Hi there, as with all PHA "hits" the original data are retained and saved for perpetuity. The unadjusted data are the ultimate foundation for all of our analysis products. Each month, we start with the unadjusted ("raw") data. The values that are flagged are either held out of the assessment (as in the case for Barrow), or are adjusted to correct for the perceived issue (the algorithm needs much longer segments to build enough confidence to make the adjustment).

Again, to re-emphasize: the unadjusted data are preserved and we use this as the foundational set for subsequent analyses.

Not only are they preserved, but they are publicly available at https://www1.ncdc.noaa.gov/pub/data/ghcn/v3/  In that directory the latest average temperature at each station ("tavg") is available in raw, unadjusted form and the adjusted dataset indicators

• https://www1.ncdc.noaa.gov/pub/data/ghcn/v3/ghcnm.tavg.latest.qca.tar.gz ("a" for adjusted)
• https://www1.ncdc.noaa.gov/pub/data/ghcn/v3/ghcnm.tavg.latest.qcu.tar.gz ("u" for unadjusted)

Thanks!
Deke