Frances Advisories

[TerryAlly]

Will get sucked up by the trough

[CaluWxBill]

Don't trust the Quickscats at all! Look how good they where with Charley

Quickscats really aren't a great indicator of exact wind speed, I think they are more for general look at rotation and forward movement of storms. I don't think it will be too long before we see Frances.

[jabber]

The trough is digging.

2 possibilities

1: It goes out to sea
2. It remains weak, becomes a TD or weak TS and dissipates moving to the west east of the islands due to strong SW shear

Do not like 1 or 2

[Guest]

yeah, future frances is looking pretty good right now.

[Guest]

I don't know about this one at this point. It could go North and out to sea if it gets picked up by the trough, It could go wnw and cross over the islands and eventually end up near the s.e coast, or it could continue into the carribean. I don't know how strong this thing may be though.

[MWatkins]

The trough is digging.

2 possibilities

1: It goes out to sea
2. It remains weak, becomes a TD or weak TS and dissipates moving to the west east of the islands due to strong SW shear

There's also a third option...called synoptic meteorology.

The trough that is progged to turn 96L hasn't even appeared on the playing field yet. It's still WAY up in extreme eastern Canada.

Here's the GFS from two days ago...note there is a 500MB low with a trailing trough extending all the way down to 25N and our tropical system approaching 40W...note also that the 500MB low is fully involved with the westerlies at that level:

http://bricker.met.psu.edu/trop-cgi/avn ... hour=120hr

Here's the same model run 2 days later...same verify time...

http://bricker.met.psu.edu/trop-cgi/avn ... hour=072hr

What's the key differences? Two huge changes in the model.

1. The 500MB low is 600 nautical miles to the west of the previous projection.
2. It gets CUT OFF from the westerly flow...and ends up sinking down to the south to join up with the tropical system later on.

The 06Z is even more pronounced in developing a cut-off low in the steering layers...and not a trough.

With these large-scale features changing so abruptly in the last 48 hours...it CANNOT be determined with certainty that this system is kicking out. We have to watch the features...especially what happens with the system currently over far eastern Canada. If the models continue to trend toward a weaker system and not a trough there...then some leftward adjustments to the guidance will happen. If it drops down 10 degrees past the storms longitude...then it misses it all together.

MW

[Brent]

The trough is digging.

2 possibilities

1: It goes out to sea
2. It remains weak, becomes a TD or weak TS and dissipates moving to the west east of the islands due to strong SW shear

Do not like 1 or 2

Me either, LOL I still think it could go either way.

[Air Force Met]

Lots of lower level cu moving east in the vis loop. Looks like most of the convection is north of the LLC...but there is an LLC since the CU is moving east.

[Guest]

TD #6 which I believe it is right now regardless will NOT get grabbed by the trough IMO. I disagree with Derek as I don't agree with #2 option either I think this eventually strengthens and heads towards the Carribean.

[Derek Ortt]

Have just looked at a 500mb analysis. There is a ridge currently over the storm and 1 to the west. However, there is a nice weakness currently at 55W. With another weakness coming down, this is a near certainty to not be a significant threat to land, unless it stays very weak the entire way across the Atlantic

[Air Force Met]

I am currently on a military trip...and only have dial-up (argggghh)...a slow one at that...which limits my ability to analyze the data...but here is my stab on it:
I think the trof lifts it enough to allow it to clear the Islands. It then has two choices...based on how strong it is:
1) If the system is a hurricane...it will recurve and become a fish.
2) If the system remains fairly weak to a strong TS, then it gets pulled poleward by the trof...the trof doesn't grab it...and it eventually gets shoved back under the ridge and heads more west...but it stays north of the Islands.

So...my gut call is that it recurves because I think it will be a hurricane...but even then I think there is a slight chance of it turning back to the west. I do believe...whatever the scenario...that the Islands will be spared...or in a worst case scenario...clipped.

Of course...I have no data to look at...so...who knows

[Guest]

Derek I don't see the shear you referered to, also I agree the he will move more northwest in the weakness but get pushed back west again afterwards. THen the question is does he get pushed out by the next trough.

[Nimbus]

I'm with MW its too early to tell. This wave is moving west a little slower than the previous few waves. The Upper level low that was predicted earlier to steer the storm north around 40 has been retreating WNW.

The upper level low that was over the Bahamas has been sinking at an alarming rate and may very well cut off and allow a ridge to build right up the middle of the two ULL's ahead of Frances.

You would think that any trough dropping south would be delayed by interference from the westward moving ULL but the models may have factored all this in despite the rapid dynamics in the upper level environment.

[MWatkins]

Big shift with the 12Z gfs on handling the Central Atlantic 500MB low. The previous runs were creating a huge trough...the 00Z backed down to a cut-off low that would hang around for a while...now the 12Z guidance LIFTS out the low during days 6 and 7. Check out the model runs for the same verify time on day 6

00Z at 144:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_144s.gif

12Z at 132:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_132s.gif

MW

[cycloneye]

Hummm Mike very interesting development that change of GFS in this run.

[rbaker]

i agree just because the weakness is there now at 55w when the td is at 35w, doesn't mean it won't be there in about 3-4 days, even if its prog to be there at latest runs. As seen by gfs its been backing off the trough coming down as far south, or as strong as thought before.

[cycloneye]

Well as time has gone by today the models haved trended a little more to the west as the system has not developed and is basicly moving westward.The question continues to be the same as I posted this morning.What effects if any will the trough comming down from Canada will have on the system as it moves more west in longitud.

[caribepr]

I hope it's north...packing up to leave Thursday for a week in Maryland with the radar looking progressively interesting means pulling out all the big old Tupperware tubs for books, computer, precious stuff and hoping it will all be here when I get back. I live about 30 meters from the edge of the water on our bay here - lots of mangroves but a few open spots. Oh well, this little place made it through the last couple of bad ones when most of the island bought it...and maybe it will all fizzle fish out. Yep, I'm going with that scenario, under the old 'prepare for the worst, hope for the best' motto!

[cycloneye]

I hope it's north...packing up to leave Thursday for a week in Maryland with the radar looking progressively interesting means pulling out all the big old Tupperware tubs for books, computer, precious stuff and hoping it will all be here when I get back. I live about 30 meters from the edge of the water on our bay here - lots of mangroves but a few open spots. Oh well, this little place made it through the last couple of bad ones when most of the island bought it...and maybe it will all fizzle fish out. Yep, I'm going with that scenario, under the old 'prepare for the worst, hope for the best' motto!

Good thinking about that and have a safe trip.

[caribepr]

Thanks cycloneye...I'll be checking in from MD for opinions from you and the rest here, most definitely