Which Hurricane Forecast Model Should You Trust?

By: Dr. Jeff Masters , 1:05 PM GMT on August 07, 2013

The National Hurricane Center (NHC) set a new record in 2012 for accuracy of their 1, 2, 3, and 4-day Atlantic tropical cyclone track forecasts, but had almost no skill making intensity forecasts, according to the 2012 National Hurricane Center Forecast Verification Report, issued in March 2013. The new records for track accuracy were set despite the fact that the season’s storms were harder than average to forecast. The average error in a 1-day forecast was 46 miles, and was 79 miles for 2 days, 116 miles for 3 days, 164 miles for 4 days, and 224 miles for 5 days. The official track forecast had a westward bias of 10 - 17 miles for 1 - 3 day forecasts (i.e., the official forecast tended to fall to the west of the verifying position), and was 38 and 75 miles too far to the northeast for the 4- and 5-day forecasts, respectively.


Figure 1. Verification of official NHC hurricane track forecasts for the Atlantic, 1990 - 2012. Over the past 15 - 20 years, 1 - 3 day track forecast errors have been reduced by about 60%. Track forecast error reductions of about 50% have occurred over the past ten years for 4- and 5-day forecasts. Image credit: 2012 National Hurricane Center Forecast Verification Report.

NHC Intensity Forecasts: Little Improvement Since 1990
Official NHC intensity forecasts did better than usual in 2012, and had errors lower than the 5-year average error for 1, 2, 3, 4, and 5-day forecasts. However, 2012's storms were easier to predict than usual, due to due to a lack of rapidly intensifying hurricanes. These rapid intensifiers are typically the source of the largest forecast errors. The skill of official NHC 24-hour intensity forecasts made in 2012 for the Atlantic basin were only about 15% better than a "no-skill" forecast; 2, 3, 4, and 5-day intensity forecasts had no skill.


Figure 2. Verification of official NHC hurricane intensity forecasts for the Atlantic, 1990 - 2012. Intensity forecasts have shown little to no improvement since 1990. Image credit: 2012 National Hurricane Center Forecast Verification Report.

Which Track Model Should You Trust?
As usual, in 2012 the official NHC forecast for Atlantic storms was almost as good as or better than any individual computer models--though NOAA's GFS model did slightly better than the NHC official forecast at 12, 24, and 48-hour periods, and the European model forecast was slightly better at 12-hour forecasts. Despite all the attention given to how the European Center (ECMWF) model outperformed the GFS model for Hurricane Sandy's track at long ranges, the GFS model actually outperformed the European model in 2012 when summing up all track forecasts made for all Atlantic named storms. This occurred, in part, because the European model made a few disastrously bad forecasts for Tropical Storm Debby when it was in the Gulf of Mexico and steering currents were weak. For several runs, the model predicted a Texas landfall, but Debby ended up moving east-northeast to make a Northwest Florida landfall, like the GFS model had predicted. However, the best-performing model averaged over the past three years has been the European Center model, with the GFS model a close second. Wunderground provides a web page with computer model forecasts for many of the best-performing track models used to predict hurricane tracks. The European Center does not permit public display of tropical storm positions from their hurricane tracking module of their model, so we are unable to put ECMWF forecasts on this page. Here are some of the better models NHC regularly looks at:

ECMWF: The European Center's global forecast model
GFS: NOAA's global forecast model
NOGAPS: The Navy's global forecast model (now defunct, replaced by the NAVGEM model in 2013)
UKMET: The United Kingdom Met Office's global forecast model
GFDL: The Geophysical Fluid Dynamics Laboratory's hurricane model, initialized using GFS data
HWRF: The intended successor for the the GFDL hurricane model, also initialized using GFS data
CMC: The Canadian GEM model
BAMM: The very old Beta and Advection Model (Medium layer), which is still useful at longer ranges

If one averages together the track forecasts from the first six of these models, the NHC official forecast will rarely depart much from it. As seen in Figure 3, the HWRF and UKMET were well behind the ECMWF and GFS in forecast accuracy in 2012, but were still respectable. The simple BAMM model did well at 3, 4, and 5-day forecasts. The GFDL and CMC models did quite poorly compared to the ECMWF, GFS, UKMET, and HWRF. The Navy's NOGAPS model also did poorly in 2012, and has been retired. Its replacement for 2013 is called the NAVGEM model.


Figure 3. Skill of computer model forecasts of Atlantic named storms in 2012, compared to a "no skill" model called "CLIPER5" that uses just climatology and persistence to make a hurricane track forecast (persistence means that a storm will tend to keep going in the direction it's current going.) OFCL=Official NHC forecast; GFS=Global Forecast System model; GFDL=Geophysical Fluid Dynamic Laboratory model; HWRF=Hurricane Weather Research Forecasting model; UKMET=United Kingdom Met Office model; ECMWF=European Center for Medium Range Weather Forecasting model; TVCA=one of the consensus models that lends together several of the above models; CMC=Canadian Meteorological Center (GEM) model; BAMM=Beta Advection Model (Medium depth.) Image credit: National Hurricane Center 2012 verification report.

Which Intensity Model Should You Trust?
Don't trust any of them. NHC has two main statistical intensity models, LGEM and DSHP (the SHIPS model with inland decay of a storm factored in.) In addition, four dynamical models that are also use to track hurricanes--the GFS, ECMWF, HWRF, and GFDL models--all offer intensity forecasts. With the exception of the GFS model, which had a skill just 5% better than a "no-skill" intensity forecast for predictions going out 36 hours, all of these models had no skill in their intensity forecasts during 2012. The ECMWF and HWRF models were the worst models for intensity forecasts of 3, 4, and 5 days, with a skill of 20% - 60% lower than a "no-skill" forecast. The LGEM model, which was a decent intensity model in 2011, tanked badly in 2012 and had near-zero skill. The only model that was any good in 2012 was the IVCN "consensus" model, which averages together the intensity forecasts of two or more of the intensity models such as LGEM, GFDL, HWRF, and DSHP.

Some Promising Models From the Hurricane Forecast Improvement Project (HFIP)
Last year was the fourth year of a ten-year project, called the Hurricane Forecast Improvement Project (HFIP), aimed at reducing hurricane track and intensity errors by 50%. The new experimental models from HFIP generally performed poorly in 2012. However, the new FIM9 15-km global model was competitive with the ECMWF and GFS models for track, and the new CIRA Statistical Intensity Consensus (SPC3) model for intensity performed better than many of the traditional intensity models.

For those interested in learning more about the hurricane forecast models, NOAA has a 1-hour training video (updated for 2011.) Additional information about the guidance models used at the NHC can be found at NHC and the NOAA/HRD Hurricane FAQ.

Sources of Model Data
You can view 7-day ECMWF and 16-day GFS forecasts on wunderground's wundermap with the model layer turned on.
Longer ten-day ECMWF forecasts are available from the ECMWF web site.
FSU's experimental hurricane forecast page (CMC, ECMWF, GFDL, GFS, HWRF, and NAVGEM models)
NOAA's HFIP model comparison page (GFS, ECMWF, FIM, FIM9, UKMET, and CMC models.)
Experimental HFIP models

Quiet in the Atlantic
There are no tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for tropical cyclone formation is predicting development during the coming seven days. I plan on having a detailed update on Friday to discuss the latest long-range forecasts for the coming peak part of hurricane season.

Jeff Masters


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

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Quoting 223. StormTrackerScott:
Next Tuesday Evening. Beginning to now match the Euro. Not a good looking pattern for the Caribbean Islands & FL.

Even though it is only a 1010 mb. low this is the strongest the GFS has shown a system in the Western Caribbean. Like I said yesterday, models will flip-flop on a day to day basis, it seems they are picking up development again today.
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The only crink in the next 7 days is if we can get some spin down yonder in the BOC, but even that is a tad out the box with the current and downstream looks.


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Here's a short article by livescience about hurricane sandy (1 in 700 year storm).

"Hurricane Sandy's devastating storm track is a rare one among hurricanes; a new statistical analysis estimates that the track of the storm — which took an unusual left-hand turn in the Atlantic before slamming into the East Coast — has an average probability of happening only once every 700 years.

"The particular shape of Sandy's trajectory is very peculiar, and that's very rare, on the order of once every 700 years," said Timothy Hall, a senior scientist at the NASA Goddard Institute for Space Studies who co-authored the study. That means that in any particular year, the chance of such a storm track happening is 0.14 percent.

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Dr. Masters, I think this is a post that everyone here needed, as well as the audience members that aint got a WU account. Seems to me there is always a shallow debate about which computer model is better than another, and this post clears a lot up. A model wont ever be perfect and they all have their weak spots. :D
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CYCLONE 08E
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Quiet in the Atlantic

There are no tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for tropical cyclone formation is predicting development during the coming seven days. I plan on having a detailed update on Friday to discuss the latest long-range forecasts for the coming peak part of hurricane season.
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It's good to hear they finally retired the NOGAPS model. We've been saying here for some time that NOGAPS was NO Good At Predicting Storms. :)
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Quoting 208. SLU:
The EATL has trended warmer in the last 2 weeks compared to early July. Crow will be extinct by year end with the number of naysayers calling the season a bust on August 7th. :P

This season will be a bust...
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Quoting 217. washingtonian115:
"The GFS for 12Z absolutely just blew the 06Z & 00Z run out of the water!." You forgot to add no pun intended :).


LOL!
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Next Tuesday Evening. Beginning to now match the Euro. Not a good looking pattern for the Caribbean Islands & FL.

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Quoting 216. 69Viking:


Because of climate change there's a good chance storms like Sandy could become more normal.


Oh, no - not climate change.
And I don't think there's a "good chance" of a another Sandy affecting the N.E. part of the U.S.
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Quoting 190. StormTrackerScott:


It won't as the Death Ridge is now merging with the Bermuda High.

24hrs


48hrs


That would be really good, we don't need anymore rain for a while!
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And if I say to you tomorrow. Take my hand, child, come with me.
It's to a castle I will take you, where what's to be, they say will be.


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Forgot one.

UKMET = EGRI
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218. flsky
Quoting 197. opal92nwf:
Ahh, the epitome of hurricane season. Sometimes when things are quiet in the Atlantic like now, I just watch old coverage to fill the void.
img src="">
img src="">

Thank you for posting these videos of past storms. I sometime think some people on here think hurricanes can be fun - the serious reality, however, is that they are very dangerous and often life threatening.
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Quoting 210. SouthernIllinois:
Holy Schmoly! The GFS for 12Z absolutely just blew the 06Z & 00Z run out of the water! Precipitation Values are MUCH HIGHER this run.

*The excitement and anticipation builds!!!*

12Z


06Z


00Z
"The GFS for 12Z absolutely just blew the 06Z & 00Z run out of the water!." You forgot to add no pun intended :).
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Quoting 183. Sfloridacat5:


Anything's possible with weather. But the chance of another Sandy type hurricane hitting the N.E. is extremely small.
Sandy was a freak of a storm. It was a combination of many things. People wearing winter jackets in 50 degree air standing on the beach.
It was a huge storm and that's what gave it so much power in the form of its storm surge.

A run of the mill cat 1/tropical storm wouldn't produce anywhere close to the same damage as Sandy.


Because of climate change there's a good chance storms like Sandy could become more normal.
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Good afternoon everyone

Very rainy day over here. Actually killing time, waiting for it to let up so I can take care of some dog sitting duties (two MASSIVE chocolate labs). The one thing I hate to do on this island is to drive while it's raining. The roads and drivers are bad enough in good weather....you get my drift, I'm sure...

Lindy
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Quoting 212. yoboi:



Thanks for the info.......
he said 9
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Quoting 206. ncstorm:
If I see anyone discount the Nogaps..I will be sure to bring up this written in Dr. Masters blog today...best performing models in regards to track

ECMWF: The European Center's global forecast model
GFS: NOAA's global forecast model
NOGAPS: The Navy's global forecast model (now defunct, replaced by the NAVGEM model in 2013)
UKMET: The United Kingdom Met Office's global forecast model
GFDL: The Geophysical Fluid Dynamics Laboratory's hurricane model, initialized using GFS data
HWRF: The intended successor for the the GFDL hurricane model, also initialized using GFS data
CMC: The Canadian GEM model
BAMM: The very old Beta and Advection Model (Medium layer), which is still useful at longer ranges

NOGAPS = NAVGEM
GFS = AVN
CMC = GEM
Same models just upgraded, in fact most if not all of the major Global Models have had upgrades recently within the past year to the latest which was the CMC, if I'm not mistaken.
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I remember when Ike was getting near the Bahamas shear was starting to weaken it..Then the shear lessened and the basta__ was back up to cat 4 status.Those poor people.If shear would have continued to kill Ike he would be a low end cat 2 in the southern Bahamas and cuba.2 over a 4 is better any day.
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my shot in the dark

I have reduced the numbers
down from the may forecast

2013 SEASONAL OUTLOOK
16 TO 18 STORMS
8 TO 10 CYCLONES
1 TO 3 MAJORS


we have had 4 that leaves 12 to 14 to come
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208. SLU
The EATL has trended warmer in the last 2 weeks compared to early July. Crow will be extinct by year end with the number of naysayers calling the season a bust on August 7th. :P

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Quoting 190. StormTrackerScott:


It won't as the Death Ridge is now merging with the Bermuda High.

24hrs


48hrs

Area forecast discussion
National Weather Service Tallahassee Florida
1112 am EDT Wed Aug 7 2013

Short term [thursday through friday]...

During the rest of the period, upper high pressure to our west and
east merge to produce elongated west-East Ridge and near zonal flow over
Gulf region by early thurs. However during thurs, TUTT advances westward
across Bahamas and begins to erode srn ridge while energy moves
east over Ohio Valley into mid-Atlc states eroding nrn boundary but
at same time nudging it swd.
On Fri, TUTT moves further into southeast
Gulf of mex with assocd mid level dry air ahead of it spreading
nwwd to impact ern half of County Warning Area. By eve, TUTT exits west of County Warning Area
with ridge restrengthening over Alabama/Georgia and with moist air on
backside beginning to impact southeast Big Bend.
This reflected in area
model soundings I.E. Tlh GFS with precipitable waters above 2 inches thru thurs
night then dropping to around 1.5 inches on Fri before rising to
1.8 inches at night. At surface, ridge axis remaining to our
north,
expect type 2 (moderate southeast flow) seabreeze on thurs
favoring storms over North Florida with focus on Panhandle. Will go with
40-60% NE-SW pop gradient on thurs, 20-40% east-west gradient on Fri.
Expect inland highs in the mid 90s each aftn with heat indices 100
to 105 degrees on thurs, dropping to around 100 degrees on Fri.

Long term [friday night through tuesday]...


Mostly zonal upper level flow will be experienced through next
Tuesday as a thin upper ridge will sit over our local area between a
TUTT passing over the Gulf, and a longwave trough across the
northern half of the country. At the surface, the local area will be
under the influences of the western reaches of the Bermuda high.

This will result in near average rain chances and temperatures each
day.

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If I see anyone discount the Nogaps..I will be sure to bring up this written in Dr. Masters blog today...best performing models in regards to track

ECMWF: The European Center's global forecast model
GFS: NOAA's global forecast model
NOGAPS: The Navy's global forecast model (now defunct, replaced by the NAVGEM model in 2013)
UKMET: The United Kingdom Met Office's global forecast model
GFDL: The Geophysical Fluid Dynamics Laboratory's hurricane model, initialized using GFS data
HWRF: The intended successor for the the GFDL hurricane model, also initialized using GFS data
CMC: The Canadian GEM model
BAMM: The very old Beta and Advection Model (Medium layer), which is still useful at longer ranges
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Quoting 199. yoboi:
Dr Masters....What are your Atlantic hurricane numbers for this year?????? TIA......
9
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Quoting 149. TropicalAnalystwx13:
Last four runs of the CFS:



I have a feeling it will get active in due time. Just give it that. ;)
Those look sexy! From where is that?
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Quoting 194. GTstormChaserCaleb:
Thanks for the link. I still hold firm that Ike was a Category 3 at landfall which would put him as the last major hurricane to hit the CONUS.


Infact, the 0Z Euro looks like a Charley track "IF" system can form in the Caribbean over the next 7 days. Something to watch as the MJO is heading back to the Caribbean this week.
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Ike was a beautiful storm. I expect to see at least one like him this year.

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Quoting 199. yoboi:
Dr Masters....What are your Atlantic hurricane numbers for this year?????? TIA......
The Doc said he doesn't do outlooks.
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Ahh, the epitome of hurricane season. Sometimes when things are quiet in the Atlantic like now, I just watch old coverage to fill the void.
img src="">
img src="">
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Quoting 189. zoomiami:


Many people are too young to remember when there was no such thing as an invest, you didn't know what they were looking at for development, and there was no sharing of the model info etc.

Many people are too young to remember when there was no such thing as an invest, you didn't know what they were looking at for development, and there was no sharing of the model info etc.

The explosion of information available to the public in the last 8 years was unfathomable in 1992. Now people act like someone is doing something wrong if the models can't tell you what is going to happen in the next five days.

Definitely the "get in now" generation. There are days that I truly hate the current technology.
I hate almost every song on the radio now-a-days but that's for another topic....I remember people use to not worry about a tropical cyclone until it was in their vicinity.For example a day before Gloria hit we were aware and did the usual preparing and waiting for the storm to come.I personally didn't know about the storm until it was 5 days away from doing any type of damage to the U.S not when it first came off of Africa and developed.I still remember those weather graphs that look cheesy today compared to all those HD computer graphics you see today.Technology in weather has come a long way for sure.
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Quoting 152. opal92nwf:
Here's a good example of a Caribbean born hurricane

And BTW, I have to agree with this article
Hurricane Camille Was Not a Category 5 at Landfall
Thanks for the link. I still hold firm that Ike was a Category 3 at landfall which would put him as the last major hurricane to hit the CONUS.
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Quoting 185. GTstormChaserCaleb:
If something develops in the Western Caribbean next week. I am tipping my hat to the FIM models. Right now I have FIM-ritis.



I posted this morning that the 0Z Euro has latched on and brings it into SW FL at 192hrs due to a trough coming down and a strong one at that. Just ask the people in Michigan early next week when they wake up to lows in the 30's & 40's.
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Quoting 180. boandjoe:



why show an area if its zero pct? are they bored?
I think the percentage is slightly above 0%, so they probably be safe to put it as an area they are watching...IMO, its a waste of time.
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Quoting 175. 69Viking:
It's starting to get moist in the Gulf. Those storms that gave me 1.25" more of rain when they pushed through last night seem to be firing back up today. If that energy in the center of the country pushes into the Gulf it could get interesting in a few days!



It won't as the Death Ridge is now merging with the Bermuda High.

24hrs


48hrs
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Quoting 101. nrtiwlnvragn:


All of the data from the NHC verification reports that the Doc has in his post are only for storms at the Tropical Depression level or greater. None of that data is for invest systems.


Many people are too young to remember when there was no such thing as an invest, you didn't know what they were looking at for development, and there was no sharing of the model info etc.

The explosion of information available to the public in the last 8 years was unfathomable in 1992. Now people act like someone is doing something wrong if the models can't tell you what is going to happen in the next five days.

Definitely the "get it now" generation. There are days that I truly hate the current technology.
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IntelliGeoff is in lurk mode, but keeping a close eye for possible development :)...

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I agree in general but looking at every forecast for every storm even if just over the last five years is more than a "little study". Better to pull down the error data, look at the biggest errors, then go to the archives to study those cases. That alone would make for a good study.


i'm guessing...that if you studied 5 random storms...you would be able to see if you agree or disagree with doc's analysis....i'm guessing that doc...didn't just make this up...or pull it off a chart...but knows that his data is valid....happy hunting
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...week of Nov. 4th...major...to hit FL!
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Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather