ATL: KATIA - Post Tropical - Discussion

[lonelymike]

Nogaps, HRWF and Ukmet are fun to look at for speculation but are not very reliable tropical models historywise.

[lonelymike]

Katia ain't gonna be no Katrina

[meriland23]

Katia ain't gonna be no Katrina

That is a very rough opinion. Who is to say it wont be? I wonder how many people rolled their eyes the same before Katrina hit.. a lot.

[Deputy Van Halen]

Katia ain't gonna be no Katrina

Well, maybe WE know that, but THEY (the public) don't know that.

[cycloneye]

HURRICANE KATIA DISCUSSION NUMBER 20
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 PM AST FRI SEP 02 2011

A SERIES OF MICROWAVE IMAGES DURING THE LATE AFTERNOON CLEARLY
SHOWED THE MID-LEVEL CENTER DISPLACED TO THE NORTH OF THE LOW-LEVEL
ONE. THIS MEANS THAT KATIA CONTINUES SUFFERING FROM SOUTHERLY SHEAR
AND HAS NOT INTENSIFIED. THE CLOUD PATTERN IS NOT VERY IMPRESSIVE
FOR A HURRICANE...BUT THE INITIAL INTENSITY IS CONSERVATIVELY KEPT
AT 65 KNOTS BASED ON T-NUMBERS FROM TAFB AND SAB. THERE IS A
SIGNIFICANT EXPANSION OF THE OUTFLOW IN THE WESTERN SEMICIRCLE
GIVING THE FALSE IMPRESSION THAT THE SHEAR IS WEAKENING. THIS IS
EXPECTED TO BE TRANSIENT SINCE WATER VAPOR IMAGES STILL SHOW THAT
THE UPPER-LEVEL TROUGH CAUSING THE SHEAR IS STILL THERE...AND
GLOBAL MODELS BASICALLY KEEP POSTPONING ITS WEAKENING. ACTUALLY...
THE SHIPS MODEL INDICATE THAT UPPER-LEVEL WIND ENVIRONMENT WILL
REMAIN HOSTILE FOR 24 TO 36 HOURS...WHILE THE ECMWF KEEPS IT
HOSTILE EVEN LONGER. ON THIS BASIS...THE OFFICIAL FORECAST CALLS
FOR NO CHANGE IN INTENSITY FOR ABOUT TWO DAYS AND FOR STRENGTHENING
THEREAFTER.

KATIA IS MOVING TOWARD THE NORTHWEST OR 305 DEGREES AT 10 KNOTS.
GLOBAL MODELS UNANIMOUSLY BUILD THE SUBTROPICAL RIDGE WESTWARD AND
WEAKEN THE TROUGH OVER THE WESTERN ATLANTIC. THIS FORECAST PATTERN
CALLS FOR A GENERAL NORTHWEST TO WEST-NORTHWEST TRACK WITH NO
SIGNIFICANT CHANGE IN SPEED THROUGH FIVE DAYS AS INDICATED IN THE
NHC FORECAST. WITH THE EXCEPTION OF THE UK MODEL WHICH BUILDS A
STRONGER SUBTROPICAL RIDGE THAN THE OTHER MODELS AND KEEPS KATIA ON
A MORE WESTWARD TRACK...THE REST OF THE TRACK MODELS ARE IN GOOD
AGREEMENT. THE OFFICIAL FORECAST IS IN THE MIDDLE OF THE GUIDANCE
ENVELOPE AND IS VERY CLOSE TO THE ECMWF AND THE GFS GLOBAL MODELS.


FORECAST POSITIONS AND MAX WINDS

INIT 03/0300Z 18.5N 54.3W 65 KT 75 MPH
12H 03/1200Z 19.5N 55.4W 65 KT 75 MPH
24H 04/0000Z 20.5N 57.0W 65 KT 75 MPH
36H 04/1200Z 21.5N 59.0W 65 KT 75 MPH
48H 05/0000Z 22.5N 60.5W 75 KT 85 MPH
72H 06/0000Z 24.5N 63.5W 85 KT 100 MPH
96H 07/0000Z 26.5N 66.5W 95 KT 110 MPH
120H 08/0000Z 28.0N 69.5W 95 KT 110 MPH

$$
FORECASTER AVILA

[cycloneye]

Saved image.

[beoumont]

If Katia shows any indication of threatening the east coast, I bet that the fact that this was Katrina's former place in the list will help to fuel the hype, since people will see it as an "omen". Even people who don't follow hurricanes closely will notice the similarity in the names.

And one can bet that some of the TV "meteorologists" won't fuel this fire.

One can also assume that only a few of the general public realize the storm names are on a 6 yr. rotating list.

[gatorcane]

Looking at the latest nhc discussion, guess the NOGAPS, CMC, and HWRF don't count. Only the UKMET

All kidding aside, it's not a bad idea to just go in-between the GFS and ECMWF. Most of the time they are correct.

[AdamFirst]

Looking at the latest nhc discussion, guess the NOGAPS, CMC, and HWRF don't count. Only the UKMET

They've been heavily leaning on the GFS and EURO anyway.

[Steve H.]

Be careful of the way you talk about Katia. I don't trust this girl. A lot of dynamics going on both upstream and in the north Atlantic that could affect her future track. I have seen enough divergence in the models that cause me to wonder how this will all play out. Do not let your guard down on her.

This is just my opinion and not to be taken as anything official.. certainly not. My gut just tells me that she ain't just a fish! Refer to NHC forecasts for rationale data.

[Zarniwoop]

Storm watching is just blindingly addictive it seems...

Keep those graphics and predictions with reasoning coming. It's a lot of fun for me to (succeed and fail to) decipher =P

[meriland23]

Nogaps, HRWF and Ukmet are fun to look at for speculation but are not very reliable tropical models historywise.

I saw a historical chart like 3 days ago and I can not find it. Well, it was a chart of model PP accuracy, EURO of course was over-all best. But I forgot if it was nogaps or ukmet, but one of the two was far superior than all (including euro) models in the long range, notso much on short range.

[westwind]

looks to be organising at the moment despite the shear, with cold cloud tops in the centre and a convective band starting to wrap around it. I think it will strengthen by 5-10kt in the next 6 hours.

[meriland23]

looks to be organising at the moment despite the shear, with cold cloud tops in the centre and a convective band starting to wrap around it. I think it will strengthen by 5-10kt in the next 6 hours.

from nhc 11 pm update

"THE CLOUD PATTERN IS NOT VERY IMPRESSIVE
FOR A HURRICANE...BUT THE INITIAL INTENSITY IS CONSERVATIVELY KEPT
AT 65 KNOTS BASED ON T-NUMBERS FROM TAFB AND SAB. THERE IS A
SIGNIFICANT EXPANSION OF THE OUTFLOW IN THE WESTERN SEMICIRCLE
GIVING THE FALSE IMPRESSION THAT THE SHEAR IS WEAKENING. THIS IS
EXPECTED TO BE TRANSIENT SINCE WATER VAPOR IMAGES STILL SHOW THAT
THE UPPER-LEVEL TROUGH CAUSING THE SHEAR IS STILL THERE''

[AdamFirst]

I dont have the energy to post the 00z GFS plots...someone else can do it.


zzzzzzzz

[gatorcane]

00z GFS running

[meriland23]

ill do it since I have nothing else to do

[meriland23]

h24

[meriland23]

h48

[meriland23]

h72