72 hr. forecast a mere 60 mph off on Ophelia

[beoumont]

I wonder if any previous hurricane intensity forecast has been this far off. The 72 hr. intensity prog. from NHC was 60 mph too low - 3 categories off. I am one who usually takes the NHC's side; and I guess I can again here, as they often note that intensity forecasts are far from perfected.

11 pm advisory today has intensity at 140 mph.

NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
1100 PM AST SAT OCT 01 2011

...OPHELIA MOVING QUICKLY NORTHWARD WITH 140 MPH WINDS...


FORECAST POSITIONS AND MAX WINDS - intiated 3 nights ago:

INIT 28/2100Z 19.3N 60.6W 45 KT 50 MPH
12H 29/0600Z 20.2N 61.0W 50 KT 60 MPH
24H 29/1800Z 21.6N 61.7W 55 KT 65 MPH
36H 30/0600Z 23.3N 62.5W 60 KT 70 MPH
48H 30/1800Z 25.2N 63.2W 65 KT 75 MPH
72H 01/1800Z 31.0N 62.5W 70 KT 80 MPH
96H 02/1800Z 40.0N 59.0W 70 KT 80 MPH
120H 03/1800Z 52.0N 49.0W 50 KT 60 MPH...POST-TROP/EXTRATROP

[bexar]

2010's Julia was way off by 55 KTs.

INITIAL 12/2100Z 13.3N 22.8W 30 KT
12HR VT 13/0600Z 13.7N 24.6W 35 KT
24HR VT 13/1800Z 14.6N 27.1W 45 KT
36HR VT 14/0600Z 15.6N 29.0W 55 KT
48HR VT 14/1800Z 16.9N 30.6W 65 KT
72HR VT 15/1800Z 20.4N 34.2W 65 KT
96HR VT 16/1800Z 24.0N 39.5W 65 KT
120HR VT 17/1800Z 27.1N 45.5W 65 KT

2008's Paloma was also off by about 50 KTs

INITIAL 05/2100Z 14.0N 81.8W 25 KT
12HR VT 06/0600Z 14.3N 82.2W 30 KT
24HR VT 06/1800Z 14.8N 82.5W 40 KT
36HR VT 07/0600Z 15.5N 82.9W 50 KT
48HR VT 07/1800Z 16.5N 83.0W 65 KT
72HR VT 08/1800Z 18.0N 82.5W 75 KT
96HR VT 09/1800Z 19.5N 80.0W 75 KT
120HR VT 10/1800Z 21.5N 75.5W 50 KT

[RL3AO]

Wilma was off 70kt at 24 hr and 80 at 72 hr. RI is very hard to forecast

[Ptarmigan]

Proof that we have a long way to go for predicting intensification. We can predict where they can go for the most part.

[brunota2003]

Yep...something I've been working on...I was closer for Ophelia, but still was a good 20 or 30 knots too low. I did mention the chance of RI, but wasn't sure if she was really going to do it.

[beoumont]

Proof that we have a long way to go for predicting intensification. We can predict where they can go for the most part.

I would only go so far as to say: when the mid and high altitude planes fly the wide grid in advance of a hurricane, the next 24 hrs. of forecasted motion has become very accurate.

The 48 and 72+ hr. forecasts have become more accurate over the years; but sometimes are still quite far off.

[Category 5]

Predicting RI is a tricky tricky business. I do weather forecasts for RU-tv here at Rutgers, and as much as I wanted to say Ophelia was going to easily exceed Category 1, the risks of swinging and missing on such a bold prediction to the general public are massive.

[Ad Novoxium]

RI does tend to produce the highest errors:

Mitch (3 days):
INITIAL 24/0300Z 13.5N 78.2W 50 KTS
12HR VT 24/1200Z 14.1N 78.3W 55 KTS
24HR VT 25/0000Z 15.0N 78.5W 60 KTS
36HR VT 25/1200Z 15.4N 79.4W 65 KTS
48HR VT 26/0000Z 15.8N 80.1W 70 KTS
72HR VT 27/0000Z 17.0N 81.5W 75 KTS

(Actual intensity: 155 KTS)

Keith (1 day):
INITIAL 30/0900Z 18.1N 86.3W 60 KTS
12HR VT 30/1800Z 18.7N 86.7W 70 KTS
24HR VT 01/0600Z 19.5N 87.0W 80 KTS
36HR VT 01/1800Z 20.4N 87.2W 85 KTS
48HR VT 02/0600Z 21.5N 87.5W 70 KTS...INLAND
72HR VT 03/0600Z 23.5N 87.5W 85 KTS

(Actual intensity: 115 KTS)

Ike (didn't reach the 12 hour mark):
INITIAL 03/2100Z 21.6N 52.7W 70 KT
12HR VT 04/0600Z 22.6N 55.1W 75 KT
24HR VT 04/1800Z 23.8N 57.9W 85 KT
36HR VT 05/0600Z 24.3N 60.4W 80 KT
48HR VT 05/1800Z 23.8N 63.1W 80 KT
72HR VT 06/1800Z 22.5N 68.0W 90 KT
96HR VT 07/1800Z 22.5N 72.0W 100 KT
120HR VT 08/1800Z 23.5N 76.0W 100 KT

(Actual intensity: 100 KTS (higher peak, but this was its intensity at the time. The 12 hour intensity after this was 125 knots)

RI is still quite a hard part to predict. However, rapid dissipation is also a similar beast:

Earl 2004 (2 days):
INITIAL 14/1500Z 10.4N 52.2W 30 KT
12HR VT 15/0000Z 11.5N 55.1W 40 KT
24HR VT 15/1200Z 12.9N 58.8W 50 KT
36HR VT 16/0000Z 14.2N 62.4W 60 KT
48HR VT 16/1200Z 15.5N 66.0W 65 KT
72HR VT 17/1200Z 17.5N 73.0W 70 KT
96HR VT 18/1200Z 19.0N 79.0W 75 KT
120HR VT 19/1200Z 20.5N 84.0W 80 KT

(Actual intensity: 35KT tropical wave)

It's quite a double edged sword as Category 5 said.