ATL: 90L - ERIKA Remnants - Models

[Dean4Storms]

A bigger wave like this has a harder time maintaining itself as a TC at fast forward speeds. I think that is the problem here in both the ECM and GFS solutions. It might develop for a while but once that ridge takes over the forward speed just creates too much separation between the surface and the mid level.

[tolakram]

12Z Euro starts to develop the vorticity after it crosses Florida.

240 hours so high fantasy range.

[Bocadude85]

An important question to ask is whether or not the Euro and GFS are showing a weaker system due to interaction with the islands or is it more environment/shear related? GFS seems closer to the islands than the HWRF. Does anyone have a shear map for the 120 hour range?

SFT

It's forward speed is all the shear it needs! The GFS has it moving between 20-30kts.

That is true...with the big ridge to its north the forward speed should be pretty quick, just like the GFS shows.

Yea but 30kts may be overdoing it a little. I would think 15-20kts would allow some development.

[tolakram]

Well look at this (also in GFS fantasy range).

A piece of vorticity breaks off and does something east of Florida.

[tolakram]

[floridasun78]

my weather man say shear moving west and 98l fighting shear to nw he weather from ch4 wfor in miami he i meet person he good with tropical work with Bryan Norcross here

[tolakram]

[SouthFLTropics]

A bigger wave like this has a harder time maintaining itself as a TC at fast forward speeds. I think that is the problem here in both the ECM and GFS solutions. It might develop for a while but once that ridge takes over the forward speed just creates too much separation between the surface and the mid level.

I think it will depend on how well the inner core is established before the ridge takes over. A well stacked core can move fairly quickly and not have any issues. We've seen many storms over the years do this. Andrew was a pretty good example. Emily in 1987 remained a hurricane while moving off into the North Atlantic at almost 70 mph.

SFT

[SouthFLTropics]

Is that the extremely rare Savannah, Ga hit coming up???

[SouthFLTropics]

Well look at this (also in GFS fantasy range).

A piece of vorticity breaks off and does something east of Florida.

If you look back at hour 138 you can see that vort break off just north of between Cuba and Haiti and follow it's progression through the rest of the run.

SFT

[tolakram]

Nope, it hugs the coast and then moves off east. Probably nothing.

[SouthFLTropics]

Nope, it hugs the coast and then moves off east. Probably nothing.

GFS phantom at that time frame...

[floridasun78]

i look at cmc gem invest 98 mslp show it going north less strong high. didnt want put models get server overload

[Riptide]

Nope, it hugs the coast and then moves off east. Probably nothing.

We will be tracking 98L for a long time it seems.

[Dean4Storms]

A bigger wave like this has a harder time maintaining itself as a TC at fast forward speeds. I think that is the problem here in both the ECM and GFS solutions. It might develop for a while but once that ridge takes over the forward speed just creates too much separation between the surface and the mid level.

I think it will depend on how well the inner core is established before the ridge takes over. A well stacked core can move fairly quickly and not have any issues. We've seen many storms over the years do this. Andrew was a pretty good example. Emily in 1987 remained a hurricane while moving off into the North Atlantic at almost 70 mph.

SFT

True, but keep in mind those were situations where they were being absorbed by fronts moving Northward in tandem a bit with the SW flow. This is a fast westward movement where even the slightest wind shear aloft from the west, sw or nw is increased due to the systems forward speed into it.

[Blown Away]

18z:



Let's hope all this is wrong because at 132 hours most models have a strengthening hurricane entering the SE Bahamas...

[SouthFLTropics]

A bigger wave like this has a harder time maintaining itself as a TC at fast forward speeds. I think that is the problem here in both the ECM and GFS solutions. It might develop for a while but once that ridge takes over the forward speed just creates too much separation between the surface and the mid level.

I think it will depend on how well the inner core is established before the ridge takes over. A well stacked core can move fairly quickly and not have any issues. We've seen many storms over the years do this. Andrew was a pretty good example. Emily in 1987 remained a hurricane while moving off into the North Atlantic at almost 70 mph.

SFT

True, but keep in mind those were situations where they were being absorbed by fronts moving Northward in tandem a bit with the SW flow. This is a fast westward movement where even the slightest wind shear aloft from the west, sw or nw is increased due to the systems forward speed into it.

From the NHC website about Andrew... "The associated steering flow over the tropical storm became easterly. Andrew turned toward the west, accelerated to near 16 kt, and quickly intensified."

Made a beeline west and intensified the whole way in...his core was well established, but the shear was in his favor as well.

[SouthFLTropics]

Anyway, back to the models...perhaps the GFS is overdoing the forward speed a bit. And many of the other models are now showing a cane entering the SE Bahamas. It's hard to go against the globals but I'm sure not going to ignore the others right now...especially with how well the HWRF did with Danny.

SFT

[SouthDadeFish]

18Z GFS actually shows an upper-level anticyclone in place over the Bahamas between 120-144 hours. It appears 98L slightly outruns the anticyclone aloft and fails to take advantage of low shear conditions. I noticed the HWRF really pumps up a ridge aloft, which allows 98L to intensify. It seems forward speed and initial intensification can play a huge role down the road.

[gatorcane]

18Z GFS actually shows an upper-level anticyclone in place over the Bahamas between 120-144 hours. It appears 98L slightly outruns the anticyclone aloft and fails to take advantage of low shear conditions. I noticed the HWRF really pumps up a ridge aloft, which allows 98L to intensify. It seems forward speed and initial intensification can play a huge role down the road.

Yep look at that upper-high just off the SE Coast of Florida: