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Tropical Hurricane Dorian

I always like to frame tropical threats as having the ball on the court. Need a system in the deep southwestern Atlantic to be a threat because once west of 75W it has to move east to miss. Of course that happens more often than not but without the ball on the court then it is never a threat.

This one looks like it has potential to be a threat.
 
I always like to frame tropical threats as having the ball on the court. Need a system in the deep southwestern Atlantic to be a threat because once west of 75W it has to move east to miss. Of course that happens more often than not but without the ball on the court then it is never a threat.

This one looks like it has potential to be a threat.
Yup...this might be a scary one....
 
Yup...this might be a scary one....

Well scary is relative. Florence was scary early because of the projected cat 4 landfall. In the end she made level in a much tamer and not with any really special strength. What made her scary was the stall and 40 inch rainfall totals. This one could be a sheared out mess by the time it gets far enough west to be a concern.
 
Well scary is relative. Florence was scary early because of the projected cat 4 landfall. In the end she made level in a much tamer and not with any really special strength. What made her scary was the stall and 40 inch rainfall totals. This one could be a sheared out mess by the time it gets far enough west to be a concern.
I don't like either scenario...lol.....NHC didn't dance around this one.
 
How’s the pattern right now for the track? I know at this point we can’t tell where it will make landfall but we can look at the steering currents to consider some possible scenarios.
 
How’s the pattern right now for the track? I know at this point we can’t tell where it will make landfall but we can look at the steering currents to consider some possible scenarios.

Anything from the eastern Caribbean to just north of Puerto Rico/Hispaniola is fair game. The longwave pattern w/ a ridge over Atlantic Canada and a trough near to just west of the Lakes usually leads to east coast hits or far western Atlantic/last second recurves but that actually assumes we'd have a storm to begin with and it stays far enough to the north of the Greater Antilles. A track through the central Caribbean graveyard at an intensity of anything less than a bonafide major hurricane usually spells the end of small storms like this except in/around October when the low-level trade wind divergence reaches its climatological minimum. (Matthew (2016) for ex))
 
The visible loop is very impressive this morning w/ 99L, thanks to its position in the ITCZ & a CCKW it has a huge envelope of westerly winds to the south, so it won't have much issue closing off a low-level center if one were to form in the next 48 hours.

It looks like it's trying to close off very quickly. Would you be surprised to see it in a cherry state of potential by 8pm tonight if this level of organization maintains? I wouldn't
 
It looks like it's trying to close off very quickly. Would you be surprised to see it in a cherry state of potential by 8pm tonight if this level of organization maintains? I wouldn't

Recent ASCAT pass did show a closed yet broad/elongated low-mid level low so this has some work to do but I could see it becoming a tropical cyclone as early as later tonight or tomorrow morning.

GOES16_1km_vis_201908231335_3.75_17.25_-51.50_-32.25_vis1_ltng16_hgwy_warn_ascata_ascatb_weath...png
 
This one is rather unique in it being projected to move at no more than about 3 degrees west in longitude per day in its WNW averaged track. For the current position (central MDR) in late August, that is unusually slow. I’d say that an average late August to early Sep WNW TC track in that area is probably close to double that or about 5-6 degrees west per day while moving WNW. Look back at historical storm tracks to verify. I’d say that a slow WNW central MDR movement like this is closer to the average much later in the season, say, in early Oct. when things tend to slow down on average in that area. If I get time, I’ll look at old maps to see if I can find slower late August movers in this area and see what they ultimately did.
Any thoughts about this?
 
Obviously shear will play a factor but there is no worries for this one when it comes to warm water
sea-temperature.png
 
Recent microwave pass just reaffirms what we saw earlier with ascat. This invest is already on the doorstep of becoming a tropical depression. Typically you see banding features like this on microwave with tropical cyclones only or invests that are about to become one.
Tbh I think at the rate we’re going, we will see this become tropical depression five sometime early-mid day tomorrow unless 98L miraculously beats 99L to the punch. Obviously I could be wrong for reasons related to semi-subjective forecaster analyses at the nhc and small systems like this are hard to forecast.
We shall see what happens but at least we have something to track and keep ourselves temporarily preoccupied while we wait for winter to approach.

05753286-53FC-43AE-9EA0-34F1D0557C96.png
 
Lol GFS runs it into central America, what's left heading for the Pacific....
 
This one is rather unique in it being projected to move at no more than about 3 degrees west in longitude per day in its WNW averaged track. For the current position (central MDR) in late August, that is unusually slow. I’d say that an average late August to early Sep WNW TC track in that area is probably close to double that or about 5-6 degrees west per day while moving WNW. Look back at historical storm tracks to verify. I’d say that a slow WNW central MDR movement like this is closer to the average much later in the season, say, in early Oct. when things tend to slow down on average in that area. If I get time, I’ll look at old maps to see if I can find slower late August movers in this area and see what they ultimately did.
Any thoughts about this?
Larry, what’s actually happening at least in the near term to cause this slightly more northerly track is beta advection from when invest 99L’s vorticity rolls up and detaches from the ITCZ. Thereafter, the ridge axis is pretty far to the north and it’s slow forward movement also means this NW tug provided by beta advection, even after 99L has become its own entity separate from the ITCZ, constitutes a proportionately larger steering influence on the system. Oth, there’s a cut-off upper level trough forecast to slice the azores Bermuda high in half in the medium range, if 99L is strong enough to feel that weakness or its LLC forms further north that makes a solution towards PR and the northern Antilles more likely and vis versa.
 
Code ORANGE

Recent satellite wind data indicate that a low pressure area has
formed in association with a tropical wave located about 1300
miles east-southeast of the Windward Islands. Additional
development of this system is possible during the next few days, and
a tropical depression could form late this weekend or early next
week as it moves generally westward to west-northwestward near 15
mph.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.
 
Code ORANGE

Recent satellite wind data indicate that a low pressure area has
formed in association with a tropical wave located about 1300
miles east-southeast of the Windward Islands. Additional
development of this system is possible during the next few days, and
a tropical depression could form late this weekend or early next
week as it moves generally westward to west-northwestward near 15
mph.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.

Lol they're playing catch up likely don't wanna immediately jump from nothing to high risk of genesis in 12 hours.
 
Looks like the 12z GFS op run into Cen. America was an outlier, only a handful of EPS members develop this and GEFS runs it over all the islands (with exception of a couple), only see one that gets it to H strength and as you can see it goes north of all the islands... I think once it develops and where that center is (how far N) models might get a better handle,

1566591391557.png
1566591400056.png
 
Looks like the 12z GFS op run into Cen. America was an outlier, only a handful of EPS members develop this and GEFS runs it over all the islands (with exception of a couple), only see one that gets it to H strength and as you can see it goes north of all the islands... I think once it develops and where that center is (how far N) models might get a better handle,

View attachment 21884
View attachment 21885
If it cuts across PR, Hispaniola, it's dead; if south, then watch out for something unkind; if north, the fish will have fun ...
 
If it cuts across PR, Hispaniola, it's dead; if south, then watch out for something unkind; if north, the fish will have fun ...

Anything’s possible nowadays. Just look at Florence’s track.


Sent from my iPhone using Tapatalk
 
Anything’s possible nowadays. Just look at Florence’s track.


Sent from my iPhone using Tapatalk
Florence was an exception as it was in the process of trying to recurve but was sent further west due to a high pressure in the right place at the right time from what I can remember. There are other storms that were as well. It's best to think about the setup and look at what we are coming up to. I'd be worried about having a high in place anywhere between Bermuda and the east coast when the low is past Hispaniola, then the US would be at risk if the storm is strong. All it has to do is skirt the islands like Irma or stay just south of them to avoid being shredded and make it to the Gulf and there will be trouble. Of course it could always recurve or get shredded. It's safe to go with climo on this one since it's in a very climo-like position.
 
Florence was an exception as it was in the process of trying to recurve but was sent further west due to a high pressure in the right place at the right time from what I can remember. There are other storms that were as well. It's best to think about the setup and look at what we are coming up to. I'd be worried about having a high in place anywhere between Bermuda and the east coast when the low is past Hispaniola, then the US would be at risk if the storm is strong. All it has to do is skirt the islands like Irma or stay just south of them to avoid being shredded and make it to the Gulf and there will be trouble. Of course it could always recurve or get shredded. It's safe to go with climo on this one since it's in a very climo-like position.
100%
May I humbly add ... despite the fact that each storm is different, and they sometimes seem to have a mind of their own, the best (not only and certaintly not deciding, but the best) factors to look at and combine 4, 5, 6, 7, 8 days out are sheer and steering currents (and also what's up top to the NW can't be ignored) ... seems obvious but seems many overlook them in favor of what past storms did ... just sayin' ... :cool:
 
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GFS makes landfall off the coast of Mexico at the end of the run. Boarder line hurricane, much stronger than 12z.
 
60/70 chance for this system to now develop.

Satellite imagery suggests that the circulation associated with an
area of low pressure located about 1100 miles east-southeast of
the Windward Islands has become better defined, but the thunderstorm
activity is limited at this time. Environmental conditions appear
conducive for additional development, and a tropical depression is

likely to form over the weekend or early next week while it moves
generally westward to west-northwestward near 15 mph.


* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...70 percent.30EFE58D-6582-4809-9C80-4659472D3EF3.png
 
It's been a while since SC/NC has had a major hurricane interaction, aside from Florence which was a particularly rare occurrence.
 
ALRIGHT LET PLAY THIS AGAIN.. HERE IS MY FORCASTED TRACK OF INVEST 99L. THIS IS FOR INTERTAINMENT PURPOSES ONLY AND NOT ANYKIND OF OFFICIAL FORCAST.. THIS

Capture.JPG
 
ALRIGHT LET PLAY THIS AGAIN.. HERE IS MY FORCASTED TRACK OF INVEST 99L. THIS IS FOR INTERTAINMENT PURPOSES ONLY AND NOT ANYKIND OF OFFICIAL FORCAST.. THIS

View attachment 21898
I’m tired of watching these storms form and in no way give me rain! Kind of like afternoon thundershowers
 
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