Little change to 99L, which remains very close to tropical depression status
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
Reader Comments
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 — Blog Index
OCTOBER 25-31.
No problem.
Use your site almost every day and I've also sent it to quite a few people over the past few months.
Thanks for putting it together!
I'm not sure that's irony. :o) Irony is dedicating your life to saving the whales and then getting eaten by a whale. Irony is writing an entire song about irony in which none of the examples are actually ironic.
About 17N, 82W
Thanks a lot!
12z HWRF.
900mb winds of 136 knots
LOL
OK...I respectfully withdraw the word "Ironically". Better? ;-)
(Not for the faint of heart)
5 day cone would still be in the NW Caribbean.
Probably just 1 or 2 Trolls causing trouble. Ignore!
Nice job setting in panic into the site :P haha jk. The HWRF isn't very realistic in its intensity forecast over the next 24-48 hours.
Given the model spread, the 5 day cone will likely be a giant circle with the middle being the current COC and extending from Panama to the Bahamas...might as well include Florida and New Orleans in there.
POSS T.C.F.A.
XX/XX/99L
MARK
17.73N/81.88W
Reed: Don't woory about the dowmcasting Reed haters. You are my Favorite Wishcaster. That is a complament.
Do you think it will go into FL?
5 1/4 days from now. 12Z GFDL
WHXX01 KWBC 201814
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1814 UTC WED OCT 20 2010
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
DISTURBANCE INVEST (AL992010) 20101020 1800 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
101020 1800 101021 0600 101021 1800 101022 0600
LAT LON LAT LON LAT LON LAT LON
BAMS 17.1N 82.2W 16.9N 82.1W 16.2N 82.3W 15.2N 82.9W
BAMD 17.1N 82.2W 17.5N 81.5W 17.6N 81.3W 17.7N 81.6W
BAMM 17.1N 82.2W 16.8N 82.0W 16.3N 82.3W 15.7N 83.0W
LBAR 17.1N 82.2W 17.2N 81.5W 17.9N 81.3W 19.1N 81.4W
SHIP 30KTS 32KTS 35KTS 38KTS
DSHP 30KTS 32KTS 35KTS 38KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
101022 1800 101023 1800 101024 1800 101025 1800
LAT LON LAT LON LAT LON LAT LON
BAMS 14.4N 83.7W 12.9N 85.7W 13.0N 88.1W 14.4N 90.2W
BAMD 17.8N 82.3W 17.4N 85.1W 17.3N 89.7W 18.2N 92.9W
BAMM 15.0N 84.1W 13.7N 87.5W 12.9N 91.1W 12.7N 93.3W
LBAR 20.7N 81.5W 24.6N 81.9W 28.0N 80.7W 30.9N 73.9W
SHIP 45KTS 59KTS 61KTS 60KTS
DSHP 35KTS 28KTS 30KTS 29KTS
...INITIAL CONDITIONS...
LATCUR = 17.1N LONCUR = 82.2W DIRCUR = 120DEG SPDCUR = 4KT
LATM12 = 17.8N LONM12 = 82.9W DIRM12 = 90DEG SPDM12 = 3KT
LATM24 = 17.4N LONM24 = 83.4W
WNDCUR = 30KT RMAXWD = 70NM WNDM12 = 30KT
CENPRS = 1008MB OUTPRS = 1012MB OUTRAD = 200NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
$$
NNNN
Still rather unrealistic.
(Click for FULL run)
99L is a prime candidate for a center relocation to the deep convection off to the East near Jamaica but the motion to the South is bringing it underneath the high that is shearing it off and this may allow the current center to reorganize and prevent a relocation.
Many moving parts out there with this one.
Wind Speed (WSPD): 13.6 kts
Wind Gust (GST): 15.5 kts
Wave Height (WVHT): 3.3 ft
Dominant Wave Period (DPD): 5 sec
Average Period (APD): 4.0 sec
Atmospheric Pressure (PRES): 29.75 in
Pressure Tendency (PTDY): -0.09 in ( Falling Rapidly ) Air Temperature (ATMP): 81.9 °F
Water Temperature (WTMP): 84.2 °F
Dew Point (DEWP): 75.7 °F
Heat Index (HEAT): 88.9 °F
Except that it is basically the same as the HWRF in terms of intensity. The lower intensity is because of land interaction. Same model run just prior to landfall in the Yucatan.
The XTRP model has been all over the place lately. It was due east this AM, now it's SE. odd....
I cant wait until the 18z run of the XTRP comes out.
Highly valuable model.
(Sarcasm)
I don't see them. Can you provide the post numbers?
Edited: Also, many times there may not be someone on that is able to answer your question accurately.
I don't see that. The wind has been out of the WSW there for quite some time.
Viewing: 51 - 101
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 — Blog Index