ATL: GABRIELLE - Remnants - Discussion

[ozonepete]

john hope said they need to be at least 600 miles apart for both to develop.

God bless John Hope. I loved the guy and he was a hero of mine. But (if he said that?) he was wrong on that one. And I'm willing to bet that the great John Hope actually said they typically need to be 600 miles apart. I can't believe he said that 600 miles was the absolute minimum distance. He was too smart for that. And you once again missed what I said: I've seen it. In fact I think it happened more than once in 2005 when good old John was not around to see it. And I don't have any more time to post it but one of the models (NAVGEM I think) forecast such a scenario just recently. And those models are programmed to stick with the laws of physics - they don't forecast impossible scenarios.

[ozonepete]

00z surface analysis tracks low thru Mona Channel.

That seems quite likely. And really wet for P.R.

[Hammy]

john hope said they need to be at least 600 miles apart for both to develop.

there is no magic number of miles that systems need to be apart, especially if there is precedent for them developing closer together.

[ozonepete]

If both systems develop into separate systems then how would that affect the track of each one?

They are too weak right now to have much influence on each other at all. The only thing you can infer is that the lead system is moving faster and to the northwest now while the follower is moving more slowly and more westerly right now. I don't think you can say much until the more westerly one gets northwest past Puerto Rico and heads for the Bahamas. Then they will be more separated and more can be inferred about how the steering flow would affect the second one.

[ROCK]

agree....the NAVGEM had this scenario on a prior run. the lead low gets absorbed into the east low....basically they merge North of DR....but I have seen TS develop right next to each other...

[SouthDadeFish]

john hope said they need to be at least 600 miles apart for both to develop.

God bless John Hope. I loved the guy and he was a hero of mine. But (if he said that?) he was wrong on that one. And I'm willing to bet that the great John Hope actually said they typically need to be 600 miles apart. I can't believe he said that 600 miles was the absolute minimum distance. He was too smart for that. And you once again missed what I said: I've seen it. In fact I think it happened more than once in 2005 when good old John was not around to see it. And I don't have any more time to post it but one of the models (NAVGEM I think) forecast such a scenario just recently. And those models are programmed to stick with the laws of physics - they don't forecast impossible scenarios.

Ozonepete, some may question if the NAVGEM sticks to the laws of physics Just joking.

This certainly is shaping up to be quite a soaker for PR. Hopefully the mid-level dry air keeps choking out the convection.

[ozonepete]

john hope said they need to be at least 600 miles apart for both to develop.

God bless John Hope. I loved the guy and he was a hero of mine. But (if he said that?) he was wrong on that one. And I'm willing to bet that the great John Hope actually said they typically need to be 600 miles apart. I can't believe he said that 600 miles was the absolute minimum distance. He was too smart for that. And you once again missed what I said: I've seen it. In fact I think it happened more than once in 2005 when good old John was not around to see it. And I don't have any more time to post it but one of the models (NAVGEM I think) forecast such a scenario just recently. And those models are programmed to stick with the laws of physics - they don't forecast impossible scenarios.

Ozonepete, some may question if the NAVGEM sticks to the laws of physics Just joking.

This certainly is shaping up to be quite a soaker for PR. Hopefully the mid-level dry air keeps choking out the convection.

Ha ha ha! My last laugh of the night. Thanks. Although in fairness the new "improved" NAVGEM has been performing pretty well this season so I'm still willing to give it a chance.

And yes let's hope that the expected QPFs for PR don't pan out. I know our Luis is rightfully concerned.

['CaneFreak]

I just don't see both areas developing. In fact, I don't see either one of them developing any time soon. Going to be interesting to see how this all unfolds though. The reason for the decrease in convection over 97L this evening is likely due to a lack of surface convergence. The best convergence at the present time is with the wave currently northeast of 97L. My gut feeling is that the wave northeast of 97L and 97L are going to converge near or over Puerto Rico and 97L may try to develop before reaching Puerto Rico but it likely will not be able to do so due to competition for low level inflow and/or upper level outflow issues. The NHC was very smart in not raising the percentages too early given the proximity to land and the mid-level dry air that is likely still getting ingested into this thing from the ULL to the north that is now retrograding to the northwest underneath the surface ridge. The height gradient from the upper level high in the eastern Caribbean and the upper level low to the north is causing a BUNCH of shear in the path of this disturbance (moving northwest). If you want this thing to develop, you better hope the upper low to the north weakens.

Low level convergence: http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=conv&zoom=&time=

Upper level divergence: http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=dvg&zoom=&time=

Low level vorticity: http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=vor&zoom=&time=

Upper level vorticity: http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=vor1&zoom=&time=

[ROCK]

good point Canefreak.....the EURO didnt seem all to keen on development....the NAVGEM had both lows develop but eventually the east low won out and they merged north of the islands.

[Fego]

Stay in 30/50 percentage.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT WED SEP 4 2013

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. THE BROAD AREA OF LOW PRESSURE OVER THE NORTHEASTERN CARIBBEAN SEA
HAS CHANGED LITTLE IN ORGANIZATION OVER THE PAST SEVERAL HOURS.
UPPER-LEVEL WINDS APPEAR FAVORABLE FOR SOME DEVELOPMENT OVER THE
NEXT FEW DAYS...BUT INTERACTION WITH THE LAND MASSES OF HISPANIOLA
AND PUERTO RICO COULD INHIBIT TROPICAL CYCLONE FORMATION AS THE
SYSTEM MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT AROUND 10 MPH.
THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A MEDIUM
CHANCE...50 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 5 DAYS. REGARDLESS OF TROPICAL CYCLONE FORMATION...LOCALLY
HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED TO AFFECT PORTIONS OF
THE NORTHERN LESSER ANTILLES FOR THE NEXT DAY OR SO...AND SPREAD
OVER PUERTO RICO LATER TODAY. AN AIR FORCE RESERVE RECONNAISSANCE
AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS DISTURBANCE THIS
AFTERNOON...IF NECESSARY.

[hurricaneCW]

It's looking a bit more interesting tonight, some nice bursting going on. Almost looks like a real developing storm.

[northjaxpro]

The convective burst tonight is rather impressive and appears to be right near where the LLC is approximately located. It is the best I have seen 97L look to this point. If the convection can sustain itself, 97L may be on its way of finally beginning to spin up later today

[fci]

:uarrow: agree....the NAVGEM had this scenario on a prior run. the lead low gets absorbed into the east low....basically they merge North of DR....but I have seen TS develop right next to each other...

Rock; when did you see TS develop right next to each other.
Asking you saves me from having to search for it.

[beoumont]

"ninel conde"

joe bastardi has a theory about that. the trailing low might force the lead low more west. if both did develop i feel they would just march on out to sea, yet one may get left behind under the growing wheel.

That would be the Fujiwhara effect; not a theory of Joe Bacardi: The storm to the west would "tend" to track more westward, the storm to the east more northward -- all other factors being equal, of course.

<<<<<When cyclones are in proximity of one other, their centers will begin orbiting cyclonically (counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere) about a point between the two systems due to their cyclonic wind circulations. The two vortices will be attracted to each other, and eventually spiral into the center point and merge. It has not been agreed upon whether this is due to the divergent portion of the wind or vorticity advection. When the two vortices are of unequal size, the larger vortex will tend to dominate the interaction, and the smaller vortex will orbit around it. The effect is named after Sakuhei Fujiwhara, the Japanese meteorologist who initially described it in a 1921 paper about the motion of vortices in water>>>>>

[USTropics]

Not sure about the Atlantic, but In 2005 we saw TD Lidia and TD Max (eventually became Hurricane Max). They developed in close proximety (not sure what the exact distance was). Lidia briefly gained TS status before eventually being absorbed by the larger system of Max.

[Hammy]

From what I can tell I don't see much of a circulation left, much of the low clouds are going west, even to the S now, and to the north storms are developing in a line well ahead of where the center is supposed to be.

[Boriken]

[Boriken]

[GCANE]

Looks like we have ignition - hot tower firing off and maintaining strong convection.

http://www.nrlmry.navy.mil/htdocs_dyn_p ... bean.0.jpg

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html


UL Conditions look excellent with the ULL at 23N 46W ready to suck in a poleward outflow channel.

http://tropic.ssec.wisc.edu/real-time/a ... g8wvir.GIF


Anti-cyclone nearly on top of it.

http://tropic.ssec.wisc.edu/real-time/a ... wg8shr.GIF


Not too shabby for the east Carib.

Stay safe everybody in PR.

[NDG]

From what I can tell I don't see much of a circulation left, much of the low clouds are going west, even to the S now, and to the north storms are developing in a line well ahead of where the center is supposed to be.

Is tough to tell, I think it still does have a surface circulation but is elongated. But it has one nice mid level vorticity just north of the deep ball of convection as seen on satellite and radar.