CAT 5 Hurricane Dean - Archived threads

[oyster_reef]

that's a little further south on the NHC 5 day forcast. Right?

[jhamps10]

I'm looking at this via extrapolation (which I know is bad to do), and I'm thinking that Cuba would kill this thing on the angle NHC has, again just focusing on the dot, AND NEVER USE THAT FOR YOUR CERTAIN FORECAST.

[Brent]

TROPICAL STORM DEAN DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007
500 PM EDT TUE AUG 14 2007

DEAN'S STRUCTURE HAS NOT IMPROVED DURING THE AFTERNOON. CONVECTION
HAS WANED AND REMAINS ESPECIALLY LIMITED IN THE NORTHEASTERN
SEMICIRCLE...THOUGH THIS MAY BE A DIURNAL FLUCTUATION. BOTH TAFB
AND SAB GAVE DVORAK ESTIMATES OF T2.5 OR 35 KT...WHILE AN AMSU PASS
AT 1623 UTC SUGGESTED A SUBSTANTIALLY STRONGER INTENSITY. GIVEN THE
LACK OF CONVECTIVE VIGOR...THE INTENSITY OF DEAN IS KEPT AT 35 KT.

INITIAL MOTION OF DEAN IS 265 DEGREES AT 18 KT...A BIT SLOWER THAN
THE LAST ADVISORY. DEAN IS SOUTH OF A DEEP-LAYERED RIDGE WHICH
SHOULD STEER THE CYCLONE TOWARD THE WEST OR WEST-NORTHWEST FOR THE
NEXT FEW DAYS. THE MODEL GUIDANCE SHIFTED SOMEWHAT TO THE WEST AND
FASTER COMPARED TO THE 06 UTC RUNS...PERHAPS DUE TO A WEAKER AND
LESS DIGGING TROUGH OFF OF THE U.S. EAST COAST BY DAY 5. THE
OFFICIAL TRACK FORECAST IS TO THE LEFT OF AND FASTER THAN THE
PREVIOUS ADVISORY...BUT REMAINS TO THE RIGHT OF THE CONSENSUS OF
THE GFS...GFDL...AND HWRF. COMPARED TO THE OTHER MODELS...TRACK
SOLUTIONS FOR THE NOGAPS AND ECMWF ARE SLOWER BECAUSE THEY DO NOT
APPEAR TO HAVE A GOOD HANDLE ON DEAN'S FAST INITIAL FORWARD SPEED.

DEAN IS CURRENTLY EXPERIENCING MODERATE NORTHEASTERLY SHEAR...IS
OVER 27.5C SSTS...AND IS WITHIN A MOIST ENVIRONMENT. THE SHEAR
SHOULD DROP WHILE THE SSTS WARM OVER THE NEXT FEW DAYS...SO THE
ENVIRONMENT APPEARS TO BE CONDUCIVE FOR GRADUAL INTENSIFICATION.
THE INTENSITY FORECAST IS CLOSE A CONSENSUS OF THE HWRF...
GFDL...SHIPS...AND LGEM THROUGH 72 HR. THEREAFTER...THE INTENSITY
FORECAST RELIES PRIMARILY UPON THE GFDL AND LGEM MODELS. BY DAY
5...DEAN IS FORECAST TO BE A STRENGTHENING HURRICANE AND COULD
REACH MAJOR HURRICANE STATUS BY THEN.

FORECAST POSITIONS AND MAX WINDS

INITIAL 14/2100Z 11.6N 41.0W 35 KT
12HR VT 15/0600Z 11.7N 43.6W 40 KT
24HR VT 15/1800Z 12.0N 46.9W 45 KT
36HR VT 16/0600Z 12.3N 50.2W 50 KT
48HR VT 16/1800Z 12.6N 53.5W 60 KT
72HR VT 17/1800Z 14.0N 59.5W 70 KT
96HR VT 18/1800Z 15.5N 64.5W 85 KT
120HR VT 19/1800Z 17.5N 69.5W 95 KT

$$
FORECASTER LANDSEA/KNABB

[chadtm80]

I must again suggest the Skeetobiteweather maps

http://www.skeetobiteweather.com

[canegrl04]

Dean is not dying.Hes just not strengthening quickly.Theres plenty of time for him to build up.I think he will be a hurricane by Friday.And its conceivable a 900mb cane if he hits the right spots

[Wx_Warrior]

Let's hope CUBA CUBA CUBA hinders...NHC says Cat 3 at Cuba?

[ALhurricane]

It is amazing to me how some can say the storm is looking better and then 10 minutes later say it is dying.

I find these conclusions that Dean is not going to make it downright silly. If anything, the overall structure of the cyclone has made great strides today. Once we get into the diurnal max this evening, I fully expect another solid round of convection to develop.

[miamicanes177]

I believe the hwrf model is supposed to be the #1 intensity model of them all. However, the NHC says they are relying on the gfdl beyond 72 hours. The likely reason is because they do not trust the hwrf showing 900mb. Although it seems unreasonable to them that tropical storm Dean can reach category 5 status in 126 hours, it is not impossible. For all the talk about how they are not where they would like to be on intensity forecast, it might serve them well if they wouldn't be afraid of trusting their best model when it shows rapid intensification. HWRF says cat 5, NHC says cat 2. We'll see who was right in 126 hours.

[Brent]

The Weather Underground track is not updated for me, had this same problem at 11. and yes I have hit refresh many times.

[Brent]

It is amazing to me how some can say the storm is looking better and then 10 minutes later say it is dying.

I find these conclusions that Dean is not going to make it downright silly. If anything, the overall structure of the cyclone has made great strides today. Once we get into the diurnal max this evening, I fully expect another solid round of convection to develop.

NHC:

CONVECTION
HAS WANED AND REMAINS ESPECIALLY LIMITED IN THE NORTHEASTERN
SEMICIRCLE...THOUGH THIS MAY BE A DIURNAL FLUCTUATION. BOTH TAFB
AND SAB GAVE DVORAK ESTIMATES OF T2.5 OR 35 KT...WHILE AN AMSU PASS
AT 1623 UTC SUGGESTED A SUBSTANTIALLY STRONGER INTENSITY.

DEAN IS CURRENTLY EXPERIENCING MODERATE NORTHEASTERLY SHEAR...IS
OVER 27.5C SSTS...AND IS WITHIN A MOIST ENVIRONMENT. THE SHEAR
SHOULD DROP WHILE THE SSTS WARM OVER THE NEXT FEW DAYS...SO THE
ENVIRONMENT APPEARS TO BE CONDUCIVE FOR GRADUAL INTENSIFICATION.

[GeneratorPower]

5PM Discussion written in part by my favorite, Dr. Chris Landsea, an expert on both land and sea.

[artist]

Hey Derek, Mike or anyone that knows - since when has Landsea been forecasting for the NHC on updates? Do you know?

I noticed that also - been trying to post!

[canegrl04]

Let's hope CUBA CUBA CUBA hinders...NHC says Cat 3 at Cuba?

That freaks me out Camille jogged BY Cuba as a cat 3

[Wx_Warrior]

Wow...Didn't Camille go east of NOLA?

[HarlequinBoy]

Where is everyone getting Cuba from? I see Dean off the coast of Hispaniola at Day 5, not Cuba.

[canegrl04]

Wow...Didn't Camille go east of NOLA?

Yep

[jhamps10]

Wow...Didn't Camille go east of NOLA?

Yeah. made landfall somewhere near Biloxi. Camille, first storm to still be a TD in Illinois IIRC.

[Derek Ortt]

Chris Landsea is on shift I believe two times a week

[Wx_Warrior]

Derek, your gut observations at all on any area of landfall this far out?

[WxGuy1]

For all the talk about how they are not where they would like to be on intensity forecast, it might serve them well if they wouldn't be afraid of trusting their best model when it shows rapid intensification. HWRF says cat 5, NHC says cat 2. We'll see who was right in 126 hours.

A good forecaster knows how to use each tool effectively. It is not prudent to base all of your forecast reasoning on a single model, particularly when that model forecasts something that is not supported by other models and is not common. Sure, they could go bang busters with the intensity forecast, but that probably isn't the most likely outcome. More often than not, the verification lies between the model forecasts. Sure, this means that the NHC may miss a rapid intensification cycle, but it's a game of whether they aim high and overforecast a bunch of times to hit one rapid intensification cycle or if it's better to be a little more conservative and use a model consensus (with one's own experience and knowledge) that verify more forecasts better (even if that means they miss a very-difficult-to-forecast rapid intensification cycle). That's why NHC exists, otherwise we'd just use model output as "official forecasts".