ATL: FLORENCE - Post-Tropical - Discussion

[Bocadude85]

Tropical Storm FLORENCE
As of 06:00 UTC Sep 08, 2018:

Location: 24.6°N 53.8°W
Maximum Winds: 55 kt Gusts: N/A
Minimum Central Pressure: 997 mb
Environmental Pressure: 1014 mb
Radius of Circulation: 130 NM
Radius of Maximum Wind: 15 NM
Eye Diameter: N/A

[TheDreamTraveler]

by the way.. looking at the convective pattern.. convection has wrapped to the south side of the CIRC> we very well might have a hurricane by 5am .. shear just dropped so suddenly. FLO is down around 24.2 and may wobble more as the convection builds.. ..

Yeah. It'll be interesting to see how much this influences it's track if it's able to get stronger faster than the models are currently saying. She was able to go more north when she was a cat 4 and has been able to go a bit wsw recently because of how weak and sheared she was.

[HurricaneIrma]

South Carolina may be a bad place to be next week, I hope everybody in the Carolinas is watching Flo..this could be really bad for you guys.

I live in South Carolina

[jlauderdal]

South Carolina may be a bad place to be next week, I hope everybody in the Carolinas is watching Flo..this could be really bad for you guys.

statistics say at this range you want to be at ground zero...last year irma was poised to landfall in miami a few days out, it didnt...thursday night before irma i really thought we were going to test my roof with 120+, point is you want to be in the crosshairs especially at this range..good luck to whoever gets this because its going to be a major hurricane for someone

[Hurricane Andrew]

Wow...Steward isn't messing around.

The upper-level environment is expected to improve to significantly
during the next 12 h and beyond with the current 20 kt of
southwesterly shear forecast to give way to shear of less than 10
kt. By 72 h and beyond, light shear from the southeast and east
along with the development of strong upper-level outflow jets to
the north of Florence is expected to create an environment that
favors significant and possibly even rapid strengthening. The new
NHC intensity forecast has been increased over the previous advisory
in anticipation of these very favorable dynamical conditions
developing, and now shows Florence becoming a hurricane by Sunday
and a major hurricane in 3 days, followed by additional
strengthening over the very warm Atlantic waters of at least 29 deg
C that are about 2 deg C above normal right now. The consensus
models IVCN and HCCA were closely followed, which are a little
below the FSSE model.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased. However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts. Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 24.5N 54.2W 55 KT 65 MPH
12H 08/1800Z 24.6N 55.0W 60 KT 70 MPH
24H 09/0600Z 24.6N 56.0W 65 KT 75 MPH
36H 09/1800Z 24.6N 57.2W 75 KT 85 MPH
48H 10/0600Z 24.9N 59.0W 90 KT 105 MPH
72H 11/0600Z 26.0N 64.0W 105 KT 120 MPH
96H 12/0600Z 28.0N 70.2W 120 KT 140 MPH
120H 13/0600Z 30.9N 75.8W 125 KT 145 MPH

$$
Forecaster Stewart

[jlauderdal]

This should be concerning to people in georgia and north florida
as its all about a strong ridge, that bend to the NW in the current track and modeling seems to pronounced, lets see how it plays out


Jax NWS
A STRONG HIGH PRESSURE RIDGE EXTENDING FROM THE WESTERN
ATLANTIC INTO THE MID- ATLANTIC STATES WILL STEER FLORENCE
WESTWARD TOWARDS THE EAST COAST WHILE STRENGTHENING BY MID TO LATE
WEEK.

MIA NWS
LONG TERM (TUESDAY THROUGH LATE WEEK): THE ATLANTIC RIDGE BUILDS
BACK IN BEGINNING TUESDAY AS THE TYPICAL SUMMERTIME PATTERN
RESUMES WITH EAST TO SOUTHEAST WINDS AND SEABREEZE DRIVEN
CONVECTION.

HOWEVER IF THE
CURRENT TRACK HOLDS OR SHIFTS SOUTHWARD

[HurricaneIrma]

For Thursday and Friday, will follow the latest WPC guidance on the
Florence circulation which is currently a compromise of the more
eastern GFS (impacting the eastern half of NC) and the more western
track of the ECMWF (impacting the central/western Carolinas more
squarely.) This will yield a steady uptick in northeasterly flow and
solid shower thunderstorm chances. This part of the forecast is
highly uncertain given the model spread along the east coast. Stay
tuned.

[HurricaneIrma]

For Thursday and Friday, will follow the latest WPC guidance on the
Florence circulation which is currently a compromise of the more
eastern GFS (impacting the eastern half of NC) and the more western
track of the ECMWF (impacting the central/western Carolinas more
squarely.) This will yield a steady uptick in northeasterly flow and
solid shower thunderstorm chances. This part of the forecast is
highly uncertain given the model spread along the east coast. Stay
tuned.

This is from the upstate South Carolina NWS

[FLeastcoast]

South Carolina may be a bad place to be next week, I hope everybody in the Carolinas is watching Flo..this could be really bad for you guys.

statistics say at this range you want to be at ground zero...last year irma was poised to landfall in miami a few days out, it didnt...thursday night before irma i really thought we were going to test my roof with 120+, point is you want to be in the crosshairs especially at this range..good luck to whoever gets this because its going to be a major hurricane for someone

I am near Jax and definitely keeping a close eye on this thing. What category do you guess it might strengthen to?

[NotoSans]

Typical evolution of cloud patterns when shear starts to relax. Latest microwave imagery shows that Florence is re-establishing its inner core, and I wouldn't be surprised to see her becoming a hurricane sooner than expected.
Also, it is quite rare to see NHC going that aggressive for its intensity forecast, and the discussion is very well-written as well.

[cycloneye]

BULLETIN
Tropical Storm Florence Advisory Number 36
NWS National Hurricane Center Miami FL AL062018
500 AM AST Sat Sep 08 2018

...FLORENCE FORECAST TO BECOME A HURRICANE BY SUNDAY...
...EXPECTED TO BECOME A MAJOR HURRICANE AGAIN EARLY NEXT WEEK...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...24.5N 54.2W
ABOUT 840 MI...1350 KM SE OF BERMUDA
ABOUT 720 MI...1155 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 9 MPH...14 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES


Tropical Storm Florence Discussion Number 36
NWS National Hurricane Center Miami FL AL062018
500 AM AST Sat Sep 08 2018

Although Florence remains a sheared tropical cyclone, satellite
imagery during the past 6 h also indicates that the shear has
started to abate somewhat, which has allowed the dense cirrus
canopy to build back over the previously exposed low-level
circulation center. Furthermore, deep convection with overshooting
cloud tops near -80C and an abundance of lightning activity have
developed very close to the center. Based on these data along with
Dvorak intensity estimates of T3.5/55 kt from TAFB and SAB, the
initial intensity has been raised to 55 kt.

The initial motion estimate is 265/8 kt. The mid-latitude flow
across CONUS and the northern Atlantic is forecast to flatten out
and become more zonal over the next 48 h or so, resulting in the
development of a narrow east-west oriented ridge along 35/36N
latitude. This large-scale feature is expected to steer Florence
in a general westward direction during that time. By days 3-5,
however, the flow across the central and western U.S. is forecast
to buckle and become more meridional as a deep mid-/upper-level
trough over the northeast Pacific pushes inland over the western
U.S., causing downstream ridging over the northeastern U.S. and
northwestern Atlantic. The global models agree on this general
change in the synoptic-scale flow pattern, but they differ
noticeably on where a downstream mid-/upper-level high pressure cell
takes up residence over the Atlantic either to the northwest or
northeast of Bermuda. The farther west/east the high develops will
determine how far west/east Florence will eventually move and
possibly affect the U.S. east coast beyond the 5-day forecast
period. The new official forecast track is close to the previous
advisory track through 48 h, and then was nudged a little to the
left or west of the previous track, which is close to the consensus
model TVCN and is north of the corrected-consensus models FSSE and
HCCA since the bulk of the NHC model guidance lies north of those
latter two models.

The upper-level environment is expected to improve to significantly
during the next 12 h and beyond with the current 20 kt of
southwesterly shear forecast to give way to shear of less than 10
kt. By 72 h and beyond, light shear from the southeast and east
along with the development of strong upper-level outflow jets to
the north of Florence is expected to create an environment that
favors significant and possibly even rapid strengthening. The new
NHC intensity forecast has been increased over the previous advisory
in anticipation of these very favorable dynamical conditions
developing, and now shows Florence becoming a hurricane by Sunday
and a major hurricane in 3 days, followed by additional
strengthening over the very warm Atlantic waters of at least 29 deg
C that are about 2 deg C above normal right now. The consensus
models IVCN and HCCA were closely followed, which are a little
below the FSSE model.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased. However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts. Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 24.5N 54.2W 55 KT 65 MPH
12H 08/1800Z 24.6N 55.0W 60 KT 70 MPH
24H 09/0600Z 24.6N 56.0W 65 KT 75 MPH
36H 09/1800Z 24.6N 57.2W 75 KT 85 MPH
48H 10/0600Z 24.9N 59.0W 90 KT 105 MPH
72H 11/0600Z 26.0N 64.0W 105 KT 120 MPH
96H 12/0600Z 28.0N 70.2W 120 KT 140 MPH
120H 13/0600Z 30.9N 75.8W 125 KT 145 MPH

$$
Forecaster Stewart

[txwatcher91]

Core has improved significantly. Also looks like she’s moving west or wnw.
http://tropic.ssec.wisc.edu/real-time/m ... hr_09.html

[jlauderdal]

I am near Jax and definitely keeping a close eye on this thing. What category do you guess it might strengthen to?

regardless of 4 or 5, all residents from jax to the sc/nc line better start preparing this weekend for a 3+, start your generator today and makes sure its a go, amazes me before a hurricane the number of people that own a generator but it doesnt start, duh

[Slughitter3]

I hope I did this image this image thing right, anywho. She's taken in a little bit of dry air at the lower levels this morning. Strictly an observation, I just enjoy this stuff, no real education over here just a hobby. We'll see how long it takes her to cough it up.

Image from weather.cod.edu SAT Viewer.

[FLeastcoast]

regardless of 4 or 5, all residents from jax to the sc/nc line better start preparing this weekend for a 3+, start your generator today and makes sure its a go, amazes me before a hurricane the number of people that own a generator but it doesnt start, duh

I agree. People should basically prepare right at the beginning of the season for the most part. I have a generator, but have never had to use it. That is a HUGE advantage to being on the same grid as a fire station. Very QUICK to get power restored!

[jlauderdal]

I agree. People should basically prepare right at the beginning of the season for the most part. I have a generator, but have never had to use it. That is a HUGE advantage to being on the same grid as a fire station. Very QUICK to get power restored!

start your generator, know how to use it..have all your cords, etc ready so you can deploy it in the dark if needed

[FLeastcoast]

regardless of 4 or 5, all residents from jax to the sc/nc line better start preparing this weekend for a 3+, start your generator today and makes sure its a go, amazes me before a hurricane the number of people that own a generator but it doesnt start, duh

I agree. People should basically prepare right at the beginning of the season for the most part. I have a generator, but have never had to use it. That is a HUGE advantage to being on the same grid as a fire station. Very QUICK to get power restored!

start your generator, know how to use it..have all your cords, etc ready so you can deploy it in the dark if needed

That is good advice. I do need to go do that ..just in case. Thanks!

[SouthFLTropics]

This mornings visible RGB loop is stunning. The outflow to the North and NW is amazing. Still looks to be moving around 260 or 265...just a tick south of due west.

[Mouton]

It appears to me to be picking up some forward speed. Bears watching because that fantasy (IMO) path shown on some models based on a weaking ridge (!) shows slow motion for a few days as the ridge diminishes.

[Blown Away]

Amazing what a few hours can do.