SPC storm ingredients: feeds current
SPC storm ingredients: Feed current; checked .
Checked means retrieved, not newly issued. Each graphic retains its issue, observation, initialization or valid time. Site publishing status is separate.
Storm ingredients: SPC’s hourly analysis
Shear: Effective bulk shear (kt)
How much the wind changes through the part of the atmosphere a storm draws on. More of it lets storms organise and last; with instability, it is what separates brief storms from long-lived ones.
The technical reading
The bulk wind difference across the lower half of the effective inflow layer’s storm depth, in knots, drawn only where an effective inflow layer exists. About 25–40 kt supports organised storms, 40 kt and more supercells.
An ingredient, not a forecast: SPC’s analysis of the hour, from observations and a short-range model’s first guess. No one value is a warning or an outcome; storms need several ingredients together, and something to start them.
SPC mesoanalysis checked · Data: NOAA/SPC
Not an official warning service. Warnings and watches are the National Weather Service’s, outlooks and reports the Storm Prediction Center’s and the Weather Prediction Center’s (Data: NOAA/NWS, NOAA/SPC, NOAA/WPC). When a warning is issued for you, act on it, and use weather.gov or a NOAA Weather Radio for where you are.