Tropical Depression #9 (Future Imelda): Satellite imagery, weather analysis and reports from reconnaissance aircraft indicate that now Tropical Depression #9 is becoming better organized today with clusters of thunderstorm activity occurring from the southeastern Bahamas southward through eastern Cuba to far western Haiti. Additionally, reconnaissance aircraft have found a low-level center with this system just north of the northeastern coast of Cuba and because of this, it is now a depression. I expect that TD 9 will likely strengthen into a tropical storm as soon as later tonight or during Sunday.
The forecast of TD 9 continues to be a very difficult one as there are no less than 4 weather features influencing the track and strength of this system. These weather features include (1) A weak upper level low pressure system located over the Florida Straits, which seems to be guiding the depression to the north right now; (2) An upper level low pressure system that’s located over the southeastern United States, which should help guide TD 9 northward as we get into Sunday; (3) A high pressure ridge, that’s located near Bermuda, which is expected to slide to the east and weaken, allowing for a possible “escape route” for TD 9 & (4) Almost Category 5 Hurricane Humberto that’s located to the east of the depression, which might try to use its strength and size to pull TD 9 away from the US Southeast Coast causing it to get close to the coast of South Carolina, but not make landfall.
The forecast track of TD 9 throughout the weekend looks fairly straight forward as it’ll be guided towards the north-northwest by the high pressure ridge near Bermuda & the upper level low pressure system over the southeastern United States. This means that this system will head from southeast to northwest through the Bahamas over the weekend & then parallel Florida’s East Coast during Monday. That said, it is expected that this system should remain about 100 miles or so to the east of Florida’s East Coast & because of this, significant rain and wind impacts are not expected across the Florida Peninsula. Instead, expect some occasional showers across the Florida Peninsula with wind gusts of up to 40 mph at times along Florida’s East Coast from Monday through Tuesday, especially from Melbourne to Jacksonville.
As we get into Monday night and Tuesday, the forecast of TD 9 becomes A LOT more complicated and uncertain. What is expected to happen is that the upper level low pressure system over the Southeastern US will be trying to pull future Imelda northwestward towards the Carolinas. At the same time this is occurring, Hurricane Humberto will be trying to capture the depression and pull it eastward. You can see this push and pull between these two weather features on the depression in the latest model guidance.
There has been a notable shift eastward in all of the model guidance’s track of TD 9. It seems that the model guidance are sensing that Category 4 Hurricane Humberto is exerting a bigger influence on TD 9 than what was previously thought. Also, the upper level low pressure system over the Southeastern United States could end up being weaker leading it to exert less influence on the track of the depression. This has led to most of the models to now forecast the depression to slow way down in forward speed just barely offshore of the Carolinas and then turn abruptly to the east leading it to get close, but not make landfall.
The 12Z hurricane track models all seem to suggest a quick yank to the east on Tuesday before TD 9 reaches the Carolinas.
Last night’s Canadian model initially shows a track that yanks the depression away from the Carolinas. It should be noted that the Canadian model does forecast Humberto not fully capturing TD 9 leading to the depression to turn back to the north and ultimately making it as far north as Southern New England next weekend.
The European ensemble model guidance members show that there are up to 40 percent of their members that indicate a stall just barely offshore of the Carolinas followed by a turn back towards the west later next week
The 06Z run of the European AI model shows a lot of meandering just offshore of the Carolinas during next week followed by this system making landfall in the Outer Banks and heading up the Chesapeake.
The most recent run (12Z) of the GFS model seems to have trended towards future Imelda tracking closer to Florida’s East Coast on Monday. These model trends will definitely need to be watched as this trend westward by the GFS model would put heavier squalls into the Treasure Coast, the Space Coast and parts of the First Coast of Florida during Monday. Beyond this, the 12Z run of the GFS model shows TD 9 being yanked to the east just offshore of the South Carolina coast by Wednesday.
Here Are My Thoughts About TD 9’s Track Towards The Carolinas: It cannot be emphasized enough of how complicated and uncertain the forecast still is for TD 9 as it tracks towards the Carolinas as we get into Tuesday and Wednesday.
That upper level low pressure system over the Southeastern United States looks to try to pull TD 9 northwestward towards the Carolinas, but it appears that Humberto’s strength and size may be large enough to pull it to the east instead.
What, to me, looks to possibly occur is that future Imelda will slow way down in forward speed just barely offshore of the South Carolina coast during Tuesday into Wednesday. My thinking is that the center of TD 9 may end up tracking as close as about 100 miles or so offshore of the South Carolina coast during Tuesday and Tuesday night. As we get into Wednesday though, Humberto may partially capture TD 9 and pull it eastward increasing the distance it is from the Carolinas.
Ultimately though, it is possible that Humberto may end up leaving TD 9 behind around late next week leading to even more uncertainty as to where it could end up tracking – whether it be back westward towards the Carolinas or a turn to the northwest and north leading it to head for the Mid Atlantic or New England.
I do think that the depression will get close enough so that there will be heavy rain and gusty winds along the Georgia, South Carolina and North Carolina coasts starting on Tuesday and continuing through Wednesday and perhaps into Thursday. Additionally, some coastal flooding is also possible depending on how close the center of TD 9 gets to the coast.
Even though it is looking increasingly more likely that TD 9 will stay offshore, flooding from rainfall is still a very real threat across eastern North Carolina and eastern South Carolina throughout the first half of next week. Rainfall totals could end up being in the neighborhood of 3 to 7 inches across much of eastern South Carolina and southeastern and eastern North Carolina during next week.
Bottom Line Is That Everyone along Florida’s East Coast, as well as across southeastern Georgia, eastern South Carolina and eastern North Carolina should pay very close attention to the updates of TD 9/Imelda. My biggest concern with TD 9 is the potential for rainfall produced flash flooding in the coastal Carolinas next week & you should be concerned too, if you live in these areas.
I’ve spent so much time trying to figure out TD 9/Imelda that I’m not going to cover Hurricane Humberto. Just know that Humberto should still pass far enough west of Bermuda to not bring hurricane conditions to the island. It looks quite possible though that Humberto could bring tropical storm conditions to Bermuda during the day on Tuesday.
Model Track Forecast:
Satellite Imagery:
The next tropical weather discussion will be issued on Sunday.