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

Share this Blog
4
+

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.

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: 3456 - 3406

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76Blog Index

Quoting mikatnight:


Fish Storm means it doesn't strike land, or doesn't make landfall.


something fishy in that explanation...
Member Since: Posts: Comments:
Quoting P451:
African Coastline including TD2 - 22 hour loop.



Looks like it jogged southwestward on those last few frames. Interesting...
Member Since: Posts: Comments:
Quoting juniort:
Good morning to all, can someone explain what does fish storm mean and also what is SAL


It is a storm that turns into the open Atlantic and will not effect land. and Sal means Saharan air layer.



Member Since: March 19, 2009 Posts: 0 Comments: 1421
Quoting serialteg:


saharan air layer = sal

a fish storm is just that, a storm full of fish


"Fish" is used to refer to a storm that heads out to sea without affecting land
Member Since: Posts: Comments:
Quoting juniort:
Good morning to all, can someone explain what does fish storm mean and also what is SAL


Fish Storm means it doesn't strike land, or doesn't make landfall.
Member Since: Posts: Comments:
Quoting juniort:
Good morning to all, can someone explain what does fish storm mean and also what is SAL


saharan air layer = sal

a fish storm is just that, a storm full of fish
Member Since: Posts: Comments:
I'm out for now. Just a wait and see game for the rest of the day.

Will catch up later.
Member Since: Posts: Comments:
3449. WxLogic
Quoting kmanislander:


Good morning.

I had half expected to see TD2 as a TS this morning but it continues to struggle with organization. The wave that just came off the coast may do better as it is further S.

It would be ironic if the "Bill" wave became "Ana"


lol... no doubt.
Member Since: Posts: Comments:
Quoting StormW:
Good morning!

Hot off the press.

TROPICAL WEATHER SYNOPSIS / T.D.2 AUGUST 12, 2009 ISSUED 8:10 A.M. EDT


very good!

i have to laugh with the acronyms ... especially at the end it gets rather dense for us bare amateurs. "the GOMEX SST's on the THCP for SEUS" hehe
Member Since: Posts: Comments:
3447. juniort
Good morning to all, can someone explain what does fish storm mean and also what is SAL
Member Since: Posts: Comments:
Quoting mikatnight:
Mornin'folks,
I see the WU GFS (initialized at 0z on 8/12) is back to kickin' Florida butt.





But, it looks like we're not the only ones...





Thanks to all of you who post these models. It's hard to look them up at work!
Member Since: Posts: Comments:
Thanks Storm...Nice Update
Member Since: Posts: Comments:
Yeah can become Ana at any point.. it's not like it has to make a major leap to TS status.. 5mph and that's all.

It just won't do much else at this stage until it sorts itself out and/or finds a slightly better environment.
Member Since: Posts: Comments:
3442. java162
Quoting P451:


I tend to agree. Somewhere around 12.5-13.0 right? Subtle but seems to be there.

WV 22HR



yep, exactly


Member Since: Posts: Comments:
Homegirl and Chicklit, those are great images showing where the COC is. In fact, near exposed centers are a common feature of sheared systems or ones that are impacted by very dry air on one side of the circulation.
Member Since: Posts: Comments:
I think it will "Ana" by 11am today, jmo.
Member Since: Posts: Comments:
Mornin'folks,
I see the WU GFS (initialized at 0z on 8/12) is back to kickin' Florida butt.





But, it looks like we're not the only ones...



Member Since: Posts: Comments:
Quoting WxLogic:


Morning Kman...


Good morning.

I had half expected to see TD2 as a TS this morning but it continues to struggle with organization. The wave that just came off the coast may do better as it is further S.

It would be ironic if the "Bill" wave became "Ana"
Member Since: Posts: Comments:
The center looks to be catching up with the main area of convection now if you closely at visible loops.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
3431. KEEPEROFTHEGATE (Mod)
002

WHXX01 KWBC 120650

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

0650 UTC WED AUG 12 2009



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



TROPICAL CYCLONE TWO (AL022009) 20090812 0600 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

090812 0600 090812 1800 090813 0600 090813 1800



LAT LON LAT LON LAT LON LAT LON

BAMS 14.6N 31.9W 14.9N 34.1W 15.2N 36.6W 15.6N 39.4W

BAMD 14.6N 31.9W 15.1N 34.2W 15.3N 37.1W 16.0N 40.1W

BAMM 14.6N 31.9W 15.2N 34.0W 15.5N 36.6W 16.1N 39.4W

LBAR 14.6N 31.9W 14.9N 34.1W 15.5N 36.6W 16.2N 39.7W

SHIP 30KTS 36KTS 44KTS 49KTS

DSHP 30KTS 36KTS 44KTS 49KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

090814 0600 090815 0600 090816 0600 090817 0600



LAT LON LAT LON LAT LON LAT LON

BAMS 16.0N 42.3W 17.7N 49.1W 19.9N 56.5W 22.9N 64.3W

BAMD 16.9N 42.8W 19.5N 47.6W 22.8N 51.1W 25.0N 53.1W

BAMM 16.8N 42.1W 18.8N 48.1W 21.4N 54.5W 24.4N 60.8W

LBAR 17.0N 42.6W 19.5N 48.0W 23.1N 52.2W 27.5N 52.3W

SHIP 54KTS 62KTS 56KTS 47KTS

DSHP 54KTS 62KTS 56KTS 47KTS



...INITIAL CONDITIONS...

LATCUR = 14.6N LONCUR = 31.9W DIRCUR = 270DEG SPDCUR = 10KT

LATM12 = 14.6N LONM12 = 29.9W DIRM12 = 273DEG SPDM12 = 10KT

LATM24 = 14.4N LONM24 = 27.9W

WNDCUR = 30KT RMAXWD = 30NM WNDM12 = 25KT

CENPRS = 1006MB OUTPRS = 1012MB OUTRAD = 150NM SDEPTH = M

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting cajunkid:
Link

models
Thanks!
Member Since: Posts: Comments:
Quoting Cotillion:


Have certainly been worse looking tropical storms. Barry of '07 comes readily to mind.


I think if the convection is misplaced but still connected to the low level coc and the wins speed is over 40 mph they almost have to name it.
Member Since: Posts: Comments:


This is a great image to show where the circulation is in association with the convection. I know I already posted it, but as quick as it's moving, I figured some might have missed it. You can see the LLC is clearly on the E side of the main convection and partially exposed. KMan is right, the storm can't strengthen with the lack of organization.
Member Since: Posts: Comments:
Quoting TreasureCoastFl:


Where is the high now and where will it be when it moves west? The ridge will block storms from going north?


According to the map here Link

There seems to be a high in the gulf now. I think the ridge would block a storm from going north.
Member Since: Posts: Comments:
Link

models
Member Since: Posts: Comments:
3424. WxLogic
Quoting kmanislander:
Good morning all

Based upon the QS pass and the sat images it would appear that the COC with TD2 is very near the NE edge of the convection and at risk of exposure. This is a poorly organized TD with all the heavy convection off to the SW of the low center.


Morning Kman...
Member Since: Posts: Comments:
Quoting CybrTeddy:
They've declared TD's tropical storms that have exposed Circulations.


Have certainly been worse looking tropical storms. Barry of '07 comes readily to mind.
Member Since: Posts: Comments:
They've declared TD's tropical storms that have exposed Circulations.
Member Since: July 8, 2005 Posts: 259 Comments: 23918
Hey all, I just got a pop up on my Mac that wanted me to open a .pdf file . I didn't but thought I'd let you all know.
Member Since: Posts: Comments:
Quoting kmanislander:


That is where I see it. It will not reach TS strength lopsided like that but there is always the possibility of the COC relocating deep within the heavy convection. If that were to happen it would dramatically alter both track and intensity forecasts.


Yes, indeed. Shear is the main problem, though dry air is a seeming constant. The shear's on its south side, and will remain like that for a few hours. In about 6-12 hours it should get past the 20kts of shear, to more conducive environment of 5-15.

The tendency isn't showing any major change from this either. May improve tonight unless as you say, it relocates prior to then.
Member Since: Posts: Comments:
Quoting cajunkid:


yep, but the models keep bridging the high all the way back to the Gulf. This blog is going to go crazy today.
can you post a link to those models please?
Member Since: Posts: Comments:
Quoting P451:



I don't know about that image. How can the center be so far displaced to the ENE?

I think something is off there...


The image is correct. See this from the Discussion

"Microwave and shortwave infrared data suggest the center remains on
the eastern side of the convection and not well-embedded within the
main convective cluster."
Member Since: Posts: Comments:
Quoting cajunkid:


yep, but the models keep bridging the high all the way back to the Gulf. This blog is going to go crazy today.


Freakin' madhouse!
Member Since: Posts: Comments:
NHC 8 am out threeyellow and one TD. No a storm yet
Member Since: Posts: Comments:
Looks like TD2 (Ana to be)? may have its center exposed on the east side shortly.
Member Since: Posts: Comments:
Quoting IKE:


If it developed quickly, odds are it would be a fish-storm.

One huge wave...may take time to really get going.


yep, but the models keep bridging the high all the way back to the Gulf. This blog is going to go crazy today.
Member Since: Posts: Comments:
P451, thanks for those movies! Awesome.

I imagine the lopsided convection/lack of organization is what's keeping the NHC from upgrading at this time.

I agree with you though WXlogic, I've seen the NHC classify a TS with less than what's there now.
Member Since: Posts: Comments:
Quoting Cotillion:


That is where I see it. It will not reach TS strength lopsided like that but there is always the possibility of the COC relocating deep within the heavy convection. If that were to happen it would dramatically alter both track and intensity forecasts.
Member Since: Posts: Comments:
Quoting homelesswanderer:
NWS Lake Charles is not too impressed with anything. Not a mention of a trough, wave, anything. But they did say this fwiw

THE FRONT WILL GRADUALLY WASH OUT BY THE WEEKEND AS THE
BERMUDA HIGH BUILDS WEST.


Where is the high now and where will it be when it moves west? The ridge will block storms from going north?
Member Since: Posts: Comments:
Good morning,
Navy chart for TD2 this a.m.

Looks like Navy has it at 14.5N 32W at 6 a.m. Zulu time.
Member Since: Posts: Comments:
3407. java162
looking at the last couple of loops of the new african wave, it appears that the system is begining to spin.
Member Since: Posts: Comments:
Post 3385. Thanks, all that needs is a TD. Question for all. yellow means Tropical activity may start. TD meana tropical activity has started?
Member Since: Posts: Comments:

Viewing: 3456 - 3406

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76Blog 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.

Local Weather

Mostly Cloudy
77 °F
Mostly Cloudy