Post by tornado on Mar 10, 2016 18:02:59 GMT -5
Recently there has been discussion about how the NWS is not supporting some sites, in gaining access to past edit logs, so that they can be printed.
It seems like we will have to do this ourselves.
The above screenshot highlights a recent foggy morning. The duty observers were well ahead of what ASOS would have reported.
At 0602, while ASOS was recording CLR, the sky condition was actually VV001. The duty observer determined that from past
experience, not from any "taps" in the raw ASOS data. While ASOS was determining the visibility to be 8SM at 0602, the duty
observer edited the VIS field to record 1/4SM. At 0606, the total obscuration lifted, revealing some cirrus; the duty observer
edited the sky condition to show BKN000; yet ASOS was recording CLR at that time. At 0614, when ASOS finally began dropping
the VIS- to 6SM- the observer reported 1/2SM.
At 0627, ASOS finally recorded a total obscuration, but as VV016. The duty observer was reporting VV002 at that time. The next
screen shot shows the raw data. ASOS did not record a "tap" under 1,000 feet until 0630. That was 27 minutes after the CWO sent a
SPECI including 1/4SM VV001 ! The obscuration eventually settled in at 160-230 feet, or a reportable value of 200 feet, according
to ASOS. Yet the CWO reported VV002 as early as 0628.
The human eye and brain, are just better and faster than ASOS, with regards to fog!
It seems like we will have to do this ourselves.
The above screenshot highlights a recent foggy morning. The duty observers were well ahead of what ASOS would have reported.
At 0602, while ASOS was recording CLR, the sky condition was actually VV001. The duty observer determined that from past
experience, not from any "taps" in the raw ASOS data. While ASOS was determining the visibility to be 8SM at 0602, the duty
observer edited the VIS field to record 1/4SM. At 0606, the total obscuration lifted, revealing some cirrus; the duty observer
edited the sky condition to show BKN000; yet ASOS was recording CLR at that time. At 0614, when ASOS finally began dropping
the VIS- to 6SM- the observer reported 1/2SM.
At 0627, ASOS finally recorded a total obscuration, but as VV016. The duty observer was reporting VV002 at that time. The next
screen shot shows the raw data. ASOS did not record a "tap" under 1,000 feet until 0630. That was 27 minutes after the CWO sent a
SPECI including 1/4SM VV001 ! The obscuration eventually settled in at 160-230 feet, or a reportable value of 200 feet, according
to ASOS. Yet the CWO reported VV002 as early as 0628.
The human eye and brain, are just better and faster than ASOS, with regards to fog!
