ATL: PALOMA - Tropical Depression - Discussion

[AdamFirst]

Will definitely keep an eye on this one.

Should be an interesting week if this thing spins up into something

[jconsor]

There seems to be a widespread perception that November tropical cyclones in the Atlantic Basin are overwhelmingly weak.

Here are some interesting stats:

Between 1900 and 2007, 20 tropical storms formed outside the western Caribbean between Oct. 30 and Nov 15. 12 became hurricanes, and none became major hurricanes.

Between 1900 and 2007, 19 tropical storms formed in the western Caribbean (west of 75W) between Oct 30 and Nov 15. 11 (58%) became hurricanes, and 4 (21%) became major hurricanes.

In an average season, 10 tropical storms form, 5.9 become hurricanes, and 2.5 major hurricanes. The percentage of western Caribbean tropical storms forming between Oct 30 and Nov 15 that became hurricanes and major hurricanes is very close to the percentages for the entire Atlantic Basin for the whole season. This makes sense, considering that SSTs typically remain between 28C and 30C across the entire Caribbean through the first half of November, while shear values are typically the lowest in the Atlantic Basin.

On the other hand, while 60% of non-western Caribbean cyclones in this same time period became hurricanes, there seems to be a cap on their intensity related to cool SSTs, since none became major hurricanes.

Based on these statistics and the forecasted upper level pattern, which features an upper-level anticyclone moving north in tandem with 93L, it is not at all unreasonable that 93L could become a hurricane.

[jinftl]

Conditions on the surface….by that I mean ocean temp and oceanic heat content….are still plenty warm in the sw caribbean north through the yucatan, cuba, and into the straits of florida. Water temps around the southern peninsula of florida and into the Bahamas are in the 80 degree range +/-, warm enough to at least be able to maintain a tropical system. Whether or not the atmospheric conditions are hostile (shear, for example) is another story. But when the atmospheric conditions align with the favorable surface conditions, you can get a Mitch or Lenny type system in the Caribbean in late October and early November.

There seems to be a widespread perception that November tropical cyclones in the Atlantic Basin are overwhelmingly weak.



Here are some interesting stats:

Between 1900 and 2007, 20 tropical storms formed outside the western Caribbean between Oct. 30 and Nov 15. 12 became hurricanes, and none became major hurricanes.

Between 1900 and 2007, 19 tropical storms formed in the western Caribbean (west of 75W) between Oct 30 and Nov 15. 11 (58%) became hurricanes, and 4 (21%) became major hurricanes.

In an average season, 10 tropical storms form, 5.9 become hurricanes, and 2.5 major hurricanes. The percentage of western Caribbean tropical storms forming between Oct 30 and Nov 15 that became hurricanes and major hurricanes is very close to the percentages for the entire Atlantic Basin for the whole season. This makes sense, considering that SSTs typically remain between 28C and 30C across the entire Caribbean through the first half of November, while shear values are typically the lowest in the Atlantic Basin.

On the other hand, while 60% of non-western Caribbean cyclones in this same time period became hurricanes, there seems to be a cap on their intensity related to cool SSTs, since none became major hurricanes.

Based on these statistics and the forecasted upper level pattern, which features an upper-level anticyclone moving north in tandem with 93L, it is not at all unreasonable that 93L could become a hurricane.

[gatorcane]

There seems to be a widespread perception that November tropical cyclones in the Atlantic Basin are overwhelmingly weak.

Here are some interesting stats:

Between 1900 and 2007, 20 tropical storms formed outside the western Caribbean between Oct. 30 and Nov 15. 12 became hurricanes, and none became major hurricanes.

Between 1900 and 2007, 19 tropical storms formed in the western Caribbean (west of 75W) between Oct 30 and Nov 15. 11 (58%) became hurricanes, and 4 (21%) became major hurricanes.

In an average season, 10 tropical storms form, 5.9 become hurricanes, and 2.5 major hurricanes. The percentage of western Caribbean tropical storms forming between Oct 30 and Nov 15 that became hurricanes and major hurricanes is very close to the percentages for the entire Atlantic Basin for the whole season. This makes sense, considering that SSTs typically remain between 28C and 30C across the entire Caribbean through the first half of November, while shear values are typically the lowest in the Atlantic Basin.

On the other hand, while 60% of non-western Caribbean cyclones in this same time period became hurricanes, there seems to be a cap on their intensity related to cool SSTs, since none became major hurricanes.

Based on these statistics and the forecasted upper level pattern, which features an upper-level anticyclone moving north in tandem with 93L, it is not at all unreasonable that 93L could become a hurricane.

Thanks for sharing this info. Indeed I think there is a perception that November systems are generally weak and hence the lack of interest with 93L by the board --- but that may change if 93L manages to make it to depression status, I think the board will dramatically pick up.

Also, current 12Z model runs coming in suggest a big split between one camp sending 93L into the western part of the NW Caribbean and others sending 93L NE into Eastern Cuba south of South Florida.

It will be interesting to see which camp wins out here.

[HURAKAN]

[Blown Away]

Link to read about Hebert Box: http://www.hurricanecity.com/hebertbox.htm
93L will be a Hebert Box candidate if it develops, I'm a big believer in this theory and if 93L develops Caymans/Cuba/SFL/Bahamas should pay close attention.

[gatorcane]

000
ABNT20 KNHC 031732
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
100 PM EST MON NOV 3 2008

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A BROAD AND NEARLY STATIONARY LOW PRESSURE AREA OVER THE
SOUTHWESTERN CARIBBEAN SEA IS ACCOMPANIED BY DISORGANIZED
CLOUDINESS...SHOWERS...AND THUNDERSTORMS. SOME SLOW DEVELOPMENT OF
THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF DAYS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$

FORECASTER PASCH

[HURAKAN]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON NOV 03 2008

...SPECIAL FEATURE...
IN THE W CARIBBEAN...A SURFACE TROUGH EXTENDS ACROSS CUBA NEAR
20N78W JUST W OF JAMAICA TO A 1009 MB SURFACE LOW IN THE SW
CARIBBEAN NEAR 11N80W. BROAD MID LEVEL TURNING IS OBSERVED.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE AREA WITHIN
200 NM OF THE SURFACE TROUGH S OF 20N TO INLAND OVER PANAMA
ENHANCED BY UPPER LEVEL DIFFLUENCE. SOME SLOW DEVELOPMENT OF
THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF DAYS.

[gatorcane]

There is plenty of "juice" in the Western Caribbean and NW Caribbean as this SST map shows. SSTs could support a hurricane and a major one also albeit if upper-level winds are favorable. Upper-level winds are likely to be stronger the farther north 93L heads preventing a major hurricane from forming.

[cycloneye]

Best track at 18:00 UTC:

AL, 93, 2008110318, , BEST, 0, 113N, 804W, 20, 1009, DB,

[wxman57]

http://img83.imageshack.us/img83/6872/93lgo3.jpg
Link to read about Hebert Box: http://www.hurricanecity.com/hebertbox.htm
93L will be a Hebert Box candidate if it develops, I'm a big believer in this theory and if 93L develops Caymans/Cuba/SFL/Bahamas should pay close attention.

There is some confusion as to the meaning/use of the Hebert Box. The box represents an area through which a high percentage of storms passed prior to hitting south Florida. One cannot conclude that if a storm passes through this box that it will threaten Florida, however. So it's not a tool to forecast where a storm might track, it's more of a tool to indicate where a storm probably won't track. I.E., if a storm does not pass through the box, then there may be a lesser chance of it impacting south Florida.

In this case, an approaching cold front late in the week combined with increasing SW flow aloft across the NW Caribbean should keep Florida in the clear as far as any potential impact.

[Blown Away]

http://img83.imageshack.us/img83/6872/93lgo3.jpg
Link to read about Hebert Box: http://www.hurricanecity.com/hebertbox.htm
93L will be a Hebert Box candidate if it develops, I'm a big believer in this theory and if 93L develops Caymans/Cuba/SFL/Bahamas should pay close attention.

There is some confusion as to the meaning/use of the Hebert Box. The box represents an area through which a high percentage of storms passed prior to hitting south Florida. One cannot conclude that if a storm passes through this box that it will threaten Florida, however. So it's not a tool to forecast where a storm might track, it's more of a tool to indicate where a storm probably won't track. I.E., if a storm does not pass through the box, then there may be a lesser chance of it impacting south Florida.

In this case, an approaching cold front late in the week combined with increasing SW flow aloft across the NW Caribbean should keep Florida in the clear as far as any potential impact.

I agree with you 100%, I was not implying that 93L will come to SFL if it goes through the box because there have been many that have gone through the box and missed SFL, but for me a system gets a little extra attention if it does go through the box. I rely much more on the Hebert box when a system does not go through, with Ike I was torn I could not believe Ike went above the box and below SFL all the way to Texas, legendary IMO!!

[cycloneye]

57,you think it may pull an Omar track?

[wxman57]

57,you think it may pull an Omar track?

Similar track, farther west, though. May pass just west of Jamaica around Friday/Saturday then NE-ENE across eastern Cuba, weakening after making the turn.

[Blown Away]

57,you think it may pull an Omar track?

Similar track, farther west, though. May pass just west of Jamaica around Friday/Saturday then NE-ENE across eastern Cuba, weakening after making the turn.

What is the probability the trough coming this weekend is going to miss this low? The models seem to stall this out in the NW Caribbean after moving over CA?

[Ed Mahmoud]

Amateur eyeballing of the low cloud elements, made easy by sparse convection near it, there is a surface/near surface closed low.


I think it will be a go for development, unofficially, as it looks to be slowly organizing.


And people worried about November. It could be a month of tropical, severe t-storm and winter storm activity, providing plenty to talk about.

[wxman57]

57,you think it may pull an Omar track?

Similar track, farther west, though. May pass just west of Jamaica around Friday/Saturday then NE-ENE across eastern Cuba, weakening after making the turn.

What is the probability the trough coming this weekend is going to miss this low? The models seem to stall this out in the NW Caribbean after moving over CA?

The 120 hr models don't appear to go out far enough to show the front moving into the NW Caribbean and picking it up. European has the right idea, I think, though it may be a bit slow. And if it doesn't get picked up it will likely ingest a lot of dry air, experience increasing wind shear, and either dissipate or move westward into southern Mexico while weakening.

[wxman57]

Right now the models are split. We have the LGEM, UKMET, GFDL, and GFS bringing 93L farther west into the NW Caribbean and Western Cuba, and the BAMD, HWRF (and TVCN) bringing 93L into Eastern Cuba and SE Bahamas.

Note that LGEM isn't a track model, it's an intensity model. The NHC typically sets the track points to match the BAMM for a disturbance. Once it develops, the LGEM will match the NHC forecast track. The BAM models will be useless for this system as they won't see the changing steering currents. With strong W-WNW winds digging into the SE Gulf and NW Caribbean by Fri/Sat, there's no way this is coming your way, gatorcane.

[Dean4Storms]

This system may very well miss getting picked up by this trough, the longer it sits in the general area it is in and slower the development the better chance of this scenario IMO.

[Sanibel]

Another Michelle track?