HINEYCAST

While Stavrocast predicts future rainfall, Hineycast looks to the rear. Its purpose is to quickly map and chart how much rain has fallen in recent hours, days, months, or years. The map shows high definition rainfall estimates in recent hours or days, and the chart allows you to look further back.

Hineycast draws on two primary data sources:

• The accumulation chart uses gridded climate data from the PRISM Climate Group (via the ACIS API). It plots this year's observed daily precipitation as a running total against a 30-year daily normal (1991–2020) for the same spot. Because PRISM publishes about a day behind, the most recent day or two are filled with NRCC Interpolated (Grid 1) estimates from NOAA's Northeast Regional Climate Center (the dotted “provisional” tail on the chart), and are replaced by PRISM once it publishes.
• The map shows Quantitative Precipitation Estimates (QPE) produced by NOAA's 13 NWS River Forecast Centers. Each center blends 88D radar with automated and manual rain-gauge reports and satellite estimates, and the regional grids are mosaicked into one national product. Because the radar field is bias-corrected against real gauges, it beats radar alone. One quirk: the 1-hour through 24-hour layers refresh hourly, but the 2-day and 3-day totals are cut once a day at 12Z — so a multi-day total can end almost a full day before the shorter ones, and can even read lower than the 24-hour total. The line beneath the map states the exact window each total covers.

A few caveats apply to both sources. PRISM and RFC QPE are both ~4km gridded products interpolated from a limited network of ground stations, so a highly localized downpour (or dry pocket) that falls between stations can be smoothed out or missed entirely. Coverage is the contiguous United States for the chart, and the lower 48 plus Alaska and Puerto Rico for the map; data for the most recent days is provisional and subject to revision.