NATL: IMELDA - Post-Tropical - Discussion

[cycloneye]

A Tropical Storm Watch has been issued for the east coast of Florida
from the Palm Beach/Martin County Line northward to the
Flagler/Volusia County Line.

[ScottNAtlanta]

Given the risk of tropical-storm-force winds along the east coast of
Florida, a Tropical Storm Watch has been issued from the Palm
Beach/Martin County Line northward to the Flagler/Volusia County
Line. Although it is still too early to specify the details of
potential impacts along the remainder of the southeast U.S. coast,
there remains a risk of heavy rainfall, storm surge, and wind
impacts.

[skillz305]

I am officially in a tropical storm watch here in Vero Beach, FL

[ScottNAtlanta]

I think intensity wise this might just over perform the forecast if it can get it's structure settled

[GCANE]

Looking at where the vorticity is located, It is a bit east of where the 8am fix is located
https://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8vor5.GIF
https://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8vor.GIF

Its elongated in the same direction of a wave.
Land interaction is keeping it from closing off.

Morning GCANE, quick question, do you have any idea how the southern end of the wave axis has clung on for the past few days, given that the two halves of the wave were physically separated?

Good morning Zonacane.

Waves are higher up in altitude, most of the structure is around 700mb altitude.
Winds on the east side of the axis move from SE to NW. Winds on the west side of the axis move from NE to SW.
Turning occurs at the top of the wave. Winds move from east to west here.
So, the structure is high enough to survive mountainous terrain.
However, to get the top of the wave to close off and make a surface low, large convection such as a hot tower, needs to fire off so that sudden lift creates a surface vortex.
Thus winds begin turn from west to east near the top of the axis due to the lift from the convection.
So, to really close off and get a tropical depression, large and sustained convection needs to occur near the top of the wave axis.

I hope that answers your question.

[syfr]

NHC 11AM now has the "brick wall" right angle eastern turn off the coast of Ga, rather than SC.

[Weathertracker96]

I am officially in a tropical storm watch here in Vero Beach, FL

I’m Vero beach myself. Been watching this as these systems are unpredictable.

[skillz305]

11am NHC graphic

[GCANE]

The GOM front is really enhancing mid-level and upper-level outflow.

https://weather.cod.edu/satrad/?parms=r ... =undefined

[GCANE]

Looks like its starting to pickup some EPAC moisture thru Panama.
As the surface low deepens, it will pull in more moisture.

https://tropic.ssec.wisc.edu/real-time/ ... anim=html5

[Weathertracker96]

The GOM front is really enhancing mid-level and upper-level outflow.

https://weather.cod.edu/satrad/?parms=r ... =undefined

Is the front still moving as forecast? I know you mentioned this morning about some storms possibly eroding the front. Thanks for all your posts/analysis.

[cycloneye]

Looks like is starting to move a little faster than in the past 24 hours and is organizing.



Zoom to the center.

[GCANE]

Winds on the east side of the wave axis persist as a surface low is created.
This pulls in moist air from the south and becomes the so called "feeder band".
Low level winds are basically moving south to north along the feeder band.
However higher level winds move from west to east due to outflow from the tropical depression.
This twist in the winds create directional shear which fires convection over the feeder band.
Looks like a feeder band is being setup thru the Windward Passage.

https://weathernerds.org/satellite/?ini ... itgefs=Off

[eastcoastFL]

I just got the tropical storm watch text so we might see a little weather tomorrow and Monday as it passes through the Bahamas. Interesting track though, might save the Carolinas from serious flooding.

A Tropical Storm Watch has been issued for your area.
For more info https://evbg.co/t0jijv .

[GCANE]

The GOM front is really enhancing mid-level and upper-level outflow.

https://weather.cod.edu/satrad/?parms=r ... =undefined

Is the front still moving as forecast? I know you mentioned this morning about some storms possibly eroding the front. Thanks for all your posts/analysis.

Actually, looking at run-to-run GFS, the bottom of the front seems to be pulling back west a bit.
This is probably why Humberto is giving it more of a tug to the east from Fujiwhara.
Hopefully that trend continues.

[GCANE]

Seeing some decent convection north of the Yucatan.
Hopefully that will erode the front even more.

[tolakram]

saved loop

[tolakram]

Big picture

[GCANE]

Hmm.
Keeping an eye on the tail of the front in the GOM that just popped up on the 200mb vort product from CIMSS.
Lots of curve balls here.


https://tropic.ssec.wisc.edu/real-time/ ... oom=&time=

[boca]

Hmm.
Keeping an eye on the tail of the front in the GOM that just popped up on the 200mb vort product from CIMSS.
Lots of curve balls here.


https://tropic.ssec.wisc.edu/real-time/ ... oom=&time=

What does that mean as far as track of TD9?