MikeC
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Loc: Orlando, FL
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Update - Sunday 07/06, 1130PM ET
Bertha has been intensifying during the day and evening and is nearing hurricane strength, with maximum sustained winds near 65mph, and a minimum central pressure of 994mbs. There is even indications of an eye-wall formulation. This is all likely a result of favorable deep layer shear profiles combined with the fact that she has been moving over gradually warming SSTs. She is currently located near 18.6N/ 48.9W and continues moving west to west-northwest at a brisk 20mph.
This range of motion is being strongly dictated by pervasive Atlantic Basin subtropical ridging and is expected to persist for the next 3 days, keeping Bertha on the west-northwest general heading. After that things get complicated. Modeling solutions range from a rather discerned polar-ward motion ensuing roughly at 72 hours, taking Bertha east of even Bermuda, to bringing Bertha to the outer Bahamas.
Bertha's developmental prospects look good for the next 2 days, after which, some shear may impact her. However, by then she may be a bit stronger of a system and more capable of fending off a harsher environment; provided said environment doesn't become overwhelming, of course. The official call at this hour is 70kts by 24 hours, then hold her own through the end of the 5 day outlook. Position at that time, 30N/66W
Stay tuned!
John
Update - Saturday 07/05, 1230PM ET
After passing over marginal SSTs during the last day, 1000mb Bertha has struggled a bit to maintain a 45kt (~50mph) wind. The TC is now entering a region of somewhat warmer water, some intensification is likely to resume. Currently Bertha is carrying a rather well defined and persistent convection plume along her NW semi-circle.
According to the 11am advisory, she was moving more due west over the last 6-12 hours, but the longer term average is really 280 degrees at a rather brisk 21mph. This rapid forward motion may also contribute to some limitation on development. Officially, Bertha is forecast to reach hurricane strength by hour 72.
The forecast philosophy is currently that the subtropical ridge over the breadth of the Atlantic Basin will essentially remain intact enough to persist a general west or west-northwest steering field. As is usually the case, the picture becomes a little less clear nearing day 4 and beyond. Previously, there was modeling indication that a weakness would evolve near the 60W longitudes, and that this would induce a bit of a turn toward the northwest. However, now the models have backed off on that idea and instead lift the weak trough axis back north prior to Bertha's nearing that longitude. Thus, the 3 day modeled average has shifted somewhat south of those earlier indications, even though the very recent trends may have shifted the day 5 position a little north. These types of shifting in model position are not unusual. The best way to correct for them is to assess the general synopsis, then balance those solution against to attain the most plausible scenario. That said, it would seem we will have to monitor this system for a few days.
John
Update - Thursday 07/03, 1130PM ET
Bertha's intensity has been increased to 40kts (45mph). This is a compromise in estimates of tools giving 45 and 35kts. Minimum central pressure is estimated at 1006mb, which is consistent with these wind speeds. She is moving at 280 or essentially west at 14mph. Currently, satellite presentation has improved this evening. It is possible that a nocturnal phase of intensification is underway.
The forecast philosophy is essentially unchanged. Bertha is expected to continue moving on a west-northwest motion for the next 3 days, after which, some shear and a weakness in the steering field ridge may belay further intensification, as well as turn her more toward the NW, respectively. Still, the official intensity call is upwards toward 60kts (near 70mph) by 72 hours, and then holding that intensity through 120.
John
Update - Thursday 07/03, 1130AM ET
TD2 in the far eastern Atlantic has been upgraded to Tropical Storm Bertha - currently relocated about 190 miles south of the Cape Verde Islands. Maximum sustained winds are at 35 knots and the minimum central pressure is 1006MB. Bertha is moving to the west northwest and that forward motion should continue for the next few days. Only slow intensification is forecast as the cyclone moves over some cooler SSTs (26C) in about 24 to 36 hours. After about 4 days, the future motion of Bertha will hinge on the strength of the Atlantic high pressure ridge.
Invest 93L, beginning to experience some increase in windshear, has not changed much in the past 24 hours and continues to move to the west northwest to northwest at about 10 knots in the eastern Caribbean Sea.
We'll continue to monitor both of these systems over the holiday weekend.
ED
Update - Thursday 07/03, 700AM ET
The area that was tracked as (92L) has now formed into Tropical Depression #2
Update - Wednesday 07/02, 1030PM ET
Newly designated Invest 93L about to enter the eastern Caribbean near Martinique. See the Storm Forum thread for additional details.
ED
Original Post
A potential early-off Africa storm may be forming over the next few days from what is being tracked as 92L, this system has been showing signs of potential development for the last day or so.
If it does form, it will likely not become any more than a named Tropical Storm, and it likely will not last too long as the conditions ahead of it aren't the greatest. Even so, it appears this will move out to sea before having a chance to affect any land areas. If it does form it will be the first to form this far east in July since Bertha in 1996. The track, however, appears to be much further north than Bertha.
We'll be watching in case any of this changes, but other than being something to watch in the Atlantic, there isn't much to be concerned about here.
Bertha Event Related Links
SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page
[https://flhurricane.com/floatanimator.php?year=2008&storm=2 Flhurricane Satellite Floater Animation of Bertha
GOES Floater
Animated Model Plot of Bertha
Clark Evans Track Model Plot of Bertha
(Animated!) Model Plots in Google Earth - In Google Maps
Clark Evans Intensity Model Plot of Bertha (Animated!)
Clark Evans Track Plot of Bertha
Other Model Charts from Clark
Clark Evans Top 10 Analog Storms for Bertha
More model runs on from RAL/Jonathan Vigh's page
NRL Info on Bertha -- RAMMB Info
COD Atlantic Satellite View
Edited by typhoon_tip (Sun Jul 06 2008 11:19 PM)
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cieldumort
Moderator
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Loc: Austin, Tx
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TCFA has been hoisted for 92L.
There was a little confusion earlier when 92L was errantly being listed by and others as 02L.
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Rich B
British Meteorologist
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Posts: 498
Loc: Gloucestershire, England, UK
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Satellite imagery shows that the disturbance (92L) still remains somewhat well organsied, but needs to consolidate a little more before classification i would imagine. Model support at the moment doesnt seem to take the system above Tropical Storm strength generally. Oh note, and perhaps of more 'threat' is the new 93L - the area just east of the Lesser Antilles. Satellite shows a rapidly developing and well organised disturbance, but no mention of it currently from the .
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Rich B
SkyWarn UK
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Lee-Delray
Weather Master
Reged: Thu
Posts: 429
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looks like we have 93L to look at as well
my.sfwmd.gov/sfwmd/common/images/weather/plots/storm_93.gif
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Random Chaos
Weather Analyst
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Posts: 1024
Loc: Maryland
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SSD is now listing 92L as 02L, but nothing on or about an upgrade to a Tropical Depression. Is SSD jumping the gun?
http://www.ssd.noaa.gov/PS/TROP/positions.html
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Hugh
Senior Storm Chaser
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Loc: Okaloosa County, Florida
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The SSD "floaters" page doesn't show 92L at all, but it does show 93L. Very odd.
The link you posted shows 92L, but not 02L, for me at least.
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Hugh
Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)
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Random Chaos
Weather Analyst
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Loc: Maryland
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Looks like SSD changed one of the two 02L's back to 92L, but they missed one.
As for the floater, SSD won't have a floater on 92L yet - it's out of range of the satellite they use (SSD uses the geosynchronous weather satellites, as I recall). Near-Africa storms are usually on different satellites - only place I can seem to find storm-centered current satellite imagery for it is ; for some reason the Africa region at NASA GOES is two years out of date (the rest are current).
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cieldumort
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Invest 92L is now being listed as 02L on . Overnight, deep convection continued to blossom within the heart of the system. A recent QuikSCAT pass showed that as early as yesterday 92L has had a very coherent surface circulation, with thunderstorms appropriately co-located.
Ironically, the next name on the Atlantic list of names this year, of all possible names given the nature of 02L, is Bertha.
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CoconutCandy
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Loc: Beautiful Honolulu Hawaii
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============================================
UPDATE: has just Upgraded TD Two to Tropical Storm Bertha. No wonder the Depression was looking so much like a Tropical Storm already in the pic below.  Amazing! A Cape Verde Storm on July 3rd!
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Well I am quite surprised to see the wave held together so well, and the convective max last night gave it just the energy input needed to facilitate cyclogenesis.
I can't remember when I've seen such a well organized Cape Verde depression that looks like a TS already, so very early in the season. Almost certainly, that pocket of anomalous SST's a few degrees above climo just off the west coast of Africa provided the 'fuel for the fire' and allowed the cyclone to form this early in the season. A harbinger of things to come ?!?
It'll be of little consequence as a 'fish spinner', except to shipping lanes. But of much greater consequence is what this implies for the rest of this coming hurricane season. A bumper crop of storms, perhaps?
And, were it not for the shear, we'd have another cyclone forming over the Leeward Islands right now. The tropics are really starting to percolate early this year. July may be quite active. August and September will very likely be 'Bingo-Bango', to bandy some recent vernacular. Interesting times, tropical weather-wise!
It's seems quite likely that, if the shear relaxes for most of the season like in 2005, and with the SST's running a tad warmer than usual, we'll be seeing a conveyor belt of cyclones again this year. Best to be *Extra Prepared* this season!
- Norm in Honolulu (Former Coconut Grove, Florida Resident from '77 - '80 - Survived David in Miami 1979, Allen in Key West 1980, Iwa 1982, Iniki 1992)
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JustMe
Weather Guru
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Posts: 128
Loc: Orlando, Florida
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I have been watching storms for many years now and I have to agree this is very early to have activity in the Cape Verde area although the dry area ahead of it will not help with it's matruing. The loft winds will turn it to sea .. Like you I am uneasy about waht our year has to unfold
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I have survived Betsy Miss, Camille Miss., Andrew Fl, Charley Fl, Frances FL, Jeanne FL,
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MichaelA
Weather Analyst
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Loc: Pinellas Park, FL
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I find it interesting that the former early July CV storm was also named Bertha (1996) and it affected the US from the mid-Atlantic coast through New England. However, that storm formed more to the Southwest than this incarnation has.
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Michael
PWS
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typhoon_tip
Meteorologist
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After a typical diurnal drop off in convection during the day today (Thursday), Bertha seems to have developed a fairly tightly compact and robust circulation core this evening. Nocturnal phase of development may be underway. Current satellite takes on the appearance of - though it is less likely that is the case for the time being. TPC seems to agree with intensification overall, per their 11pm advisory/discussion, and the intensity has been raised to 40kts.
Her vitals are unchanged. She will remain in a low shear environment for at least the next 2-3 days, after which some increased shear may or may not significantly impact her. She has only marginal SSTs to work with at 25C, which is a limiting factor on any thinking for rapid intensification. We really like to see a minimum 82F SST and significantly deep thermocline (water temperature decreases with increasing depth) combined with low shear and a noticeable positive anomaly in the outflow (perhaps a channel); none of which is really observable at this time in that part of the Atlantic. This is probably why they are a bit more conservative on development than some of the tropical models are forecasting.
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cieldumort
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CDO-like feature appears to have been given a little additional boost from some shear, perhaps. Deep convection now, with possibly a pull back to the north of the LLCC, after an initial adjustment to the north, which was only followed by a readjustment to the south after some impressive and fortuitous microwave passes came in.
Doing some quick back of the hand sketching, I come up with T3.0 to T3.5 at this time, using a blend of shear, and curved band methods. Covering the bases...
SAB just came back with 3.0 at 0545 UTC. It will be interesting to see what does with the next advisory, but I suspect that whatever the next advisory comes in at might be tempered just a bit as the nocturnal maximum may have run its course.
A few ship reports that came in well outside of the coc and also outside of any deep convection were already running 20-33 knots. Wouldn't it be enlightening to have the benefit of a few center fixes right about now.
I suspect that Bertha might be worthy of at least a 55+/- MPH advisory coming up. Seems entirely plausible. It appears that Bertha is a little stronger, earlier, which adds yet more argument for her spinning off into never never land out at sea. However, its worth noting that recently has been trending a little left.
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CaneTrackerInSoFl
Storm Tracker
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Posts: 395
Loc: Israel
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Taking a look at the satellite right now, there has been a burst of deep convection to the north of the LLC that has persisted and grown over the past few hours. Now, it is still on the north side of the LLC but it is a rather impressive bloom of convection.
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Andrew 1992, Irene 1999, Katrina 2005, Wilma 2005
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LoisCane
Veteran Storm Chaser
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Posts: 1236
Loc: South Florida
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Really a period of transition in the Atlantic. Watching the WV loop there is a strong ULL spinning in the North Atlantic and a high that is going to deepen. There was a door for her to re-curve early but she missed it. SAL really got sucked into her yesterday via her bands. Today she looked like she was getting rid of the tail she was carrying and not that long tail is back with the other mentioned convection.
Have to wait and see down the road what next chance thing comes along to re-curve her but it's too early to just call her a fish and close the book.
Especially with the saying "AS THE STORM REMAINS SOUTH OF A MID-TROPOSPHERIC RIDGE.
THE TRACK HAS NOW SHIFTED WESTWARD AND HAS JOINED THE REMAINDER
OF THE MODEL GUIDANCE.."
The also intensifies her in a few days. So, keep watching and as always it's a wait and see.
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http://hurricaneharbor.blogspot.com/
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danielw
Moderator
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Loc: Hattiesburg,MS (31.3N 89.3W)
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I'm not very good with graphics, but I'll give this a layman's version of a shot.
I've cropped some of the upper air maps from to show the upper air cuurents at 850mb (5000ft) and 200mb (38000ft).
The first two are from the area around Tropical Storm Bertha. And the latter two are from the GOM and NW Caribbean area.
The links will take you to the latest upper air charts of the Atlantic and Eastern Pacific Oceans.
The contour lines indicate clockwise ( High pressure) circulation and counter-clockwise (Low pressure) circulation. The numbers are the wind speeds at that altitude at the time of the map.
Anti-cyclonic circulation at 200mb, over cyclonic circulation at 850mb would normally be favorable for strengthing. SSTs and other parameters would also have to be in place.
070408 1800Z or 2 PM EDT today.
200mb-38000ft
850mb-5000ft
Gulf of Mexico and NW Caribbean Sea
200mb-38000ft
 30-50 knots of wind shear present in W. GOM
850mb-5000ft
NHC links to the 850mb and 200mb charts.
http://www.nhc.noaa.gov/tafb/QUNA00.jpg
http://www.nhc.noaa.gov/tafb/QHQA17.jpg
Trropical Storm Bertha, appears to be slightly increasing in intensity. Due mainly to the indication of higher, colder cloud tops near the center. The 'rainbow' enhancement would seem to indicate some type of wind shear or dry air on the western side of the system. Notice the difference in the low and mid level blue-grey clouds on the left side of the storm.
The lower larger circular area underneath the storm appears to be tilted somewhat to the upper right side of the photo, or to the northeast.
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DarleneCane
Verified CFHC User
Reged: Sat
Posts: 20
Loc: Miami Beach, FL
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Is this new view of Bertha a matter of shear or is she moving more to the left/west and less to the wnw?
http://www.ssd.noaa.gov/eumet/eatl/avn-l.jpg
Her convection is very bright further to the south and her appearance is not very cyclone like. She looks more like a comet in space. However, on this loop below you see her whole circulation better.
http://www.ssd.noaa.gov/eumet/eatl/rgb.jpg
Is she having problems because of cooler water temps, shear or fast forward speed?
On one hand the fast forward speed hurts her and yet on the other hand it will get her to warmer water faster.
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Scratch my back with a lightning bolt
Thunder rolls like a bass drum note
The sound of the weather is Heaven's ragtime band
Edited by DarleneCane (Sat Jul 05 2008 09:20 AM)
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craigm
Storm Tracker
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Posts: 327
Loc: Palm City, Florida
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Bertha no longer looks to be a definite recurve.
Models are not weakening the ridge as much as they were a couple days ago. As far as her appearance not being very cyclone like this 85ghz image of Bertha actually shows good structure at the surface. The dark blues are low level clouds that return the same temperature brightness as land. Microwave reflectivity will see through and cirrus however these satellites are not geosyncronous and only update every 6 hours.
http://www.ssd.noaa.gov/PS/TROP/EATLSS85.html
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Why I'm here:
Weather hobbyist
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flanewscameraman
Weather Watcher
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Loc: Palm Beach County, FLA
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Does it appear that the high will continue to push Bertha on a more westward track
Please review rules for proper Forum use and one line posting...
Edited by Storm Cooper (Sat Jul 05 2008 10:33 AM)
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CaneTrackerInSoFl
Storm Tracker
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Posts: 395
Loc: Israel
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It actually appears as though Bertha has been jogging to the southwest this morning. Perhaps its an optical illusion due to the trying to expand but as has been stated in the discussions for many of the prior advisories, I believe it is actually jogging to the southwest as it gyrates around a general W to WNW heading.
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html
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Andrew 1992, Irene 1999, Katrina 2005, Wilma 2005
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