cptcatz

Today's 6z GFS shows a system in the gulf on May 9, not developing but maybe?

If this hits Florida as a high end TS or low hurricane, I gotta give it to the GFS.  Three weeks ago the GFS was consistently showing this exact system impacting somewhere in Florida on October 19-20.  Pretty impressive.

There's a disturbance in the central Atlantic right now that the GFS and Euro are hinting at and the CMC is going full throttle with. Will be interesting to see if the NHC mentions it at 8pm.

Subtropical Storm Melissa has formed:

000
WTNT44 KNHC 111452
TCDAT4

Subtropical Storm Melissa Discussion Number   1
NWS National Hurricane Center Miami FL       AL142019
1100 AM AST Fri Oct 11 2019

Convection increased near the center of the nor'easter centered
southeast of New England overnight. First-light visible satellite
imagery briefly showed an eye-like feature before the convection
around the immediate center began to weaken. However, a large
convective band still persists over the northern semicircle, and
this structure indicated the system has transitioned to a
subtropical cyclone. The latest Hebert-Poteat classification from
TAFB indicates an initial intensity of 55 kt, and this is also
supported by an earlier scatterometer overpass showing a large area
of winds near 50 kt in the northwest quadrant.

Melissa is currently located underneath an upper-level trough,
resulting in a light shear environment. This trough will begin to
lift northeastward later today, and strong upper-level westerlies
should begin to affect the storm by tonight. This pattern is
expected to cause a weakening trend, and Melissa is forecast to
become post-tropical by Saturday night. The post-tropical cyclone is
then expected to be absorbed by an approaching front in 3 to 4 days.

Melissa is currently embedded in weak steering flow under the upper-
level trough, and little net motion is expected today. Later
tonight, an approaching mid-latitude trough currently crossing
the upper Midwest will begin to force an east-northeastward
motion at a faster forward speed. This motion will continue until
the cyclone is absorbed by the cold front. The NHC track forecast is
closest to the ECMWF ensemble mean.

Ongoing hazards from wind and coastal flooding will continue be
covered by non-tropical products from local National Weather Service
forecast offices.

Gale-force winds that extend well northeastward of Melissa into the
central Atlantic that are not included in the wind radii, since they
are associated with a frontal boundary.

Key Messages:

1. While the nor'easter centered southeast of New England has become
Subtropical Storm Melissa, the expected magnitude of wind and
coastal flooding impacts along portions of the U.S. east coast from
the mid-Atlantic states to southeastern New England has not changed.
For information on these hazards, see products issued by local
National Weather Service forecast offices at weather.gov.

2. Melissa is expected to gradually weaken and begin moving away
from the U.S. east coast by tonight, resulting in a gradual decrease
in wind and coastal flooding impacts.

FORECAST POSITIONS AND MAX WINDS

INIT  11/1500Z 38.5N  69.6W   55 KT  65 MPH
 12H  12/0000Z 38.2N  69.3W   45 KT  50 MPH
 24H  12/1200Z 38.4N  67.7W   35 KT  40 MPH
 36H  13/0000Z 39.0N  65.1W   30 KT  35 MPH...POST-TROPICAL
 48H  13/1200Z 39.9N  61.0W   30 KT  35 MPH...POST-TROPICAL
 72H  14/1200Z 41.3N  52.6W   30 KT  35 MPH...POST-TROPICAL
 96H  15/1200Z...ABSORBED

$$
Forecaster Latto

^The NHC mentioned it in their 8pm update:

2. A broad area of low pressure is expected to form over the western
Caribbean Sea late this weekend.  This system is forecast to move
westward toward Central America early next week, and some
development is possible if the low remains over water while moving
near the coasts of Honduras, Guatemala, and Belize.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

1 hour ago, WxWatcher007 said:

That (southern) area of disturbed weather off the SE coast actually looks pretty good all things considered. There's clearly a low level swirl with convection displaced to the northeast. 40% odds for development now. 12z Euro is more robust on odds of development in the next 24 hours. 

It's been bringing tons of much needed rain here in SE Florida.  It's been thunderstorming almost nonstop for the past two days in Boca Raton.

The GFS is still loving that storm developing in the south Caribbean on October 13, although it keeps going back and forth on it moving north towards Cuba or west into Central America.  It's been forecasting it for over a week now... attached is 9/28, 10/2 and today, all showing 18z October 13.  Pretty darn consistent.  

18z GFS now shows two storms brewing in the Caribbean around October 13. The western one still very big. 

1 hour ago, Windspeed said:

All known category 5 hurricanes whether by operational, post-analysis or historical reanalysis have made landfall at minimal hurricane intensity or stronger in the Atlantic basin. If Lorenzo makes landfall over Corvo or Flores islands in the Azores archipelago, that streak will continue. Best track has it just missing them for now. A slight deviation east is needed for any official landfall.

Interesting.  I wonder if there have been cat 4's that did not impact land that weren't investigated closely because there was no threat from them, and if they were investigated more closely, they would have been found to actually be cat 5.  I'm still new to hurricane watching... if there was a Lorenzo-type storm 20 years ago that posed no threat to land, would there have been recon flights into it?  If there were no recon flights, maybe they would have just kept it as a cat 4? 

12z GFS still has the big Caribbean storm at the end of the run, and the 12z Euro shows a small African wave trying to develop this Wednesday.  The model shows it barely getting across the Atlantic, but if it makes it into the eastern Caribbean, that could be another one to watch.

The past couple days of GFS runs all have a powerful hurricane forming in the south Caribbean in a couple weeks. It's obviously really far down the road but will be interesting to see if the models keep it up. 

18z GFS still showing significant impacts in UK

Now the interesting thing to watch is how strong it stays and where it exactly it ends up.  The 12z Euro shows it slamming into England...

Looks like this time next week we could have a developing system coming off of Africa and another one in the western Caribbean. The African one looks like a low rider with a big ridge above it, could make it across the Atlantic without turning out to sea. The Caribbean one would make landfall somewhere. 

Looks like on IR that it's trying to wrap some convection around the center.

NHC 11am advisory:

"Except for the possibility of dry air in the circulation, it's not quite evident why Karen has not been able to sustain organization.... It's difficult to ignore what's being shown by the global models, since there must be something in the environment that they're deeming to be negative for continued strengthening."

In other words:

Maybe I'm just wishcasting but I don't see how Karen doesn't get its act together today.  It's sitting over hot water, low shear, and moist air.  It also looks like it's trying to get banding together on satellite rather than being just a blob of convection. 

Can someone explain why Karen isn't rapidly intensifying right now?  There's basically no wind shear and no dry air in sight... what's hindering it?

^Yep, right at the western coast of St. Croix

6 minutes ago, NJwx85 said:

A relocation of the center a bit further SW would probably end up hurting Karen in the long run because the steering flow is still to the North and a track a bit further to the West would bring the center across the heart of PR. Some of the peaks in that part of the island are over 3000 feet.

How have previous storms fared moving through PR in a direct south-to-north direction?  The entire island is only about 35 miles wide and the mountains are probably about 20 miles wide.  A storm moving at 10 mph would cross the mountains in a couple hours and clear the entire island in 3.5 hours.

No changes at all with the 11am advisory.  I'm a little surprised since it's looking much better on satellite.  

It'll be interesting to see how fast this strengthens once the environment allows strengthening to begin.  Dorian, Humberto, and Jerry all strengthened much quicker than the NHC predicted once their environments started to improve.

18z GFS has it totally dissipating around Puerto Rico. It'll be interesting to see if it can keep itself together until then. 

Convection has really blown up on 99L in the past few hours. 

The 12z Euro has an interesting development of current 99L.  It has it going north through the eastern Caribbean and then turning to the southwest before meandering a little.  This could be an interesting one to watch.