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
Tornado index: Significant tornado parameter (effective layer) (no units)
An index SPC combines from instability, cloud-base height, shear and low-level spin. Above 1 the environment has looked like those of strong tornadoes. It is not a tornado forecast and says nothing where storms do not form.
The technical reading
Effective-layer STP, with CIN: (MLCAPE / 1500 J/kg) × ((2000 − MLLCL) / 1000 m) × (effective SRH / 150 m²/s²) × (effective bulk shear / 20 m/s) × ((200 + MLCIN) / 150 J/kg), with SPC’s limits, dimensionless. Most significant tornadoes have occurred with values above 1 in an environment with 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
Northern Mariana Islands briefing
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.