The formula takes the latest
information from the National Weather Service and combines it with
a more detailed
source.
Accounted for are several weather parameters such as temperature,
precip intensity, precip type, chance precip and solar radiation.
The severity, timing and likelihood of these metrics are used to
gauge the probability of closed, delay, early release and on time.
Typically once per hour.
For the formula to work, it
needs to ignore the next 2 hours of weather information. You can
correct for this by adding the expected road snow accumulation over
the next two hours to the current street snow cover in the advanced
section.
When processing your search,
the site does its best to match your query with a location within
the United States. Sometimes this means the site will load the
wrong location. For best results, try using a zip code. If the site
was unable to find a location, it will default to New York, New
York.
Snow threshold refers
to the amount of side street snow cover that it typically takes to
disrupt school operations. Imagine the snow has accumulated right
before school and crews have not had time to start clearing.
Current side street snow cover refers to the average amount
of snow currently on side streets. Take measurements for best
results.
Each location is assigned a
snow threshold based on their coordinates. The minimum is 0.3” and
the maximum is 8” across all locations. These assignments are
general and may not accurately reflect every location. If you think
your location isn’t accurate, feel free to adjust.
Yes. Each snow threshold is
associated with a range of possible street clearing times that
activate when the formula thinks the storm will end. The average
spans non-linearly from over 24 hours at 0.1”, 6 hours at 4" and
2 hours at 8”+. This means if you set a high threshold and a
relatively high snow cover and school doesn’t begin for several
hours, the majority category will often be on time.
Other than no wintry weather
at all, the most likely reason for this is that the back end
weather forecast shows the potential for freezing rain. As of now,
a freezing rain threshold cannot be set and the formula assumes
that 0.01" ice accumulation is enough to disrupt school at any
location.
If school is delayed, then:
% closed=% closed % delay =% delay + % early r. + % on
time % on time=0% % early r.=0%
If school is canceled... then school is canceled.
If school is on time... then school is on time.
The website uses nws data
and sometimes they have outages. As of now, the hourly works
because of a backup source. A backup is being worked on for
weekly.
Mountainous areas. While
the formula attempts to correct for imperfect forecasts, weather
forecasts in these regions are often wrong beyond the formula
corrections. In addition, the pre-set threshold is most likely
inaccurate in these areas, so please set manually.
