ATL: FIONA - Post-Tropical - Discussion

[Aric Dunn]

cmc way west.. only reason for recurve is from spurious system near bermuda weakens the ridge

[Caneman12]

Expect it to continue to trend west

[Yellow Evan]

Code: Select all

   AL, 06, 2016081706,   , BEST,   0, 129N,  347W,  30, 1007, TD,  34, NEQ,    0,    0,    0,    0, 1012,  160,  50,   0,   0,   L,   0,    ,   0,   0,        SIX, M,  0,    ,    0,    0,    0,    0, genesis-num, 013,

[Yellow Evan]

This could also just as easily recurve east of where the models have it too

Knowing model biases, I'd say that is somewhat unlikely.

[cycloneye]

BULLETIN
TROPICAL DEPRESSION SIX ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062016
500 AM AST WED AUG 17 2016

...TROPICAL DEPRESSION MOVING NORTHWESTWARD OVER THE CENTRAL
TROPICAL ATLANTIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 35.2W
ABOUT 775 MI...1245 KM WSW OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES



TROPICAL DEPRESSION SIX DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062016
500 AM AST WED AUG 17 2016

The depression's cloud pattern is gradually becoming better
organized. It consists of a central mass of deep convection and a
newly formed band over the northern half of the circulation. The
low-level center appears to still be located near the northeastern
edge of the main convective mass, likely due to some northeasterly
shear. Satellite classifications are T2.0 from TAFB and SAB, and
support maintaining the initial intensity estimate of 30 kt.

The northeasterly shear is forecast to decrease while the cyclone
moves over marginally warm waters during the next 24 to 36 hours.
These two factors should favor some intensification during this time
frame. However, the global models, and the ECMWF in particular,
show the cyclone moving into a much drier environment after 48 hours
and encountering strong southwesterly shear in association with a
mid- to upper-level trough. Thus weakening is forecast to begin by
day 3 despite the cyclone's trek over warmer waters, and there is
the possibility that the system could degenerate into a remnant low
by day 4 or 5 as depicted in the ECMWF. The new NHC intensity
forecast is somewhat higher than the previous one and the multi-
model consensus in the short term but lower later in the forecast
period and a little below most of the guidance.

The depression has been responding to a weakness in the subtropical
ridge between 40w and 50w by moving on a northwesterly track, and
the initial motion estimate is 305/13. The track guidance remains
split into two distinct camps, with GFS-based deterministic models
and GFS ensemble members showing a deeper system moving more
poleward. The ECMWF and its ensemble solutions are much farther to
the south as a result of the model's forecast of a weaker, shallower
system moving on a more westerly course. Based on the assumption
of a weaker system, the NHC track forecast is adjusted toward the
ECMWF solution, and is well south of the previous one and a little
to the left of the multi-model consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 17/0900Z 13.2N 35.2W 30 KT 35 MPH
12H 17/1800Z 14.3N 36.8W 40 KT 45 MPH
24H 18/0600Z 15.5N 38.3W 45 KT 50 MPH
36H 18/1800Z 16.8N 39.9W 50 KT 60 MPH
48H 19/0600Z 17.8N 41.4W 50 KT 60 MPH
72H 20/0600Z 19.2N 44.7W 45 KT 50 MPH
96H 21/0600Z 21.6N 48.9W 40 KT 45 MPH
120H 22/0600Z 23.6N 52.3W 35 KT 40 MPH

$$
Forecaster Kimberlain

[tolakram]

Already headed NW. At 8 a.m. it was due west. Clearly a fish spinner.

Clearly? So many people making such definitive statements.

Euro has trended weaker and west again.

[Kingarabian]

I think that's because it runs into a wall of strong shear. And the Euro pretty much takes it to a latitude that even if it survives the shear it'll miss the GOM where conditions are favorable.

[Nimbus]

All the steering elements south of 20 N are evolving and rotating west.
Could be a TUTT starting to form near -42 W


http://weather.msfc.nasa.gov/GOES/goeseasthurrwv.html

[cycloneye]

Looks like we will have FIONA at 11 AM.

12z Best Track:

As of 12:00 UTC Aug 17, 2016:


Location: 13.6°N 35.8°W
Maximum Winds: 35 kt Gusts: N/A
Minimum Central Pressure: 1006 mb
Environmental Pressure: 1011 mb
Radius of Circulation: 140 NM
Radius of Maximum Wind: 40 NM
Eye Diameter: N/A

[Kazmit]

Looks like we will have FIONA at 11 AM.

12z Best Track:

As of 12:00 UTC Aug 17, 2016:


Location: 13.6°N 35.8°W
Maximum Winds: 35 kt Gusts: N/A
Minimum Central Pressure: 1006 mb
Environmental Pressure: 1011 mb
Radius of Circulation: 140 NM
Radius of Maximum Wind: 40 NM
Eye Diameter: N/A

Looks like Fiona the fish is about to be born.

[Aric Dunn]

Wouldn't write it off yet. definitely a large spread in the models ( and trending west) and left turn looks more likely. then very weak steering afterwards.

Its also fighting SAL so a more westward trend will likely continue per the recent EURO and other models.

[znel52]

Bermuda might still be in play here. Some of the models indicate that future Fiona might end up in the vicinity of the island. Is it the most likely scenario? Maybe not but if I was I in Bermuda I would definitely keep an eye on it.

[Kazmit]

Bermuda might still be in play here. Some of the models indicate that future Fiona might end up in the vicinity of the island. Is it the most likely scenario? Maybe not but if I was I in Bermuda I would definitely keep an eye on it.

It's possible. The models are trending more to the West, which increases the chance of it recurving into the island. It should be quite weak by the time it reaches them, if it does at all.

[chaser1]

:uarrow:

I think that's because it runs into a wall of strong shear. And the Euro pretty much takes it to a latitude that even if it survives the shear it'll miss the GOM where conditions are favorable.

On the other hand, there have been a number of noteable past hurricanes which have reached a position of approx. 22N and 55W that did make landfall on the CONUS East Coast, some having significant impact.

[znel52]

Looks like dry air starting to erode the convection a bit. Can it continue to fight off its effects?

http://rammb.cira.colostate.edu/ramsdis ... display=12

[wxman57]

Got a good ASCAT hit a couple hours ago. Strongest winds were 30kts. Couldn't find a 35kt barb. Convection is on the weak side. NHC may not upgrade yet. While I don't think it's any threat to the Caribbean islands or the East U.S. Coast, it may pass closer to the NE Caribbean than is currently forecast.

[chaser1]

Bermuda might still be in play here. Some of the models indicate that future Fiona might end up in the vicinity of the island. Is it the most likely scenario? Maybe not but if I was I in Bermuda I would definitely keep an eye on it.

Whether or not Fiona directly threatens Bermuda, the Bahamas or the CONUS there have been a number of past season storms which either weakened or degenerated only to restrengthen at some point where conditions were once again favorable. Those that believe this storm will weaken and/or die around 96hr. - 120hrs. with little to no chance of reintensifying might be taking an overly simplistic view of the present conditions or blind faith in the long range models.

[tarheelprogrammer]

This system looks like crap to put it kindly. Not sure how/why it would get an upgrade to TS but so far it seems to be struggling to even produce convection. Earl was an invest earlier this month and still looked better than this.

[floridasun78]

it look catch up dry air to west

[Florida1118]

This system looks like crap to put it kindly. Not sure how/why it would get an upgrade to TS but so far it seems to be struggling to even produce convection. Earl was an invest earlier this month and still looked better than this.

It looks fine. The convection has waned somewhat; hardly makes it "crap". It's still a well defined system, and it's only a 5kt difference between a TD and TS, your hyperbole on its "crappy" looks aside. If the NHC decides to wait, it will probably be due to the ASCAT pass.