A Brazilian tropical disturbance to watch
An area of disturbed weather has formed off the coast of Brazil, near 18S 38W. This disturbance has the potential to develop into subtropical or tropical depression early next week. Satellite winds estimates from the WindSat instrument show an elongated area of converging winds, but no organized surface circulation. Satellite loops show little organization to the cloud pattern, and only limited heavy thunderstorm activity. Wind shear over the region is about 20 knots, which is rather high, and should keep any development slow. Sea surface temperatures are about 28°C, about 1°C above average, and plenty warm enough to support a tropical storm.
Figure 1. Morning visible satellite image of the Brazilian disturbance.
Several global models, such as the ECMWF, UKMET, and NOGAPS models have been developing this system in recent runs. Phase space diagrams form Florida State University confirm that this storm is expected to primarily be a warm-cored system, meaning it will probably be classifiable as a subtropical or tropical storm if it attains surface wind speeds of at least 39 mph. The system is capable of bringing heavy rains to the Brazilian coast while it is in its formative stages over the next few days, but I doubt that these rains would be heavy enough to cause flooding concerns. By Monday, the storm should be headed southwards or south-eastwards out to sea, and it appears unlikely that Brazil would see tropical storm-force winds of 39+ mph from this system. I give this storm a low (< 30% chance) of developing into a tropical or subtropical depression by Sunday.
Figure 2. The MODIS instrument on-board NASA's Aqua satellite captured this true-color image of a rare tropical cyclone in the South Atlantic ocean just off the coast of Santa Catarina and Rio Grande do Sul, Brazil's southernmost states. The National Hurricane Center in Miami estimated the storm was a full-fledged, Category I hurricane with central winds between 75 mph and 80 mph (121 kph to 129 kph), making it the first hurricane in the South Atlantic in recorded history.
Comparisons to Cyclone Catarina
Brazil has had only one landfalling tropical cyclone in its history, Cyclone Catarina of March 2004. Catarina is one of only six known tropical or subtropical cyclones to form in the South Atlantic, and the only one to reach hurricane strength. Tropical cyclones rarely form in the South Atlantic Ocean, due to strong upper-level wind shear, cool water temperatures, and the lack of an initial disturbance to get things spinning (no African waves or Intertropical Convergence Zone exist in the proper locations in the South Atlantic to help spawn tropical storms). Today's disturbance is located much closer to the Equator than where Catarina formed. Thus, it has warmer waters to work with, and potentially less wind shear.
I'll probably do a quick update this weekend.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 — Blog Index
It usually is boring....at least if you've lived here a long time, especially the last few years. I don't generally pay much attention to the weather here unless something like today happens. We're used to snow here, and that's the only form of severe weather we ever get. Some of the last few summers have seen some scary stuff though. 2005 (a freaky year in every way) was the hottest summer I can remember, and we had a tornado 60 miles to the north of me. To put that in perspective, there was only 1 tornado reported in Alaska before that in recorded history, and that was in the interior where convection generally forms. We only get 1 or 2 thunderstorms per year here because we're close to the water.
In 2005 we had cloud-to-ground lighting during the night but I didn't get to see it (I still have never seen lightning in my life), and more thunderstorms than any other summer. The National Weather Service had to issue a severe thunderstorm warning for my county for the first time ever.
LOL! I don't think SO, at least not today!
Your baby boy's first spring is coming, xcool!
I bet. The downpours must be insane too. The maximum dBZ I've seen here was like 40 (light orange on WU radar). My brother has been on one trip to Wisconsin in the summertime and said the thunderstorms are like taking a shower, like literally pouring water, when you step outside.
Lol
A Gulf coast summer thunderstorm rain is painful, like bb's.
Lol wow...
SL 80 2010030500 BEST 0 181S 253W 20 1007 TD
SL 80 2010030506 BEST 0 187S 270W 20 1007 TD
SL 80 2010030512 BEST 0 194S 284W 20 1007 TD
SL 80 2010030518 BEST 0 200S 300W 20 1009 TD
1974 (Sub Tropical)
1991
2004 (2 storms Catarina and a TD)
2006
2009 (Subtropical)
Those seasons look like this
so really there is no correlation between South Atlantic and North Atlantic hurricanes
The posts have no snow on top of them because the temperature has actually risen a little bit above freezing at sea level because we are now in the warmest quadrant of the storm, but tonight the temperature will crash into the teens and lake-effect could dump another foot on us overnight.
GFS RUN
CAN.GEM.MODEL
I didn't know you could do that with html lol.
This is the site to go to for most up-to-date imagery (every hour). The disturbance is more disorganized than yesterday and is currently just an open surface trough of low pressure with scattered moderate convection. I'm not nearly as impressed with it, but it still has time to play around, and there is still a small chance for tropical development. It's starting to look like this system can't handle 20 knots of westerly shear though.
Were not even sure it will develop
nice to get a taste of hurricane season again though
how are you able to do that?
Thanks for the link, I hope it does develop! It would be fun to watch a South Atlantic Cyclone.
HTML tag but I have a problem with WU, and I have no idea why. Everyone else seems to be able to use tags in here like font and marquee but I never have been able to. Whenever I enter the correct code it just shows normal text as if I had not entered any html. It drives me nuts.
Do you use Firefox, IE?
Chrome....in Firefox I can't even see Keeper's text scrolling, but in Chrome I can. Even the font tag doesn't work for me watch:
this text should be big and red
hmm thats odd...
Now I'll try the same thing in Firefox and see if it works:
this text should be big and red
Edit: nope....sigh
Don't think so. I type up basic HTML all the time in here (Chrome doesn't have the buttons for images and links on top of the comment box so I have to do the code manually). But outside of the very basic tags none of them will work....right down to the simple font tag that works everywhere and is used in here all the time by other people. It's frustrating...
Quote him and look at the format of the code in your active typing box. It's there, just be careful with the reproduction of it. Right, KOG? :)
I did...it's a simple code and it doesn't work. I did the same thing when tampaspin uses the font tag and it's all correct but it doesn't work.
The question is, what's different? You are not bound by your browser. It's in the format. Good luck ! Gotta go >>> L8R
I can see the eye, lol
LOL...yeah well the low center isn't quite where the eye is :P
Yeah you can see it very visible just northeast of Homer, Alaska on the radar.
The back side seems to have less moisture, but probably more windy, with the straight line winds coming off the band going over homer.
Viewing: 101 - 151
Page: 1 | 2 | 3 | 4 | 5 — Blog Index