• Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!

Tropical Major Hurricane Florence

SD said:
I was trying to say this yesterday but the contingent that thought this would go NE bc the gfs wouldn't accept it.

Sent from my SM-G955U using Tapatalk
Click to expand...
Agreed..I will say kudos to GFS for seeing the stall and movement back SW or W. but euro has been pretty dang rock solid.
 
metwannabe said:
Personally I'm starting to feel a little better for mby and I'll probably wait until the 12 Z Suites to really start to relax somewhat. But I am starting to get concerned for the SC folks

Sent from my SM-G920V using Tapatalk
Click to expand...

Yep. I agree with you. The euro the night before last give the first warning shot for SC. That ridging means business as modeled by the euro last night. Our governor is looking very smart right now by ordering a mandatory evacuation yesterday that has gone into effect today.


Sent from my iPhone using Tapatalk
 
Rain Cold said:
It’s pretty crazy to have less clarity as we get closer to the event.
Click to expand...

I was surprised this morning to wake up and the EURO went back west, and the GFS starting doing loop da loops. I thought everything was going to just keep shifting east. Not sure what's going to happen now. (HPC 5 am discussion below). Just goes to show, we're not going to pinpoint with any accuracy where this thing is going to go until about 24 hours before.

The ECMWF has trended slower this cycle
at days 4 and 5, and as a result the NHC forecast shows slightly
less motion at those time periods. The spread in the guidance
increases by 72 hours, with the GFS and its ensemble mean along the
right side of the guidance, while the ECMWF remains along the left
edge. It should be noted that there are still a number of ECMWF
members that are even farther left. The NHC track forecast has been
nudged to the left and is close to the TVCN consensus aid. Given the
amount of uncertainty by day 3, it is important not to focus on the
exact forecast track as average NHC errors at days 3, 4, and 5 are
about 100, 140 and 180 n mi, respectively, and dangerous hazards
will extend well away from the center. Storm Surge and Hurricane
watches have been issued for a portion of the coast of South and
North Carolina. Additional watches may be required later today.
 
obviously still tons of uncertainty and at least in my opinion it comes down to how quickly that ridge builds in as to how far north, inland Florence gets before it stalls and crawls Westward. 6 to 12 hour sooner or later and a millibar or two weaker or stronger can mean the difference in 100 miles and a hundred miles is huge with a land falling TC.

Sent from my SM-G920V using Tapatalk
 
Flight level (FL) winds have increased to 145 knots (~165 mph) in Florence's northeast quad, the typical standard reduction for surface winds is ~130 KTS or so but SFMR only shows 115 KT at the moment & rightfully so. Once the surface winds catch up to the FL winds & the eyewall contracts some, Florence will be knocking on the door of category 5 status.
Screen Shot 2018-09-11 at 8.47.47 AM.png
 
Rain Cold said:
It’s pretty crazy to have less clarity as we get closer to the event.
Click to expand...

Yes, it is. Euro looks better for us now, but the UK still has Flo coming in at Wilmington and taking a track like Fran did through Raleigh. And who knows what the GFS is doing.
 
Eric, a bit scary that her winds aloft are already strengthening again and the large eye is closing off. Would you say this is/has transitioned to an "annular" storm or is it just more the pattern of a very powerful hurricane? I know literature I've read indicates that dry air can often contribute to a storm going annular and there was a ton around Florence and she has shed the majority of her banding.. but I've seen other storms with similar looks that weren't classified that way too.
 
snowlover91 said:
Eric, a bit scary that her winds aloft are already strengthening again and the large eye is closing off. Would you say this is/has transitioned to an "annular" storm or is it just more the pattern of a very powerful hurricane? I know literature I've read indicates that dry air can often contribute to a storm going annular and there was a ton around Florence and she has shed the majority of her banding.. but I've seen other storms with similar looks that weren't classified that way too.
Click to expand...

Annular hurricanes often occur w/ aging TCs that have undergone at least one eyewall replacement cycle, are in the presence of low background relative humidity, have lukewarm SSTs (SSTs appear too warm for Florence's case), gently sloping SST gradients so as to not induce large-scale exponentially growing instabilities in/across the breadth of the core, and are in the presence of light easterly shear. Florence seems to fit many of these criteria, so it's probable we see this become annular but the environment isn't perfect (rarely is except in the Northeastern Pacific)
 
Webberweather53 said:
Annular hurricanes often occur w/ aging TCs that have undergone at least one eyewall replacement cycle, are in the presence of low background relative humidity, have lukewarm SSTs (SSTs appear too warm for Florence's case), gently sloping SST gradients so as to not induce large-scale exponentially growing instabilities in/across the breadth of the core, and are in the presence of light easterly shear. Florence seems to fit many of these criteria, so it's probable we see this become annular but the environment isn't perfect (rarely is except in the Northeastern Pacific)
Click to expand...

You can see we even have light east-southeasterly shear, which is hard to get outside the NE Pacific and far eastern Atlantic near the exit region of the African Easterly Jet (AEJ).

gfs_vortex_sounding_06L_2 (3).png
 
Definitely would be nice to see Florence turn into a big ol donut or truck tire down the line and we have an environment that's somewhat favorable for it to happen. We shall see.
 
Florence is riding in a pocket of SSTs a little warmer than have been observed in canes that developed annular characteristics. Most literature out there specifies 25-28C as the favorable oceanic environment. As it gets closer to the coastline, it will enter waters right at 28C with little to no shear in its lead up to the coast. Given that annular canes become that way after an ERC, hopefully the timing here is off, otherwise this would be worst case scenario.
 
The stall and Westward crawl solution is gaining traction
ba37fe5e59844f1206345a11ae5c9549.jpg


Sent from my SM-G920V using Tapatalk
 
You must log in or register to reply here.
Back
Top