NHC Isabel Forecast Verification

[GaryOBX]

This is the first time I've done something like this, but I believe it to be an accurate verification of the NHC forecast.

What I am attempting to show is the distance error in 120, 96, 72, 48, and 24 hour forecasts issued by the NHC.

I will use the most recent coordinates for Isabel (9/11/2003 1500z), then look at the past 5 days worth of forecasts to see how close they were.

Current Position: 21.40 N / 54.50 W

Compare 9/11/2003 1500z forecast positions:
Advisory #18 (24 Hours ago): 21.70 N / 54.50 W = 36 mile error
Advisory #14 (48 Hours ago): 19.90 N / 54.00 W = 97 mile error
Advisory #10 (72 Hours ago): 19.50 N / 55.00 W = 127 mile error
Advisory #6 (96 Hours ago): 19.00 N / 55.50 W = 195 mile error
Advisory #2 (120 Hours ago): 18.00 N / 56.60 W = 284 mile error

This proves that when NHC says errors may be large, they are correct. 120 Hours ago, the 120 Hour forecast was off by 284 miles!

[chris_fit]

It was off for sure, but in the good way (much further north than predicted)

~Chris

[jfaul]

This is the first time I've done something like this, but I believe it to be an accurate verification of the NHC forecast.

What I am attempting to show is the distance error in 120, 96, 72, 48, and 24 hour forecasts issued by the NHC.

I will use the most recent coordinates for Isabel (9/11/2003 1500z), then look at the past 5 days worth of forecasts to see how close they were.

Current Position: 21.40 N / 54.50 W

Compare 9/11/2003 1500z forecast positions:
Advisory #18 (24 Hours ago): 21.70 N / 54.50 W = 36 mile error
Advisory #14 (48 Hours ago): 19.90 N / 54.00 W = 97 mile error
Advisory #10 (72 Hours ago): 19.50 N / 55.00 W = 127 mile error
Advisory #6 (96 Hours ago): 19.00 N / 55.50 W = 195 mile error
Advisory #2 (120 Hours ago): 18.00 N / 56.60 W = 284 mile error

This proves that when NHC says errors may be large, they are correct. 120 Hours ago, the 120 Hour forecast was off by 284 miles!

nice work..nhc acknowledges i believe a 360 mile error three days out so anyone that hinks its going one way or anohter because of their 5 day track is going to be worng. dare i say you would prefer to have it coming at you on their 5 day and you will probably not get hit.

[mf_dolphin]

It was off for sure, but in the good way (much further north than predicted)

~Chris

Just remember the error can go either way

[WeatherNLU]

A five day forcast error of 285 miles is actually pretty good. It's not wonderful, but it's not bad either.