ATL: ALBERTO - Post-Tropical

[Dean4Storms]

Vis loop during the day before the sun sets, broad circulation where I place the L is very apparent this afternoon with all the convection sheared to the east of it.
The 18z GFS loses or weakens this vorticity as it moves slowly NW over the next couple of weeks then forecasts for a new one to form by the end of the week just south of Cuba, while Euro never loses or weakens this vorticity over the next couple of days as it moves NW towards the southern GOM.

https://i.imgur.com/RS3knK0.gif

And like the Bay of Campeche that area usually aids in developing surface lows..

[tolakram]

Hey, I remembered to change the year on the forum graphic before anyone asked.

*sigh* I was wrong, Luis already asked in the mod forum.

[tolakram]

COD Loop. You can change the type on the left side.

http://weather.cod.edu/satrad/exper/?parms=subregional-W_Caribbean-02-48-1-100-1&checked=map&colorbars=

[Sciencerocks]

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Mon May 21 2018

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

A broad surface low pressure area has formed over the northwestern
Caribbean Sea a couple of hundred miles east of the coast of Belize.
This low and an upper-level trough are producing widespread
cloudiness and showers extending from the northwestern Caribbean
Sea across Cuba and the Florida peninsula. While environmental
conditions are expected to be unfavorable for development during
the next couple of days, some gradual subtropical or tropical
development is possible later this week while the system moves
slowly northward into the central or eastern Gulf of Mexico.
Regardless of development, locally heavy rainfall is possible
across western Cuba and much of Florida during the next several
days. For more information on the heavy rain threat, please see
products issued by your local weather office. The next Special
Tropical Weather Outlook on this system will be issued by 800 AM
EDT on Tuesday.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

$$
Forecaster Cangialosi

[CDO62]

I'm a little surprised the NHC didn't widen the circle a little more to the East in that graphic with respect to what the GFS has been locked in on.

[Dylan]

I'm a little surprised the NHC didn't widen the circle a little more to the East in that graphic with respect to what the GFS has been locked in on.

It’s because they’re well aware that the GFS-OP is a dumpster fire. Even a good portion of the GFS ensembles are to the West with its foreign competition.

[NotSparta]

Latest infrared floater for the invest over the last three hours:

3.12 MB. Source: Generated myself using NOAA/NASA data from GOES-16. This animated GIF is not available from the SSD in this format.
https://i.imgur.com/PO57ePM.gif

I wish floaters were still around like that

[Taffy]

Following.

[Twisted-core]

Hard not to take notice. Likely will be the first tc for the basin

[gatorcane]

18Z GFS ensemble mean shifted east:

[wxman57]

GFS ensembles are just a little west of the operational, taking the low just off the west coast of Florida and inland near the big bend area of Florida. I like that solution a lot better than any track toward Louisiana across the SW-NE jet core. GFS just has a history of beating the other models in a higher shear environment.

[CrazyC83]

If the jet is set up across Louisiana, any track that way would shear it to death anyway? Although shear is a significant limiting factor no matter what.

[CrazyC83]

SHIPS kills it off quickly.

Code: Select all

  * ATLANTIC     SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA PROXY USED,      OHC AVAILABLE     *
                    *  INVEST      AL902018  05/21/18  18 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    20    21    22    23    23    24    22    22    20    18    23    23    23
V (KT) LAND       20    21    22    23    23    24    22    22    26    23    28    28    29
V (KT) LGEM       20    20    19    19    18    16   DIS   DIS   DIS   DIS   DIS   DIS   DIS
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)        29    29    32    32    30    32    27    36    31    33    27    34    32
SHEAR ADJ (KT)     0     0     0     1     1     0     3     1     2     2     4     0     1
SHEAR DIR        283   272   277   283   284   287   277   266   268   261   283   270   258
SST (C)         28.5  28.5  28.5  28.5  28.4  28.1  27.9  27.6  27.5  27.4  27.2  27.2  27.4
POT. INT. (KT)   142   141   141   141   140   135   133   128   126   125   123   122   126
ADJ. POT. INT.   131   128   127   128   126   121   118   112   109   108   106   105   111
200 MB T (C)   -54.0 -53.8 -54.0 -54.1 -53.7 -53.5 -53.4 -53.4 -53.6 -53.5 -53.7 -53.3 -53.2
200 MB VXT (C)   0.4   0.2   0.3   0.1   0.2   0.3   0.5   0.7   0.7   0.7   0.3   0.4   0.5
TH_E DEV (C)       9    10     9     8    10     9    10     9     9     9     9     9    10
700-500 MB RH     60    62    62    60    58    62    58    57    58    56    54    50    52
MODEL VTX (KT)     5     5     5     5     5     5     5     6     6     6    10    10    11
850 MB ENV VOR    52    65    68    50    40    40    23    31    37    54    64    71    90
200 MB DIV        37    32    42    38    34    42    39    21     0    19    26    22    26
700-850 TADV       0    -2    -2    -2    -1     0    -1     0    -2    -1     3     4     1
LAND (KM)        213   234   222   186   139    74    18   -10    20    64    80    68    65
LAT (DEG N)     17.8  18.0  18.2  18.5  18.8  19.6  20.5  21.2  21.7  22.1  22.3  22.2  22.1
LONG(DEG W)     84.7  85.2  85.5  85.8  86.2  86.7  87.0  87.0  87.1  87.2  87.7  87.8  87.1
STM SPEED (KT)     6     4     4     4     5     4     5     3     2     2     2     2     5
HEAT CONTENT      47    56    64    70    62    36    12    40     7     6     4     3     7

  FORECAST TRACK FROM TABM      INITIAL HEADING/SPEED (DEG/KT):280/  8      CX,CY:  -7/  1
  T-12 MAX WIND:  20            PRESSURE OF STEERING LEVEL (MB):  772  (MEAN=618)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  21.1 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  29.0 (MEAN=65.0)
  PRELIM RI PROB (DV .GE. 55 KT IN 48 HR):            0.0

[Dylan]

One thing we can’t underestimate is the ability of these large monsoonal gyre’s ability to alter or even create its own environment. The large area of convection and it’s associated outflow could bulge the shear axis northward, and even use it as a poleward outflow channel initially. Not to mention westerly or southwesterly shear is not a death sentence, and can help enhance convection. It’s northerly and northeasterly shear that are the real killers in the Gulf of Mexico (see the 2010 Hurricane Season).

[Alyono]

One thing we can’t underestimate is the ability of these large monsoonal gyre’s ability to alter or even create its own environment. The large area of convection and it’s associated outflow could bulge the shear axis northward, and even use it as a poleward outflow channel initially. Not to mention westerly or southwesterly shear is not a death sentence, and can help enhance convection. It’s northerly and northeasterly shear that are the real killers in the Gulf of Mexico (see the 2010 Hurricane Season).

It also depends if the shear is convergent, like it was with Bonnie in 2010, or divergent. Divergent shear is actually somewhat favorable for a weaker TC, assuming the low level winds are also favorable

[wxman57]

If the jet is set up across Louisiana, any track that way would shear it to death anyway? Although shear is a significant limiting factor no matter what.

Yes, it would be battling high wind shear. My initial track takes it northward across the eastern Gulf Fri-Sun, with landfall east of 85W (east of Apalachicola) Sunday morning as a sheared TS with little in the way of wind or squalls west of the track. This is west of GFS operational and closer to GFS ensembles.

[Dylan]

One thing we can’t underestimate is the ability of these large monsoonal gyre’s ability to alter or even create its own environment. The large area of convection and it’s associated outflow could bulge the shear axis northward, and even use it as a poleward outflow channel initially. Not to mention westerly or southwesterly shear is not a death sentence, and can help enhance convection. It’s northerly and northeasterly shear that are the real killers in the Gulf of Mexico (see the 2010 Hurricane Season).

It also depends if the shear is convergent, like it was with Bonnie in 2010, or divergent. Divergent shear is actually somewhat favorable for a weaker TC, assuming the low level winds are also favorable

Yep, and considering it’s position to the upper trough, I would say that it’s the case. Even the 18z MU develops it into a moderate tropical storm.

[gatorcane]

If the jet is set up across Louisiana, any track that way would shear it to death anyway? Although shear is a significant limiting factor no matter what.

Yes, it would be battling high wind shear. My initial track takes it northward across the eastern Gulf Fri-Sun, with landfall east of 85W (east of Apalachicola) Sunday morning as a sheared TS with little in the way of wind or squalls west of the track. This is west of GFS operational and closer to GFS ensembles.

Wxman57 are you using the 12Z or 18Z GFS ensembles? Seems the 18Z have many ensembles that are through South Florida or east of Florida, many more than the 12Z. But I agree, your track makes sense.

[ronjon]

Well shear is screaming now and likely to stay that way with the upper level low over the central GOM. GFS looking like high shear environment the next 5 days. ECM must be developing the surface low under the ULL and moving it in tandem. Will be interesting which solution pans out.