ATL: TROPICAL DEPRESSION ALEX - DISCUSSION

[CrazyC83]

Could this just keep going west in the shear and become more EPAC food?

[KWT]

Hmmm that apperence is interesting, probably will have just enough time if it doesn't suffer anymore setbacks to do something before the Yucatan...infact I wouldn't be shocked if it forms overland if it doesn't make it as the daytime heating will aid convection and perhaps tip it over the edge, like it has done with a few other storms that were close.

[HouTXmetro]

Could this just keep going west in the shear and become more EPAC food?

Don't know about EPAC but it could get buried in the Yucatan as the GFS has been suggesting on previous runs.

BIG blowup around where everyone think a LLC is trying to form..SW of Jamaica

[I-wall]

Pressure also falling at this buoy:

http://www.ndbc.noaa.gov/station_page.php?station=lciy2

[Aric Dunn]

pay close attention to around 79.2 W 17N for a distinct low level circ overnight..

[I-wall]

Could this just keep going west in the shear and become more EPAC food?

Don't know about EPAC but it could get buried in the Yucatan as the GFS has been suggesting on previous runs.

BIG blowup around where everyone think a LLC is trying to form..SW of Jamaica

Looks to me like the strongest convection is still well to the north of where we think the LLC is trying to form.

[djones65]

Even though the satellite presentation is chaotic and totally disorganized, I also see some low level rotation west southwest of Jamaica. I am really "impressed" though with the buoy observations Irak and I-wall have posted... I remember reading one of the criteria that NHC specialists look for when evaluating potential development of a disturbance is surface pressure falls of 2-3 mb within a 24 hour period. Obviously there will be diurnal variability of rising and falling pressures so simply "falling" or "rising" is not something that important. However, when you compare the surface pressures to 24 hours previous and we are now seeing near 2 mb pressure falls during the past 24 hours over the western Caribbean Sea I think that is significant. I am thinking the surface low may actually be trying to develop late this afternoon even though satellite presentation is unimpressive, I agree with Sanibel that pressure trumps satellite imagery. Lowest pressure so far is 1009 mb which is at least 2 mb lower than I have previously observed. The ATCF Best track has always had this wave at 1010 mb but I have not seen any surface obs that verified that until today, and now it shows slightly lower than 1010. I think the long awaited development "trend" maybe begining. That being said, I still would be surprised to see tropical cyclone formation until Friday when the energy from the wave over the eastern Caribbean currently along 67W can be absorbed into this system, in my humble opinion.

[KWT]

Could this just keep going west in the shear and become more EPAC food?

As I said in the model thread, its very unlikely, even the more southerly models still would probably too far north for it to have much shot in the EPAC...

Besides I'm still pretty confident this one will develop, even if it doesn't do it on the Caribbean side of the Yucatan I'd feel confident still.

Anyway need to watch in case the D-max sets up the first stage of development.

[jasons2k]

I still don't see anything special; it's just so disorganized and disjointed. It's still just an open wave and it's not even on the cusp of closing off. Any semblance of a LLC, MLC, and convergence are not aligned. The pressure readings posted on here don't excite me either...it's close to sunset so that's what we would expect to see. On top of all that, all the action over in the EPAC isn't helping it. In other words, it's still going to be a long wait before a cyclone can form out of this.

Not only is this like watching paint dry, it's like watching oil-based paint dry. With thinner to boot.

[vbhoutex]

pay close attention to around 79.2 W 17N for a distinct low level circ overnight..

After taking a good look at the visible sat pic I must agree.
Good observations djones65.

[Rockin4NOLA]

Again I'm less than a novice at this stuff..but am I way off base in thinking there appears to be some rotation around 77-ish W (near where Tolakram pointed it out)?

[Weatherfreak000]

The D-Max tonight is going to be crucial in determining the future of this new location. Curiously, the system is having no problems firing off tons of convection even without an LLC. I think based on that conditions are good for a great D-Max.

[lrak]

Not only is this like watching paint dry, it's like watching oil-based paint dry. With thinner to boot.

[Ntxwx]

Could currently being seeing developing stages. Im not 100% onboard with Alex yet, but by this weekend would be when we would look for a potential Tropical Storm/Hurricane forming.

[lrak]

Hmmm....http://www.ndbc.noaa.gov/station_page.php?station=42057

Big fall djones65

[ronjon]

Max vorticity now SW of JAM which is evident on the VIS SAT - If it starts wrapping convection around the west side we may have a player.

http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8vor4.html

[I-wall]

pay close attention to around 79.2 W 17N for a distinct low level circ overnight..

Hmm. This satellite loops indicates that 79 W cuts through the tip of the Yucatan. Surely that's not right. Are some of the NHC floaters prone to having incorrectly located lat/lon grids?

http://www.ssd.noaa.gov/goes/flt/t1/flash-vis.html

[KWT]

I still don't see anything special; it's just so disorganized and disjointed. It's still just an open wave and it's not even on the cusp of closing off. Any semblance of a LLC, MLC, and convergence are not aligned. The pressure readings posted on here don't excite me either...it's close to sunset so that's what we would expect to see. On top of all that, all the action over in the EPAC isn't helping it. In other words, it's still going to be a long wait before a cyclone can form out of this.

Not only is this like watching paint dry, it's like watching oil-based paint dry. With thinner to boot.

True its got some way to go but I do see the possible start of something possibly and it looks more advanced then yesterday at this point, still going to be a close call as to whether it develops before the Yucatan but its got every shot IMO of at least making it to TD status before then.

[alienstorm]

This system is capable of forming anywhere from sw of Jamica to south of Haiti, the further east it develops the more critical it will become for a US landfall.

This is a very large envelope and once it consolidates (if it does) it will be in line for very fast development from there.

We need to keep close tabs on it, tonight will be critical and shall see how it looks tomorrow morning.

[lonelymike]

From Mobile AFD:

ATTENTION REMAINS FOCUSED ON THE TROPICS AND WHAT CURRENT SFC WAVE
BETWEEN JAMAICA AND HAITI/DOMINICAN WILL DO. MEDIUM RANGE MODELS
CONTINUE TO DIVERGE BUT ARE CLOSER TO EACH OTHER THAN THIS TIME
YESTERDAY. THE ECMWF CONTINUES TO BE AN OUTLIER AND WILL BASE
FORECAST ON NHC BLENDED MODELS AND 12Z/23 OPERATIONAL GFS WHICH TAKE
THE WAVE WEST TOWARD THE YUCATAN PENINSULA BY THIS WEEKEND. THE GFS
AMPLIFIES AN UPR TROUGH ACROSS THE ERN CONUS WHICH SHOVES THE UPR
HIGH SOUTH AND KEEPS THE POTENTIAL SYSTEM FROM TURNING NORTH/EAST.
MEANWHILE...THE 12Z/ECMWF IS NOT AS AMPLIFIED WITH UPR TROUGH AND
THEREFORE SHIFTS THE RIDGE EAST...ALLOWING THE POTENTIAL TROPICAL
SYSTEM TO CROSS THE YUCATAN AND ENTER THE GULF/BAY OF CAMPECHE BY
MONDAY/TUESDAY. THE GOOD NEWS FOR THE GULF COAST IS THAT EVEN THE
ECMWF TAKES THE SYSTEM WEST INTO MEXICO BY THE MIDDLE TO END OF
NEXT WEEK.

OF COURSE...MODEL SOLUTIONS WILL CHANGE EACH DAY AS WILL THE
ORGANIZATION/INTENSITY OF THE CURRENT WAVE. AT THIS TIME...THE
BEST FORECAST IS A "WAIT AND SEE" APPROACH UNTIL BETTER RUN-TO-RUN
CONSISTENCY DEVELOPS. NADLER.83


Guess someone loves the GFS