PSL Map Room Weather Products
NCEP (NMC) ENSEMBLE FORECAST PRODUCTS
FAQ: Frequently Asked Questions
Question:Can you explain the difference between the 850 mb temp mean anomaly and the 850 mb mean normalized anomaly?
Answer:The 850 mb Temp Anomalies are calculated as follows:
- The ensemble mean 850 mb temp anomaly is calculated by subtracting a 1979-95 climatology from the forecast data at a particular forecast hour.
- This is the mean 850 mb temp anomaly which is then plotted.
- The ensemble mean is calculated as in step one above.
- The ensemble mean anomaly is then divided by a 1979-95 standard deviation climatology of the 850 mb temperature. This is the mean normalized anomaly which is then plotted.