Category 4 Giovanna battering Madagascar

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

Share this Blog
25
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 387 - 337

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9Blog Index

5.6 magnitude earthquake shakes northern California
Posted on February 13, 2012

February 13, 2012 – SAN FRANCISCO – A 5.6 magnitude earthquake struck northern California 50 km (31 miles) from Eureka, Ca. and 352 km from Sacramento according to the USGS. The earthquake had a preliminary depth of 32 km (20.4 miles) below the surface. The earthquake is the second to strike the region in 24 hours.
Member Since: Posts: Comments:
0400Z
Enhanced Infrared (IR) Imagery (4 km Mercator)




Member Since: July 3, 2005 Posts: 426 Comments: 129090
Tropical Cyclone Giovanna





















Click Images for larger image.
Member Since: Posts: Comments:
384. HadesGodWyvern (Mod)
Fiji Meteorological Services
Tropical Disturbance Summary
TROPICAL DEPRESSION 13F
12:00 PM FST February 14 2012
=================================

At 0:00 AM UTC, Tropical Depression 13F (1007 hPa) located at 16.6S 161.0E is reported as slow moving. Position fair based on multisatellite visible imagery with animation and peripheral surface observations. Sea surface temperature is around 29C.

Organization has improved slightly in the past 24 hours. Convection has increased slightly in the past 24 hours. Llcc partially exposed. Cyclonic circulation extends upto 700 HPA. TD 13F lies under 250 HPA ridge axis in a low sheared environment.

Global models are yet to pick the system.

The potential for this system to develop in to a tropical cyclone in the 24-48 hours is low.
Member Since: May 24, 2006 Posts: 51 Comments: 46145
383. HadesGodWyvern (Mod)
Fiji Meteorological Services
FLASH
TROPICAL CYCLONE JASMINE (12F)
15:00 PM FST February 14 2012
=================================

TROPICAL CYCLONE WARNING.
A GALE WARNING REMAINS IN FORCE FOR THE TONGATAPU GROUP.
A STRONG WIND WARNING REMAINS IN FORCE FOR THE VAVA'U AND HA'APAI GROUP.


At 3:00 AM UTC, Tropical Cyclone Jasmine, Category One (987 hPa) located at 21.0S 176.4W has 10 minute sustained winds of 45 knots. The cyclone is reported as moving north at 4 knots.
Member Since: May 24, 2006 Posts: 51 Comments: 46145
Quoting AussieStorm:
VIDEO: Mini tornado near Newcastle


Just once in my life I'd like to experience something like this. Then again, I might even piss my pants too.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting aspectre:
365 KoritheMan "Interesting that most of the deep convection in relation to Giovanna is in the northern semicircle. In the Northern Hemisphere we would expect this, but in the Southern Hemisphere, westerly flow is found north of the center. Hard to get moisture with offshore flow."

Atmospheric saturation caused by Kelvin-Helmholts instability?...

..playing off of Madagascar's mountainous spine instead of the condo towers in PanamaCity,Florida?


Even I learned something new today. Thank you!
Member Since: Posts: Comments:
VIDEO: Mini tornado near Newcastle
Member Since: Posts: Comments:
Quoting WxGeekVA:


You can tell the EWRC was just beginning at the end of the loop....



Don't appear that way to me....if you look you can see the double eye wall and the inner eye wall collapsed and a NEW eye had already begin to form as ONE!
Member Since: Posts: Comments:
365 KoritheMan "Interesting that most of the deep convection in relation to Giovanna is in the northern semicircle. In the Northern Hemisphere we would expect this, but in the Southern Hemisphere, westerly flow is found north of the center. Hard to get moisture with offshore flow."

Atmospheric saturation caused by Kelvin-Helmholtz instability?...

..playing off of Madagascar's mountainous spine instead of the condo towers in PanamaCity,Florida?
Member Since: Posts: Comments:
Well its my bedtime. be back tomorrow morning! Madagascar residents, your in my prayers!
Member Since: August 4, 2011 Posts: 46 Comments: 4488
Member Since: Posts: Comments:
Quoting TampaSpin:


You can tell the EWRC was just beginning at the end of the loop....
Member Since: September 3, 2011 Posts: 13 Comments: 3476
372. flsky
Hurricanes a threat to off-shore wind farms.

Link
Member Since: Posts: Comments:
Quoting Marcineonkomba:
We were expecting huge storms on nosy Komba the early hours of the morning & today , but all calm. We did have rain but nothing like we expected.
Pulled our boats out of the water too.
Is the cyclone still coming?


ok after googling where that is(LOL) i found u!

You may get some heavy rainfall at times from Giovanna, but since your up towards extreme northern madagascar, you will likely avoid the worst rainfall :D

Correct me if i wrong guys.
Member Since: August 4, 2011 Posts: 46 Comments: 4488
Member Since: Posts: Comments:
Quoting Tropicsweatherpr:
Here is invest 99S,the next concern for Madagascar? First visible shows is organizing at a good rate.



I mention that and the future of that system in my new blog with 99S and Giovanna, Link
Member Since: August 4, 2011 Posts: 46 Comments: 4488
Quoting KoritheMan:
Interesting that most of the deep convection in relation to Giovanna is in the northern semicircle. In the Northern Hemisphere we would expect this, but in the Southern Hemisphere, westerly flow is found north of the center. Hard to get moisture with offshore flow.


Sometimes that happens as the Eye Wall cycling and Angular Momentum favors the Opposite Semi-circle rather than the one expected.

That would be a good thesis subject if not covered in depth already maybe.
Member Since: July 3, 2005 Posts: 426 Comments: 129090
Member Since: Posts: Comments:
Interesting that most of the deep convection in relation to Giovanna is in the northern semicircle. In the Northern Hemisphere we would expect this, but in the Southern Hemisphere, westerly flow is found north of the center. Hard to get moisture with offshore flow.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting Patrap:
All we can do is watch, wait, and maybe send one up to one's deity or Higher Power as Millions are under that CDO..





CDO is nearly on top of the capital city...NOT GOOD!
Member Since: Posts: Comments:
Quoting uncwhurricane85:


nice im only about 10 miles from you down 495.....how bout that huge snow 2 nights ago...we got a dusting actually cause it was so dry and piled up next to everything there is still some on the left side of the house where the son hath not shine!
im hopeing these models stay together and we at least get a 3+ inch snow storm before this winter is over


Same here on both counts. I had a dusting, and I really hope it does snow on Sunday!!!
Member Since: September 3, 2011 Posts: 13 Comments: 3476
Komba is Far Nwest Madagascar and will only feel fringe effects.

Antsohihy, Madagascar wunderpage








Member Since: July 3, 2005 Posts: 426 Comments: 129090
Very well explained....

Member Since: Posts: Comments:
Quoting washingtonian115:
I live in N.W D.C


nice im only about 10 miles from you down 495.....how bout that huge snow 2 nights ago...we got a dusting actually cause it was so dry and piled up next to everything there is still some on the left side of the house where the son hath not shine!
im hopeing these models stay together and we at least get a 3+ inch snow storm before this winter is over
Member Since: Posts: Comments:
Radiation hits Tokyo from 2/13 to 2/15
Posted by Mochizuki on February 13th, 2012 · 7 Comments

Meteocenter Swiss forecast the radiation flow from Fukushima.
According to the report, wind of 10m and 500m height will blow from Fukushima to Tokyo.
Radiation is assumed to widely hit Tokyo from 3:00 AM 2/14/2012 to 8:00 AM 2/15/2012 (JST).
It’s better to wear a mask or stay inside as much as possible.





Fall-out intensively increased in Fukushima
Posted by Mochizuki on February 13th, 2012 · 4 Comments

While reactor2 was being heated, fall-out level in Fukushima intensively increased.

Until 9:00 AM of 2/11/2012,
Cesium 134 : 4.45 MBq/km2
Cesium 137 : 6.46 MBq/km2


However, 9:00 AM 2/11/2012 ~ 9:00 AM 2/12/2012,
Cesium 134 : 98.2 MBq/km2
Cesium 137 : 139 MBq/km2
Member Since: Posts: Comments:
We were expecting huge storms on nosy Komba the early hours of the morning & today , but all calm. We did have rain but nothing like we expected.
Pulled our boats out of the water too.
Is the cyclone still coming?
Member Since: Posts: Comments:
Can you believe it went down to 44F in Puerto Rico? Yes,it occured early on Monday morning in Adjuntas on the Central part of the island.It tied the record low made in 1980.

Link
Member Since: April 29, 2009 Posts: 75 Comments: 14557
All we can do is watch, wait, and maybe send one up to one's deity or Higher Power as Millions are under that CDO..



Member Since: July 3, 2005 Posts: 426 Comments: 129090
Quoting wunderweatherman123:
what category did giovanna make landfall?


Current Intensity Analysis



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

----- Current Analysis -----
Date : 14 FEB 2012 Time : 020000 UTC
Lat : 18:47:17 S Lon : 48:00:13 E


TROPICAL CYCLONE OVER LAND
NO ADT ANALYSIS AVAILABLE





Member Since: July 3, 2005 Posts: 426 Comments: 129090
Hello Tropical Depression 13F...No clue where you came from because I don't typically track these systems in the Southern Pacific and Hemisphere, but ok.

Member Since: Posts: Comments:
352. HadesGodWyvern (Mod)
351. wunderweatherman123 2:56 AM GMT on February 14, 2012

110-115 knots estimate from the RSMC advisories. Category 3 at least..
Member Since: May 24, 2006 Posts: 51 Comments: 46145
what category did giovanna make landfall?
Member Since: Posts: Comments:
Quoting uncwhurricane85:


yes in springfield!! obvisouly you do, what part are you in?
I live in N.W D.C
Member Since: Posts: Comments:
303 aspectre "Hokay. Anybody know the coordinates of Giovanna's landfall? it's current position?"
304 KoritheMan "Isn't that your forte? ;) "

Nope, I just draw straight lines through other people's coordinates. But shoulda refreshed before asking. Patrap almost posted the answer with the windfield map in 300.


306 TropicalAnalystwx13 "That's your job. Use your mappy thing. :P "

Hokay, eyeballing the wind map, looks like the center is at 19.5s49.07e offshore. Which makes a landfall 104miles(167kilometres) southsouthwest of Toamasina(TMM) at 19.55s48.9e plausible after drawing a straight line through JTWC's last reported position for Giovanna's center and the center coordinate eyeballed off the windfield map.

Not perfect, but then neither is my eyeball.
Extending the line further, Giovanna's center should pass ~83miles(~133kilometres) south of Antananarivo(TNR)
TNR to TMM is ~134miles(~215kilometres)

Copy&paste nos, tmm-tnr, 18.7s51.5e-19.5s49.07e, 19.5s49.07e-19.55s48.9e, 18.7s51.5e-20s47.48e, tmm-19.55s48.9e, tnr-20s47.48e into the GreatCircleMap for a closer look at details.
Member Since: Posts: Comments:
Note the SST's during the 36 to 48 hr marks

Member Since: July 3, 2005 Posts: 426 Comments: 129090
Towers erupting in the Invest's Convective structure.


SH992012 - INVEST


Storm Relative 1km Geostationary Visible Imagery





Enhanced Infrared (IR) Imagery (4 km Mercator)

Member Since: July 3, 2005 Posts: 426 Comments: 129090
Quoting sunlinepr:
Mystery epidemic devastates Central American region
By FILADELFO ALEMAN, MICHAEL WEISSENSTEIN
updated 2/12/2012 6:13:41 AM ET


In town in Nicaragua's sugar-growing heartland, studies have found more than one in four men show symptoms of chronic kidney disease....

A mysterious epidemic is devastating the Pacific coast of Central America, killing more than 24,000 people in El Salvador and Nicaragua since 2000 and striking thousands of others with chronic kidney disease at rates unseen virtually anywhere else. Scientists say they have received reports of the phenomenon as far north as southern Mexico and as far south as Panama.

Link

On the scale of things 24,000 people since 2000 is really not to much. Seasonal flu death avg is about 36,000/yr. No need to panic but still needs be looked at for sure.
Member Since: Posts: Comments:
345. HadesGodWyvern (Mod)
Quoting allancalderini:
If 99S is name how it would be calL?


who ever has the responsibility of naming it as it makes Tropical Storm winds using the 10 minute average.

Australia would be Koji
Mauritius would be Hilwa

however if Australia names it and it moves west of 90E it would be Koji-Hilwa.
Member Since: May 24, 2006 Posts: 51 Comments: 46145
If 99S is name how it would be calL?
Member Since: Posts: Comments:
Mystery epidemic devastates Central American region
By FILADELFO ALEMAN, MICHAEL WEISSENSTEIN
updated 2/12/2012 6:13:41 AM ET


In town in Nicaragua's sugar-growing heartland, studies have found more than one in four men show symptoms of chronic kidney disease....

A mysterious epidemic is devastating the Pacific coast of Central America, killing more than 24,000 people in El Salvador and Nicaragua since 2000 and striking thousands of others with chronic kidney disease at rates unseen virtually anywhere else. Scientists say they have received reports of the phenomenon as far north as southern Mexico and as far south as Panama.

Link
Member Since: Posts: Comments:
. I am surprised the doc has not been in for a visit.
Member Since: September 27, 2007 Posts: 1 Comments: 21744
Quoting uncwhurricane85:


yes in springfield!! obvisouly you do, what part are you in?


Fairfax City here!!!
Member Since: September 3, 2011 Posts: 13 Comments: 3476
Member Since: Posts: Comments:
Look at the massive amount of moisture Giovanna pulled into its circulation. Incredible.
Member Since: September 27, 2007 Posts: 1 Comments: 21744
338. HadesGodWyvern (Mod)
TCWC Perth is mentioning Christmas (Cocos Island) right now.. CMC about next week shows models near Rodriques.. St. Brandon islands.
Member Since: May 24, 2006 Posts: 51 Comments: 46145
Member Since: Posts: Comments:

Viewing: 387 - 337

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9Blog Index

Top of Page

About

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