Best track
NOAA HURDAT2, the post-season re-analysis published by the
National Hurricane Center and the Central Pacific Hurricane Center. It is the
authoritative record of where each storm actually went. The eastern and central
Pacific file starts in 1949, so 1950 is the first storm here.
The forecasts
NOAA ATCF a-decks, tech code OFCL. Every line is an
official forecast exactly as it was issued — position and intensity at each
lead time. Nothing is re-computed with hindsight. Machine-readable official
forecasts begin in 1988; before that only the track survives.
NHC distributes the a-deck archive as working files, not quality
controlled. This build rejects what it can prove wrong — three points
were dropped, two null positions at 0°N/0°W and one in the wrong ocean —
and prints every rejection. Errors it cannot detect will still be here.
Storms in progress
The season in progress is not in HURDAT2 yet, so those storms come from
NOAA's operational feeds instead — the working best
track and the public forecast decks. That data is provisional and gets
revised, sometimes substantially, in the post-season re-analysis. Live and
preliminary storms are labelled as such.
Known gaps
Central Pacific forecasts issued from Honolulu were not written into the a-decks
until the mid-1990s. Iniki (1992) therefore keeps only the four
advisories issued before Honolulu took over. Ema (2019) is absent
from the ATCF archive entirely. Storms are labelled where coverage is partial.
A storm whose forecasts cover less than half its life is replayed on its
observed track instead, 6-hourly, with the archived forecasts
appearing at the hours they were issued. That is how Iwa (1982), which has no
forecast at all, and Iniki still replay hour by hour with the satellite and wind
layers running.
Layers & imagery
Infrared cloud tops from NOAA GridSat-B1, the 3-hourly
geostationary record that runs unbroken from 1980. A storm in progress runs
ahead of that record, so its frames come from GOES-West live
and are swapped for GridSat once the archive catches up — the legend
credits the live feed until the swap is complete. True-colour photos and rain
rate from NASA Worldview / GIBS — VIIRS and MODIS from
2000, GPM IMERG rainfall from 1998. Wind fields are the recorded
34, 50 and 64 kt radii: forecast from the ATCF decks (2000 onward), observed
from HURDAT2 (2004 onward). Coastlines from Natural Earth.
The uncertainty shading is measured from this archive, not copied
from NHC. Every official forecast here is paired with the track that followed, so
the error distribution is computed per era: the two-thirds radius at 24 hours
runs 78 nm in the 1990s and 36 nm in the 2020s. It is a reconstruction of
a Hawaii-approaching sample, not the official cone.
Hawaii's forecasts come from the
Central Pacific Hurricane Center
in Honolulu, which issues every watch and warning for these islands. For a storm
happening now, go there, not here. Storms east of 140°W are the
National Hurricane Center's until they cross.
This is an independent archive, built from public NOAA and NASA data. It is
not affiliated with, nor endorsed by, the Central Pacific Hurricane Center, the National
Hurricane Center, NOAA or NASA. It redraws forecasts that were issued in the past, and its
uncertainty shading is reconstructed from this archive's own record of past errors.
It is not the official product and it carries no watches or warnings.
We acknowledge the use of imagery from NASA's
Worldview, part of the Earth
Observing System Data and Information System (EOSDIS), and of GPM IMERG precipitation
data from the Goddard Earth Sciences Data and Information Services Center. Infrared
imagery is the NOAA
GridSat-B1 Climate Data Record from NCEI, with GOES-18 ABI
imagery for storms in progress, redistributed by Unidata. Best track and forecasts
are NOAA NHC/CPHC HURDAT2 and ATCF. Coastlines are Natural Earth, public domain.
Every storm also has its own reference page, with the key numbers
and a link into the replay: every storm since 1950. The
archive also carries measured analyses and
Hawaiʻi-specific preparation guides.