Guide to Late Cycle Track Plots

This page lists the TECH identifiers of the various intensity forecast aids that may appear in the late cycle track plots on this site. To learn more about TECH identifiers, click here. For general information about the difference between late cycle and early cycle forecast aids, click here. To learn what a vortex tracker is, click here.

TECHs of the forecast aids shown in this plot

The TCGP plotting system is currently configured to plot the tracks of the following late cycle forecast aids. Note that the late cycle guidance come from the previous model cycle, so they are 6-hr older than the early cycle guidance. If one of the forecast aids listed here does not appear in the plot, this means that it was not available in the source a-deck at the time the plot was created. When a system has been newly designated or upgraded to a tropical depression, it is common to only have a few forecast aids available.

Official forecast:

• OFCL: NHC official forecast

Multilayer global-dynamical models: deterministic runs

• AVNO: NWS Global Forecast System (GFS) model
• NGPS: Navy Operational Global Prediction System (NOGAPS)
• CMC: Environment Canada Global Environmental Multiscale (GEM) model
• EGRR: UK Met Office model with subjective quality control applied to the tracker (the official version, distributed on GTS)
• UKM: UK Met Office model using the development tracker (no quality control on tracker output, only run at 0000 and 1200 UTC)

Multilayer global-dynamical models: ensemble mean

• AEMN: ensemble mean of the NWS Global Ensemble Forecast System (GEFS)
• CEMN: ensemble mean of the Environment Canada Global Environmental Multiscale (GEM) model 

Multilayer regional-dynamical models

• HWRF: NWS/Hurricane Weather Research and Forecasting (HWRF) model
• GFDL: NWS/Geophysical Fluid Dynamics Laboratory (GFDL) model 
• GFDT: NWS/GFDL model (using the GFS vortex tracker)
• GFDN: NWS/GFDL model (using the NOGAPS model fields) 
• COTC: Navy COAMPS model (HFIP version)

Frequently asked questions

Often users ask why other forecast aids are not included in the late cycle track plots. This section is meant to answer these questions.

Where can I find more information about the details of these different models and forecast aids?

In the future we plan to offer a comprehensive guide to all the forecast aids featured in this site. In the meantime, please refer to the very useful Technical Summary of the National Hurricane Center Track and Intensity Models.

Why don't you include the projections of the European Centre for Medium Range Forecasting (ECMWF) model?

The ECMWF model is run by a 28-nation European consortium who jointly fund the operations and development of that model. As such, access is generally restricted to member states or commercial users who are willing to pay for the model output. They do provide low resolution fields of their deterministic run, although these are at too coarse of a resolution to run a vortex tracker on.

Why don't you include the projections from the North American Model (NAM)?

The NAM model's track projections are normally not very skillful compared with the other dynamical track models shown here. In the future, TCGP may feature another type of plot for experimental or less skillful track models. We will include the NAM in that new type of plot.

Why don't you include the consensus track models in the late cycle plots?

All of the consensus forecast aids for track are actually early cycle aids since they use the adjusted output of late models in their averaging. Users should look at the early cycle track plots to see the consensus aids.