Little change to 99L, which remains very close to tropical depression status

By: Dr. Jeff Masters , 7:11 PM GMT on October 20, 2010

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A tropical disturbance (Invest 99L) centered 160 miles southwest of the Cayman Islands is moving south to southeast at 5 - 10 mph. A Hurricane Hunter flight arrived in the storm at about 11am this morning, and found a closed circulation with top winds at flight level (700 feet) of 33 mph. A closed circulation and 30 mph surface winds are necessary conditions for a tropical depression to exist, but the storm must also have a great deal of heavy thunderstorm activity near the center that persists for many hours. In the judgment of NHC, 99L does not qualify as a tropical depression in that regard. The storm is bringing heavy rain to the Cayman Islands; 4.14" inches has fallen over the past 2 1/2 days at Savannah on Grand Cayman Island. Heavy rains have diminished over the Cayman Islands, but have spread to western Jamaica and west-central Cuba this afternoon. Recent satellite imagery shows that the surface circulation center is exposed to view, and 99L has a relatively meager amount of heavy thunderstorm activity. The center is more than 80 miles west of the heaviest thunderstorm activity, and it is likely that 99L's center will relocate itself to the east to be more underneath the heaviest thunderstorms. Wind shear is marginal for development, 15 - 20 knots, due to the clockwise flow of air around an upper-level high pressure system near the coast of Honduras. The high is bringing strong upper-level winds out of the southwest to 99L. Water vapor satellite loops show considerable dry air to the west and north of 99L, and the strong southwesterly winds over the storm are bringing some of this dry into into the core of the storm, keeping all the heavy thunderstorm development confined to the east side of the center. The waters beneath 99L are very warm, 29°C, but 99L will not be able to take advantage of these warm waters until the shear relaxes. A new hurricane hunter aircraft will be in the storm tonight near 8pm EDT.

Forecast for 99L
The current southward movement of 99L is carrying the storm into a region of lower wind shear, and we should see 99L accumulate more heavy thunderstorm activity near its center beginning tonight. The latest SHIPS model forecast predicts that wind shear over the Western Caribbean will decline below 15 knots Thursday afternoon through Saturday afternoon, which should allow the storm to become a tropical depression by Thursday. Steering currents will be weak today through Friday in the Western Caribbean, making it difficult to predict where 99L may go. The models are split into two camps, with the GFDL and HWRF models taking 99L to the west-northwest over the western tip of Cuba or the Yucatan Peninsula on Sunday as a hurricane. The rest of the models take 99L to the south over Honduras on Sunday, and keep the storm below hurricane strength. Given 99L's current southward motion and the possibility that the center will relocate farther to the east later today, this makes a track to the southwest towards Honduras more likely, I predict. NHC is giving 99L a 70% chance of developing into a tropical depression by Friday, which is a reasonable forecast. I expect this will become Tropical Storm Richard by Friday.


Figure 1. Afternoon satellite image of Invest 99L.

Death toll from Super Typhoon Megi in the Philippines remarkably low
The power is still out and communications are down over the majority of the northern portion of the Philippines' Luzon Island blasted by Typhoon Megi yesterday, so the full extent of the destruction wrought by the great storm is still unclear. However, the death toll from the great storm stands at only 19, reflecting the superior effort Philippines officials made to evacuate low-lying areas and get people out of locations prone to flash flooding and mudslides. Previous major typhoons to strike the Philippines have nearly always killed hundreds, and sometime thousands, so the preparation and evacuation efforts for Megi likely saved hundreds of lives. Megi hit Luzon on Monday morning at 3:30 UTC as a Category 5 super typhoon with sustained winds of 165 mph and a central pressure of 914 mb. Severe damage was done to Isabela Province in northern Luzon, and media reports indicate that 200,000 people are homeless.


Figure 2. Visible MODIS satellite image of Megi from NASA's Aqua satellite taken at 1:30am EDT October 20, 2010. At the time, Megi was a Category 4 typhoon with 135 mph winds. Image credit: NASA.

Passage over Luzon Island destroyed Megi's eyewall and inner core region, and the storm compensated by expanding and intensifying the portions of its circulation that were over water. Now that its center is back over water in the South China Sea, Megi has re-developed its inner core and has intensified into a formidable Category 3 typhoon with 125 mph winds. Megi has been able to maintain its larger size, and is now a much larger typhoon than when it hit the Philippines. This is similar to what happened to Hurricane Ike in 2008 when it passed over Cuba, and helped give Ike a very destructive storm surge when it came ashore over Texas. Wind shear is a low 5 - 10 knots over Megi, and the waters of the South China Sea have a very high total heat content to great depth, so Megi should be able to remain a very dangerous major typhoon through Friday. The larger size of Megi means that it will be able to deliver a significant storm surge in excess of ten feet to the coast of China of Friday or Saturday, when the storm is expected to make landfall north of Hong Kong. As the storm approaches the coast on Friday, wind shear is expected to rise to the moderate or high range, and the total heat content of the ocean will drop significantly, so some weakening is to be expected. Still, Megi will probably hit China as a major Category 3 typhoon, or as a strong Category 2, bringing a significant storm surge, high winds, and widespread torrential rains that will likely make this a multi-billion dollar disaster for China. The outer rain bands of Megi are already affecting the coast of China north of Hong Kong, as seen on Hong Kong radar and Taiwan radar.


Figure 3. Still frame of damage to NE Luzon Island from a video posted to YouTube by storm chaser James Reynolds of typhoonfury.com.

Next update
I'll have an update Thursday morning.

Jeff Masters

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Quoting doorman79:


Kman,

Please tell me this isn't gonna be the surprise of the season!


Wish I could but late season in the NW Caribbean is usually an unpleasant surprise for someone.

This will be a slow mover so lots of time to watch it.
Member Since: August 19, 2006 Posts: 0 Comments: 15842
I see that we now have Tropical Depression 19. Definitely gradually becoming better organized as the circulation center has now come more in line with the deep convection and convection has increased and deepened throughout the evening. This first forecast cone will be very interesting considering the wide model spread. People from Honduras to Florida should watch this system carefully in the coming days.
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523. 7544
now the wait for the nhc cone will it show it going north to the yucatan or west and plow into ca ? my guess will be west next
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Quoting Hurricanes101:


so basically this is no threat to the US?


If it goes into the Yucatan then no probably not much of one, though it will get drawn out into the eastern gulf eventually. If it finds a way to remain offshore then we may have something bigger to deal with, but right now the most likely solution is that this runs into the Yucatan first.
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Quoting kmanislander:


Well, if you think about it the only thing that prevented an earlier designation was the lack of convection. Everything else was in place so as soon as the center slipped under the deep convection, voila !!


Your correct there, just seems odd they would not fly. Seems they are running a buoy deployment mission Friday.

B. POSSIBLE BUOY DEPLOYMENT MISSION FOR 22/1400Z.
Member Since: January 30, 2010 Posts: 0 Comments: 3259
Quoting CyclonicVoyage:


No. This will be only the 5th time, I think, that the R name may be pulled. Not 100% on that though. I know no Richard.
Well according to some of the models.We'll not only see Richard but a hurricane.But at this time a hurricane is far fetched.Not saying it couldn't happen.Becuase history shows us that it can.And why are people quoting the most stupid comments being posted at this hor.Sad.
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Quoting kmanislander:


Now the real deal begins. It will be interesting to see the initial discussion.


Kman,

Please tell me this isn't gonna be the surprise of the season!
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Quoting kmanislander:


Now the real deal begins. It will be interesting to see the initial discussion.
Link

It's official on the Navy site now.
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Quoting CyclonicVoyage:


It's official and No Recon? Seems they canceled it or flying stealth.


Well, if you think about it the only thing that prevented an earlier designation was the lack of convection. Everything else was in place so as soon as the center slipped under the deep convection, voila !!
Member Since: August 19, 2006 Posts: 0 Comments: 15842
Quoting AEKDB1990:
Has there been a storm named Richard before in the Atlantic Basin?

No. The letter 'R' has only been reached twice before in the years since naming storms began, and those were both female: Roxanne in 1995 and Rita in 2005.
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514. 7544
we might see a speacial staement its moving est and close to jamica so they might put one out

did the planetake off to the td tonight
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Quoting MiamiHurricanes09:
Yeah, it's 19L.


invest_RENUMBER_al992010_al192010.ren


Now the real deal begins. It will be interesting to see the initial discussion.
Member Since: August 19, 2006 Posts: 0 Comments: 15842
Quoting kmanislander:
99L has disappeared from the Navy site so I guess that means TD designation about to replace it ?


It's official and No Recon? Seems they canceled it or flying stealth.
Member Since: January 30, 2010 Posts: 0 Comments: 3259
Quoting kmanislander:
99L has disappeared from the Navy site so I guess that means TD designation about to replace it ?
Yeah, it's 19L.

invest_RENUMBER_al992010_al192010.ren
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting pilotguy1:


That doesn't surprise me at considering your attitude here. I just have a lot of people on ignore because they have nothing to contribute to a weather blog.


Ummm, Quoting Cosmic. A cloud moves west!!!!!!! lol
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Quoting AEKDB1990:
Has there been a storm named Richard before in the Atlantic Basin?


No. This will be only the 5th time, I think, that the R name may be pulled. Not 100% on that though. I know no Richard.
Member Since: January 30, 2010 Posts: 0 Comments: 3259
And with that, we've got our 19th tropical cyclone of the year. Not super-rare; it happened in 1995, 2000, 2003, and--of course--2005. (2003 saw five TD's that never reached TS status, while 2000 had four, along with an unnamed subtropical storm that was discovered in post-season analysis.)
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99L has disappeared from the Navy site so I guess that means TD designation about to replace it ?
Member Since: August 19, 2006 Posts: 0 Comments: 15842
Quoting WeatherNerdPR:

Super Happy Taz Time?
I'm talking weather and insted people quotind the stu...nope not gonna say it.Anyway have been on here in a long while.So were you really affected by the heavy rains from otto?
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What's the deal with them....dollar short and a day late...SFL still in the zone...boat has bilge issues...not good....
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Quoting Levi32:


It would likely be very weak if it tried to make it all the way to the north gulf coast.
Quoting Levi32:


It would likely be very weak if it tried to make it all the way to the north gulf coast.
MR. Levi32,thank you for your very accurate and proven comments.If I may ask how this system will affect South Florida (Miami area)?,do you think that we should get prepare for a hurricane event in a few days??,thanks!!
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Good Night.
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I think the 5 day cone will resemble a shape with the NOGAPS solution on the south, and the north end running a little NW of Cancun. The NHC will say it's only that far north out of respect for the outlier HWRF. Such a cone still allows for movement in any direction AFTER 5 days.
Member Since: August 3, 2005 Posts: 10 Comments: 5606
Quoting Tazmanian:
AM HAPPY AM HAPPY AM HAPPY HAPPY HAPPY HAPPY AM HAPPY OH AM HAPPY
Are you dancing on your lawn screaming "Yes! I got a full house!"? Just kidding. Congrats Taz.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Burst of -80C tops.

Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting toddbizz:
TROPICAL UPDATE WEATHER CHANNEL....8:50 PM EST...80 % chance of 99L dev...blocking ridge to the North will dissipate and move Northward next early next week...they are no longere saying don't worry about this one...as stated last night...ummmmmmm.....


Not surprising. Call them and let them know also that it's TD19 100% chance of development.
Member Since: January 30, 2010 Posts: 0 Comments: 3259
Quoting Levi32:
NAM now coming onboard with a reasonable track idea, as well as the 18z GFDL. The models are finally catching on to what's really happening.





so basically this is no threat to the US?
Member Since: March 10, 2010 Posts: 1 Comments: 7816
Quoting WeatherNerdPR:

Super Happy Taz Time?


lol yup yup
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494. 7544
the nhc 5 day cone will have it going wnw right into ca watch
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Member Since: August 2, 2010 Posts: 21 Comments: 9821
492. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #7
TROPICAL DEPRESSION 18
9:00 AM JST October 21 2010
=================================

SUBJECT: Tropical Depression Near The Marianas

At 0:00 AM UTC, Tropical Depression (1004 hPa) located at 16.7N 143.3E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving west northwest at 12 knots

Dvorak Intensity: T1.5

Forecast and Intensity
=======================
24 HRS: 15.8N 139.0E - 35 knots (CAT 1/Tropical Storm)
Member Since: May 24, 2006 Posts: 51 Comments: 45570
491. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #63
TYPHOON MEGI (T1013)
9:00 AM JST October 21 2010
=================================

SUBJECT: Category Four Typhoon In South China Sea

At 0:00 AM UTC, Typhoon Megi (940 hPa) located at 19.5N 117.4E has 10 minute sustained winds of 90 knots with gusts of 130 knots. The cyclone is reported as moving north at 8 knots

Dvorak Intensity: T5.5

Storm Force Winds
=================
120 NM from the center

Gale Force Winds
=================
300 NM from the center in northern quadrant
240 NM from the center in southern quadrant

Forecast and Intensity
=======================
24 HRS: 21.2N 118.2E - 95 knots (CAT 4/Strong Typhoon)
48 HRS: 22.4N 118.0E - 80 knots (CAT 3/Typhoon)
72 HRS: 23.9N 116.9E - 55 knots (CAT 2/Severe Tropical Storm)
Member Since: May 24, 2006 Posts: 51 Comments: 45570
Quoting CybrTeddy:
Looks like Taz gets his full house!

invest_RENUMBER_al992010_al192010.ren



if you are all wanting to no what a full house is a full house is when 90 too 99L gets name all the way down with out going bust
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Quoting toddbizz:
TROPICAL UPDATE WEATHER CHANNEL....8:50 PM EST...80 % chance of 99L dev...blocking ridge to the North will dissipate and move Northward next early next week...they are no longere saying don't worry about this one...as stated last night...ummmmmmm.....


Its a TD now. So they're wrong.
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Quoting Tazmanian:
AM HAPPY AM HAPPY AM HAPPY HAPPY HAPPY HAPPY AM HAPPY OH AM HAPPY

Super Happy Taz Time?
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TROPICAL UPDATE WEATHER CHANNEL....8:50 PM EST...80 % chance of 99L dev...blocking ridge to the North will dissipate and move Northward next early next week...they are no longere saying don't worry about this one...as stated last night...ummmmmmm.....
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Quoting TOMSEFLA:
navy site dropped 99l
They have 19L now but no info yet.
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Quoting Tazmanian:
YES !


a full house now i this need it too be come a name and it will even be better


round 3


90L be comes hermine

91L be comes IGOR

92L be comes .KARL


93L be comes JULIA

94L be comes LISA


95L be comes Matthew

96L be comes NICOLE

97L be comes Otto


98L be comes Paula

99L be comes TD 19


RICHARD!!!!
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NRL now has 19L up
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AM HAPPY AM HAPPY AM HAPPY HAPPY HAPPY HAPPY AM HAPPY OH AM HAPPY
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Quoting TOMSEFLA:
navy site dropped 99l


Because its a td now
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Looks like Taz gets his full house!

invest_RENUMBER_al992010_al192010.ren
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Quoting TOMSEFLA:
navy site dropped 99l

And now it's 19L (TD 19). An advisory should come at 11.
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Ah we have t.d 19 now.Now the question is how strong dose it get?.Where's it going?.Well we'll get a better understanding in the coming days however I think a track twords the Yucatan is possible.And a hurricane isn't out of the question.Just like I said earlier.A Puala situation is very pluasable.I also think the gulf maybe safe from this becuase of the upper air pattern over the gulf coast.And I don't see that pattern letting up anytime soon.
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Quoting hurricaneben:


Exactly what I was saying. XD! Next thing you know they're gonna start saying Invest 1000!

LOL!
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Quoting sailingallover:

Having the RADAR instead of the wind generator is probably best but have them do a Large Solar Grid Tied array to offset the radars electrical usage...
You lost me. I just know that it will be very beneficial to the entire western Caribbean. Could really use the windfarm too though as electricity prices are nuts here.
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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.

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