Atlantic Tropical Action 2014

[Srain]

31 Years ago at this hour the center of Hurricane Alicia was passing just W of DT Houston. Alicia formed from a MCS exiting the Mississippi/Alabama Coast on August the 15th and enter the very warm waters of the Gulf where pressures were rather high (1016mb estimated) and developed into a depression later in the evening. Alicia continued moving W beneath a Ridge of High pressure that dropped S in the wake of the trough that extended from New England to the Northern Gulf Coast. Alicia continued to strengthen as it churned W to WNW and turned NW as it neared the Upper Texas Coast and began to slowly accelerate while pressures continued to fall rather rapidly. We had received heavy rain the week before Alicia made landfall across the Region and the ground was very saturated. Tree damage was substantial across SE Texas from a combination of wet soil and the many years that had passed since winds in access of 50 to 60 miles per hour with higher gusts just shy of 100 MPH reported at Hobby Airport. Many will recall the large amount of broken windows in the High Rise buildings throughout DT Houston damaged by flying debris. Almost 10 inches of rain would fall across Liberty County and the Brownwood subdivision along the Upper Galveston Bay in the Eastern part of Baytown would be severely damaged from storm surge and years of subsidence that plagued the area in the 70's due to subsurface water being pumped by industry and municipalities for drinking and cooling water. The conversion to surface water from the various area lakes had already began in 1983 when Alicia struck the West end of Galveston Island in what we SE Texas folk know as the worse case scenario for a landfallIng Major Hurricane affecting the Houston/Galveston Area. 23 Tornadoes were associated with Alicia which was a small Hurricane when compared to Hurricane Carla which hit Port O'Connor along the Middle Texas Coast in September of 1961. Alicia caused an estimated 2 Billion Dollars damage by 1983 standards and if a Hurricane the size of Carla were to take the same track...some estimates suggest that the Dollar damage would exceed 4 times the amount that Alicia brought to the SE Texas/Upper Texas Coastal area.
 

 

 

[Max]

What's going on down in the western gulf today?

[Srain]

What's going on down in the western gulf today?

Just a typical upper low spinning near Tampico enhanced by a shear axis across Texas.

 

[Superstorm93]

Still no agreement among the models...

 

GFS ensembles: 

 

[Superstorm93]

Interesting trends tonight. GEM has a hurricane and so does the UKMET (text is below)

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 48 HOURS

FORECAST POSITION AT T+ 48 : 12.5N 52.9W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

00UTC 21.08.2014 12.5N 52.9W WEAK

12UTC 21.08.2014 15.9N 54.5W WEAK LITTLE CHANGE

00UTC 22.08.2014 15.3N 58.2W WEAK LITTLE CHANGE

12UTC 22.08.2014 16.0N 61.1W WEAK LITTLE CHANGE

00UTC 23.08.2014 16.7N 63.9W WEAK INTENSIFYING SLIGHTLY

12UTC 23.08.2014 17.4N 66.6W WEAK INTENSIFYING SLIGHTLY

00UTC 24.08.2014 18.2N 68.4W MODERATE INTENSIFYING SLIGHTLY

12UTC 24.08.2014 19.5N 70.4W STRONG INTENSIFYING RAPIDLY

00UTC 25.08.2014 20.7N 72.1W STRONG LITTLE CHANGE

GGEM(Fwiw):

 

 

 

ECMWF is also starting to show a more interesting period coming up with a ridge building over the SW Atlantic right when the CATL disturbance reaches this area. 

 

[Eyewall2005]

[Srain]

Heh...seriously the current activity across the Atlantic is rather far S across the ITCZ near 10N. The dust (SAL) is abating W of 40W and with the stout Kelvin wave slowly moving E across the EPAC, there is some potential for TC genesis in the Caribbean Sea in about a week or so. The Bermuda Ridge continues to expand W into the SE suggesting a general W to WNW steering flow. We will see.

 

[Kory]

Models have really picked up on these waves moving WNW reaching a certain point and developing them in the Western Caribbean, Gulf, or off the Southeast Coast.  The Euro, GFS, and GEM are all showing some sort of development.  I'm not particularly paying attention to which wave develops on which model, just note the region they all develop in, the only area of the basin that's conducive for development. 

 

East Coast Instability:

 

Caribbean Instability:

 

Gulf Instability:

[CCHurricane]

Seems like a few models are coming on board with a TC forming and potentially impacting an area within the Gulf (GFS, GGEM) or perhaps the eastern seaboard (Euro, NAVGEM). Wide spread however so will be interesting to see this develop moving forward.

[Kory]

The global models really want to build a ridge over the Eastern U.S. extending into the western Atlantic.  If that pattern comes to fruition, it would certainly open the door to any system.  The Euro just appears a little slower with that, which is why the system starts re-curving sooner than the GFS/CMC.    

[Eyewall2005]

WEATHER RECONNAISSANCE FLIGHTS

CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.

1000 AM EDT TUE 19 AUGUST 2014

SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)

VALID 20/1100Z TO 21/1100Z AUGUST 2014

TCPOD NUMBER.....14-080

I. ATLANTIC REQUIREMENTS

1. NEGATIVE RECONNAISSANCE REQUIREMENTS.

2. OUTLOOK FOR SUCCEEDING DAY.....POSSIBLE LOW LEVEL INVEST

NEAR 15.0N 55.0W AT 21/1730Z.

[hurricaneman]

If the shear lowers in the Western Caribbean there will most certainly be a dangerous hurricane with those TCHP heat potential number I'm seeing so lets hope that the shear stays moderate to strong there the next week to 10 days

[CCHurricane]

12z GFS and 12z CMC point towards GOM TC in the future. Slightly different paths but they both make it to the Gulf.

[phil882]

There is also a significant CCKW currently moving into the western caribbean that will likely be superimposed over the disturbance in question within the next 48 hours. The vast majority of the global models really underestimated the amount of cummuls convection that is observed with the monsoon trough / ITCZ today. 

 

Current location of the CCKW over central america

 

 

 

Current Infrared Satellite Image

 

 

Forecast GFS IR from 24 hours ago at this time suggest that the model was overestimating the subsidence over the Atlantic basin given today's convection. This could be a manifestation of a deficiency in the cummulus parametrization as convection occurring out in the EPAC which isn't as expansive or deep as the GFS was suggesting. As the CCKW moves overhead, we should see convection continue to flare as the equatorial wave also aids in the generation of low-level cyclonic vorticity equatorward of the disturbance as it passes by. 

 

 

In the end, I think the more recent global model forecast are not off their rocker and have a lot of validity right now. Even the 00z ECMWF run was suggesting an intensifying TC just north of cuba at 180 hours, but it was keying on a different area further west along the monsoon trough becoming the primary vortex.

 

tl;dr... this threat is legit.  

[hurricaneman]

Disorganized shower and thunderstorm activity continues in
association with an elongated area of low pressure that extends from
the northeastern coast of South America into the central tropical
Atlantic. Environmental conditions are forecast to be more conducive
for gradual development of this system during the next few days as
it approaches the Lesser Antilles and moves into the Caribbean Sea.
* Formation chance through 48 hours...medium...30 percent.
* Formation chance through 5 days...medium...40 percent.

 

I think that invest 96L is about ready to be born

 

edit: 96L is designated

 

AL, 96, 2014081818, , BEST, 0, 119N, 438W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 96, 2014081900, , BEST, 0, 113N, 453W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 96, 2014081906, , BEST, 0, 108N, 467W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 96, 2014081912, , BEST, 0, 104N, 479W, 20, 1009, DB, 0, , 0, 0, 0, 0, 1012, 100, 30, 0, 0,
AL, 96, 2014081918, , BEST, 0, 100N, 490W, 20, 1009, DB

[Superstorm93]

I like this ones chances. 

 

GFS has this in a wicked upper-level environment in addition to the most unstable part of the basin. 

 

[Superstorm93]

Kind of guessed that the statistical models would blow this up into a major. Position change made the models go wild.

 

Now up to Cat 3

 

 

 

NHC 96L INVEST 20140819 1800 100N 0490W 250 062 1009 1010 0278 10 000 -999 -999 -999 -999 M -999 -999 -999 -999 -9 -99N -999W -999 -999 -999 -999 
NHC 96L INVEST 20140819 1800 095N 0505W 250 062 1009 1010 0278 13 000 -999 -999 -999 -999 M -999 -999 -999 -999 -9 -99N -999W -999 -999 -999 -999

 

 

[Cheeznado]

FWIW the 12Z ECMWF has basically nothing.

[yoda]

FWIW the 12Z ECMWF has basically nothing.

 

The EURO looked at the GFS and laughed, and then promptly showed no ATL action at all pretty much

[Superstorm93]

FWIW the 12Z ECMWF has basically nothing.

 

Yeah. It was nice having it on board while it lasted lol

[thewxmann]

Go Climo! Beat the Euro!

[hurricaneman]

I would disreguard the Euro intensity until we have a low to track then we might have something more realistic

[Ground Scouring]

I would disregard the Euro

Famous last words for…oh…every "system" thus far in the ATL. The CCKW won't be enough to save the system as very dry mid-level air will be wrapping around from the NE as the system passes through the Lesser Antilles in a few days. By day three dry air kills the system on the ECMWF. Given how dry the desert latitudes are in the ATL, even a slight NE or ENE wind vector will advect very dry air (RH equal to or less than 15%) into the core of the potential system. I see no real reason to disregard the ECMWF since it has consistently beaten the stuffing out of every other model in the short range.

[AvantHiatus]

Famous last words for…oh…every "system" thus far in the ATL. The CCKW won't be enough to save the system as very dry mid-level air will be wrapping around from the NE as the system passes through the Lesser Antilles in a few days. By day three dry air kills the system on the ECMWF. Given how dry the desert latitudes are in the ATL, even a slight NE or ENE wind vector will advect very dry air (RH equal to or less than 15%) into the core of the potential system. I see no real reason to disregard the ECMWF since it has consistently beaten the stuffing out of every other model in the short range.

Excuse me but Phil882 > Euro, and the current presentation has potential. Euro is the lone wolf here, in regards to the model consensus.

[Ground Scouring]

Excuse me but Phil882 > Euro, and the current presentation has potential. Euro is the lone wolf here, in regards to the model consensus.

I respect Phil's opinion a lot, but given seasonal trends I don't see why we should trust every other model when only the ECMWF has a record (limited though it may be) in accurate short-term forecasting for TCs once a closed low is initialized. Even in situations where the ECMWF was the "lone wolf" this year, it consistently trumped every other model in the short term (within three days). The fact that it went from fairly aggressive development to no development is a big red flag. I'm sorry if I seemed sarcastic, but literally every potential system this year hasn't had a chance given the excruciatingly dry conditions in the central ATL.

[Srain]

I respect Phil's opinion a lot, but given seasonal trends I don't see why we should trust every other model when only the ECMWF has a record (limited though it may be) in accurate short-term forecasting for TCs once a closed low is initialized. Even in situations where the ECMWF was the "lone wolf" this year, it consistently trumped every other model in the short term (within three days). The fact that it went from fairly aggressive development to no development is a big red flag. I'm sorry if I seemed sarcastic, but literally every potential system this year hasn't had a chance given the excruciatingly dry conditions in the central ATL.

 There is certainly evidence that supports the fact that other global dynamical models do just fine in regards to TC genesis besides the ECMWF.

[RGweathergeek]

The continuing dry air in the Atlantic is a concern for this system. That being said the fact the models have been picking up on something for the last week gives me pause. I would like to see a few more model runs before writing this one off.

 

The wonderful and very even-headed Eric Berger of the Houston Chronicle sent out a special afternoon blog post about this wave. Eric is not one who hypes things up so the fact he is mentioning something leans me more towards that this may end up developing into something. 

[blizzardof96]

I respect Phil's opinion a lot, but given seasonal trends I don't see why we should trust every other model when only the ECMWF has a record (limited though it may be) in accurate short-term forecasting for TCs once a closed low is initialized. Even in situations where the ECMWF was the "lone wolf" this year, it consistently trumped every other model in the short term (within three days). The fact that it went from fairly aggressive development to no development is a big red flag. I'm sorry if I seemed sarcastic, but literally every potential system this year hasn't had a chance given the excruciatingly dry conditions in the central ATL.

I agree with you on several accounts, the euro has been the superior model inside 3 days and any NE wind vector will be very detrimental to the system if/when it can emerge from the monsoonal trough. At the same time, no closed low has been initialized or established yet and an upper level anticyclone has formed just to the NE of the system which the euro has initialized too far north. This upper high stays significantly more coupled with the system on the GFS/GEM models, which is one of the reasons why intensification is stronger over the caribbean on those models.

[Kory]

I wouldn't just write this system off just yet.  How many times have we've seen a system limp along until they reach the western Caribbean, Gulf, or off the SE Coast.  The MJO being in phase one seems to be helping it gain some convection considering the past few days it has really been fighting the hostile conditions in the Atlantic.  

 

Not to mention, the Caribbean/Bahamas/Gulf is loaded with potential.  

[EasternUSWX]

Till something forms, just go with the euro.