Beware of news-teasing
by the mainstream news media
, shamelessly telling audiences to stay tuned for "the latest updates from the National Hurricane Center
" (or "National Weather Service") at the "top of the hour
" (never mind the "bottom of the hour"): 20 times out of 24 (or 16 times out of 24) the media is deliberately lying
There are only 4 official NHC advisories
(i.e., per-storm updates) every 24 hours
: 5 a.m., 11 a.m., 5 p.m., and 11 p.m. [#
] Except that as a storm nears U.S. soil, intermediate advisories
are added, at the +3-hour
marks: 2 a.m., 8 a.m., 2 p.m., and 8 p.m. NHC intermediate advisories
are not complete updates; they do not recompute all graphic content [*
That my warning is true can be confirmed by studying various pages at <https://www.nhc.noaa.gov/
>. As casual evidence, e.g., exactly 24 hours between 11 a.m. Wednesday and Thursday, inclusive, advanced the advisory
numbers for Hurricane Florence only from 53
(so, 53 54 55 56 57, hmmm
The cited NHC main page, as a temporary feature, provides links to the local NWS-radar stations in N.C. & S.C.
They continuously scan the skies, but the computation that's required imposes an overall update cycle of a handful-or-so of minutes, even within the animated displays. But each is a genuinely updated image
: I'm sure that the tight match to the times of the local t.v. news broadcasts, established in days before cable t.v., was coöperation "in the public interest".
: I've forgotten the details from Irma last year, but it seems to me that on the forecast charts (i.e., maps), the storm position is updated, but times-of-arrival at geographic positions (i.e., dots) on the chart might not be, and the forecast track is not.