Wave in Central Caribbean

[Stormavoider]

Now you can also see a swirl just south east of PR both on the radar and here
http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[Rainband]

If you look at the frames just prior to that burst of convection, you can see a good spin where the burst is now.

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

I went back all the way to sunrise on a high res imagery...a lot higher res than what you are seeing on the SSD floater...and they are every 15 minutes...opposed to every 30 minutes on the floater...

...AND there was no spin whatsoever prior to the development of the deep convection north of PR. The northerly winds in PR were probably a combo of 1) An outlfow boundry and 2) Sea Breeze...perhaps.

There is nothing but straightline ESE flow over this area...and no LLC
anywhere....and hasn't been.

Although I agree with the statement, I can see where the confusion might be..Click this link and you will see what appears to be a "turning" north west of PR...


http://radar.weather.gov/ridge/radar.ph ... A&loop=yes

http://www.storm2k.org/phpbb2/viewtopic.php?t=87311

[Air Force Met]

Although I agree with the statement, I can see where the confusion might be..Click this link and you will see what appears to be a "turning" north west of PR...


http://radar.weather.gov/ridge/radar.ph ... A&loop=yes

Well...that very slight twist is sitting at 12,000+ feet because of the curvature of the earth and the .5 degree up angle of the radar. Not exactly close to the surface.

[Air Force Met]

Now you can also see a swirl just south east of PR both on the radar and here
http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

That swirl is in the cirrus deck. That's WAY upper level. It's mid and upper level vorticity that is left over from the convective burst...now dissipating. Happens all the time in the tropics. Nothing is even close to the sfc.

[hial2]

There's no guarantee that the spin you see 6 miles above the surface extends down to the surface....quote by WXMAN57

Thank you for the info...So you're saying that there is a "spin", but not all the way "down"?....And aren't you leaving open the possibility that the "spin" does extend all the way down?..I'm just an observer with no formal training in this matter...

[AJC3]

There's no guarantee that the spin you see 6 miles above the surface extends down to the surface....quote by WXMAN57

Thank you for the info...So you're saying that there is a "spin", but not all the way "down"?....And aren't you leaving open the possibility that the "spin" does extend all the way down?..I'm just an observer with no formal training in this matter...

If you don't see cyclonic motion within either:

1) the low level CU elements on vis imagery
2) Cellular convection relatively close to the radar site (not stratiform debris rain) on radar imagery

Then you have no cyclonic flow at the lower levels.

[Air Force Met]

There's no guarantee that the spin you see 6 miles above the surface extends down to the surface....quote by WXMAN57

Thank you for the info...So you're saying that there is a "spin", but not all the way "down"?....And aren't you leaving open the possibility that the "spin" does extend all the way down?..I'm just an observer with no formal training in this matter...

Yes...when there is other evidence. What he is saying...and is true...is that you cannot base the existence of a LLC on radar data alone because of the "height from base" factor. If you have buoy data or satellite data that shows you MIGHT have something and you see it in the mid-levels on radar...then it may b at the surface...OR...it might be READY to work down to the sfc in that area.

However, in this case...the data from satellite alone is enough to settle the issue that it does not extend to the sfc.

And here is another factor....whether you are looking at radar or satellite...you have to be careful NOT to look at a feature as if it was sitting still...when it is not. In this case...even though it seems to have a spin...the southern part of the rain elements on radr are STILL moving west...just not as fast as the northern parts.

What that means is it has vorticity to it...but it is not closed of as a low. If it was...the spin would be such that you would see those rain elements headed east..and not west.

Same thing with clouds on satellite imagery. If you see something that looks like a LLC...look at the southern most cloud elements. If they are still moving WEST...then it is not closed off...even if it looks like it...because if it were closed...they would be moving east.

It's called storm relative motion....and when looking at radar and satellite the natural tendancy is to view a system that way...and it leads to the optical illusion that something is actually closed off when it isn't. You have to stay geographically centered.

[Johnny]

Ok, AFM...I'm gonna call you out again.

So far you have been pretty much spot on this year regarding the tropics. I'm hearing from some respectable sources that this wave could emerge in the gulf and could become our first hurricane of the year. I know it is still a ways off BUT, what is your overall take on this wave and what it might or might not do?

[Air Force Met]

Ok, AFM...I'm gonna call you out again.

So far you have been pretty much spot on this year regarding the tropics. I'm hearing from some respectable sources that this wave could emerge in the gulf and could become our first hurricane of the year. I know it is still a ways off BUT, what is your overall take on this wave and what it might or might not do?

Well...It's got to hold together another 2-3 days before it has a chance to do anything. I think it will head into the GOM and if the structure of the wave has not been ripped apart by the Big-3...it has a chance...but given the way the ridging is...is might be headed south of the border if it waits too long to develop.

I haven't paid too much attention to it yet because of all the rain we had here yesterday...and all the warnings I had to deal with. I'll be watching it though...but it has to shake the upper low first.

[Derek Ortt]

first hurricane?

It needs to survive about 3 days of very strong shear first, which many waves have not survived. Plus, none of the global models are showing anything with this feature, even the aggressive Canadian

[Extremeweatherguy]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

My prediction for this wave:

-By tomorrow I think this is in or near the Bahamas as a strong wave with gusty, squally weather.

-By Saturday I think this will be on the SE coast of Florida spreading squally weather across much of the east coast with the threat of heavy rains across the southern 1/3rd of the state.

-By next Monday I think this is in the central Gulf (85-90W) and starting to get organized. It could potentially be a TD or TS at this point, but I am not making any bets on that happening (yet).

-By next Tuesday/Wednesday this system is either:

A) Approaching Texas as a developed system.

OR

B) Heading into Mexico as a tropical wave.

**I also think there is a chance this wave could split. In that case, I think one piece would impact FL and the SE, and the other would work through the Caribbean and into the southern Gulf.**

I will likely change this prediction in the days to come as new developments arise. For example, if the northern end of the wave dies out and the southern end picks up, I might have to shift the predicted track southward.

I do think there is a chance this could become a hurricane in the Gulf, but I am not going to call for that until after this system has developed into something more substantial.

~I will have to watch this system closely as I will be driving from the EC of Florida back to Houston sometime on late Sunday, Monday and possibly Tuesday.~

[jasons2k]

In one corner.......we have the pro mets

In the other corner........we have EWG

*ding*

let the match begin

[Air Force Met]

My prediction for this wave:

-By Saturday I think this is in the Bahamas as a strong wave with gusty, squally weather.

-By Sunday I think this will be on the SE coast of Florida spreading squally weather across much of the east coast with the threat of heavy rains across the entire southern 2/3rds of the state.

-By next Tuesday ...-

I agree with some of your prediction...but I think you are too slow with it. If it takes two days to get to the Bahamas...then it is only moving at about 10 knots. It should continue to move at about 15 knots...which means it will be closer to Florida in 2 days (the outer edges of the wave)...even with a slow down....but given the fact the ridge is also progged to move west...and a 45 knot flow at 850 will exist north of Hispanolia...I don't see it slowing. If anything, it might actually speed up a knot or two.

In three days time it should be in the eastern GOM....maybe near 85W.

NOw..I agree that this is the place it will strengthen...if it does at all. If it doesn't...it will most likely provide some rain to south TX and Mexico...cause that's where it will head.

[NYCHurr06]

first hurricane?

It needs to survive about 3 days of very strong shear first, which many waves have not survived. Plus, none of the global models are showing anything with this feature, even the aggressive Canadian

Voice of reason...

Weather forecasting is much more then just looking at models, but if none of the good models show any substantial development, would you forecast any?

[AJC3]

My prediction for this wave:

-By Saturday I think this is in the Bahamas as a strong wave with gusty, squally weather.

-By Sunday I think this will be on the SE coast of Florida spreading squally weather across much of the east coast with the threat of heavy rains across the entire southern 2/3rds of the state.

-By next Tuesday ...-

I agree with some of your prediction...but I think you are too slow with it. If it takes two days to get to the Bahamas...then it is only moving at about 10 knots. It should continue to move at about 15 knots...which means it will be closer to Florida in 2 days (the outer edges of the wave)...even with a slow down....but given the fact the ridge is also progged to move west...and a 45 knot flow at 850 will exist north of Hispanolia...I don't see it slowing. If anything, it might actually speed up a knot or two.

In three days time it should be in the eastern GOM....maybe near 85W.

NOw..I agree that this is the place it will strengthen...if it does at all. If it doesn't...it will most likely provide some rain to south TX and Mexico...cause that's where it will head.

WRT Florida, I'll give you the southern 1/3 of FL instead of 2/3. Any farther north and my forecasts and AFD's of the last several days would wind up busting.

[Extremeweatherguy]

My prediction for this wave:

-By Saturday I think this is in the Bahamas as a strong wave with gusty, squally weather.

-By Sunday I think this will be on the SE coast of Florida spreading squally weather across much of the east coast with the threat of heavy rains across the entire southern 2/3rds of the state.

-By next Tuesday ...-

I agree with some of your prediction...but I think you are too slow with it. If it takes two days to get to the Bahamas...then it is only moving at about 10 knots. It should continue to move at about 15 knots...which means it will be closer to Florida in 2 days (the outer edges of the wave)...even with a slow down....but given the fact the ridge is also progged to move west...and a 45 knot flow at 850 will exist north of Hispanolia...I don't see it slowing. If anything, it might actually speed up a knot or two.

In three days time it should be in the eastern GOM....maybe near 85W.

NOw..I agree that this is the place it will strengthen...if it does at all. If it doesn't...it will most likely provide some rain to south TX and Mexico...cause that's where it will head.

Good point AFM. I will go ahead and speed up my prediction a bit.

[Opal storm]

I do not see this becoming a hurricane in the Gulf,that ridge will most likely push this thing south of the Gulf and into the Yucatan and eventually into the BOC.There,it might briefly develop into a T.D/weak T.S before heading into northern Mexico.If the wave does split,I think the northern half will have a much better chance if it merges with that cold front off the S.E coast.

[Extremeweatherguy]

My prediction for this wave:

-By Saturday I think this is in the Bahamas as a strong wave with gusty, squally weather.

-By Sunday I think this will be on the SE coast of Florida spreading squally weather across much of the east coast with the threat of heavy rains across the entire southern 2/3rds of the state.

-By next Tuesday ...-

I agree with some of your prediction...but I think you are too slow with it. If it takes two days to get to the Bahamas...then it is only moving at about 10 knots. It should continue to move at about 15 knots...which means it will be closer to Florida in 2 days (the outer edges of the wave)...even with a slow down....but given the fact the ridge is also progged to move west...and a 45 knot flow at 850 will exist north of Hispanolia...I don't see it slowing. If anything, it might actually speed up a knot or two.

In three days time it should be in the eastern GOM....maybe near 85W.

NOw..I agree that this is the place it will strengthen...if it does at all. If it doesn't...it will most likely provide some rain to south TX and Mexico...cause that's where it will head.

WRT Florida, I'll give you the southern 1/3 of FL instead of 2/3. Any farther north and my forecasts and AFD's of the last several days would wind up busting.

Also a good point. I will change my wording in my prediction. Don't want your AFD's to bust.

[Stormavoider]

Humor me. This blob of convection moved past PR and is approaching Haiti. As it is approaching Haiti it slurped up the the low clouds just north of the west end. The clouds appear as an arc as they get pulled in.
Is this an indication of low level energy???


http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[Extremeweatherguy]

The HPC has this wave right on the Texas/Mexico coast at 12Z (early morning) on Tuesday August 1st.

http://www.hpc.ncep.noaa.gov/medr/9lh.gif

This could be an interesting drive home for me along the northern Gulf (especially if something develops). It would be like i'm chasing the wave/system.