For snow plow, salting and ice-control contractors, and the property managers who pay them
How much snow fell in that storm, and when?
Per-storm billing needs a record both sides can check. Enter a property address and up to a month of dates. AtmosDays finds every storm with snow, sleet or freezing rain, and for each one shows when it started and stopped, how much snow people measured nearby, ice, refreeze and blowing snow afterward, and the National Weather Service winter warnings for the address. Download one PDF per storm to attach to an invoice, or one for the month, plus a spreadsheet.
Start, stop and how long
When snow, sleet or freezing rain started and stopped at the nearest airport, in local time, from the airport's own reports, word for word. Breaks under 6 hours count as one storm.
How much fell
Measured snowfall from NOAA daily records (airports, co-op observers, CoCoRaHS volunteers) and the snowfall reports the National Weather Service collects, with the distance to each, the nearest and the range.
What came after
Ice build-up, the low in the 24 hours after the storm (refreeze), hours of blowing and drifting snow, and the winter warnings and advisories for the address.
Your trigger, marked
Pick your contract's trigger (for example 2 inches) and each storm shows whether its nearest measurement reached it, and how many of the measurements nearby did. AtmosDays marks the weather against the number you chose; whether a storm is billable is for your contract to say.
Why links to the source matter
Snow varies across a city, and a property manager may question a bill. Each record names the airport and every observer it used, how far each is from the property, and links to the original NOAA and National Weather Service records for the same dates. Times are in the property's local time.
What it isn't
AtmosDays documents the weather only. It does not measure snow at the property, track trucks or crews, or decide what was plowed, salted or billable. The airport and the observers can be miles away. NOAA posts daily records a few days late, so a record made the morning after a storm may fill in more a few days later. Records are public data summaries, not expert testimony; NOAA's National Centers for Environmental Information can provide certified copies of station records.
Where the data comes from
Airport weather reports (METAR) from the Iowa Environmental Mesonet archive at Iowa State University; NOAA NCEI daily station records (GHCN-Daily), which include CoCoRaHS volunteer observers; National Weather Service local storm reports and winter warnings from the Iowa Environmental Mesonet archive. All public.
Price
New accounts get 14 days of Pro, then 30 days of Plus, no card needed. Snow storm records come with Plus ($19 a month, 40 PDFs) and Pro ($39 a month, 150 PDFs). Looking at storms on screen is free; each PDF counts as one. Extra PDFs are 25 for $15.