ATL: CRISTOBAL - Post-Tropical - Discussion

[Hammy]

Is it me or does 96l seem to be moving quicker then the models have forecast?

Yes, the system seems to be about 6-10 hours ahead of the models from 48 hours ago.

[NDG]

That crazy shear zone just to the west of the storm if it does not abate and gets blocked is going to eat 96L for breakfast. Looking at Rainbow you can see how nuts it is in the upper levels.

That inverted UL trough of low pressure creating the shear ahead of 96L has been steadily retrograding westward, if anything it has been helping in creating a UL divergence, moistening the environment for 96L nicely. GFS and Euro are still forecasting fairly good UL conditions when it reaches the SE Bahamas with the UL anticyclone following 96L staying fairly close to it.

[ScottNAtlanta]

Very easily seen low level clouds have thrashed around on the western side of the LLC twice now.
Small center is just north of the Punta Cana, Dominican Republic.

What I'm not sure about is what is going to happen with the high pressure over the CONUS?
Looks like there will be a westward jog in the storm track at the least in the near term. If the high rolls further east or splits there would be a weakness to take Crystobal out later, but I don't think the timing of that event can be modeled with certainty this far out.

If there was to be an LLC north of Punta Cana they would had not been reporting east winds. I think the vorticity is still above the ground, it is still a sharp trough of low pressure at the surface. Tomorrow morning is when I think it will finally start developing an LLC, once it slows down like others have mentioned.

They are currently reporting WNW winds at Punta Gorda

[Aric Dunn]

Looks like the last hour or so that the circ might have become a little better defined as it has moved north of the eastern part of the DR.. I can see more defined low level CU clouds moving from west to east. likely a product of the forcing from the mountains. as the winds pile up they are forced both upwards and the sides. this angle of approach to the DR can often help aid the development of a circ if positioned right..

[NDG]

Is it me or does 96l seem to be moving quicker then the models have forecast?

Yes, the system seems to be about 6-10 hours ahead of the models from 48 hours ago.

In some cases a good 12 hrs ahead of schedule from the forecast 48 hrs ago.

[SFLcane]

Is it me or does 96l seem to be moving quicker then the models have forecast?

yea that's key might miss trof if it doesn't slow down.

[TheStormExpert]

Is it me or does 96l seem to be moving quicker then the models have forecast?

yea that's key might miss trof if it doesn't slow down.

I still see this recurring one way or the other. Like many (including me) have said, these troughs have been abnormally strong this summer and that pattern is just going to keep going on IMO.

[NDG]

Very easily seen low level clouds have thrashed around on the western side of the LLC twice now.
Small center is just north of the Punta Cana, Dominican Republic.

What I'm not sure about is what is going to happen with the high pressure over the CONUS?
Looks like there will be a westward jog in the storm track at the least in the near term. If the high rolls further east or splits there would be a weakness to take Crystobal out later, but I don't think the timing of that event can be modeled with certainty this far out.

If there was to be an LLC north of Punta Cana they would had not been reporting east winds. I think the vorticity is still above the ground, it is still a sharp trough of low pressure at the surface. Tomorrow morning is when I think it will finally start developing an LLC, once it slows down like others have mentioned.

They are currently reporting WNW winds at Punta Gorda

The problem is that your Punta Gorda is in SW Florida not the Dominican Republic

[Weatherboy1]

Big model spread on this one for sure, and if that is a center forming just off the coast of the DR then it would be SW of some of the recurve model points already. We will have to see if the CMC, UKMET and now BAMS are on to something. Just my opinion as always!

[Blown Away]

IF 96L were classified in the next 24 hours, I would think the track would look something like this...

[GeneratorPower]

IF 96L were classified in the next 24 hours, I would think the track would look something like this...

Whoa! That's the best post I've seen all day. Genius.

[GeneratorPower]

Though to be fair, Jeanne was forecast using 2004-quality models. I have to believe forecasting has improved since then.

[Blown Away]

Though to be fair, Jeanne was forecast using 2004-quality models. I have to believe forecasting has improved since then.

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JEANNE DISCUSSION NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SAT SEP 18 2004

THERE CONTINUE TO BE DIFFERENCES AMONG THE GLOBAL MODELS ON THE
EVOLUTION OF THE MID-LEVEL REMNANTS OF IVAN. THE 00Z GFS BREAKS
OFF A SIGNIFICANT PIECE OF IVAN AND TAKES IT SOUTHWESTWARD JUST OFF
THE CAROLINAS IN ABOUT TWO DAYS. IN THIS SCENARIO...JEANNE IS
LIFTED NORTHWARD AROUND THE EAST SIDE OF THESE REMNANTS AND THEN
NORTHEASTWARD UNTIL LATE IN THE FORECAST PERIOD. THE 00Z NOGAPS
SCENARIO IS FOR IVAN'S MID-LEVEL CIRCULATION TO WEAKEN AND/OR TO
CONTINUE NORTHEASTWARD...RESULTING IN JEANNE GETTING TRAPPED MORE
QUICKLY UNDER THE STRONG HIGH FORECAST TO MOVE THROUGH THE GREAT
LAKES IN 3-5 DAYS. THE UKMET TRACK IS EVEN MORE EMPHATIC ABOUT A
CAPTURE. YET ONE THING ALL THESE MODELS HAVE IN COMMON IS AN
IMMEDIATE NORTHWARD MOTION OF A VERTICALLY WELL-CONNECTED TROPICAL
CYCLONE. SATELLITE IMAGERY SHOWS A EXPOSED CIRCULATION WITH ONLY A
LITTLE BIT OF CONVECTION IN THE NORTHEAST QUADRANT...NOT ENOUGH TO
MAKE ONE THINK THAT JEANNE HAS MUCH VERTICAL COHERENCE. YET...THE
LAST TWO RECONNAISSANCE FIXES DID GIVE AN ALMOST DUE NORTHWARD
MOTION. WHETHER THE MODELS ARE SEEING SOMETHING I DON'T SEE...OR
WHETHER THE CENTER IS ONLY BEING DRAGGED TEMPORARILY TO THE RIGHT
BY THE CONVECTION IS NOT YET CLEAR. THE OFFICIAL FORECAST THINKING
IS THAT JEANNE IS NOT QUITE READY TO GO AS FAST TO THE NORTH AS THE
GLOBAL MODELS ARE FORECASTING...BUT RATHER IS IN BETTER AGREEMENT
WITH THE SIMPLER BAM STEERING MODELS...AT LEAST FOR THE FIRST 48
HOURS OR SO. IF JEANNE DOES IN FACT TURN NORTH ONLY SLOWLY...IT
WOULD MOST LIKELY BE FORCED BACK TO THE WEST BY THE END OF THE
FORECAST PERIOD. GIVEN ALL THE ABOVE...IT IS PROBABLY OBVIOUS THAT
THIS IS NOT A HIGH CONFIDENCE FORECAST.

RECONNAISSANCE DATA SHOW 55 KT OF WIND AT A FLIGHT LEVEL OF 1500 FT.
IF JEANNE WERE A MORE CONVECTIVE STORM THAT WOULD CORRESPOND TO 45
KT AT THE SURFACE...BUT GIVEN THE PRESENT STRUCTURE I WILL HOLD THE
INITIAL INTENSITY AT 40 KT. JEANNE IS CURRENTLY JUST TO THE
SOUTHEAST OF AN UPPER-LEVEL SHEAR AXIS...RESULTING IN MODERATE
WESTERLY SHEAR OVER THE LOW-LEVEL CIRCULATION. SHOULD JEANNE TURN
MORE NORTHWARD IT COULD FIND ITSELF UNDER A MORE FAVORABLE UPPER
PATTERN IN A COUPLE OF DAYS...WHILE A MORE WESTWARD TRACK WOULD
KEEP JEANNE UNDER UNFAVORABLE SOUTHWESTERLY SHEAR. THUS IT WOULD
SEEM UNLIKELY THAT A STRONG SYSTEM COULD MAKE ANY SIGNIFICANT
WEST-NORTHWESTWARD PROGRESS. IN FACT...A NOT UNREASONABLE
ALTERNATIVE TO THE FORECAST BELOW WOULD BE FOR THE LOW-LEVEL CENTER
TO CONTINUE TO THE WEST-NORTHWEST AND DISSIPATE...AS DEBBY DID IN
THIS AREA FOUR YEARS AGO.

This was the Disco for Jeanne just before they forecasted the left turn/loop... Funny how they referred to the Ukmet...

[SFLcane]

Apparent llc found by recon is south of most model guidance.

[Aric Dunn]

watch in this area before recon leaves..

[Weatherboy1]

I find it very hard to imagine this thing doesn't get designated today. The overall satellite presentation is the best yet, we've had hours and hours of sustained convection, and it's in a relatively favorable environment. We shall see! (Just my opinion and all that jazz!)

[Aric Dunn]

Apparent llc found by recon is south of most model guidance.

thats not a LLC down in the mona passage...

[Hammy]

Satellite presentation is really meaningless, all that matters is at the surface and the recon continues to show a wind shift but no actual LLC. Forward speed and proximity to land are likely keeping it from developing, not to mention the wind shift is getting closer and closer to the shear line to the west.

[stormlover2013]

@TropicalTidbits: Recon just found closest thing to an LLC we'll get out of 96L. Shift to south wind off tip of Dominican Republic: http://t.co/XUBx1lEAfn

[chaser1]

I would almost guess that the disruption that land might be causing, would practically aid the "one" more dominant center to take advantage of the lessor competition for surface convergence and finally spin up here shortly. I'll say this much, this has been one of the more nutty tropical disturbances to track.