Caribbean disturbance 93L continues to grow more organized

By: Dr. Jeff Masters , 2:42 PM GMT on November 05, 2008

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An area of disturbed weather (93L), a few hundred miles east of the coast of Nicaragua, continues to slowly organize. This morning's QuikSCAT pass revealed that the circulation center is broad and ill-defined, and the satellite noted winds of about 30 mph in the heaviest thunderstorms. Visible satellite images show that heavy thunderstorm activity has shown a moderate increase in intensity and areal coverage this morning. An upper-level outflow channel has opened to the north, but there is no evidence of low-level spiral bands forming yet.


Figure 1. Current satellite image of 93L.

The forecast
Wind shear has dropped to a low 5-10 knots this morning, and is expected to remain in the low to moderate range, 5-15 knots, over the next three days. The phase of the Madden-Julian Oscillation has changed to positive over the Western Caribbean over the past few days, and this should act to reduce wind shear and enhance the storm's updrafts and instability. Nearly all of the tropical cyclones that have formed in the Atlantic this season have formed under a positive Madden-Julian phase. Water temperatures are warm, 29.5°C, and this warm water extends to great depth. These are favorable conditions for intensification, and both the GFDL and HWRF models predict 93L will become a hurricane, with the HWRF predicting a major hurricane. The SHIPS intensity model is less aggressive, predicting a strong tropical storm with 65 mph winds by Saturday. I give 93L a 50% chance of eventually becoming a hurricane, and a 20% chance of becoming a major hurricane. These odds will increase tomorrow if 93L can avoid passing close enough to the northeast coast of Nicaragua for significant weakening due to land interaction. This storm has the potential to imitate Hurricane Michelle of 2001. Michelle formed in the same region at the same time of year, and took just three days to intensify from a tropical depression to a Category 4 hurricane. Michelle made landfall in central Cuba as a Category 4 hurricane, then weakened to a Category 1 hurricane as it passed through the Bahamas.

A slow north-northwest motion to a point just offshore the Nicaragua-Honduras border is likely for 93L through Thursday. At that time, a strong trough of low pressure will be approaching the U.S. East Coast. Only one major model, the NOGAPS, predicts that this trough will be too weak to turn 93L northwards, and I am discounting this solution at present. The other five major models agree on a northward motion, bringing 93L near the Cayman Islands or western Jamaica on Saturday, followed by a northeast turn. On Sunday morning, 93L should make landfall in Western Cuba, then pass through the central or eastern Bahamas on Sunday afternoon as it accelerates to the northeast.

Given the current increasing trend in organization, I believe 93L will become a tropical depression tonight or Thursday morning. NHC is giving 93L a high (>50% chance) of developing into a tropical depression by Friday morning. There is the potential that 93L could enter a period of rapid intensification on Saturday, bringing it to hurricane status. Residents of the Cayman Islands, Jamaica, and western Cuba should anticipate the possibility of a hurricane affecting them Saturday and Sunday. If 93L crosses Cuba as expected and moves into the Bahamas, it will weaken due to the interaction with land and the presence of very high wind shear of 30-50 knots just north of Cuba. These effects should weaken the storm by at least 40 mph before it passes through the Bahamas. The HWRF model predicts 93L could be a Category 2 hurricane in the Bahamas, but I think a tropical storm is more likely.

Northeastern Nicaragua and northeastern Honduras are at risk of heavy rains from 93L today through Friday morning. Total rainfall amounts of 4-8 inches are likely. Rains of 1-2 inches fell last night in Jamaica, and heavy rains of 4-8 inches should affect Jamaica and the Cayman Islands Thursday through Saturday. The first Hurricane Hunter flight into 93L is scheduled for this afternoon.

Links to follow
Wundermap for 16N 83W

I'll have an update this afternoon when the new model runs are in and the Hurricane Hunter data is available.

Jeff Masters

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Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 213 - 163

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213. kmanhurricaneman
8:41 PM GMT on November 05, 2008
TS by 6 pm, wanna bet?
Member Since: August 14, 2008 Posts: 0 Comments: 1002
212. 7544
8:41 PM GMT on November 05, 2008
early track
Link
Member Since: May 6, 2007 Posts: 0 Comments: 6618
210. hurricanemaniac123
8:37 PM GMT on November 05, 2008
NEW BLOG!
Member Since: September 21, 2008 Posts: 9 Comments: 688
209. pottery
8:37 PM GMT on November 05, 2008
New Blog.....
Member Since: October 24, 2005 Posts: 0 Comments: 23105
207. Orcasystems
8:35 PM GMT on November 05, 2008
Hmmm
I appear to be lost :(
Member Since: October 1, 2007 Posts: 81 Comments: 26493
205. IpswichWeatherCenter
8:34 PM GMT on November 05, 2008
Hello depression 17.
Member Since: April 27, 2008 Posts: 29 Comments: 2097
204. Orcasystems
8:34 PM GMT on November 05, 2008
Complete Refresh Blog
Mirror Site

Area of Interest ... Invest 93L
Hurricane Hunter & Vortex Reports ... Invest 93L
Satellite Picture ... Invest 93L
Member Since: October 1, 2007 Posts: 81 Comments: 26493
203. lawntonlookers
8:34 PM GMT on November 05, 2008
Out for the day, and will be on the road on Thursday so I will be back on Friday to see how things are picking up. Have a good evening everyone.
Member Since: March 22, 2006 Posts: 9 Comments: 1570
202. 7544
8:32 PM GMT on November 05, 2008
Quoting StormW:
192. cchsweatherman 3:28 PM EST on November 05, 2008
Quoting hurricane23:


The 200mb flow is really favorable for 93 to develop and in a few days maybe quite rapidly.


Have you been following the visible satellite imagery? In the past hour, this has really become much better organized around a defined center. We're approaching diurnal minimum and are continuing to watch expanding, deepening convection. Right now, I find a compromise between the GFDL/HWRF and SHIP model intensities appropriate for the future strength of this system.


Definitely looking good, cchs!


ok storm w and chhs agrees td 17 at 5pm now will it stay south of fla which i believe the first nhc will show then future cones might trend further north tough one to call right now
Member Since: May 6, 2007 Posts: 0 Comments: 6618
201. IKE
8:31 PM GMT on November 05, 2008
Quoting sporteguy03:


76 days and its over!


LOL....think you meant 26?

50 days til Christmas...lol....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
200. Bonedog
8:31 PM GMT on November 05, 2008
Yes lawnlookers I have :) I have been following this system when it was a blip on the long range models. Really impressive system and a sense of foreboding as to what our winters will look like up here. Seems almost every week now since the begining of October we have seen a system run up the coast =)
Member Since: July 14, 2005 Posts: 14 Comments: 7418
199. futuremet
8:31 PM GMT on November 05, 2008
Quoting cchsweatherman:


Have you been following the visible satellite imagery? In the past hour, this has really become much better organized around a defined center. We're approaching diurnal minimum and are continuing to watch expanding, deepening convection. Right now, I find a compromise between the GFDL/HWRF and SHIP model intensities appropriate for the future strength of this system.


Good point...
Member Since: July 19, 2008 Posts: 43 Comments: 4051
198. lawntonlookers
8:30 PM GMT on November 05, 2008
Firefly;

It would be interesting to know how much surching they actually did. That would be a good reasearch story for the local papers in your area to pick up on. JUST BECAUSE FEMA HASN'T RELEASED MONEY TO CLEAN UP SOME UNPOPULATED AREAS, WE DON'T LOOK FOR BODIES.
Member Since: March 22, 2006 Posts: 9 Comments: 1570
197. cchsweatherman
8:30 PM GMT on November 05, 2008
Quoting lawntonlookers:


Yes I have been watching this since yesterday. Really looking impresive. I don"t know if you saw my link to Buoy 44014, but the have 16.4 ft waves and 60 + wind gust.

BUOY


To be honest, those observations don't surprise given how vigorous the circulation is and how widespread the system is. Lookin very impressive and appears to be deepening as we speak.
Member Since: April 14, 2007 Posts: 8 Comments: 5030
195. futuremet
8:29 PM GMT on November 05, 2008
Quoting hurricane23:


This cyclone is surely getting better organized.

Look at the cirrus clouds at the northwestern, which indicates good upper level divergence. Look at the vigorous flare up of thunderstorm near the center of circulation, which indicates good lower level convergence. The weak developing anticyclone developing to its north should provide further aid to it. All-in-all, this system should become a depression.
Member Since: July 19, 2008 Posts: 43 Comments: 4051
194. fireflymom
8:28 PM GMT on November 05, 2008
Capeobserver they have to get permission to search due to environmental concerns from the EPA through FEMA many toxic chemicals ect. set free by the storm.
Member Since: June 5, 2007 Posts: 0 Comments: 574
193. sporteguy03
8:28 PM GMT on November 05, 2008
Quoting IKE:
From the afternoon Key West,FL. discussion...

"Model guidance gets murky on Saturday night through Monday. The
general theme is that the low in the western Caribbean will lift
northeast across Cuba and into the Bahamas during this time frame.
The low will have trouble maintaining strength if it does this...due
to moderate shear aloft.
In any case...Keys will be on the weak
side of a weak low moving to the east. Will only increase probability of precipitation and
winds a bit through this period...then drop them even a little more
on Tuesday."


76 days and its over!
Member Since: July 7, 2005 Posts: 0 Comments: 5120
192. cchsweatherman
8:28 PM GMT on November 05, 2008
Quoting hurricane23:


The 200mb flow is really favorable for 93 to develop and in a few days maybe quite rapidly.


Have you been following the visible satellite imagery? In the past hour, this has really become much better organized around a defined center. We're approaching diurnal minimum and are continuing to watch expanding, deepening convection. Right now, I find a compromise between the GFDL/HWRF and SHIP model intensities appropriate for the future strength of this system.
Member Since: April 14, 2007 Posts: 8 Comments: 5030
191. 7544
8:27 PM GMT on November 05, 2008
good job you guys call it right again congrades now lets see if the models will shift further north imo they just might
Member Since: May 6, 2007 Posts: 0 Comments: 6618
190. Orcasystems
8:27 PM GMT on November 05, 2008
Complete Refresh Blog
Mirror Site

Area of Interest ... Invest 93L
Satellite Picture ... Invest 93L

Present Satellite Area of Interest ... Atlantic Seaboard
Member Since: October 1, 2007 Posts: 81 Comments: 26493
189. Sfloridacat5
8:27 PM GMT on November 05, 2008
The upper level winds (see water vapor loop) just South of Florida will push 93L to the East if it moves too far north (protecting Florida).
Member Since: September 16, 2007 Posts: 0 Comments: 4805
188. extreme236
8:26 PM GMT on November 05, 2008
I guess we will just have to wait until they either designate it on the NHC page or if a STWDS is issued telling us it hasn't developed.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
187. lawntonlookers
8:25 PM GMT on November 05, 2008
Quoting Bonedog:
I am cch :) Rain bands moving in as we speak. Checked some bouys out there, 40knt sustained gusting 55knt pressures down to 998 and falling


Yes I have been watching this since yesterday. Really looking impresive. I don"t know if you saw my link to Buoy 44014, but the have 16.4 ft waves and 60 + wind gust.

BUOY
Member Since: March 22, 2006 Posts: 9 Comments: 1570
186. pottery
8:25 PM GMT on November 05, 2008
LOL
Member Since: October 24, 2005 Posts: 0 Comments: 23105
185. extreme236
8:25 PM GMT on November 05, 2008
Oh wait...my bad...that was the eastern pacific...my computer text messed up and didnt tell me if that was Atlantic or EP
Member Since: August 2, 2007 Posts: 19 Comments: 19234
184. hurricane23
8:24 PM GMT on November 05, 2008
Quoting cchsweatherman:
Based upon the latest satellite imagery, it appears that this system has begun to rapidly organize as convection has been getting pulled into and around the circulation center. No invest this season has had such a well-defined circulation center. If the current trends continue, we may be looking at Tropical Storm Paloma before day's end.


The 200mb flow is really favorable for 93 to develope quite rapidly.
Member Since: May 14, 2006 Posts: 8 Comments: 13597
183. IKE
8:24 PM GMT on November 05, 2008
From the afternoon Key West,FL. discussion...

"Model guidance gets murky on Saturday night through Monday. The
general theme is that the low in the western Caribbean will lift
northeast across Cuba and into the Bahamas during this time frame.
The low will have trouble maintaining strength if it does this...due
to moderate shear aloft.
In any case...Keys will be on the weak
side of a weak low moving to the east. Will only increase probability of precipitation and
winds a bit through this period...then drop them even a little more
on Tuesday."
Member Since: June 9, 2005 Posts: 23 Comments: 37858
182. extreme236
8:24 PM GMT on November 05, 2008
Quoting pottery:
CCHS, can you change the designation on your graphic to 93L. It reads 92L.


Well I guess he can now call it TD 17 lol
Member Since: August 2, 2007 Posts: 19 Comments: 19234
181. cchsweatherman
8:23 PM GMT on November 05, 2008
We now have Tropical Depression 17.
Member Since: April 14, 2007 Posts: 8 Comments: 5030
180. cchsweatherman
8:23 PM GMT on November 05, 2008
Based upon the latest satellite imagery, it appears that this system has begun to rapidly organize as convection has been getting pulled into and around the circulation center. No invest this season has had such a well-defined circulation center. If the current trends continue, we may be looking at Tropical Storm Paloma before day's end.
Member Since: April 14, 2007 Posts: 8 Comments: 5030
179. fireflymom
8:22 PM GMT on November 05, 2008
Lawtonlooker that is how I read it and I live in the general area, hubby works on the Island. I know they have had teams of search dogs out there but I do not know if that is only in approved areas? Maybe someone else on here will know to find out that information. Perhaps Patrap or Presslord has a better resource.
Member Since: June 5, 2007 Posts: 0 Comments: 574
178. pottery
8:22 PM GMT on November 05, 2008
CCHS, can you change the designation on your graphic to 93L. It reads 92L.
Member Since: October 24, 2005 Posts: 0 Comments: 23105
177. hurricane23
8:22 PM GMT on November 05, 2008
Member Since: May 14, 2006 Posts: 8 Comments: 13597
176. extreme236
8:21 PM GMT on November 05, 2008
invest_RENUMBER_ep932008_ep172008.ren
Member Since: August 2, 2007 Posts: 19 Comments: 19234
175. pottery
8:20 PM GMT on November 05, 2008
LOL 7544. The last frame also clearly shows the dreaded pin-hole...........
Member Since: October 24, 2005 Posts: 0 Comments: 23105
174. Bonedog
8:20 PM GMT on November 05, 2008
I am cch :) Rain bands moving in as we speak. Checked some bouys out there, 40knt sustained gusting 55knt pressures down to 998 and falling
Member Since: July 14, 2005 Posts: 14 Comments: 7418
173. cchsweatherman
8:19 PM GMT on November 05, 2008
Photobucket
Member Since: April 14, 2007 Posts: 8 Comments: 5030
172. futuremet
8:19 PM GMT on November 05, 2008
168

beautiful storm indeed
Member Since: July 19, 2008 Posts: 43 Comments: 4051
171. cchsweatherman
8:18 PM GMT on November 05, 2008
Quoting Bonedog:


Impressive Nor'Easter forming, some models show it going warm core, might be a STS.


Haven't paid much attention to the system, but must agree that this looks like a very formidable Nor'easter. Classic comma shape with far-reaching rainshield. Have fun with this one Bonedog.
Member Since: April 14, 2007 Posts: 8 Comments: 5030
170. lawntonlookers
8:17 PM GMT on November 05, 2008
Firefly. That is ashame. By the sounds of this, all of the debris piles that are in the area haven't even been looked at to try to recover bodies. Maybe I am reading it the wrong way.
Member Since: March 22, 2006 Posts: 9 Comments: 1570
169. 7544
8:15 PM GMT on November 05, 2008
hmm could the coc relocate to 16/ 81 a see spin there with lots of convection around it new coc ?

Link
Member Since: May 6, 2007 Posts: 0 Comments: 6618
168. Bonedog
8:15 PM GMT on November 05, 2008


Impressive Nor'Easter forming, some models show it going warm core, might be a STS.
Member Since: July 14, 2005 Posts: 14 Comments: 7418
167. futuremet
8:15 PM GMT on November 05, 2008
Quoting hurricane23:


Just dont see anything that indicates a possible threat to south florida at this time.Areas like Haiti/cuba might have some trouble on there hands.


Hurricane23, I do know that it is always best to remain conservative. However, you should not deny any possible scenarios. Tropical cyclones are notorious for their unpredictability, especially when the model forecasts are ambiguous. A synoptic scale anticyclone is expected to form over the eastern U.S. about 120 hours (5 days) from now. Depending on where this system is located during that time will be the determine where it will go. The 12Z GFS (2nd link) model expects 93L to be cut off from the trough's weakness as a result of that high.

Despite of all this, it is best to remain conservative and not to neglect any possible case scenarios. At first, the GFS expected IKE to go out to sea when it was in the Atlantic.....and where did it end up?
Member Since: July 19, 2008 Posts: 43 Comments: 4051
166. CapeObserver
8:13 PM GMT on November 05, 2008
What's the current timing on the trough? When is it expected to drop through and how far south is it expected to go? The locals here have been saying the it is going to stall out and not make it down the peninsula of FL.
Member Since: August 24, 2008 Posts: 0 Comments: 320
165. CapeObserver
8:11 PM GMT on November 05, 2008
156. fireflymom

So they aren't searching the debris field in their county because no one from their county is listed as missing and because FEMA hasn't agreed to pay for the search? What kind of moral values do these people have? One can only assume that because they are presumed dead they no longer matter to anyone in authority? Sad.
Member Since: August 24, 2008 Posts: 0 Comments: 320
164. kmanhurricaneman
8:11 PM GMT on November 05, 2008
well may be so but is it gonna disapate? i dont think so! so do they believe it is gonna stay the way it is and do nothing but cause rain mmmmmm nope! so it is organising and fast. i understand that we dont want to cause a panic but we must face reality 93l is imo a storm and will be a hurricane soon , no doubt in my mind .
Member Since: August 14, 2008 Posts: 0 Comments: 1002
163. hurricane23
8:10 PM GMT on November 05, 2008
.
Member Since: May 14, 2006 Posts: 8 Comments: 13597

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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.