ATL GUSTAV: Tropical Depression - Discussion

[Nexus]

Center appears to be back over water with a pressure of 992 millibars. Latest satellite shows convection firing big time near the center with great shape. I expect this to strength very very fast now.

Agree. Nothing but bathtub water temps and little shear in the near term. Shear in the gulf may be the last buffer for this.

[Cyclenall]

Man alive, this thing is already shooting and Jamaica is still in it's way. I just can't imagine what it would be now if it had not encountered any of those land areas. I bet Hurricane Wilma is looking down from TC heaven on the Caribbean grinning at this thing...

[Jagno]

I wish she'd call him home to TC Heaven then. Why do I get the feeling I'm gonna wake up in a couple of hours to more shock and awe with this storm? Oh wait, I've got to go to bed first...........this is all a bad nightmare for coastal residents in LA.

[Cyclenall]

I wish she'd call him home to TC Heaven then. Why do I get the feeling I'm gonna wake up in a couple of hours to more shock and awe with this storm? Oh wait, I've got to go to bed first...........this is all a bad nightmare for coastal residents in LA.

Not without being retired first. The ones that don't get retired are just recreated 6 years later.

I won't be shocked to find this a hurricane in the next few hours. Then it will bomb out and find more landmass to harass.

[KWT]

Convection really blowing up over the center, will be very interesting to see what this does over the next 12hrs, if it develops quickly then expect this to really explode over the high heat content.

[HarlequinBoy]

It looks pretty healthy.

Just remember a few days ago this was forecast to ride the length of Cuba.

[KWT]

The thing is you can see the way Gustav is wrapping round the convection and its only been off land for about a couple of hours. This could be getting strong by the time it reaches the Caymans it seems.

This is what stands out to me:

HOWEVER...IT WOULD BE NO SURPRISE IF RAPID
INTENSIFICATION OCCURRED AND GUSTAV BECAME A CATEGORY 4 OR 5
HURRICANE BY 72 HR.

[HarlequinBoy]

WTNT42 KNHC 290853
TCDAT2
TROPICAL STORM GUSTAV DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008
500 AM EDT FRI AUG 29 2008

SATELLITE IMAGES SHOW THAT GUSTAV HAS AN EXPANDING CLOUD SHIELD AND
IMPRESSIVE BANDING FEATURES. AN AIR FORCE RECONNAISSANCE PLANE THAT
HAS BEEN SAMPLING THE STORM'S CIRCULATION FOUND THAT THE SIZE OF
GUSTAV HAS SIGNIFICANTLY INCREASED. ALTHOUGH THEY HAVE BEEN UNABLE
TO SAMPLE THE CENTER...PEAK FLIGHT LEVEL WINDS OF 52 KT WERE
OBSERVED...ALONG WITH SIMILAR VALUES FOR THE SFMR. THE INITIAL
INTENSITY REMAINS 55 KT.

THE BEST ESTIMATE OF INITIAL MOTION IS 285/7. THERE IS A COMPLICATED
EVOLUTION TO THE STEERING CURRENTS AROUND GUSTAV DURING THE
FORECAST PERIOD. THE MID-LEVEL RIDGE OVER FLORIDA THAT HAS BEEN
STEERING THE STORM WESTWARD IS FORECAST TO WEAKEN TODAY. THE
BERMUDA HIGH IS THEN EXPECTED TO BUILD IN FROM THE WESTERN ATLANTIC
AND CAUSE GUSTAV TO MOVE MORE TOWARD THE NORTHWEST OVER THE
WEEKEND. ONE BIG QUESTION IS THE EVOLUTION OF A MID- TO UPPER-
LEVEL LOW OVER THE SOUTHEASTERN UNITED STATES. SOME OF THE
MODELS...SUCH AS THE GFS/GFDL/HWRF...ARE SHOWING THIS LOW CREATING
ENOUGH OF A WEAKNESS IN THE BERMUDA HIGH TO ALLOW A MOTION MORE
TOWARD THE NORTH-NORTHWEST AS THE SYSTEM CROSSES CUBA. IT WOULD NOT
BE SURPRISING IF THAT TRACK BRIEFLY OCCURRED...BUT IN THE
LONGER-TERM...A HIGH OVER THE OHIO VALLEY IS EXPECTED TO CAUSE
GUSTAV TO GRADUALLY BEND TO THE LEFT. HOWEVER...THERE IS A LARGE
UNCERTAINTY IN THE TIMING AND SHARPNESS OF THE BEND. THE UKMET AND
GFS HAVE HAD LARGE CHANGES TO THEIR FORECAST FROM THE PREVIOUS
RUNS...AND GIVEN THE INCREASING MODEL SPREAD...WE'VE OPTED TO KEEP
THE FORECAST SIMILAR TO THE PREVIOUS ONE. HOPEFULLY A G-IV MISSION
LATER TODAY WILL HELP RESOLVE SOME OF THESE DIFFERENCES.

AFTER THE STORM MOVES AWAY FROM JAMAICA...SIGNIFICANT
INTENSIFICATION IS POSSIBLE. VERTICAL WIND SHEAR IS FORECAST TO BE
VERY LIGHT DURING THE NEXT COUPLE OF DAYS...AND COMBINED WITH THE
DEEP WARM CARIBBEAN WATERS...COULD PRODUCE A STRONG HURRICANE VERY
QUICKLY. THE OFFICIAL FORECAST WILL SHOW RAPID INTENSIFICATION
BEFORE IT REACHES WESTERN CUBA AND COULD BE CONSERVATIVE AS SOME
MODELS SHOW CATEGORY FOUR STRENGTH AT THAT TIME. A LARGE TROUGH
CURRENTLY SEEN IN WATER VAPOR IMAGES OVER THE CENTRAL GULF OF
MEXICO IS EXPECTED TO MOVE WESTWARD SLOWLY DURING THE NEXT DAY OR
TWO. THIS TROUGH MAY IMPART SOME SOUTHWESTERLY SHEAR ON GUSTAV
AS IT ENTERS THE CENTRAL GULF OF MEXICO. ALTHOUGH THE FORECAST
SHOWS SOME WEAKENING DUE TO THE SHEAR...GUSTAV IS EXPECTED TO BE A
LARGE POWERFUL HURRICANE AS IT APPROACHES THE NORTHERN GULF COAST.


FORECAST POSITIONS AND MAX WINDS

INITIAL 29/0900Z 18.1N 78.1W 55 KT
12HR VT 29/1800Z 18.6N 79.3W 60 KT
24HR VT 30/0600Z 19.6N 81.0W 75 KT
36HR VT 30/1800Z 21.0N 82.8W 90 KT
48HR VT 31/0600Z 22.7N 84.6W 100 KT
72HR VT 01/0600Z 26.4N 88.1W 110 KT
96HR VT 02/0600Z 29.0N 91.0W 100 KT
120HR VT 03/0600Z 30.0N 93.0W 85 KT...INLAND



110 KT in 3 days.

[HarlequinBoy]

The new 5 day cone is a nightmare for the Louisiana coastline.

[KWT]

Yep pretty close to a category-4 and note they are being conservative as well, very interesting to see!
I think this will ramp up faster then they are expecting however...

Also track is a real pain as the WNW motion would mean that it could landfall nearly anywhere in LA depending on the various factors.

[mpic]

Since Cuba is much bigger than Jamaica, will we see more of the same when it reaches Cuba? Or does Cuba have less mountains and Gustav will just steam roll over it?

[KWT]

It may not even touch Cuba yet and even if it does it'll go over the western tip, its at best got a few hills put it that way and at the speed it'll be moving it won't do anything really to a strong hurricane.

[Stratosphere747]

[deltadog03]

That is an interesting track.....

[KWT]

Sure is deltadog, its not easy to know when and if any westerly bend back occur, it may not do it fast enough for it to show that bend back or it may bend back whilst still well out in the gulf, not easy to know.

However I think given the strength Gustav is likely to be I'll be surprised if this doesn't end up a little east of where some of the globals expect.

Also worth noting pressure now down to 990mbs.

[Stratosphere747]

SUCH AS THE GFS/GFDL/HWRF...ARE SHOWING THIS LOW CREATING
ENOUGH OF A WEAKNESS IN THE BERMUDA HIGH TO ALLOW A MOTION MORE
TOWARD THE NORTH-NORTHWEST AS THE SYSTEM CROSSES CUBA. IT WOULD NOT
BE SURPRISING IF THAT TRACK BRIEFLY OCCURRED...BUT IN THE
LONGER-TERM...A HIGH OVER THE OHIO VALLEY IS EXPECTED TO CAUSE
GUSTAV TO GRADUALLY BEND TO THE LEFT. HOWEVER...THERE IS A LARGE
UNCERTAINTY IN THE TIMING AND SHARPNESS OF THE BEND. THE UKMET AND
GFS HAVE HAD LARGE CHANGES TO THEIR FORECAST FROM THE PREVIOUS
RUNS...AND GIVEN THE INCREASING MODEL SPREAD...WE'VE OPTED TO KEEP
THE FORECAST SIMILAR TO THE PREVIOUS ONE. HOPEFULLY A G-IV MISSION
LATER TODAY WILL HELP RESOLVE SOME OF THESE DIFFERENCES.

[xironman]

Just off land from the radar fix 18.1N 78.0W.

[KWT]

Radar fix is a little off according to recon, the center is a little to the SW of that fix.

[xironman]

How were you able to figure that out from the recon? I missed it.

[KWT]

Latest recon actually does show that the radar presentation has improved but there was a note about it in an earlier message saying about the center being a little off the radar one, not by a great deal.

Center is indeed 18.1/78