Jamaica system continues organizing

By: Dr. Jeff Masters , 1:44 AM GMT on October 15, 2005

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A broad 1005 mb low pressure area centered just south of the island of Jamaica continues to become better organized tonight. The areal coverage of the deep convection continues to increase, and a very impressive thunderstorm blow-up with very cold cloud tops has appeared just east of the island. Upper-level outflow has now appeared on the west and north sides of the system, and an upper level anti-cyclone has developed on top. Wind shear continues to drop, but more slowly than this afternoon, and is still in the 5 - 10 knot range. All these factors support continued development, and a tropical depression is likely to form here by Sunday. One complicating factor may be the presence of Jamaica so close to where the center is trying to form. This may slow development by half a day or so at most, since Jamaica is a relatively small island.

Global computer models forecast that the shear will continue to decrease over the area Saturday and Sunday, and the disturbance is expected to stay in the central or western Caribbean for at least the next five days, which would give ample time for this system to grow into a hurricane. The latest 18Z (2pm EDT) run of the GFS model is very unimpressed with this system, and keeps it a weak disturbance that gets swept up in a trough and pulled northeastward into the Bahamas. While this track is certainly possible, the GFS is probably underdoing the intensity. The environment this system is embedded in is very favorable for intensification into a hurricane. However, the 18Z run of the GFDL model is definitely overdone; it brings the system up to hurricane strength Saturday night, and then to a major hurricane by mid-week as it slowly tracks towards Honduras or Belize. While the GFDL is bringing this system to hurricane strength too fast, it does have the right idea about this potentially being a major hurricane. I believe that if this system stays in the western Caribbean for the next five days, the chances of it becoming a major hurricane are good. The GFDL had a very similar idea with Hurricane Rita--only it was too fast with its intensity forecast, and Rita ended up being a major hurricane three days after the GFDL originally forecasted this to happen.

It bears repeating that the eventual track of any tropical storm or hurricane that forms is impossible to forecast with any reliability, since steering currents are very weak and a some erratic motion is likely. The UKMET and NOGAPS models favor a track towards Honduras and Belize, while the GFS takes the system northeast across Cuba and the Bahamas. The early track models (i.e., BAM, LBAR and VICBAR models) have not been run yet for this system, but I will post them when they become available. If this system does eventually affect the U.S., the most likely target would be the Florida Keys or southwest Florida, as there are many troughs of low pressure whizzing by that would grab this system and steer it to the northeast once it got far enough north.

Cape Verdes tropical disturbance
A tropical disturbance about 500 miles southwest of the Cape Verde Islands continues to have some potential for slow development as it tracks west-northwest over the open ocean.

New England
New England continues to suffer the onslaught of a very wet stream of tropical air from the southeast that has caused nine straight days of rain. The axis of moisture has shifted slightly eastwards today, finally giving New York City a break from the 6 - 8 inches of rain that has fallen the past two days alone. This tropical onslaught will continue moving northeast over the weekend before exiting northern Maine on Sunday.


Figure 2. Lots of rain in the Northeast the past week, but currently just a few areas of major river flooding, in New Jersey.

Katrina's winds revisited
In my last blog entry on this subject, we discussed the Florida Sun-Sentinel article commenting on new findings that indicate Katrina was only a Category 3 hurricane at first landfall near the mouth of the Mississippi, and a Category 1 hurricane over New Orleans. The article was rather imprecise in its use of the Category system for ranking hurricanes, and I interpreted the article to mean that Katrina was a Category 1 at landfall in Mississippi. Upon re-reading the article, I think what they were trying to say was that Katrina had Category 1 force winds over New Orleans, not that the storm itself was a Category 1. As several of you have pointed out, it is pretty difficult to have a hurricane with a 927 mb pressure (Katrina's pressure at landfall in Mississippi) with just Category 1 winds. Katrina was a least a strong Category 2, and perhaps a weak Category 3 hurricane at landfall in Mississippi. While Katrina did have unusualy high winds aloft compared to surface winds (which NHC noted on one of their discussions during the storm), this difference was not enough to make Katrina a Category 1 hurricane at landfall in Mississippi. Sorry for sowing the confusion!

My next post will be Saturday morning about 11am.

Jeff Masters

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118. Skyepony (Mod)
2:21 PM GMT on October 15, 2005
Jeff's got his new post up
Member Since: August 10, 2005 Posts: 161 Comments: 37360
117. snowboy
2:14 PM GMT on October 15, 2005
Morning all,

IR and WV satellite images of "Wilma-to-be" seem to show continued development of heavy convection and thunderstorms and also that the whole system has moved a bit to the west.

Any guesses on when Wilma-to-be gets TD status? My bet is by the 5 pm update today.
Member Since: September 21, 2005 Posts: 10 Comments: 2547
116. billsfaninsofla
2:12 PM GMT on October 15, 2005
Poof......... be gone....
Member Since: September 5, 2005 Posts: 0 Comments: 5461
115. palmettobug53
1:06 PM GMT on October 15, 2005
Morning, all. Lefty, thanks for that link last night on the southern cyclone last year. Now that I think back on it, I do remember hearing about it. Too much trivia in the brain had it blocked! lol
Member Since: October 7, 2005 Posts: 232 Comments: 24977
114. MysteryMeat
1:02 PM GMT on October 15, 2005
Lefty -- the Brazil hurricane was actually named Catalina, because of where she (?) landfalled. The Brazilians were all "durh that's not a hurricane we never get hurricanes here never mind that's a weather system with a warm core and a distinct eye" and the NHC was all "yeah whatever you morons it's a hurricane".

There WERE Katrinas in the Eastern Pacific in 1967, 1971 and 1975, the last of which, oddly enough, was the strongest storm of the season with 135 mph sustained winds. There were also Katrinas in the Australian region in the 80's and 90's. Rita also does the trifecta as a North Pacific name in 1941, a Fiji list name (which could come up this year) and of course our cane. Those girls get around.

Member Since: September 25, 2005 Posts: 0 Comments: 260
113. Hecker
12:23 PM GMT on October 15, 2005
Is anyone else getting "forbidden" errors when trying to access the Navy microwave data? Whaat is going on here?
Member Since: June 29, 2005 Posts: 24 Comments: 308
112. Hecker
12:20 PM GMT on October 15, 2005
Latest QuickScat on Jamaica area


and Atlantic wave
Member Since: June 29, 2005 Posts: 24 Comments: 308
111. Sheraqueenofthebeach
11:39 AM GMT on October 15, 2005
With that....POOF!
Member Since: August 2, 2005 Posts: 156 Comments: 3140
110. Sheraqueenofthebeach
11:38 AM GMT on October 15, 2005
SAD
Member Since: August 2, 2005 Posts: 156 Comments: 3140
109. Sheraqueenofthebeach
11:36 AM GMT on October 15, 2005
SAD is not a lack of Vitamin D BTW....
Member Since: August 2, 2005 Posts: 156 Comments: 3140
108. olefosse
11:10 AM GMT on October 15, 2005
Looks like a teeny-weenie typo snook in there....
"develepåment" is what comes out of fingers with the agility of elbows trying to write "development"................
107. olefosse
11:06 AM GMT on October 15, 2005
Is something brewing in the Bay of Campeche?
Formation of high, cold clouds and winds seen in the 30 knot range. I think the conditions for develepåment of a depression here look favorable.
The thing over Jamaica should be named soon. If this is not a depression by now, I don't know what it takes to be one. It Looks like it is growing up quickly now.
106. leftyy420
7:35 AM GMT on October 15, 2005
sj u out there?
Member Since: August 24, 2005 Posts: 35 Comments: 1987
105. theboldman
7:24 AM GMT on October 15, 2005
leftyy wait im going to have to get used to michael lol

listen to your aunt she means bissness lol
Member Since: September 8, 2005 Posts: 25 Comments: 2
104. theboldman
7:21 AM GMT on October 15, 2005
well michael iu dont know really
Member Since: September 8, 2005 Posts: 25 Comments: 2
103. leftyy420
7:11 AM GMT on October 15, 2005
so bold man why u have to post messages from my family in here lol
Member Since: August 24, 2005 Posts: 35 Comments: 1987
102. theboldman
5:52 AM GMT on October 15, 2005
wow there iis someone here
Member Since: September 8, 2005 Posts: 25 Comments: 2
101. weatherspirit
5:45 AM GMT on October 15, 2005
might help if I posted the link, huh?
Link
100. weatherspirit
5:44 AM GMT on October 15, 2005
i've updated my blog with pics of my gilfriend's house and neighborhood, showing how it faired during Katrina's winds... bringing it a little closer to home...
99. theboldman
5:38 AM GMT on October 15, 2005
hello anyone here
Member Since: September 8, 2005 Posts: 25 Comments: 2
98. cirrocumulus
5:23 AM GMT on October 15, 2005
Rain totals were high in New York and elsewhere.
Member Since: September 30, 2005 Posts: 0 Comments: 1606
96. theboldman
5:02 AM GMT on October 15, 2005
Posted By: LeftysAunt at 9:57 PM PDT on October 14, 2005.
Michael, what a great site and it will be nice to stay in touch with your life this way. I look forward to your future posts and your future pictures. These last ones were great....you really need to search out a school for weather reporting and do it. Life is so short and you don't want to have any regrets as you get older. Take the time to follow your dreams now.......I am very proud of you and I love you....

**** Like my handle? :) ****
Member Since: September 8, 2005 Posts: 25 Comments: 2
95. Skyepony (Mod)
4:58 AM GMT on October 15, 2005
Jamaica cam Link
Member Since: August 10, 2005 Posts: 161 Comments: 37360
94. Skyepony (Mod)
4:48 AM GMT on October 15, 2005
Another weekend of new tropical depression & football. That's easy to predict. Happened every 2 or 3 weeks during the season so far. We're overdue.
Jamacia's gettin drenched tonight Link (IR)
Member Since: August 10, 2005 Posts: 161 Comments: 37360
93. theboldman
4:47 AM GMT on October 15, 2005
hey all whats going on
Member Since: September 8, 2005 Posts: 25 Comments: 2
92. taco2me61
4:10 AM GMT on October 15, 2005
Hi all it sure has been a while for me but I thought I would at least say hey to everybody and know that we will have Wilma real soon and where she goes only god knows...
Member Since: July 7, 2005 Posts: 6 Comments: 3237
91. CrazyC83
4:05 AM GMT on October 15, 2005
Looks like (God forbid) another Mitch...please, say it ain't so! Don't let Wilma send Central America back to the Stone Age!
Member Since: September 19, 2005 Posts: 0 Comments: 142
90. FLPanhandle
3:55 AM GMT on October 15, 2005
Good night Lefty. Thanks for your perspective and all the info you provide and I wouldn't worry about the jealousy others have. I guess they resent that they themselves are not the go to guys on this blog for data or perspective and feel they must teach humility.
89. code1
3:45 AM GMT on October 15, 2005
Good luck with family and daughter Panhandle. Know the feeling. Nite 8888.
Member Since: September 18, 2005 Posts: 66 Comments: 13872
88. FLPanhandle
3:44 AM GMT on October 15, 2005
Does code1 refer to the status of an aircraft after a flight?
87. FLPanhandle
3:42 AM GMT on October 15, 2005
I don't go as often as I should. I travel quite a bit for work also and between preparing for storms this summer, helping family in MS, raising a 7 year old, and trying to keep my 21 year old in college there has not been much time for other things. Hope your daughter continues to be cured of her cancer.
86. 8888888889gg
3:39 AM GMT on October 15, 2005
NIGHT TOO
85. code1
3:34 AM GMT on October 15, 2005
Sorry, didn't read the post, no I don't want to hear Willllma either. I go to the island as well, unless I go with her. Much quieter there and no tourists. Not home much though as I travel for work. Feel like I went to the beach more before I moved here a few years ago.
Member Since: September 18, 2005 Posts: 66 Comments: 13872
84. FLPanhandle
3:29 AM GMT on October 15, 2005
Good night, I won't be much longer either.
83. FLPanhandle
3:28 AM GMT on October 15, 2005
Yes, but it has been a while since I have been. Went in my younger days when I was all over. We normally go to the island now. Also used to go to Navarre.
82. code1
3:28 AM GMT on October 15, 2005
Mail Leftyy. Nite all going to bed!
Member Since: September 18, 2005 Posts: 66 Comments: 13872
81. palmettobug53
3:23 AM GMT on October 15, 2005
Yeah, way past time for me to log out and hit the hay.
Member Since: October 7, 2005 Posts: 232 Comments: 24977
80. code1
3:22 AM GMT on October 15, 2005
Be safe coming home Finn! Everyone else, beware of melanoma in the sun. My daughter had a bad scare at 24 years old. Just released this year (will be 27 in a few weeks) for 6 months. After the major surgery and 21 biopsies later. And she was raised up north. Blond and blue eyed though. She still goes to the beach some now, but wears 50 sunscreen and sits under a tent. This is at the WhalesTale for Shalimar, you know where it is.
Member Since: September 18, 2005 Posts: 66 Comments: 13872
79. FLPanhandle
3:21 AM GMT on October 15, 2005
Good night.
78. leftyy420
3:20 AM GMT on October 15, 2005
nite
Member Since: August 24, 2005 Posts: 35 Comments: 1987
77. LakeWorthFinn
3:19 AM GMT on October 15, 2005
hate to go, probably you'll all witness Wilma named while I sleep Grrrrrrrr night al and THANKS
Member Since: October 6, 2005 Posts: 67 Comments: 7279
76. leftyy420
3:18 AM GMT on October 15, 2005
heres a really good ir loop of the south atlantic hurricane

Link
Member Since: August 24, 2005 Posts: 35 Comments: 1987
75. palmettobug53
3:18 AM GMT on October 15, 2005
That's why I put the link in. Everyone can just go read about it. LOL
Member Since: October 7, 2005 Posts: 232 Comments: 24977
74. hurigo
3:18 AM GMT on October 15, 2005
Sometimes, here on this blog, I feel that we are all like those great characters in OJ's in Donald Westlake's Dortumunder novels.
Member Since: October 9, 2005 Posts: 100 Comments: 6729
73. leftyy420
3:16 AM GMT on October 15, 2005
it says podssible cause is lack of meltonin. i think like with all mental health issues its really hard to pin point exactly what it is. but its likley a combo of meltonin and vitamin d. whi knows lol
Member Since: August 24, 2005 Posts: 35 Comments: 1987
72. LakeWorthFinn
3:16 AM GMT on October 15, 2005
FLPanhandle, LOL
Member Since: October 6, 2005 Posts: 67 Comments: 7279
71. hurigo
3:14 AM GMT on October 15, 2005
And Finland diet high in fish (omega protein)low mealtonin. Okay, I'll stop as this is tropical blog.
Member Since: October 9, 2005 Posts: 100 Comments: 6729
70. palmettobug53
3:13 AM GMT on October 15, 2005
Went back and looked it up. Ain't Vit. D. It's melantonin, which was what I was thinking but didn't want to say in case I was wrong.
Here's a link:


Link
Member Since: October 7, 2005 Posts: 232 Comments: 24977
69. FLPanhandle
3:12 AM GMT on October 15, 2005
Jupiter,

With some of the people on this blog you might want to add female between blond and Finn. LOL
68. hurigo
3:12 AM GMT on October 15, 2005
Currently there is a South Indian Ocean Storm Advisories
Tropical Cyclone 01s ...
Member Since: October 9, 2005 Posts: 100 Comments: 6729

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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.