Forecast verification updated 8:00pm EST - 22 Feb 2011
The main verification there we will be looking at is the amount of precipitation that was predicted to fall within the 24 hour time frame of 12z on 20 Feb to 12z on 21 Feb 2011. The GFS and NAM models were used as forecasting tools, and the Stage 4 NCEP multi-sensor precipitation analysis was used to verify the total 24 hour accumulation values.
This image shows the 20 Feb 18z run of the GFS211 model. This is the total precipitation amounts for a 24 hour time period valid from 12z on the 20 to 12 z on the 21 of February. The Indianapolis metro area was forecasted to have around .75-1.00 inches(19.05-25.4 mm) of measurable precipitation within this timeframe.
This shows the NAM20 18z run for Feb 20 showed around .63-.83 inches(16-21.2 mm) of measureable precipitation for the Indianapolis metro area, and has higher amounts in the southern Indiana area.
This graphic is the NCEP Stage 4 model, which gives hourly multi-sensor precipitation analysis. The analysis is based off data directly from radar and rain gauge sensors/data. For a 24 hour accumulation, this shows the actual amount of precipitation valid from 12z on the 20 to 12 z on the 21 of February. For the Indianapolis metro area there was approximately 5-10 mm, which is around .3 to .4 inches of measurable precipitation. Indianapolis and points south did not recieve as much measurable precipitation as the previous NAM and GFS models had predicted.
today's forecast verification graphic was produced by Kate Demchak