2018 Atlantic Hurricane Season

[AfewUniversesBelowNormal]

[Boston Bulldog]

We now have Subtropical Storm Debby in the North Atlantic. Should dissipate soon.

[yoda]

2 hours ago, Boston Bulldog said:

We now have Subtropical Storm Debby in the North Atlantic. Should dissipate soon.

Subtropical Storm Debby Discussion Number   1
NWS National Hurricane Center Miami FL       AL042018
1100 AM AST Tue Aug 07 2018

The non-tropical low that NHC has been tracking over the North
Atlantic for the past few days has developed subtropical
characteristics and has been upgraded to subtropical storm status.
The tropical-storm-force winds associated with Debby are well
removed from the center as indicated by a recent ASCAT pass and are
occurring within a cyclonically curved band of moderate convection.
Although transition to a tropical cyclone is possible, no
significant strengthening is anticipated since the cyclone will soon
be moving over cool water and become fully embedded within a larger
mid-latitude trough approaching from the west. Debby is expected to
dissipate in about 48 hours or earlier.

The best estimate of the initial motion is toward the north or 355
degrees at 14 kt. The subtropical storm should continue on this
general track with a decrease in forward speed for the next 24
hours or so and then turn to the northeast ahead of the trough,
which will eventually absorb Debby.

FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 38.9N  48.5W   35 KT  40 MPH
 12H  08/0000Z 41.0N  48.5W   35 KT  40 MPH
 24H  08/1200Z 42.7N  48.5W   35 KT  40 MPH
 36H  09/0000Z 44.0N  47.0W   30 KT  35 MPH
 48H  09/1200Z...DISSIPATED

$$
Forecaster Avila

 

[yoda]

Maybe something (i.e. weak crap) in the mid-Atlantic developing next week?

 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Fri Aug 10 2018

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

1. An area of disturbed weather is located about midway between Africa
and the Lesser Antilles. Strong upper-level winds are likely to
limit development of this system for the next day or two, but some
gradual development is possible after that time while the system
moves slowly westward through early next week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

2. A non-tropical area of low pressure is forecast to form over the
central Atlantic in a few days. The low could gradually acquire
subtropical or tropical characteristics while moving slowly
northeastward for couple of days thereafter.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

Forecaster Zelinsky

[yoda]

Hooray... looks like another STS will be appearing in the North Central Atlantic later today per the 2am TWO from the NHC... should only be around for a few days though

[yoda]

Just now, WxWatcher007 said:

lol @ all these subtropical systems this season. 

STS Ernesto has appeared lol

[USCAPEWEATHERAF]

Invest 99L is born.

[Windspeed]

Positioning of the Azores High and the easterly jet is absolutely in no way conducive for healthy waves and the ITCZ much less tropical cyclone development right now. Anything that could or would consolidate in the MDR is only going to have gaps of very limited developmental time surrounded by hostile atmospheric conditions. As things are going, we're likely going to be waiting until mid-late September, perhaps even early October, for any substantial activity originating from the MDR this season. However, we still may have opportunities for development near the Bahamas, the western Caribbean and Gulf of Mexico with possible interactions of hanging stationary frontal boundaries and weak-to-moderate tropical waves. That would be an issue of timing though. Remember, it only takes one surface low in the right position to make for a memorable event. But at least for now or until a significant pattern shift, I'm not very keen on significant MDR development in 2018 with the current pattern that is in place.

 

 

 

 

 

 

[Climate175]

On 8/15/2018 at 10:59 AM, WxWatcher007 said:

lol @ all these subtropical systems this season. 

4 of the last 5 storms were subtropical at one point.

[Jonger]

The system over Nebraska is more interesting than anything in the Atlantic.... and it's August 19th.

[bigtenfan]

11 hours ago, Jonger said:

The system over Nebraska is more interesting than anything in the Atlantic.... and it's August 19th.

Taking it a bit further the entire 384 GFS run which takes us to Sept 5 shows very little if any threats. Even the African wave train going forward through the 384 run looks pretty quiet for this time of the year

[MJO812]

What a dud this season is turning out to be.

[nycwinter]

2 hours ago, Snow88 said:

What a dud this season is turning out to be.

the action is in the pacific whether lane will impact hawaii..

[bigtenfan]

7 hours ago, Snow88 said:

What a dud this season is turning out to be.

After last season as a Florida home owner I have no complaints about that.

[shaggy]

On 8/20/2018 at 7:51 PM, WxWatcher007 said:

It's wayyyy too early to close the shades on the season. Bearish? Sure. Calling dud before we even hit the peak of the season? Let's hold off on that lol. 

Sure its early to call it a dud but we don't even have any fantasy storms to track. Conditions just aren't favorable at this time. All we've had is mid latitude sub tropical garbage with the exception of chris.

[nycwinter]

On 8/20/2018 at 11:29 AM, Snow88 said:

What a dud this season is turning out to be.

in late august 1992 we did not have our first named storm of the season until andrew came along .. it only takes one huge storm to make a season..

[Windspeed]

The Atlantic has been quiet and the MDR virtually dead so far, however, the MJO is forecast to head into phases 8-1 and potentially enhancing convection over the GOM, Caribbean and portions of the Atlantic in a few weeks. Granted, you still need cooperative Azores ridging and easterlies without a suppressed regime into the ITCZ to get an increase in activity out of the MDR. But favorable MJO phases could lead to a little fireworks from mid September into early October. Models will probably flip-flop for another week but it's at least something to keep an eye on as there is little else.

 

The ECMWF weeklies hint at a cooler pattern in the SE CONUS with some fronts that manage to swing through, becoming stationary boundaries over Florida, the Bahamas and W. Caribbean. Definitely could lead to some development closer to home out of any persistent surface troughs with a favorable phase in place. The models are also starting to suggest some stronger easterly waves in the coming week, even closing one off into a TC before moving into the central Atl., though showing little support beyond initial development. As things stand, I am not yet confident that the atmosphere over the MDR will be all that favorable by September 10th. But even if it is not, remember, as the previous poster mentioned Andrew, that was also a Cape Verde system that managed to survive a similarly unfavorable MDR and hostile upper level environment. Andrew held together and snuck under a favorable extended W. Atantic ridge, being in the right place at the right time; the rest is history.

[hawkeye_wx]

The euro continues to try to develop something in the Bahamas/Gulf early next week.

[Windspeed]

GFS continues to be very bullish with a Cape Verde hurricane turning up into the central Atlantic and becoming a major hurricane. ECMWF has also been consistent with the same TC moving into the central Atlantic, but much weaker and traversing a less favorable upper level environment. I think we probably do end up getting our first long-tracking TC out of the MDR, but the GFS is being way too favorable and overdoing intensity. Whether a hurricane or struggling tropical storm, at least we'll have something to track.

 

 

[Windspeed]

12z ECMWF follows 0z and forms Gordon in eastern GOM and then crawls across the NW GOM coastal plain. Boy track position is going to be super critical if that resolves. Though not substantially deep, upper layer SSTs are running 29-31°C right on the coast. 200 miles north or south could be the difference between a coastal flooder or a Cat 3.

[shaggy]

Models hunting at some development soon. Fv3 most aggressive.

[NavarreDon]

 

Up to 40% 2 day & 70% 5 day.

 

 

.

 

[LongBeachSurfFreak]

I guess no one cares about leslie, one of the most prolific swell generators of all time. The entire western Atlantic has had swell for over a week already with more to come

[KPITSnow]

1 hour ago, LongBeachSurfFreak said:

I guess no one cares about leslie, one of the most prolific swell generators of all time. The entire western Atlantic has had swell for over a week already with more to come

I know it is over a week away, but is Leslie going to make landfall in west Africa eventually? I’d have to think that would be an all time rare occurrence. 

[MNstorms]

5 hours ago, KPITSnow said:

I know it is over a week away, but is Leslie going to make landfall in west Africa eventually? I’d have to think that would be an all time rare occurrence. 

It's happened once. Tropical Storm Delta in 2005.

[hawkeye_wx]

I've been casually paying attention to Leslie.  However, I didn't realize until now that it might be snaking around the Atlantic for another 10 days.  That's pretty nuts.

[bugalou]

Several of the models for Leslie are trying to turn her westward again towards the week's end.  Even if it doesn't its going to be interesting to see a Sahara or Portugal landfall, or if it manages to sneak into the Mediterranean!

[bugalou]

Wow! most of the models have now fallen in line to Leslie making a U turn and heading back west!  This is going to further extend a lifespan that was already impressive.  Michael is going to wreck havoc on the NE gulf coast, but man, Leslie has been one of the most interesting storms I have seen in a while.  It will be interesting to continue to watch the evolution of this system.

[yoda]

Leslie be like I don't know where I want to go just yet... please wait while I decide from the HUGE spread... even Blake is tired of Leslie lol

Hurricane Leslie Discussion Number  55
NWS National Hurricane Center Miami FL       AL132018
1100 PM AST Tue Oct 09 2018

Satellite and microwave data indicate that Leslie has become a
hurricane again, almost exactly a week after it did the first time.
A WindSat pass from earlier today showed the development of an eye
feature, and with the Dvorak estimates from TAFB and SAB at
hurricane strength, the initial wind speed is set to 65 kt.  The
latest GOES-16 proxy visible imagery suggests that a ragged eye has
formed, although the eyewall is open on the southwestern side.

Leslie is atypically intensifying while moving south-southeastward
at 8 kt.  The hurricane should continue to lose latitude for a day
or so then get accelerated east-northeastward by a mid-latitude
trough until Friday.  After that time, there is a ginormous spread
in the model ensembles with Leslie's final destination ranging from
Ireland all the way to missing the trough and turning around to the
southwest due to a building eastern Atlantic subtropical ridge.
Compared to 12 hours ago, more of the ensemble members are showing
Leslie getting left behind, which is also reflected in the latest
deterministic runs as well.  Something tells me that Leslie has at
least one more trick up its sleeve, so the official forecast shows
this trend, but is very low confidence.

With fairly low shear and marginally warm waters for the next day
or two, there is no reason to expect that Leslie won't continue to
intensify.  Model guidance is higher than the last cycle, with the
normally conservative ECMWF and GFS models even suggesting that
Leslie becomes a category 2 hurricane in a couple of days.  Most of
the rest of the guidance is lower than those models, but the
intensity forecast is shaded in the direction of the ECMWF/GFS,
and is higher than the last NHC prediction.  After that time, an
increase in shear and lower SSTs should cause Leslie to weaken. It
is even possible it will become a post-tropical cyclone by day 5,
but I'm not going to show that at this time since I was too
premature last night in this transition.


FORECAST POSITIONS AND MAX WINDS

INIT  10/0300Z 29.5N  42.6W   65 KT  75 MPH
 12H  10/1200Z 28.4N  42.3W   70 KT  80 MPH
 24H  11/0000Z 28.0N  41.6W   75 KT  85 MPH
 36H  11/1200Z 28.6N  39.8W   80 KT  90 MPH
 48H  12/0000Z 29.9N  36.4W   80 KT  90 MPH
 72H  13/0000Z 32.2N  27.0W   75 KT  85 MPH
 96H  14/0000Z 32.0N  21.0W   55 KT  65 MPH
120H  15/0000Z 30.0N  22.0W   40 KT  45 MPH

$$
Forecaster Blake

[hlcater]

Let us remember this excerpt from then Subtropical Storm Leslie Adv 1 all the way back on September 23rd:

Quote

ADVISORY #1  ...SUBTROPICAL STORM LESLIE FORMS IN THE NORTH ATLANTIC... ...FORECAST TO BE A SHORT-LIVED CYCLONE..."

Yea that didn't really pan out well. To make things worse, Leslie has had like 25 aces up her sleeve since then, the NHC just cant pin her down. GFS proceeds to keep Leslie alive through FH240 on the 00z.