POST-TROPICAL CYCLONE FRANCINE (2024)

Coastal Watches/Warnings and Forecast Cone for Storm Center

Forecast Length*	Forecast Track Line	Initial Wind Field
Full Forecast 3 days	On Off	On Off

* If the storm is forecast to dissipate within 3 days, the "Full Forecast" and "3 day" graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecastuncertainty is conveyed by the track forecast "cone", the solid whiteand stippled white areas in the graphic. The solid white area depictsthe track forecast uncertainty for days 1-3 of the forecast, while thestippled area depicts the uncertainty on days 4-5. Historical dataindicate that the entire 5-day path of the center of the tropicalcyclone will remain within the cone about 60-70% of the time. Toform the cone, a set of imaginary circles are placed along theforecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions,where the size of each circle is set so that it encloses 67% of theprevious five years official forecast errors. The cone is then formedby smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Theireffects can span many hundreds of miles from the center. The areaexperiencing hurricane force (one-minute average wind speeds of at least74 mph) and tropical storm force (one-minute average wind speeds of39-73 mph) winds can extend well beyond the white areas shown enclosingthe most likely track area of the center. The distribution of hurricaneand tropical storm force winds in this tropical cyclone can be seen inthe Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, thechances that any particular location will experience winds of 34 kt (tropical storm force),50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented intabular form for selected locations and forecast positions. This information is also presented ingraphical form for the 34 kt, 50 kt,and 64 kt thresholds.

Note: A detailed definition of the NHC track forecast cone is also available.