CourierPR wrote:LarryWx wrote:LarryWx wrote:
Today's 18Z GFS/GEFS still has it, but other models still have at most only a very weak low. So, I'm keeping it in the back of my mind mainly because it is showing it in the SW Caribbean, but only as a small chance due to the lack of outside support and climo, which says only small chance (~10% in La Nina). If other models were to suddenly join in, that would surely get my attention and I'd raise the chance in my mind.
Followup: the 12Z GFS still has a weak surface low form in the SW Caribbean this weekend that gets down only to 1004 mb with no clearcut TCG vs a good number of stronger lows with actual TCG on some earlier runs. Other models continue to have no more than a very weak low. Climo says that if something were to form then, this would be about the most favored area in mid Nov with about a 10% chance. Based on all of the above, I think the chance for actual TCG this weekend down there is very low.
On what do you base that 10% figure?
Mid-November La Niña TCG in SW Caribbean since 1851:
-Otto 2016
-Laura 1971
-#20 of 1933
-#15 of 1916
Per Eric Webb's tables, there have been ~46 La Niña seasons since 1851. So, 4/46 or once every eleven La Niña seasons has had a mid-November SW Caribbean TCG. So, a small but nontrivial chance.
Webb's ENSO data since 1850:
https://www.webberweather.com/ensemble- ... index.html
Mid November genesis locations 1851-2015 shows 7 TCGs in the SW Caribbean with 3 of these during La Nina: (need to add 2016's Otto to this to make 4 during La Nina):
https://www.nhc.noaa.gov/climo/images/nov_11_20.png
Past TC tracks by year from NHC archives:
https://www.nhc.noaa.gov/data/