight on Tues by the time system nears SE Caribbean we should get a better idea on what it will do

1174. JRRP7
Well I don't know about all the conspiracy stuff but I do know that the pattern over the last few years has favored recurvature away from the U.S. when a hurricane has threatened.
Quoting 1166. stormwatcherCI:

It is also not about teaching proper English. It IS about tropical weather so please let's stick to that instead of trying to correct everyone's written or spoken word. Thank you.


Yes, and a lot of people don't realize that English is a second language to many of the blog members. So I don't understand why anyone would criticize someone for using improper spelling in a weather blog?
We finally have a lot of action in the tropics and we're discussing crime in Miami and spelling errors.

Back to the weather.
I will be very interested to see if the 12Z Euro continues to show a similar path to the 12Z GFS. I thought the Euro was out to lunch, but now I'm not so sure.
I believe the models will shift back to the west with time, but that's assuming the system stays weaker than forecast in the eastern Caribbean.
Quoting 1171. CybrTeddy:

Big difference in the 12z GFS is the position of the ULL predicted to develop over the Mid-Atlantic and Ohio Valley. 06z GFS shows the ULL dissipating, whereas the 12z GFS shows the low sticking around over VA/NC and causing 97L to recurve. While this is a clear trend to the 00z ECMWF, I'll point out that the 00z EPS disagreed with the ECMWF and showed the low dissipating and being replaced by solid ridging. Highly, highly uncertain forecast setting up. The idea here is that we need to wait and see. Right now the only thing I have some confidence in is 97L developing into a tropical depression by Tuesday.
And moving into the Caribbean. The position and strength of that ULL will be the key to the forecast track after 5 days.
1180. Grothar
Quoting 1146. wunderweatherman123:

Levi just said pattern over north America that far out is hard to predict. Throw in a hurricane in the caribbean and models have no clue what to do. Extreme low level of confidence after Day 5


Awesome!
The present invest is too far, too low in latitude; moreover, it has a broad circulation and is a fast mover. Hence, the higher probability is for it to cross the Antilles at a low latitude (> 75 % to me) and continues that way to CA (50 % to me). That if it do not have a serious evolution in strength in the next 24 hours.
Quoting 1174. JRRP7:


ah yes the HWRF, what a reliable model LOL
Choose Your Own Adventure: Tropical Series
Written By: GFS Ensembles



From the Yucatan to New England, the GFS Ensembles can fit your wishcasting desires.
1184. SLU
1185. Gearsts
Shifted east and some even between PR and DR.
Why is anyone showing the HWRF, it always blows up storms way past where they'll be way to early. If i remember correctly, it showed Hermine as a Cat 5 storm slamming into Florida two days out.
Quoting 1184. SLU:


This is a joke
Quoting 1185. Gearsts:

Shifted east and some even between PR and DR.



Showing a disagreement with the operational run too. The cut-off low weakens and starts to move out by 120 hours.

1189. SLU
I've never seen the eye of a hurricane over an island in the Windwards in my lifetime.

The HWRF has been the laughing stock over on the Atlantic side.It also blew up Karl and had the storm smacking Bermuda as a cat 4.
30/90
1192. pottery
Quoting 1184. SLU:



EXcuse me ?????
I think I'll delete that !

In the meantime, loud grumblings from just north of my house, with flashing bolts of electricity.
And I'm about to go there, in a few minutes.
Oh well, I'll take my Parasol......
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SUN SEP 25 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center has issued the last advisory on
Post-Tropical Storm Karl, located several hundred miles south-
southeast of Cape Race, Newfoundland.

Showers and thunderstorms associated with a low pressure area about
1500 miles east-southeast of the Windward Islands are showing some
signs of organization. Environmental conditions are expected to be
conducive for gradual development, and a tropical depression is
likely to form later this week while the low moves westward to west-
northwestward at 15 to 20 mph. Interests in the Windward Islands,
the southeastern and south-central Caribbean Sea, as well as the
northern coast of South America, should monitor the progress of this
system.
* Formation chance through 48 hours...low...30 percent
* Formation chance through 5 days...high...90 percent



when was the last time we saw 90% for day five ?
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SUN SEP 25 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center has issued the last advisory on
Post-Tropical Storm Karl, located several hundred miles south-
southeast of Cape Race, Newfoundland.

Showers and thunderstorms associated with a low pressure area about
1500 miles east-southeast of the Windward Islands are showing some
signs of organization. Environmental conditions are expected to be
conducive for gradual development, and a tropical depression is
likely to form later this week while the low moves westward to west-
northwestward at 15 to 20 mph. Interests in the Windward Islands,
the southeastern and south-central Caribbean Sea, as well as the
northern coast of South America, should monitor the progress of this
system.
* Formation chance through 48 hours...low...30 percent
* Formation chance through 5 days...high...90 percent

$$
Forecaster Kimberlain
1195. pottery
Quoting 1189. SLU:

I've never seen the eye of a hurricane over an island in the Windwards in my lifetime.



Ivan ?. Grenada ?
1196. SLU
Quoting 1192. pottery:


EXcuse me ?????
I think I'll delete that !

In the meantime, loud grumblings from just north of my house, with flashing bolts of electricity.
And I'm about to go there, in a few minutes.
Oh well, I'll take my Parasol......


That's a big storm there pottery.
Quoting 1177. washingtonian115:

Well I don't know about all the conspiracy stuff but I do know that the pattern over the last few years has favored recurvature away from the U.S. when a hurricane has threatened.


The re-curve just to the east of the U.S. is the most favored path for tropical systems. That's just the way it is. The U.S. is lucky that this is the general pattern and the majority of tropical systems miss the U.S.
Probability of a Hurricane. You can see it follows the classic pattern of storms curving just off the East Coast of the U.S.

1198. JRRP7
WNW
looks like 97L has slow down a bit


NHC upped 97L 30/90%

Cone shift W

1. Showers and thunderstorms associated with a low pressure area about
1500 miles east-southeast of the Windward Islands are showing some
signs of organization. Environmental conditions are expected to be
conducive for gradual development, and a tropical depression is
likely to form later this week while the low moves westward to west-
northwestward at 15 to 20 mph. Interests in the Windward Islands,
the southeastern and south-central Caribbean Sea, as well as the
northern coast of South America, should monitor the progress of this
system.
* Formation chance through 48 hours...low...30 percent
* Formation chance through 5 days...high...90 percent

Forecaster Kimberlain

No doubt we should have a TC this week.
JeffMasters has created a new entry.
Quoting 1067. Gearsts:

KoritheMan will hate this run on the gfs ;)


WKC too.
1204. pottery
Quoting 1196. SLU:



That's a big storm there pottery.

Here in Central T&T, still as a Tomb, Humid as steam, Hot and Dread.
Not very nice.
1205. ackee
90/30 from the Nhc this far looks like recon could check out 97L very early I do agree with levi the only area seem sure be impact windward island south American beyond those area huge guess game by the models
We have 30/90 chances at 2pm update
1207. Gearsts
Quoting 1200. wunderkidcayman:

NHC upped 97L 30/90%

Cone shift W
I need to see a cone comparison!
Quoting 1189. SLU:

I've never seen the eye of a hurricane over an island in the Windwards in my lifetime.


Looks like it goes over the smaller islands of St. Vincent and the Grenadines.
97L is going too be a big big storm


look at the sizes of it


Quoting 1181. juracanpr1:

The present invest is too far, too low in latitude; moreover, it has a broad circulation and is a fast mover. Hence, the higher probability is for it to cross the Antilles at a low latitude (> 75 % to me) and continues that way to CA (50 % to me). That if it do not have a serious evolution in strength in the next 24 hours.
I really believe that Central America is out of the woods unless it stays weak which is not happening as its gathering strength as we speak. I feel that Cuba, Jamaica, Cayman Islands and Hispañola are the more at risk. Will see though but if it goes into Central Ameria I will be happy :)
Quoting 1189. SLU:

I've never seen the eye of a hurricane over an island in the Windwards in my lifetime.


I remember that day Ivan Grenada 2004, scary hurricane.
1212. kwad
Since the center of 97L is at about 8.5N and thunderstorm is developing north of it, between 10N and 15N, how huge will be this system when its center is above 10N

Quoting 1169. SLU:

Far more realistic run from the HWRF







This run make more sense to me, I don't think it will be so far south
might reach 15 degrees north when it reaches the lesserAntilles
and a strong tropical storm intensifying
New data for 97L out (18z)

Models shifted S and W more or less