Category 4 Giovanna battering Madagascar

By: Dr. Jeff Masters , 2:45 PM GMT on February 13, 2012

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Earth's most dangerous storm of 2012 is Tropical Cyclone Giovanna, which is bearing down on Madagascar as a powerful Category 4 storm with 145 mph winds. Giovanna is predicted to hit a heavily populated portion of the east coast of the island near 22 GMT tonight as a Category 3 storm, then move inland, passing near the capital of Antananarivo as a Category 1 storm on Tuesday morning. The outer spiral bands of the storm have already moved over the island, bringing heavy rains and gusty winds.


Figure 1. Visible image from NASA's Terra satellite of Tropical Cyclone Giovanna approaching Madagascar, taken at 6:35 UTC Monday February 13, 2012. At the time, Giovanna was a Category 4 storm with 145 mph winds. Image credit: NASA.


Figure 2. Webcam view of the skies over the Andila Beach Hotel in northwest Madagascar, taken at 6:15pm local time on Monday February 13, 2012. Image credit: Andilana Beach Hotel.

The forecast: not good
Recent microwave satellite imagery (Figure 3) shows that Giovanna has concentric eyewalls, and it likely that the inner eyewall will collapse today as the storm undergoes an eyewall replacement cycle. This process should gradually weaken the storm, and I expect Giovanna will weaken slightly to a still very dangerous Category 3 storm with 125 - 130 mph winds at landfall. However, the eyewall replacement cycle will spread out the storm's hurricane-force winds over a larger area, increasing the storm surge. A 70-mile long swath of the coast that is heavily populated will receive sustained hurricane-force winds tonight. Rainfall amounts in excess of eight inches in a 24-hour period are expected along the center of Giovanna's path. These rains will cause extensive flooding and major damage to the country, and the storm is likely to be one of the top three most expensive disasters in Malagasy history. The damage potential is higher than for previous storms of similar intensity, due to the considerable deforestation Madagascar has experienced over the past 30 years. Madagascar lost 8.3% of its forest cover between 1990 and 2010 and is now just 22% forested, according to mongabay.com. Flood waters run off quicker from deforested land, reach higher heights, and cause greater damage.


Figure 3. Microwave satellite image of Tropical Cyclone Giovanna taken at 12:30 UTC (7:30 am EST) Monday, February 13, 2012. The echo-free eye is surrounded by two concentric eyewalls, the sign of a storm undergoing an eyewall replacement cycle. Image credit: Navy Research Lab, Monterrey.

Madagascar's tropical cyclone history
The strongest and deadliest tropical cyclone ever recorded in Madagascar was Tropical Cyclone Gafilo, which hit the northern end of the island on March 7, 2004, as a Category 5 storm with 160 mph winds. Galfilo dumped up to 20 inches of rain on the island, and its winds and flooding rains killed 363 people and did $250 million in damage, making it the deadliest and second most expensive storm in Madagascar's history. Gafilo's central pressure of 895 mb made it the second strongest tropical cyclone ever recorded in the Southern Hemisphere, behind the 890 mb central pressure of Tropical Cyclone Zoe of December 2002, which affected Fiji and the Solomon Islands. With a central pressure of 937 mb, Giovanna is a much less intense storm than Gafilo was.

Jeff Masters

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overland significanly weaker and continues to weaken
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Quoting WxGeekVA:


Snowstorm now forecasted on 4 models on Sunday for the mid-Atlantic....


when is this?????
Member Since: August 4, 2010 Posts: 0 Comments: 570
Toamasina, Madagascar weather station:


Current Temperature: 24°C
High: 29°C | Low: 25°C
Rain/Windy
Visibility: 4.01 km
Feels like: 24°C
Humidity: 89%
Wind: 61.15 km/h

Updated Mon, 13 Feb 2012 8:59 pm EAT
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

Dvorak numbers still support Category 4 hurricane status at this moment.
they will drop take a look on satalite her eye is clouded and her eyew on ingrared is filled and collapsed reminds me of jova when she was a 115mph or 120mph cat 3
Member Since: August 23, 2011 Posts: 0 Comments: 1243
Quoting yqt1001:


Strongest landfall since Nalgae (September 2011). Strongest storm since Nalgae also. Excluding Nalgae, you have to go all the way back to Nanmandol in August to find another stronger cyclone and landfall. (Hilary peaked at 125kts in September though)

2011 was really a boring year when it came to strong cyclones. 2012 isn't shaping up to be a strong storm year either.
So? Its'nt that better?.I'm sure the Phillipines wouldn't want a repeat of 2009 and what they had to go through.Nor Florida and the Gulf coast would want a repeat of 04/05....
Member Since: August 14, 2010 Posts: 10 Comments: 15715
Quoting wunderweatherman123:
doesnt look like 145 eyewall collapsed and thanks to the shear it probably is making landfall as a cat 3 and also another EWRC aswell save madagascar from a 4 but it really doesnt matter it will have the same devastating effects

Dvorak numbers still support Category 4 hurricane status at this moment.
Member Since: July 6, 2010 Posts: 109 Comments: 30266
Quoting TropicalAnalystwx13:

145 mph winds.


Strongest landfall since Nalgae (September 2011). Strongest storm since Nalgae also. Excluding Nalgae, you have to go all the way back to Nanmandol in August to find another stronger cyclone and landfall. (Hilary peaked at 125kts in September though)

2011 was really a boring year when it came to strong cyclones. 2012 isn't shaping up to be a strong storm year either.
Member Since: November 19, 2010 Posts: 1 Comments: 1285
Quoting yqt1001:




We have landfall.
B****.
Member Since: August 14, 2010 Posts: 10 Comments: 15715
Quoting TropicalAnalystwx13:

145 mph winds.
doesnt look like 145 eyewall collapsed and thanks to the shear it probably is making landfall as a cat 3 and also another EWRC aswell save madagascar from a 4 but it really doesnt matter it will have the same devastating effects
Member Since: August 23, 2011 Posts: 0 Comments: 1243
Quoting yqt1001:




We have landfall.

145 mph winds.
Member Since: July 6, 2010 Posts: 109 Comments: 30266
Updated Reynolds SST anomaly.



S. Atlantic cold anomaly is more than offset by the warm anomalys.

Warm anomaly grew in both the Gulf and the Nw. Atlantic.




Pacific side seems to have warmed "slightly" from top to bottom.
Member Since: January 25, 2012 Posts: 32 Comments: 1503
Quoting VAbeachhurricanes:


Thats with no low pumping in cold air off the coast, if the forecast changes you could see them fall. However nothing on the GFS is showing that happening.


In this case, the GFS is the outlier....
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Quoting TropicalAnalystwx13:

That IS for Sunday.

Mine--

Sunday: Mostly sunny, with a high near 55.

Washington, D.C.--

Sunday: Mostly sunny, with a high near 50.


Thats with no low pumping in cold air off the coast, if the forecast changes you could see them fall. However nothing on the GFS is showing that happening.
Member Since: September 6, 2007 Posts: 0 Comments: 5697




We have landfall.
Member Since: November 19, 2010 Posts: 1 Comments: 1285
Quoting TropicalAnalystwx13:

That IS for Sunday.

Mine--

Sunday: Mostly sunny, with a high near 55.

Washington, D.C.--

Sunday: Mostly sunny, with a high near 50.



This is mine:

Saturday: Mostly sunny, with a high near 47.

Saturday Night: Partly cloudy, with a low around 30.

Sunday: Partly cloudy, with a high near 45.

Sunday Night: Mostly clear, with a low around 30.
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maybe it would snow some in the morning when its freezing, then change to rain during the day. i would hope to have some thunderstorms but i gotta wait for that
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Quoting Ameister12:
Giovanna is nearing landfall. Even though the storm isn't quite as strong as it was last night, it will still be a very devastating storm for Madagascar.
That looks really bad.
Member Since: September 27, 2007 Posts: 1 Comments: 19558
Quoting aspectre:
121 Remoterivers "Posting from Morondava, Madagascar.
How does the photo of a hotel and the name of the hotel in Nosy Be contribute to the worth of this page? Updated information would be more in order. We need information and look to you...
"

It doesn't except to demonstrate the extent of the area that Giovanna is affecting.
Problem is, the eg JointTyphoonWarningCenter issues reports every 6hours. The timing of the JTVC's public advisories is restricted by "agreements between sovereign nations" giving local weather services first say and more frequent say.

And those local sovereign nations' weather advisories&forecasts are only so-so. Not their fault: small and/or underdeveloped nations ain't got the multi-billion dollars to build&operate computer centers to handle all of the incoming data. Which leaves them guesstimating the latest conditions and making forecasts based on hours-old info provided by the LARGE FirstWorld weather services.

And it doesn't help that JTWC is consistently extremely late in providing updates:
eg "Tropical Cyclone 12S (Giovanna) Warning #10 Issued at 13/1500Z [3pmGMT]"
for the nominal "131200Z [noonGMT]" update.


there are plenty of other weather forecasting offices issuing updates on Giovanna then the JTWC.
Quoting TropicalAnalystwx13:

It's entirely too warm for that. Temperatures will be in the 50s here in North Carolina all the way up to D.C.


:D GFS says 47 for me, NWS 52. i expect the NWS will low theirs a few degrees until it is very close to the GFS temperature. seems they always fall into line with GFS on temperature when its close..
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Quoting TropicalAnalystwx13:

That IS for Sunday.

Mine--

Sunday: Mostly sunny, with a high near 55.

Washington, D.C.--

Sunday: Mostly sunny, with a high near 50.
Their have been times where the forecast has change dramatically in the past.I've witnessed it a few times.February 6 2007 comes to mind...Do I hope for snow?.No not this time around I have some busy things to attend to.Maybe later before it starts to warm up.
Member Since: August 14, 2010 Posts: 10 Comments: 15715
Quoting WxGeekVA:


Right now they are but Sunday they might be....

That IS for Sunday.

Mine--

Sunday: Mostly sunny, with a high near 55.

Washington, D.C.--

Sunday: Mostly sunny, with a high near 50.
Member Since: July 6, 2010 Posts: 109 Comments: 30266
Quoting TropicalAnalystwx13:

It's entirely too warm for that. Temperatures will be in the 50s here in North Carolina all the way up to D.C.


Right now they are but Sunday they might not be....
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Quoting WxGeekVA:


Snowstorm now forecasted on 4 models on Sunday for the mid-Atlantic....

It's entirely too warm for that. Temperatures will be in the 50s here in North Carolina all the way up to D.C.
Member Since: July 6, 2010 Posts: 109 Comments: 30266
Quoting WxGeekVA:


I do too but it's SNOW! There hasn't been enough so far so I could do with one weekend of being snowed in....
Well right now our local forecast has a high of 52 on Sunday.Could be some future changes then.
Member Since: August 14, 2010 Posts: 10 Comments: 15715
Quoting nymore:
Ice expands in 3 dimensions so while extent also helps cracking or heaving so does thickness. You can witness this effect if you go ice fishing. During the day when it gets warm you will hardly hear or feel the ice crack or heave, keep staying out on the ice as the temperature drops you will hear and feel more cracks and the colder it get the more violent it cracks and heaves.

Don't take my word for it ask Minnesota Mike or 1911Maker or anyone who has spent a lot of time on the ice.

Btw the larger the body of water the bigger the problem when surrounded mostly by land
Oh, I've lived and worked on and around the ice in Minnesota, Canada, North Dakota, Wyoming, etc., so I have a good understanding of its behavior. (I used to play hockey on the frozen St. Croix River, and was always amazed at just how thunderously loud the BOOM! of the cracking ice could be as the temperature dropped in the evening.) My point was, however, that compared to past years, Arctic Sea ice is not really expanding much this year at all--just a few percent of normal--so the large-scale cracking and fissuring we're seeing on satellite is most likely not due to simple expansion. (Too, there are more polynas in the area than usual, and that's a cause for wonder, if not concern.)
Member Since: Posts: Comments:
121 Remoterivers "Posting from Morondava, Madagascar.
How does the photo of a hotel and the name of the hotel in Nosy Be contribute to the worth of this page? Updated information would be more in order. We need information and look to you...
"

It doesn't except to demonstrate the extent of the area that Giovanna is affecting.
Problem is, the eg JointTyphoonWarningCenter issues reports every 6hours. The timing of the JTWC's public advisories is restricted by "agreements between sovereign nations" giving local weather services first say and more frequent say.

And those local sovereign nations' weather advisories&forecasts are only so-so. Not their fault: small and/or underdeveloped nations ain't got the multi-billion dollars to build&operate computer centers to handle all of the incoming data. Which leaves them guesstimating the latest conditions and making forecasts based on hours-old info provided by the LARGE FirstWorld weather services.

Admittedly it doesn't help that JTWC is consistently extremely late in providing public updates:
eg "Tropical Cyclone 12S (Giovanna) Warning #10 Issued at 13/1500Z [3pmGMT]"
for the nominal "131200Z [noonGMT]" update.
Member Since: Posts: Comments:
Quoting washingtonian115:
Mmmmmm is that so...I hope not.I have a very busy weekend comming up for me.Can't afford to put anything on hold.


I do too but it's SNOW! There hasn't been enough so far so I could do with one weekend of being snowed in....
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Quoting WxGeekVA:


Snowstorm now forecasted on 4 models on Sunday for the mid-Atlantic....
Mmmmmm is that so...I hope not.I have a very busy weekend comming up for me.Can't afford to put anything on hold.
Member Since: August 14, 2010 Posts: 10 Comments: 15715
Quoting bohonkweatherman:
From Snow and Sleet Sunday to 70s today, typical Texas weather.

lol
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From Snow and Sleet Sunday to 70s today, typical Texas weather.
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Quoting Tropicsweatherpr:


I fear the most for the flooding that will occur. My prayers go to them.

I am worried about that and two other things,
I am worried on the fact that there is alot of mountainous terrain and too much rain can cause mudslides (or landslides im not sure)
I just hope everyone there is secure or at least more then a half got to atleast the western part of Madagascar to seek refuge.
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Multiplatform Tropical Cyclone Surface Winds Analysis (MTCSWA)
Member Since: July 3, 2005 Posts: 415 Comments: 125628
Advanced Dvorak Technique (ADT)
Version 8.1.3
Tropical Cyclone Intensity Estimation Algorithm


Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 13 FEB 2012 Time : 183000 UTC
Lat : 19:07:19 S Lon : 49:55:54 E


CI# /Pressure/ Vmax
6.5 / 921.2mb/127.0kt


Final T# Adj T# Raw T#
6.2 6.0 6.0

Estimated radius of max. wind based on IR :N/A km

Center Temp : -45.3C Cloud Region Temp : -74.9C

Scene Type : EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 200km
- Environmental MSLP : 1002mb

Satellite Viewing Angle : 23.8 degrees



Member Since: July 3, 2005 Posts: 415 Comments: 125628
Quoting Neapolitan:
Normally there growth rate in the Arctic Sea is slowing by now, but this year it's been basically stagnant. As I mentioned earlier, in the past four weeks, just under 20,000 square kilometers of ice area have been added, a mean average of just 707 km2 per day. Over that same time span last year, more than a million square kilometers were added--an amount more than 50 times as great. IOW, there's not a lot of expanding going on at the moment. And yet the ice breaks.
Ice expands in 3 dimensions so while extent also helps cracking or heaving so does thickness. You can witness this effect if you go ice fishing. During the day when it gets warm you will hardly hear or feel the ice crack or heave, keep staying out on the ice as the temperature drops you will hear and feel more cracks and the colder it get the more violent it cracks and heaves.

Don't take my word for it ask Minnesota Mike or 1911Maker (if they have spent much time on a frozen body of water) or anyone who has spent a lot of time on the ice.

Btw the larger the body of water the bigger the problem when surrounded mostly by land
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Snowstorm now forecasted on 4 models on Sunday for the mid-Atlantic....
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Quoting earthlydragonfly:
Anyone? I think I got lost in the ICE Quake

Sorry. Yes, the left front quadrant of a Southern Hemisphere cyclone is generally the most intense. And since Giovanna is moving in a WSW direction and is about to move over a coast that runs SSW to NNE, the storm's southwestern quadrant will be at the left front.

One thing that strikes me is that Giovanna seems to be a very slow mover, and that, unfortunately means lots of time for lots of rain to fall. Lots and lots and lots of rain--over a mostly hilly and denuded landscape.

Not to sound apocryphal, but this is going to be a major flooding event.
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Quoting BobWallace:


So far no reported damage. (I live close to the epicenter and the local radio station has been getting a lot of calls.)

Someone about four miles from me called in to say that their mobile home shook badly. My house's foundation is embedded in rock and I felt nothing.

Yikes. :/
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Quoting Articuno:

Last time an earthquake of that magnitude hit that part of california was around 8-12 months ago.


So far no reported damage. (I live close to the epicenter and the local radio station has been getting a lot of calls.)

Someone about four miles from me called in to say that their mobile home shook badly. My house's foundation is embedded in rock and I felt nothing.
Member Since: February 22, 2011 Posts: 0 Comments: 1344
Quoting TropicalAnalystwx13:

T-numbers are running 6.2, 6.0, 6.0, meaning that Giovanna will make landfall with winds near 135-140 mph.

It's probably going to make landfall around that intensity, unfortunately. All we can do is pray for the people of Madagascar.
Member Since: August 9, 2009 Posts: 10 Comments: 4499
Flakes just starting to fall in C IL, 3-4" expected. Like most this yr, gone in two days as highs near 50 expected midweek.

For those who like costumed pets check out stltoday.com for pics of Soulard Mardi Gras Pet Parade.
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Quoting Ameister12:
Giovanna is nearing landfall. Even though the storm isn't quite as strong as it was last night, it will still be a very devastating storm for Madagascar.


I fear the most for the flooding that will occur. My prayers go to them.
Member Since: April 29, 2009 Posts: 75 Comments: 13311
They formatted a time stamp for us.


Member Since: July 3, 2005 Posts: 415 Comments: 125628
Quoting RitaEvac:
5.5 aint much for Cali

Last time an earthquake of that magnitude hit that part of california was around 8-12 months ago.
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Quoting Ameister12:
Giovanna is nearing landfall. Even though the storm isn't quite as strong as it was last night, it will still be a very devastating storm for Madagascar.

T-numbers are running 6.2, 6.0, 6.0, meaning that Giovanna will make landfall with winds near 135-140 mph.
Member Since: July 6, 2010 Posts: 109 Comments: 30266
Giovanna is nearing landfall. Even though the storm isn't quite as strong as it was last night, it will still be a very devastating storm for Madagascar.
Member Since: August 9, 2009 Posts: 10 Comments: 4499
Anyone? I think I got lost in the ICE Quake

Quoting earthlydragonfly:
Afternoon everyone... So since this storm is in the southern Hem... Does that mean the South West quadrant of the storm is the most dangerous?
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Quoting nymore:
At this time of year when the ice is expanding, I don't think so. As I said earlier this does not necessarily hold true for the edges of the ice or to glaciers which work on a different mechanism.
Normally the growth rate in the Arctic Sea is slowing by now, but this year it's been basically stagnant. As I mentioned earlier, in the past four weeks, just under 20,000 square kilometers of ice area have been added, a mean average of just 707 km2 per day. Over that same time span last year, more than a million square kilometers were added--an amount more than 50 times as great. IOW, there's not a lot of expanding going on at the moment. And yet the ice breaks.
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Wasn't there numerous small to moderate quakes in Japan before the big 9.0?
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5.5 aint much for Cali
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Quoting TropicalAnalystwx13:

.............

Ok..


lol my image wasn't working so I modified the comment...
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Quoting WxGeekVA:


.............

.............

Ok..
Member Since: July 6, 2010 Posts: 109 Comments: 30266

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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.