ATL: CRISTOBAL - Post-Tropical - Discussion

[tolakram]

30 frame live visible, speed up for effect.

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=19&lon=-63&info=vis&zoom=1&width=1000&height=800&quality=95&type=Animation&palette=ir1.pal&numframes=30

[Comanche]

The vorticity now NW of P.R., north of Mona's Pass, is the one taking over, good choice by the NHC to keep tracking that one instead.
It has been moving almost due west all morning long.

Looking at the following link, the vorticity appears SW of PR. You can toggle between surface, 1000, 850, 500, etc etc by clicking on the "EARTH" icon.

http://earth.nullschool.net/#current/wi ... 16.09,1829

[NDG]

The vorticity now NW of P.R., north of Mona's Pass, is the one taking over, good choice by the NHC to keep tracking that one instead.
It has been moving almost due west all morning long.

Looking at the following link, the vorticity appears SW of PR. You can toggle between surface, 1000, 850, 500, etc etc by clicking on the "EARTH" icon.

http://earth.nullschool.net/#current/wi ... 16.09,1829

Well, I really disagree with those graphics, recon is finding 1008mb and a wind shift as it passed through the vorticity clearly seen on vis satellite loop NW of P.R.

[ColdFusion]

The vorticity now NW of P.R., north of Mona's Pass, is the one taking over, good choice by the NHC to keep tracking that one instead.
It has been moving almost due west all morning long.

Looking at the following link, the vorticity appears SW of PR. You can toggle between surface, 1000, 850, 500, etc etc by clicking on the "EARTH" icon.

http://earth.nullschool.net/#current/wi ... 16.09,1829

Well, I really disagree with those graphics, recon is finding 1008mb and a wind shift as it passed through the vorticity clearly seen on vis satellite loop NW of P.R.

Agreed, that's not an exact tool by any means, and I wouldnt use it to try to pinpoint a realtime circulation.

From their own "ABOUT" page:

ocean surface current estimates - updated every five days

weather and ocean data are generated from numerical models
earth.nullschool.net implies no guarantee of accuracy

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT FRI AUG 22 2014

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

1. Shower and thunderstorm activity has increased during the past few
hours in association with a small area of low pressure located just
north of the Mona Passage between Puerto Rico and the Dominican
Republic. Satellite wind data and preliminary reports from an Air
Force Reserve Hurricane Hunter aircraft indicate that the
circulation associated with the low is poorly defined. Some
additional development of this system is possible today, but
environmental conditions are expected to be more conducive for the
development of a tropical depression or tropical storm when the
disturbance moves near or over the southeastern Bahamas on Saturday.
Regardless of whether the system becomes a tropical cyclone, gusty
winds and heavy rainfall are expected across Puerto Rico and the
Virgin Islands today, and over portions of Hispaniola and the
southeastern and central Bahamas tonight and Saturday. Interests in
the southeastern and central Bahamas should monitor the progress of
this disturbance, as tropical storm watches or warnings could be
required with short notice.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

Forecaster Brennan

[wxman57]

Looks like a weak LLC forming north of eastern DR. I think it will become a TD/TS over the weekend. Though it probably won't enter the Gulf, there is the possibility of a Mid Atlantic Coast threat next week if it gets blocked, as some of the models are indicating.

[USTropics]

Looking at the following link, the vorticity appears SW of PR. You can toggle between surface, 1000, 850, 500, etc etc by clicking on the "EARTH" icon.

http://earth.nullschool.net/#current/wi ... 16.09,1829

Well, I really disagree with those graphics, recon is finding 1008mb and a wind shift as it passed through the vorticity clearly seen on vis satellite loop NW of P.R.

Agreed, that's not an exact tool by any means, and I wouldnt use it to try to pinpoint a realtime circulation.

From their own "ABOUT" page:

ocean surface current estimates - updated every five days

weather and ocean data are generated from numerical models
earth.nullschool.net implies no guarantee of accuracy

It does not use real time data, but rather uses the atmospheric data from the GFS model and projects wind speed and direction at 3 hour intervals.

[cycloneye]

18z Best Track.

AL, 96, 2014082218, , BEST, 0, 194N, 677W, 35, 1009, DB

[tolakram]

I believe I can see the beginnings of an LLC with inflow starting just NE of Hispaniola.

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=20&lon=-68&info=vis&zoom=1&width=1000&height=800&quality=95&type=Animation&palette=ir1.pal&numframes=10

[Frank2]

I stand corrected - it does seem the circulation is centered in the Mona Passage - my concern per the WV loop is that the high to our north might be stronger (or the trough weaker)...

P.S. That's how we got in trouble with Andrew (hope not)...

Frank2

[fci]

I stand corrected - it does seem the circulation is centered in the Mona Passage - my concern per the WV loop is that the high to our north might be stronger (or the trough weaker)...

P.S. That's how we got in trouble with Andrew (hope not)...

Frank2

Good to see you posting Frank.
Hope you are well. I know you posted of health issues recently.

[TheAustinMan]

Things I'm currently seeing in regards to 96L...

[MississippiWx]

Things I'm currently seeing in regards to 96L...

Pocket of dry air you are referring to south of Hispaniola is due to down-sloping winds. Winds out of the north cause down-sloping on the south side of the island which causes the air to sink.

[summersquall]

PR receiving a healthy drink of much needed water. Without the hazards of flash flooding I hope.

[Airboy]

Really looks like it starting to form right now on sat pictures.

[Nimbus]

Very easily seen low level clouds have thrashed around on the western side of the LLC twice now.
Small center is just north of the Punta Cana, Dominican Republic.

What I'm not sure about is what is going to happen with the high pressure over the CONUS?
Looks like there will be a westward jog in the storm track at the least in the near term. If the high rolls further east or splits there would be a weakness to take Crystobal out later, but I don't think the timing of that event can be modeled with certainty this far out.

[Hammy]

I still see no inflow, the high clouds can make the low cloud movement seem different, but I've sat the mouse over various spots around the supposed circulation and everything is out of the east or south. Looks like it'll just head straight west into Hispaniola and we'll see by the end of the weekend if what is left after that can manage to develop.

[Bocadude85]

Is it me or does 96l seem to be moving quicker then the models have forecast?

[NDG]

Very easily seen low level clouds have thrashed around on the western side of the LLC twice now.
Small center is just north of the Punta Cana, Dominican Republic.

What I'm not sure about is what is going to happen with the high pressure over the CONUS?
Looks like there will be a westward jog in the storm track at the least in the near term. If the high rolls further east or splits there would be a weakness to take Crystobal out later, but I don't think the timing of that event can be modeled with certainty this far out.

If there was to be an LLC north of Punta Cana they would had not been reporting east winds. I think the vorticity is still above the ground, it is still a sharp trough of low pressure at the surface. Tomorrow morning is when I think it will finally start developing an LLC, once it slows down like others have mentioned.

[SapphireSea]

That crazy shear zone just to the west of the storm if it does not abate and gets blocked is going to eat 96L for breakfast. Looking at Rainbow you can see how nuts it is in the upper levels.