Noel 0-5 Day Forecasts
Noel 6-10 Day Forecasts
Experimental 6-10 Day Model+Climatology Fields
Clark Evans (acevans-at-met.fsu.edu), Jim Elsner, and Bob Hart
As part of an ongoing project to explore the viability of various new and existing forecast tools with respect to forecasting higher latitude tropical cyclone impacts in the Atlantic basin, 6-10 day climatological forecast tracks have been developed for all active storms in the Atlantic basin. These tracks are derived using 120 hr forecast points from all models in the "early" composite of the current run's worth of model tracks. A FORTRAN routine takes these forecast points as input, finds all matching storm tracks within +/- 0.5 degrees latitude or longitude from the 1900-2006 NHC Atlantic "best track" database (interpolated to hourly output), and creates composites of these positions at 12 hourly intervals out to 240 hours. Currently, intensity and time of year are not considered when developing these climatologies due to the small numbers of cases in each climatological composite.
In creating these tracks, the "perfect prog" technique is applied to all 5-day model forecasts. This technique assumes that if the model track verifies perfectly at five days, the 6-10 day track will have equal skill to the NHC's current baseline for measuring model forecast skill (the CLIPER model's performance). We have reached the point where the majority of dynamical model guidance has skill equal to or exceeding that from climatology at 5 days but appears to decrease past climatology beyond that (e.g. Figure 2 of the NHC's 2006 Verification Report), giving us the motivation to extend these forecasts into the future. In conjunction with the GFS Ensemble model output plots available from this page, occasionally offering forecast tracks to 10 days (and beyond), these model+climatology tracks allow us to get a measure of the potential spread of solutions at long ranges. Furthermore, they allow us to potentially be able to highlight specific regions of enhanced threat at these long ranges, particularly to higher latitude regions within the Atlantic basin.
Please note that these tracks are highly experimental and provided for research purposes only. They do have their limitations, particularly for storms that travel well inland into North America, cross into the East Pacific, or reach far to the north or far to the east within the Atlantic basin.
Example 0-5 Day and 6-10 Day Model Forecast Tracks -- Noel (2007) Just Prior to Formation
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Redistribution of these images is prohibited; however, links to this page are welcome and encouraged. These images are unofficial sources of information and can and should not be used in place of information from the NHC/TPC, CPHC, or local emergency management sources. The availability and timeliness of this data, as with all unofficial products, is not guaranteed. © 2007, Clark Evans.