Atlantic Tropical Action 2014

[Srain]

The 06Z GFS continues to shift W as the upper ridge builds E and 96L stays far enough S and misses the trough. There has been a subtle shift left with the track guidance overnight and that trend may continue today. A G-IV mission is tasked for Sunday and that should greatly assist the deterministic guidance regarding the strength of the Ridge moving E into the Tennessee and Mid Atlantic Region early next week.

[Derecho!]

GFS ensembles now with several members into the GOM.

[Srain]

Typically one would expect an increase in upper sounding data requested by the NHC and WPC across the Eastern Region for the 12Z suite and beyond. That possibly could extend as far W as the Southern Region as well.

[AutoPenalti]

Starting to get some some rotation, just needs an LLC.

[hurricaneman]

this system is having issues with Hispaniola this morning as any inflow is being blocked by its mountains

[Kory]

Recon still hasn't found any west winds.  It's going to take a while as 96L pulls away from Hispaniola before we see a LLC form.  

[Derecho!]

And of course the HWRF is OTS now...

[Kory]

And of course the HWRF is OTS now...

Strengthens it WAY too fast.  

[Srain]

Recon still hasn't found any west winds.  It's going to take a while as 96L pulls away from Hispaniola before we see a LLC form.  

You do realize that RECON is sampling well N of where the NHC placed the potential low which is about 10 miles N of Hispaniola around 20N and 70W.

 

[MJO812]

12z Hurricane models. All over the place.

[MarkSC]

A trend is now clear from the models: the ones that develop 96L quickly (notably HWRF, CMC) are showing quick recurve, while the ones that keep it weaker or slower to develop (GFS, UKMET, GFDL) are west into or near FL or the SE. That makes sense given the steering flow. My money is now on the west solutions given the likely slow strengthening today as 96L interacts with Hispaniola and a sheer axis. 

[hurricaneman]

The whole eastern part of the basin isn't out of the woods yet even Bermuda and the GOM

[Kory]

Wow...pressure of 1003.4 recorded.

 

125300 2056N 07202W 9879 00137 0034 +245 +229 095018 018 017 002 00

[Srain]

Wow...pressure of 1003.4 recorded.

 

125300 2056N 07202W 9879 00137 0034 +245 +229 095018 018 017 002 00

1002.6MB further S as RECON is heading due S on this pass. These low background pressures suggest as the disturbance moves to the WNW, conditions are very favorable for TC genesis.

[Kory]

1002.6MB further S as RECON is heading due S on this pass. These low background pressures suggest as the disturbance moves to the WNW, conditions are very favorable for TC genesis.

Looks like that was lowest pressure was found around 20.6N and 72.1W.  That's a little further west than I anticipated.  

[AutoPenalti]

Splitting hairs, thanks to the mountains of death.

[hawkeye_wx]

Visible loop shows the main surface spin centered roughly east of Inagua Island and north of the Haiti/DR border, moving nw toward Turks & Caicos.  It's pretty weak.

[r-ville]

SP

SPECIAL TROPICAL WEATHER OUTLOOK

NWS NATIONAL HURRICANE CENTER MIAMI FL

1025 AM EDT SAT AUG 23 2014

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

Special outlook issued to discuss results of aircraft

reconnaissance mission.

1. Updated...Reports from an Air Force Reserve Hurricane Hunter

aircraft and satellite imagery indicate that the disturbance located

near Hispaniola continues to lack a well-defined surface

circulation. As a result, advisories are not being initiated at this

time. However, environmental conditions are favorable for the

development of a tropical depression or tropical storm later today

or Sunday. Another Air Force Reserve Hurricane Hunter aircraft is

scheduled to investigate the system this afternoon.

This disturbance is forecast to move west-northwestward over or near

the southeastern Bahamas today, and over or near the central Bahamas

Sunday and Sunday night. Heavy rains and gusty winds are expected to

continue over Puerto Rico and Hispaniola today. Winds to tropical

storm force and heavy rains are expected to spread over the

southeastern Bahamas, the Turks and Caicos Islands, and the central

Bahamas through Sunday night. These rains could cause life-

threatening flash floods and mudslides, especially in mountainous

areas of Hispaniola and Puerto Rico. Interests in the Turks and

Caicos and all of the Bahamas should monitor the progress of this

disturbance, since tropical storm watches and warnings could be

required with little advance notice.

* Formation chance through 48 hours...high...80 percent.

* Formation chance through 5 days...high...90 percent.

Forecaster Brennan

[Eskimo Joe]

I know that you can watch the Hurricane Hunters on Tropical Tidbits but is there a site that plots the NOAA P-3 Orion?

[phil882]

I know that you can watch the Hurricane Hunters on Tropical Tidbits but is there a site that plots the NOAA P-3 Orion?

 

http://tropicalatlantic.com/recon/live/

[wxmx]

There's still no closed surface low, and visible also shows this clearly, but whatever center that could be pinpointed looks like it's a good deal well and south of what models initialized. My assessment is that it's between the triangle made by the points of Great Inagua, extreme NW Haiti and extreme SE Cuba (a little closer to Haiti).

[JSantanaNYC]

Weird storm. I'm in Hispaniola..and it's just cloudy..no rain.

[Marion_NC_WX]

12z GFS through 120 hours takes our little baby through the Bahamas and then to within about 150 miles east of Florida and then bends it hard right turn avoiding the Florida or Southeast coastline...

 

I still don't trust anything too well until we can get a definite center...current visible satellite image already shows the best spin significantly west of where the model initialization was.

[Ground Scouring]

There's still no closed surface low, and visible also shows this clearly, but whatever center that could be pinpointed looks like it's a good deal well and south of what models initialized. My assessment is that it's between the triangle made by the points of Great Inagua, extreme NW Haiti and extreme SE Cuba (a little closer to Haiti).

Reformation seems likely given that convection in the area is meager due to some dry-air intrustion and westerly shear. The real LLC will likely relocate farther NE later tonight during diurnal maximum. So the ECMWF's and the GFS's track (east of the U.S. coastline) will likely verify in line with my earlier thoughts. The FL outcome is rapidly becoming less viable--unless convection were to form over the swirl near Great Inagua Island. In that case, only a weak system would get to S FL. In each case the U.S. has nothing significant to worry about.

[StudentOfClimatology]

Reformation seems likely given that convection in the area is meager due to some dry-air intrustion and westerly shear. The real LLC will likely relocate farther NE later tonight during diurnal maximum.

Based on? That's pure speculation. Predicting microscale phenomenon like this is very difficult and poorly understood, even by the best in the field.

The FL outcome is rapidly becoming less viable--unless convection were to form over the swirl near Great Inagua Island. In that case, only a weak system would get to S FL. In each case the U.S. has nothing significant to worry about.

If anything, most of the ensemble suite has shifted west as intensity forecasts have dropped. I think the question lies in the timing and amplitude of the trough, more than anything, as well as the strength of the system itself as a secondary governing factor in a sea of forcings

[Cheeznado]

Well, one of the models that has been west more consistently, the Canadian, is now way east. I hear the fat lady warming up.....

[GaWx]

Even if it hits the SE coast (most likely S FL and/or NC as of now for any possible direct hits due to shape of coast & atmospheric setup), it may have challenges to getting to cane status (i. e., despite a climo. favorable position & time of year, very warm SST's, not much dry air, & low enough sheer ). I say this for two reasons: very large size initially would likely prevent too rapid an intensif. process & it is projected to slow down so much near Bahamas that much upwelling would occur. The strongest storms are usually not very slow movers as the slow movement really eats away at warm SST's since it takes so much heat away. For those who want a stronger storm, your better bet would be a not so slow movement IMO. Be that as it may, I'm not predicting its strength right now as this will be tough. Just don't be surprised if it stays a TS despite some pretty favorable factors.

Now, if this were to somehow make it over to the Gulf, that would be a different story as a cane would be favored IMO.

Opinions?

[Amped]

GGEM way OTS.  NAVGEM  across Florida Peninsula with a second landfall in the Panhandle. Still no agreement and the storm is in no hurry to get organized. This can make CAT1 status in the medium range assuming it is still over warm water.

 

Edit: UKMET still supports Navgem but a bit further west.

[Kory]

Even if it hits the SE coast (most likely S FL and/or NC as of now for any possible direct hits due to shape of coast & atmospheric setup), it may have challenges to getting to cane status (i. e., despite a climo. favorable position & time of year, very warm SST's, not much dry air, & low enough sheer ). I say this for two reasons: very large size initially would likely prevent too rapid an intensif. process & it is projected to slow down so much near Bahamas that much upwelling would occur. The strongest storms are usually not very slow movers as the slow movement really eats away at warm SST's since it takes so much heat away. For those who want a stronger storm, your better bet would be a not so slow movement IMO. Be that as it may, I'm not predicting its strength right now as this will be tough. Just don't be surprised if it stays a TS despite some pretty favorable factors.

Now, if this were to somehow make it over to the Gulf, that would be a different story as a cane would be favored IMO.

Opinions?

Looks like there will also be a upper level high over the Gulf, which would make Gulf conditions nearly perfect but it looks like it might induce some northerly shear over the Bahamas which will hamper some development of 96L there.

[Srain]

RECON is finding a rather sharp wave axis a bit further W than the early morning mission. It appears a broad elongated area of low pressure continues moving WNW around 10-13 kts.