ATL: FRED - Post-Tropical - Discussion

[eastcoastFL]

Fred 5pm

[AutoPenalti]

Fred 5pm

https://www.nhc.noaa.gov/storm_graphics/AT06/refresh/AL062021_5day_cone_no_line_and_wind+png/204128_5day_cone_no_line_and_wind.png

Looks about the same.

[eastcoastFL]

opical Storm Fred Advisory Number 9
NWS National Hurricane Center Miami FL AL062021
500 PM EDT Wed Aug 11 2021

...CENTER OF FRED CROSSING THE DOMINICAN REPUBLIC...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.9N 71.0W
ABOUT 75 MI...125 KM WNW OF SANTO DOMINGO DOMINICAN REPUBLIC
ABOUT 210 MI...335 KM SE OF GREAT INAGUA ISLAND
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES

[eastcoastFL]

5pm Disco

Tropical Storm Fred Discussion Number 9
NWS National Hurricane Center Miami FL AL062021
500 PM EDT Wed Aug 11 2021

During the past several hours, the center of Fred has moved inland
over the Dominican Republic. The storm continues to produce an
area of convection near and southeast of the center. However, the
low-level circulation is losing some organization as it passes over
mountainous terrain. There have been no observations near the
center recently, so the initial intensity of 35 kt is based mainly
on weakening from the previous over water intensity.

The initial motion is a somewhat uncertain 290/13. Some erratic
motion is expected during the next 12 h or so as the center moves
over the mountains of Hispaniola. After reaching the water, the
cyclone is expected to moves west-northwestward on the south side
of the subtropical ridge through about 60 h. After that, a
northwestward motion is expected through the end of the forecast
period as Fred moves toward a weakness in the ridge. The track
guidance becomes a bit divergent during this time, with the ECMWF,
Canadian, and HWRF models showing a track near or over the Florida
Peninsula, while the GFS, UKMET, and HMON models show the center
passing south and west of the Florida Keys, followed by a more
northward motion over the Gulf of Mexico. The new forecast track
is between these extremes, and it has only minor adjustments from
the previous NHC track.

Fred is expected to weaken to a depression over Hispaniola during
the next 12 h. Once back over water, the cyclone is expected to be
in a moderate westerly shear environment through at least 60 h. Due
to that, and the uncertainty in how well organized the system
will be after crossing Hispaniola, the intensity forecast shows
only modest intensification during this time. After that time, the
global models forecast that an upper-level trough over Florida
will gradually move to the north, with an large upper-level
anticyclone following near or to the southeast of Fred. How close
this anticyclone gets to Fred will determine how much the shear
decreases while the system is over the eastern Gulf of Mexico, and
the global models are not in great agreement on this. The GFS and
Canadian keep the high far enough to the east to expose Fred to
southwesterly upper-level winds, while the UKMET and ECMWF move it
closer to the storm. The intensity forecast will show a slightly
faster rate of strengthening after 72 h to match the guidance and
the previous forecast. However, there is lower than normal
confidence in this part of the intensity forecast.

KEY MESSAGES:

1. Tropical storm conditions are ongoing across portions of the
Dominican Republic. Tropical storm conditions are possible in
northern Haiti and the southeastern Bahamas this evening, and in
portions of Cuba by tonight.

2. Through early Thursday morning, heavy rainfall could lead to
flash, urban, and small stream flooding, along with possible rapid
river rises and potential mudslides in the Dominican Republic.

3. There is a risk of wind and rainfall impacts elsewhere in
portions of Hispaniola, the Bahamas, and Cuba during the next few
days, although the forecast is more uncertain than usual since Fred
is forecast to interact with Hispaniola through tonight.

4. There is an increasing risk of wind and rainfall impacts in
Florida beginning Friday night or early Saturday in the Keys and
spreading northward through portions of the Peninsula and the
Panhandle Saturday through Monday. Beginning Friday, heavy rainfall
could lead to areal, urban, and small stream flooding, and possible
rapid river rises across southern Florida. Interests throughout
Florida should monitor Fred's progress and check updates to the
forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 11/2100Z 18.9N 71.0W 35 KT 40 MPH...INLAND
12H 12/0600Z 19.8N 72.7W 30 KT 35 MPH...INLAND
24H 12/1800Z 20.9N 75.0W 30 KT 35 MPH...OVER WATER
36H 13/0600Z 21.9N 77.1W 35 KT 40 MPH
48H 13/1800Z 22.9N 79.2W 35 KT 40 MPH
60H 14/0600Z 23.9N 80.6W 40 KT 45 MPH
72H 14/1800Z 25.3N 82.0W 40 KT 45 MPH
96H 15/1800Z 28.5N 84.0W 50 KT 60 MPH
120H 16/1800Z 31.0N 85.0W 45 KT 50 MPH...INLAND

$$
Forecaster Beven

[eastcoastFL]

[AutoPenalti]

https://www.weathernerds.org/satellite/sessions/80391103.gif?0.9476875376499877

This is going to be a rough 7-8 hours.

[TallyTracker]

Fred’s doing some mountain climbing now! We’ll see what’s left on the other side…really gonna be looking forward to seeing what this gonna look like by dawn.

[SFLcane]

Rather interesting beven actually acknowledges the hwrf this time.

[eastcoastFL]

https://www.weathernerds.org/satellite/sessions/80391103.gif?0.9476875376499877

This is going to be a rough 7-8 hours.

Sure is. Also despite it being a weak storm this track may still cause devastating floods for the DR

[tolakram]

saved loops

[Weatherboy1]

Fred does seem to be heading a bit more N than W the last hour or so. Hard to tell if it's a trick of the eyes, especially with mountain interaction though. Again, gotta see what's left and where the center is 6-10 hours from now (more N = faster emergence over water, of course)

[Nimbus]

https://www.weathernerds.org/satellite/sessions/80391103.gif?0.9476875376499877

This is going to be a rough 7-8 hours.

If it comes off near Manzanillo Bay the track is more likely to stay north of Cuba.
And it could get under that high in the gulf potentially.

[tropicwatch]

saved loops

https://i.imgur.com/du6Eier.gif
https://i.imgur.com/ND8v5m1.gif

Is that the MLC close to the border with Haiti?

[tolakram]

Fred does seem to be heading a bit more N than W the last hour or so. Hard to tell if it's a trick of the eyes, especially with mountain interaction though. Again, gotta see what's left and where the center is 6-10 hours from now (more N = faster emergence over water, of course)

Nothign has to be left, that's the neat thing about crossing Hispaniola. You can see the swirl getting near the north coast. There may still be an LLC over the southern coast or not. I forget which one but there was one crossing that left a swirl on the south side of the island as a new center formed on the north side. It appears to be completely random, but maybe some models are good enough to handle it.

[tropicwatch]

saved loops

https://i.imgur.com/du6Eier.gif
https://i.imgur.com/ND8v5m1.gif

Is that the MLC close to the border with Haiti?

Upon further inspection that looks like a lower level circulation. If it holds together, could be back over water sooner.

[Dean4Storms]

From a pure satellite look perspective, it's the best Fred has ever looked.

[psyclone]

Like Elsa, it is remarkable how consistent the NHC track has remained. We're not sure what it will be, but where it's headed seems pretty relentless. If we have a coherent system, the east coast should still do well from a QPF standpoint even if the center remains west of the pensinsula...in fact as of now the QPF estimates from WPC are wetter on the east coast from vero south than they are on the west coast above Naples. Onshore flow FTW...

[Blown Away]

Look at all the cloud energy to the N of Fred... Complex workings in the environment for sure!

[Blown Away]

Excerpt From 5pm Disco:
The track guidance becomes a bit divergent during this time, with the ECMWF,
Canadian, and HWRF models showing a track near or over the Florida
Peninsula, while the GFS, UKMET, and HMON models show the center
passing south and west of the Florida Keys, followed by a more
northward motion over the Gulf of Mexico.

ECMWF > GFS
UKMET > Canadian
HWRF = HMON (U Pick'm)

Tough call, NHC went GFS/Ukmet/Hmon for now...

[BobHarlem]

Excerpt From 5pm Disco:
The track guidance becomes a bit divergent during this time, with the ECMWF,
Canadian, and HWRF models showing a track near or over the Florida
Peninsula, while the GFS, UKMET, and HMON models show the center
passing south and west of the Florida Keys, followed by a more
northward motion over the Gulf of Mexico.

ECMWF > GFS
UKMET > Canadian
HWRF = HMON (U Pick'm)

Tough call, NHC went GFS/Ukmet/Hmon for now...

Doubt the NHC touches their track much until it's cleared Hispaniola and they have a decent recon fix. But to be honest the NHC's track is a great middle of the road one, so I doubt it winds up being off much at all. Maybe the tail end of it (% day point) if anything.