Spaghetti Models, Explained
Spaghetti plots show the track predicted by many different computer models on one map. The spread between the lines is the uncertainty. They are a tool the National Hurricane Center uses, not a forecast on their own.
The models that matter
GFS
Global Forecast System
The US global model, run by NOAA. It updates every 6 hours and is one of the two most-watched models for storm track. It tends to be faster than the Euro in some setups.
ECMWF
European Centre for Medium-Range Weather Forecasts
Known as the Euro, this European global model has historically been the most accurate for track. It runs every 12 hours and is the model many forecasters weight heaviest.
HAFS
Hurricane Analysis and Forecast System
NOAA's newest hurricane-specific model. It replaced HWRF as the primary intensity model and is built specifically to resolve the inner core of a storm.
HMON
Hurricanes in a Multi-scale Ocean-coupled Non-hydrostatic
A NOAA regional hurricane model that runs alongside HAFS. It is a secondary input the NHC uses to cross-check intensity and structure.
ICON
Icosahedral Nonhydrostatic
The German global model from DWD. It is a respected independent track input because it uses a different grid structure than GFS or the Euro.
CMC
Canadian Meteorological Centre
The Canadian global model. It adds another independent take on track and is useful mainly as one more line on a spaghetti plot.
TVCN
Tropical Cyclone consensus, variable
A consensus model that averages the tracks of several individual models. Consensus models are more stable than any single model, which is why the NHC leans on them.
HCCA
HURC consensus
A second consensus blend the NHC uses. When the consensus and the individual models agree, confidence in the track is high. When they split, uncertainty is real.
A consensus model averages the tracks of several individual models. Because the average cancels out each model's biases, consensus runs are more reliable than any single line. That is why the NHC leans on consensus when building the official forecast.
How to read a spaghetti plot
- 1
Look at the cluster, not the outlier. Where most lines agree is the more likely path. A single line curving somewhere different is not a forecast, it is noise.
- 2
The spread widens with time. Lines that bunch together at 24 hours fan out by day 5. A wide fan at the end means low confidence, not a storm hitting everywhere.
- 3
Model runs update every 6 to 12 hours. A plot you saved this morning is already stale by afternoon. Always check the run time on the graphic.
- 4
Intensity is harder to predict than track. Rapid intensification and weakening are still difficult for models, so wind numbers change more than the path does.
- 5
The NHC cone is the official product. It already blends these models and adds forecaster judgment. When the cone and the spaghetti disagree, follow the cone.
Compare models on the map
This map shows the ECMWF model. Use the model switcher in the bottom-right of the map to compare with GFS and ICON.
ECMWF model wind. Use the model switcher in the bottom-right of the map to compare with GFS and ICON.
Where to see spaghetti plots
- NHC forecast graphics — the official track, cone, and intensity guidance from the National Hurricane Center.
- Tropical Tidbits — the best free source for model plots, run by meteorologist Levi Cowan.
Frequently asked questions
Which hurricane model is most accurate?
The ECMWF, or Euro, has the best long-term track record for storm track. The GFS is close behind and has improved. For intensity, HAFS is currently NOAA's leading model. No single model is right every time, which is why forecasters use a consensus.
Why do the models disagree?
Each model uses different math, different grid spacing, and different assumptions about the atmosphere. Early in a storm's life, when the system is disorganized, the models spread the most. As a storm becomes better defined, the lines usually tighten.
How often do models update?
The major global models run every 6 to 12 hours. GFS and HAFS update four times a day, the Euro twice. A spaghetti plot is only as current as its most recent model run, so check the timestamp before you share one.
Should I trust the models or the NHC cone?
Trust the NHC cone. The cone already blends the best models and adds a human forecaster's judgment. Spaghetti plots are a behind-the-scenes tool, not a finished forecast. When they disagree with the cone, the cone wins.
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