TC Bertha

[wxman57]

From the looks of that QuikSCAT image, we have TD2...

NHC won't call it a TD unless the convection is a good bit stronger AND it persists a good 24 hours. It takes more than just a closed circulation to get upgraded.

[MiamiensisWx]

I believe we are finally witnessing the beginning of more sustained and substantive convection over the LLC, since the greatest low level vorticity appears to be occurring in the immediate vicinity.

http://oiswww.eumetsat.org/SDDI/html/images/out/SDDI-20080702-2230-MPEF-09-MPE-04-1237.jpg

I'm still sticking to my unfulfilled guess that we'll see a TD classification tonight.

I'll expound on my opinion and note that convection is diminishing well SE of the Cape Verde islands... the "consolidation" is occurring in the vicinity of the LLC near 12N and 21W. I think we're finally on the steady track toward cyclogenesis and TD 2 classification tonight or tomorrow. NHC will wait for persistence.

http://oiswww.eumetsat.org/SDDI/cgi/listImages.pl?m=prod,a=0,sa=9,pr=MPEF,f=1,c=MPE,se=4,n=6,d=1,v=400,pp=0

[cycloneye]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 02 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

....SPECIAL FEATURE....

A STRONG TROPICAL WAVE IN THE FAR E ATLANTIC IS JUST EAST OF THE
CAPE VERDE ISLANDS ALONG 22W/23W S OF 19N MOVING W 10-15 KT.
SATELLITE IMAGERY REVEALS AN IMPRESSIVE CLOUD STRUCTURE WITH
WELL DEFINED 1008 MB SURFACE LOW ALONG THE WAVE NEAR 12N.
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE
FROM 9N-14N BETWEEN 19W-23W. THIS SYSTEM IS BEING CLOSELY
MONITORED AND THERE IS THE POTENTIAL FOR IT TO BECOME A TROPICAL
DEPRESSION OVER THE NEXT COUPLE OF DAYS.

[cheezyWXguy]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 02 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE....

A STRONG TROPICAL WAVE IN THE FAR E ATLANTIC IS JUST EAST OF THE
CAPE VERDE ISLANDS ALONG 22W/23W S OF 19N MOVING W 10-15 KT.
SATELLITE IMAGERY REVEALS AN IMPRESSIVE CLOUD STRUCTURE WITH
WELL DEFINED 1008 MB SURFACE LOW ALONG THE WAVE NEAR 12N.
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE
FROM 9N-14N BETWEEN 19W-23W. THIS SYSTEM IS BEING CLOSELY
MONITORED AND THERE IS THE POTENTIAL FOR IT TO BECOME A TROPICAL
DEPRESSION OVER THE NEXT COUPLE OF DAYS.

Well, it certainly is strengthening...wasnt it only 1011 this morning? Also, that convection over the center has to be helping, though it needs persistence

[Chacor]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 02 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE....

A STRONG TROPICAL WAVE IN THE FAR E ATLANTIC IS JUST EAST OF THE
CAPE VERDE ISLANDS ALONG 22W/23W S OF 19N MOVING W 10-15 KT.
SATELLITE IMAGERY REVEALS AN IMPRESSIVE CLOUD STRUCTURE WITH
WELL DEFINED 1008 MB SURFACE LOW ALONG THE WAVE NEAR 12N.
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE
FROM 9N-14N BETWEEN 19W-23W. THIS SYSTEM IS BEING CLOSELY
MONITORED AND THERE IS THE POTENTIAL FOR IT TO BECOME A TROPICAL
DEPRESSION OVER THE NEXT COUPLE OF DAYS.

Well, it certainly is strengthening...wasnt it only 1011 this morning? Also, that convection over the center has to be helping, though it needs persistence

It was 1009 mbar in the ATCF file at 12z.

[wxman57]

Well, it certainly is strengthening...wasnt it only 1011 this morning? Also, that convection over the center has to be helping, though it needs persistence

There aren't any observations near the LLC, so the pressure estimate is just that - an educated guess.

[soonertwister]

I guess the characteristics of 92L that impress me much more than I expected (admittedly, I'm an amateur) are these:

1. The symmetry of the circulation around the closed center, which is something I can't remember seeing in a system that close to Africa in a LONG time, if ever.

2. The size of the circulation for an immature tropical system. The curving wind bands that are feeding toward this thing extend a long way in all directions.

3. The convention over unnamed system 92L (or 02L) that's right over the center, with a large area of cloudtops ranging from -70C to over -80C in spots.

This to me is giving all the indications of something that could go from less than a TD to a hurricane in a relatively short period of time. The big question to me is when the recurve starts, and how far north it turns how fast.

[wxman57]

Cloud tops are now warming over the past 1-2 hours as convection drops off. As many have said, to get a TD there needs to be persistent deep convection for 24 hrs or more to maintain the inflow and allow for the surface pressure to lower and for strengthening. Too early to make the call on that for tonight. Let's see if the convection will re-fire soon.

[cycloneye]

Still a little bit far from being a TD.

02/2345 UTC 12.1N 21.0W T1.0/1.0 92L

[Matt-hurricanewatcher]

Guest what it has a well defined LLC based on quickscat data, also NO one says it needs to have any more then a closed LLC to be upgraded to a depression, that is why systems like TD4 2000, and a few others have gotten the upgrade. This has enough deep convection to be upgraded as far as I can see...I'm not slaming the nhc at all, but just questioning a little thats all.

The nhc can wait because this is nowhere more or less, but that just makes it more work for them later in the year when they expand the track eastward.

[MiamiensisWx]

Cloud tops are now warming over the past 1-2 hours as convection drops off. As many have said, to get a TD there needs to be persistent deep convection for 24 hrs or more to maintain the inflow and allow for the surface pressure to lower and for strengthening. Too early to make the call on that for tonight. Let's see if the convection will re-fire soon.

Personally, I'm looking at satellite data, and I don't see it. Regardless, new convection will undoubtedly develop.

New convection is initiating as we speak:

http://oiswww.eumetsat.org/SDDI/html/images/out/SDDI-20080703-0100-MPEF-09-MPE-04-1237.jpg

I know that these images estimate approximate precip rates, but it can indicate the development of new convection with higher tops as well.

[dixiebreeze]

We would do well to heed soonertwister's post.

[MGC]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

[canegrl04]

I forgot which Weather Channel met said it,but earlier today,they claimed nothing would come of 92L.They should be fired if it becomes even a TD

[Matt-hurricanewatcher]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

I understand that this is no where, but I'm a strong supporter and believer in one standard for the whole Atlantic, I will keep on fighting for it.

[brunota2003]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

I understand that this is no where, but I'm a strong supporter and believer in one standard for the whole Atlantic, I will keep on fighting for it.

The only problem is, we do not have recon for the entire Atlantic, either. If it was off Florida, we'd have Recon in it all the time.

[Jason_B]

I forgot which Weather Channel met said it,but earlier today,they claimed nothing would come of 92L.They should be fired if it becomes even a TD

I only listen to Steve Lyons and Cantore, they're more experienced and know what they're talking about when it comes to the tropics.

[soonertwister]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

93L is tiny compared to 92L, has no southern inflow to speak of, and the moisture is being sheared off on the north and northwest sides. The coldest cloud tops are with 92L, and the convection signature is clearly more defined. Also the diurnal pulse of intensity trails 92L by several hours, which means that 93L will be peaking while 92L will be waning.

The "one thunderstorm you were talking about was an area of intense convection more than 150 nm wide in every direction with cloudtops not less than -70C and exceeding -80C. That's no thunderstorm, not when it's right over the LLC and covers 30 thousand statute square miles.

Place your bet with 93L at your peril. This is not about where a storm might be headed, but about what looks like a storm with legitimate hurricane potential. 92L has the classic signature, 93L does not.

[MiamiensisWx]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

There are multiple thunderstorms over or near the LLC.

[Matt-hurricanewatcher]

92L needs a lot more convection than that lone thunderstorm to be upgraded. 93L has more convection this evening than 92L. 92L has a excellent circulation based on QS but until substantial convection develops near the circulation center there will be not upgrade IMO....MGC

93L is tiny compared to 92L, has no southern inflow to speak of, and the moisture is being sheared off on the north and northwest sides. The coldest cloud tops are with 92L, and the convection signature is clearly more defined. Also the diurnal pulse of intensity trails 92L by several hours, which means that 93L will be peaking while 92L will be waning.

The "one thunderstorm you were talking about was an area of intense convection more than 150 nm wide in every direction with cloudtops not less than -70C and exceeding -80C. That's no thunderstorm, not when it's right over the LLC and covers 30 thousand statute square miles.

Place your bet with 93L at your peril. This is not about where a storm might be headed, but about what looks like a storm with legitimate hurricane potential. 92L has the classic signature, 93L does not.

I agree totally, if this can get going, then this could be something to watch. It will likely recurve, but it maybe our first long "tracker" like storm like Alberto 2000. I'm not saying as long track of course!. Also, I strongly agree that the system is far stronger then 93L ever hopes to be. It has a well defined LLC with 30-35 knot winds.