Welcome to the Storm Prediction Center's "Hourly Mesoscale Analysis" page. This page features numerous technical fields that are commonly used at the SPC to determine the potential for severe thunderstorms and tornadoes. Many of the fields have been documented in AMS, NWA, and NWS publications. Others are currently being evaluated and tested for their utility.

The fields shown are calculated using a combination "real-time OA" and "model forecast" method. The SPC runs a 2-pass Barnes surface objective analysis around :05 after each hour, using the latest RUC forecast as a first guess. Next, the surface data is merged with the latest RUC forecast upper-air data to represent the best 3-dimensional atmospheric analysis available. Finally, each gridpoint is inputed into a sounding analysis rountine called "NSHARP" to calculate about 100 new fields.

The area depicted on this page will change from day to day, and will generally show a region where the SPC is closely monitoring for severe thunderstorm development. These fields are offered by the SPC to share the latest severe weather forecasting techniques with local forecasters.

These products are usually updated by :10 after each hour.
For a detailed explanation of the derived fields listed to the left, click here