ATL: ARTHUR - Post-Tropical

[jlauderdal]

yeah current surface obs from Havana, Matanzas and offhsor Bouy/ships show a closed wind field with a central low pressure with that naked vort.

Matanzas should switch to west as that vort moves closer.

with convection waning associated with the vort to the NE and some increasing moisture coming in at the mid levels .. should see convection fire off between Cuba and keys over the next several hours.

unless we get a redevelopment of the center east of key largo.

Aric, how many times have we seen this? I think that a redevelopment east of Key Largo is quite plausible. Could be a boat-load of additional precip to line up and train into Dade & Broward late this afternoon and into this evening. If that were to occur Gator & SoFla could well see 24 hr. rainfall upwards of 5"-6" or more. While overall net motion appears to be "nill", continued slow reorganization and propagation will likely result in better consolidating somewhere between the N.W. Bahamas & S.E. Florida coast on Sunday. I could see the NHC hoisting T.S. Watches (PTS Advisories) by tonight/tomm. a.m. for N. Broward & Palm Beach coastline for the Saturday night-Sunday period.

Edit: As soon as I posted this, I saw your posted HRR. Certainly would carry some nice squalls further up the coast if that occured!

90L has over performed in terms of rainfall with 3-6 inches in some SFL locations. But wind has been a non issue almost dead calm. I have yet to see your bonified squall from this system. Actually seeing some sun breaks now

4.41 storm total at my place..maybe we can generate another .25 today. The offshore activity seems to be intensifying to make a run at the coast but best dynamics are east and south.

[Jr0d]

I think it will likely traverse north/northeast right up along the Gulf Stream, just off the Southeast U.S. Atlantic Coast. Arthur imo will become a rather strong early season cyclone, and it would not surprise me to see it possibly become a Cat 1 hurricane early next week, if it can fully maximize the influence of the Gulf Stream Current.

Also, the 12Z GFS tracks future Arthur a bit closer to the NC Outer Banks by Tuesday, compared to previous runs.

I dont think the Air Force will be launching the X-37B Saturday, nor SpaceX Starlink 7 on Sunday. The conditions wont be favorable for booster recovery for awhile for the SpaceX launch. The LZ(my guestimation) is about 350 miles NE of Cape Caneveral.

[xironman]

Looks like it is consolidating NE, like the models predicted. Hopefully not the NAM.

[cycloneye]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
210 PM EDT Fri May 15 2020

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

Special Tropical Weather Outlook issued to discuss the potential
for tropical or subtropical development near the northwest Bahamas.

Satellite data and surface observations indicate that the trough of
low pressure located over the Straits of Florida has generally
changed little today. This system continues to produce
a large area of disorganized shower activity and gusty winds
across the Florida Keys, portions of southeast Florida, and
the northwestern Bahamas. Gradual development of this system is
still expected, and it will likely become a tropical or subtropical
storm on Saturday when it is located near the northwestern Bahamas.
Later in the weekend and early next week, the system is expected to
move generally northeastward over the western Atlantic.

Regardless of development, the disturbance will continue to bring
heavy rainfall and wind gusts to tropical-storm-force across
portions of the Florida Keys, southeast Florida and the Bahamas
through Saturday. In addition, hazardous marine conditions are
expected along the Florida east coast and in the Bahamas where Gale
Warnings are in effect. Dangerous surf conditions and rip currents
are possible along portions of the southeast U.S. coast this
weekend and early next week. See products from your local weather
office and High Seas Forecasts for more details. An Air Force
Reserve Hurricane Hunter aircraft is scheduled to investigate the
disturbance tomorrow morning, if necessary. The next Special
Tropical Weather Outlook on this system will be issued by 9 PM EDT
tonight, or earlier, if necessary.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.

&&

High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
available on the Web at ocean.weather.gov/shtml/NFDHSFAT1.shtml.

$$
Forecaster Cangialosi

[Aric Dunn]

Looks like it has finally begun to drift to the nne to NE likely being pulled to the convection. once we see the obs on marathon switch to north then NW we will know it is getting a move on and organizing..

HRRR seems to think enough moisture wrap around will occur in the next few hours to set off convection on the NW side..

we shall see..

[Nimbus]

Surface Pressure Tendency at Fowey Key station just NW of the center dropped .05 inches the last report.

[xironman]

There seems to be an MLC forming in the NE keys.

[SouthDadeFish]

Not expecting much, if any, development until tomorrow. Too much shear. I am enjoying the rain here in South FL though

[GCANE]

Getting decent popups over western Cuba.
That should do the trick and moisten the atmosphere tonight.
Chances looking better now for development tomorrow.

[TheStormExpert]

Already got .81 inches of rain since this morning. Definitely not as much as places further south but I'll gladly take it!

[TheStormExpert]

18az Best Track. Aric,is that the location you are looking at?

Location: 24.2°N 80.7°W
Maximum Winds: 25 kt Gusts: nan kt
Minimum Central Pressure: 1011 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 90 NM

https://i.imgur.com/RB3Po6G.png

How come the best track never updates on the map on the top of this page?

[cycloneye]

18az Best Track. Aric,is that the location you are looking at?

Location: 24.2°N 80.7°W
Maximum Winds: 25 kt Gusts: nan kt
Minimum Central Pressure: 1011 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 90 NM

https://i.imgur.com/RB3Po6G.png

How come the best track never updates on the map on the top of this page?

Yes. Every year there is a problem with it but hopefully is resolved soon.

[Kat5]

Getting a weak squall right now in davie, FL. Definitely no complaints here!

[TheStormExpert]

18az Best Track. Aric,is that the location you are looking at?

Location: 24.2°N 80.7°W
Maximum Winds: 25 kt Gusts: nan kt
Minimum Central Pressure: 1011 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 90 NM

https://i.imgur.com/RB3Po6G.png

How come the best track never updates on the map on the top of this page?

Yes. Every year there is a problem with it but hopefully is resolved soon.

https://i.imgur.com/7QYO3il.jpg

Yeah I notice it only with pre-season invests/storms.

[Slughitter3]

Getting a weak squall right now in davie, FL. Definitely no complaints here!

Very welcome rain in Davie, I can finally turn my sprinklers off for a few days. However, running through it in the Publix parking lot was not fun.

Sent from my SM-G960U using Tapatalk

[toad strangler]

 http://twitter.com/pppapin/status/1261429201560690694

[TheStormExpert]

Invest 90L was never forecasted to develop before this weekend when it’s moving away from South Florida and The Bahamas. So it’s behaving as planned!

[gatorcane]

Looking at the radar, looks like there is a circulation along the coast of Broward County (Ft Lauderdale) moving north.

[Aric Dunn]

Just offshore northern key largo like a few milies is looking very interesting...

[cycloneye]

Invest 90L was never forecasted to develop before this weekend when it’s moving away from South Florida and The Bahamas. So it’s behaving as planned!

Even our friend Aric who is a very enthusiastic peep that does good analysis has said from the start of this invest that it would be by the weekend.