notes on using the National Hurricane Center's web site
return to Unofficial weather and water info for El Portal
https://c7riochico.net/epw/
Notes on using the National Hurricane
Center's web page and the main forecast advisories there done
four times
a day. Note that the forecast shows a definite
path and timing for a storm but forecasts are always probabilistic
estimates. Future weather conditions are never certain so
forecasts project what is likely to happen and the probability
that and other outcomes. Sometimes an estimate is of what is most likely
to happen and other estimates are of when the "earliest reasonable time"
something might happen. Other estimates give percent chances of different
For some purposes an estimate of when a storm is
mostly likely to hit is useful, but if you wait until then to
go to a safe place, you may be too late. Evacuation decisions are
always based on the "earliest reasonable" time a storm might hit
which assumes 90% chance that the storm will not have arrived yet.
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The image below shows what you will see when you get to
the NHC site
and some of the many things there important for finding about the current
forecast. When a storm gets closer to us (e.g. 48 hours away) more
information appears on the page such as the storm surge forecast.
click to enlarge
"Key Messages" summarizes the most important things to consider in planning to get ready for this storm. "Forecast Discussion" is a a more technical discussion of the meteorological considerations that went in to this forecast. |
Potential Storm Surge Flooding Map (Inundation)
Tropical Storm Marco will probably soon become a hurricane and is now within 48 hours away from New Orleans. This is soon enough that the NHC's high resolution storm surge model can begin to generate a forecast of near-worst-case* storm surge amounts. Use this opportunity to learn how this graphic's controls work. click to enlarge * values indicate the water height that has about a 1-in-10 (10%) chance of being exceeded. |