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I have cautioned (non-trained forecasters) for years to ignore #SpaghettiPlots. #SharpieGate is an example of why. To the untrained eye, all forecast models are equal and have the same "weight". This however is not true and a spaghetti plot often contains data up to 12 hours old.
Some models included in a spaghetti plot (SP) are run twice / day, at 12z and 0z. When a model is run at 0z, and included on a 12z SP, the SP began its run at 11z, which contained the last avail run of the model (0z). By the time SP shows up on a server, it has 12 hr old data.
Some SP have data that isn't even a model, such as XTRP. That is just a straight-line extrapolation of the storm's current direction. And not every model works the same way. Some are new and somewhat "experimental", while others a very solid.
Trained forecasters pay close attn to each specific model from run to run. They look for clues as to how a given model is performing by validating observations against recent runs. They look at variables in the model and check those against observation as well.
Trained forecasters understand things such as the HMON being a fairly new model that is still trying to establish a firm footing, while the HWRF is revamped GFDL model code, a usually well performing product. There is also the Euro and Canadian models, and variants of the GFS.
Models like TABS, TABM, TABD are simply statistical models which are useless for track forecasting. The Euro model (ECMWF) has a good operational history, but it's not included in spaghetti plots.
A trained forecaster would never use a SP as basis for a forecast. If for anything else, because they contain old data. In the forecasting world, 12 hour old data equals 12 yr old data. For these reasons and more, SP should not be shared by politicians untrained in forecasting!
As for anyone else, there is nothing wrong with learning and trying to make your own forecast to help with decision support. But always give the most weight to NHC advisories! NHC has the best Atlantic forecasters in the world. When you see a spaghetti plot, simply ignore it. #
