TD 2 forms in the Atlantic; hundreds feared dead from Typhoon Morakot; Felicia hits

By: Dr. Jeff Masters , 1:55 PM GMT on August 11, 2009

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Tropical Depression Two has formed out of the strong tropical wave off the coast of Africa we've been watching, and has a good chance of becoming the Atlantic hurricane season's first named storm. Satellite loops of the storm show that heavy thunderstorm activity is increasing near the storm's center, and low-level spiral bands are getting better established. However, dry air to TD 2's north is interfering with this process, and the storm is being slow to organize. This morning's QuikSCAT pass missed TD 2.


Figure 1. Current satellite image of TD 2.

Wind shear over the storm is low, 5 knots, and is expected to remain low to moderate, 5 - 15 knots, through Thursday. Sea Surface temperatures are a marginal 26 - 27°C, and there is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly. However, does appear likely that TD 2 has enough going for it that it will be able to become Tropical Storm Ana later today or on Wednesday. Most of the computer models show some weak development, but none of them predict TD 2 will become a hurricane. It is unusual for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands, and the current NHC forecast track aiming TD 2 north of the islands appears to be a good one.

Elsewhere in the Atlantic
Two other tropical waves, one passing through the Lesser Antilles Islands, and one about 600 miles east of the islands, are mentioned in NHC's Graphical Tropical Weather Outlook. Both of these waves have very limited heavy thunderstorm activity that is not increasing, and are not a threat to develop over the next two days. None of the computer models develop either of these waves.

A large, disorganized tropical wave is just leaving the coast of Africa, south of the Cape Verdes Islands. The GFS and ECMWF models continue to predict the possible development of this wave late this week.


Figure 2. Track and total rain amount from Typhoon Morakot. Image credit: NASA/GSFC.

Death toll from Typhoon Morakot in the hundreds
The death toll from Typhoon Morakot continues climb, as a landslide triggered by the storm's heavy rains hit the small town of Shiao Lin in southern Taiwan. Shiao Lin has a population of 1,300, and 400 - 600 people are missing in the wake of the landslide. Morakot killed an additional 41 elsewhere on Taiwan, with 60 missing. Earlier, the storm killed 22 in the Philippines, and went on to kill 6 in mainland China, which it hit as a tropical storm with 50 mph winds and heavy rain. Morakot's heavy rains caused an estimated $1.3 billion in damage to China.

Morakot moved very slowly as it passed over Taiwan, dumping near world-record amounts of rain. Alishan in the mountains of southern Taiwan recorded 91.98" of rain over a two-day period, one of the heaviest two-day rains in world history. The world 2-day rainfall record is 98.42", set at Reunion Island on March 15 - 17, 1952. Alishan received an astonishing 9.04 feet of rain over a 3-day period. The highest 1-day rainfall total ever recorded on Taiwan occurred Saturday at Weiliao Mountain in Pingtung County, which recorded 1.403 meters (4.6 feet or 55 inches) or rain. Nine the ten highest one-day rainfall amounts in Taiwanese history were reached on Saturday, according to the Central Weather Bureau.

Felicia continues to weaken, but is a flash flooding threat to Hawaii
Tropical Storm Felicia continues to steadily weaken, thanks to high wind shear of 30 knots. Recent satellite loops show that almost no heavy thunderstorm activity remains, and what little there is has been pushed to the northeast side of the center, exposing the surface center as a swirl of low clouds.


Figure 3. Tropical storm Felicia appeared as a swirl of low clouds with one spot of heavy thunderstorm activity to the northeast as it approached Hawaii yesterday evening.

High wind shear will continue to weaken Felicia today, and the storm is unlikely to cause major flooding problems as it moves over the islands today. The greatest danger of flooding will be over the northern islands, where Felicia's main moisture is concentrated.

Link to follow:
Wundermap for Hawaii

Blog comments not recommended
Someone managed to post a comment on my blog both Saturday and Monday containing links to a malicious web site that infected some people's computers when they clicked on the link. Our tech people have identified how to stop these attacks, but it will take some development time to engineer a fix. I recommend people not click on any links in comments posted on any wunderground blog unless you are highly confident of the destination of the link, or of the strength of your anti-virus software. I'll announce when the software fix has been made. I apologize to anybody who may have been affected by this. If you have specific information on which comments may have caused the problem, and who may be responsible, please submit a support ticket to help us out. At this time, it appears that actually reading comments on wunderground blogs is not a danger.

I'll have an update Wednesday morning.

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Quoting 7544:


does anyone know here now tia


Yes, it's a new WU feature due to all the virus reports. Any link you click now WU informs you you are leaving the site and are you sure you want to do it.
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Quoting cchsweatherman:


With such a deep convective burst, its become really difficult to determine a center location.

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2954. centex
I see Ana. Maybe NHC will.
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Quoting mikatnight:


Must be as a result of yesterday's incident. You read the last paragraph of the Doc'c blog, right?


This solves the problem of not knowing where a link really leads to. Not everyone has their browser set to view the status bar, therefor they cannot see where a link goes. This is a good way to help you avoid bogus links.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
2951. 7544
did the gfdl kill maybe bill for the last run
Member Since: May 6, 2007 Posts: 0 Comments: 6704
Quoting mikatnight:


Definitely tighter, but shouldn't there be some spiral banding if it were really going?


The Dvorak looks like those are trying to set up now. Should be interesting.
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little spiral banding... annular td, lol.
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Been lurking for a long time so I too should say Happy Birthday to WS. But didn't you have another alias a while back?

Wow, looks like the tropics have decided to put on a show since I left for work, may finally soon be time to christen Anna.
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Interesting graphic showing the climatology of storms that passed near to where TD#2 formed.

Link

It's safe! (NWS Tampa Bay)
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Look for a slight WSW motion in the nearterm. Looking at steering and the best convergence divergence I think that's likely. I think it's finally coming out from under the area of NW shear.
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You maybe right cchs but put it in motion at nhc and see what you think.
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2944. sctonya
Thanks Keep and everyone else that responded. I have been on this site *mainly as a lurker* for 3 or 4 years now, and I know I have never seen that before when I click on a link. Have a good nite all, and I will be back in lurk mode in the morning.
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2942. KEEPEROFTHEGATE (Mod)
T.C.F.A.

ATL BASIN
02L TD A
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What is the deal? Can't seem to view links anymore....
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90 Hours.. TD2 "Ana" weakening while the African wave "Bill" is a Hurricane that's moving westward and strengthening.

Link
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Quoting sammywammybamy:
RAPID INTESIFICATION POSSIBLE?









It is not going to rapidly intensify. Upper-level outflow, while it is definitely becoming better established, is still quite limited, due to dry air. That is also responsible for the cyclone's small size. Also, some slight easterly shear may be somewhat restricting the outflow to the east. This, along with the dry stable environment surrounding the cyclone, along with the lack of oceanic heat content in the area, makes it unlikely, no matter how small the storm is, that rapid intensification will occur.
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2938. amd
Quoting cchsweatherman:


With such a deep convective burst, its become really difficult to determine a center location.


agreed. I have no idea if the center of circulation is still on the eastern edge of the convection, or if the center of circulation is now near the center of the strongest convection.

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2937. KEEPEROFTHEGATE (Mod)
Quoting JFLORIDA:
td2

Boy that's the real thing. cold tops and all.
yep this is not a drill
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Quoting gordydunnot:
Look at davork again at nhc floater in motion looks like a center to me at 14.4 north .


With such a deep convective burst, its become really difficult to determine a center location.
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Sammay on yours it looks to be at 14.2n
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Quoting sammywammybamy:
RAPID INTESIFICATION POSSIBLE?









Definitely tighter, but shouldn't there be some spiral banding if it were really going?
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2931. KEEPEROFTHEGATE (Mod)
Quoting sctonya:


The same thing happened to me....Is this a new feature on WU?
its a new feature of wunder ground added today as a result of cyber attacks which took place sat yesterday and today resulting in lots of infected computers this action will guide you in letting you know where you are going and if any problems where they come from i have been in contact with doc via email i am sure there will be some type of posting maybe in dev. blog
or some other admin response
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If I had to bet, I would say that we will see Tropical Storm Ana at the next advisory at 5AM EST. Right now, there is no doubt in my mind that this has already become Ana. Another thing, my current thinking lies within the southern half of the forecast cone right now since I really don't see a deep enough trough to break the ridge down the road.
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Look at davork again at nhc floater in motion looks like a center to me at 14.4 north .
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18 hours and the storm forms according to the latest GFS run...

00Z GFS Link
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2926. amd
Quoting sctonya:


The same thing happened to me....Is this a new feature on WU?


yes, it was added as a way to possibly prevent malware or virus infiltration onto the WU message boards.
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Quoting sctonya:


The same thing happened to me....Is this a new feature on WU?


Must be as a result of yesterday's incident. You read the last paragraph of the Doc'c blog, right?
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2923. 7544
Quoting sctonya:


The same thing happened to me....Is this a new feature on WU?


does anyone know here now tia
Member Since: May 6, 2007 Posts: 0 Comments: 6704
Quoting cchsweatherman:


Look at the date. That image is now nearly two days old.

Busted! More than 2 days old, actually, by 20 minutes. Sorry guys.
(Anyone know how to remove dent from forehead or desk?)
Really going, now. Need sleep. G'Nite.
Thanks for catching me CCHSW. Rather it be known than to be posting junk.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
2919. 7544
ann will prob arrive after dmax tonight if it isnt ts by now but looks like one imo
Member Since: May 6, 2007 Posts: 0 Comments: 6704
2918. sctonya
Quoting 7544:

tampa spin when i click on your links i get a pop up that says this link taakes you outside wu click yes to go is this new addition to the blog thanks all will be watching anna a dmax


The same thing happened to me....Is this a new feature on WU?
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"Everything looks like Ana is due at two O'clock."
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Quoting atmoaggie:

Aqua AMSR-E caught it well. (This does not mean it is cleared)


Look at the date. That image is now nearly two days old.
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My locals are saying TD2 should be Ana soon.... (if not already)
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2913. 7544
hnmmmm

CI# /Pressure/ Vmax
3.4 / 995.2mb/ 53.0kt
Member Since: May 6, 2007 Posts: 0 Comments: 6704
2912. KEEPEROFTHEGATE (Mod)
000
AGXX40 KNHC 111723
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL


WARNINGS

ATLC...
.NONE. TS WRNG E OF AREA.

CARIBBEAN...
.NONE.

GULF OF MEXICO...
.NONE.

$$
FORECASTER NELSON


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2911. sky1989
TD2, "Ana", reminds me a lot of Chris of 2006. I wonder if its fate will be similar... Only time will tell.
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Quoting atmoaggie:

Thanks for putting that up. Seems that it may be a little higher in latitude than GFS has been spinning it up at all day. Of course, the convection doesn't show us any circulation center for a wave...on land...etc.

Put it in motion and look at the last couple of frames. Looks like maybe circulation about 2 or 3 countries down from 15N where the convection is. (Didn't know how else to explain it.) :)
Member Since: August 22, 2008 Posts: 12 Comments: 6010
Quoting sammywammybamy:
My Predictions for tommorow( I was Right on Today):


Tommorow Morning:

TS ANA 45MPH

Tommorow Night:

TS ANA 60MPH



Its not going to be 60 if it runs into that shear the SHIPs is forecasting to halt intensification.
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If TD2 really develops, nose joway does it make it to the states or Caribbean. Stays a nothingTD...maybe, and potentially develops closer.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.