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COASTAL
WATCHES & WARNINGS
This display shows an approximate representation of coastal areas under a
hurricane warning (red), hurricane watch (pink), tropical storm warning
(blue) and tropical storm watch (yellow). The orange circle indicates the
current position of the center of the tropical cyclone. The black line and
dots show the National Hurricane Center (NHC) forecast track of the center
at the times indicated. The NHC forecast tracks of the center can be in
error, and the white area indicates the average area of uncertainty for the
position of the center.
It is important to realize tropical cyclones are not a point. Their effects
can span many hundreds of miles from the center. The area experiencing
hurricane force (one-minute average wind speeds of at least 74 mph) and
tropical storm force (one-minute average wind speeds of 39-73 mph) winds can
extend well beyond the white area shown enclosing the most likely track area
of the center. The distribution of hurricane and tropical storm force winds
in this tropical cyclone can be seen in the Cumulative Wind Distribution
graphic displayed below.
STRIKE
PROBABILITIES
This is an experimental product. This display shows the probability,
in percent, that the center of the tropical cyclone will pass within 75 statute
miles of a location during the 72 hours beginning at the time indicated in the
caption. The caption also provides the name of the tropical cyclone and the
advisory number from which the probabilities were generated. Contour levels
shown are 10%, 20%, 50% and 100%.
CUMULATIVE
WIND DISTRIBUTION
This display shows how the size of the storm has changed, and the areas affected
so far by tropical storm and hurricane force winds, in orange and red, respectively.
It is based on information contained in the set of advisories indicated in the
caption at the top of the figure. Note that the display is based on estimated
coverage of one-minute average winds, not gusts.
WIND
SPEED FORECAST AND PROBABILITY CHART
This is an experimental product. It shows the National Hurricane Center
(NHC) maximum 1-minute wind speed forecast as a broad blue line on a chart of
wind speed versus forecast period. The narrower lines, labeled 10% and 20% (or
30%), indicate the probability that the maximum wind speed will be some other
magnitude than what the NHC has forecast. For example, the cyclone could become
stronger than the NHC has forecast, with there being a 10% chance that the wind
speed will attain the level indicated by the 10% line plotted above the NHC
forecast. The probabilities are based on NHC forecasts from 1988-1997. The data
base excludes unnamed tropical depressions. Current advisory information is
shown near the bottom of the chart. When applicable, the Saffir/Simpson Hurricane
Scale is shown at right. "Inland" is indicated for periods when the cyclone
center is forecast to be over land. "Ext" indicates that the NHC forecasts the
cyclone to be extratropical at that time.
WIND
SPEED PROBABILITY TABLE
This is an experimental product. The table shows the probability that
the maximum 1-minute wind speed of the tropical cyclone will be within any of
eight intensity ranges during the next 72 hours. It is based on the outcomes
of similar NHC wind speed forecasts during the period 1988-1997. The data base
excludes unnamed tropical depressions. NA indicates data not available. TF indicates
too few (<10) similar forecasts during 1988-1997 to yield reliable results.