Service Assessment: Nashville area devastating flood last Ma

[CrazyC83]

The NWS national office released a service assessment today on what happened after the devastating flood last spring in Tennessee (with Nashville definitely hardest hit). Clearly, it admits that the Nashville NWS office and the Ohio Valley River Forecast Center did not do a good job.

http://www.nws.noaa.gov/om/assessments/ ... ooding.pdf

My opinions on the findings:

1) Clearly there was a breakdown. Further sections explain such.

2) The RFC seemed to also break down at times. I wonder if those need to be subdivided since the Ohio Valley RFC covers a huge area?

3) Not sure what they mean by "federal agencies".

4) It's underway in other areas, but now is definitely the time to introduce GIS mapping nationwide.

5) During major disasters, other areas should be allowed to bring their data up.

6) Clearly that was another case of an office breakdown. In addition, special QPF runs should be made at any time in extraordinary situations for short-term forecasts.

7) The HPC was on the ball all along in my opinion. It looked pretty obvious a major flood situation was possible (although the magnitude was beyond anyone's expectations).

8) The observed rainfall on May 1 beyond the QPF shows that such cannot always be relied upon. An ideal forecast should have said "4 to 7 inches, with locally higher amounts up to 12 inches". Since major flooding is difficult to forecast, there should be strong watches in place ahead of time. Maybe a "PDS" Flood Watch?

9) That goes back to #1. They messed up badly there. Since most of the disaster was in the Nashville WFO, they should have been on the ball there when they were not.

10) It had become clear that crests were way over forecast in Nashville right from the start. They had a model say 54 feet (about 2 feet higher than the actual peak), so why they didn't play it safe and go by 54 is beyond me. Gaylord Entertainment was on the ball when they ignored the NWS and played their own forecast, which saved many lives when the Opryland Hotel was evacuated.

11) It is difficult to plan such extreme events, but the potential was there all along. Learn from other areas (like Cedar Rapids in 2008) since it can happen anywhere! EVERY WFO should be planning for such.

12) Similar to #11, everyone needs to be prepared for the worst possible scenarios to prevent such deadly breakdowns!

13) The AFD was quite weakly worded. Agreed with the recommendation.

14) During extreme events, they definitely need to work together and possibly consult other areas, especially those with experience in such events. They should have co-ordinated with NWS Peachtree City, NWS Des Moines or someone else with experience with extreme flood events.

15) That was unacceptable right there. A Special Update should have been issued immediately. During major floods, updates should be more frequent (like every 2 hours) with special updates when major changes occur.

16) Agreed there. That goes back to the co-ordination with offices that have experience with extreme floods, and everyone else should be prepared for such as well.

17) Also agreed. In times of crisis, they have to use every available tool, and even the general public could get involved as well.

Some Best Practices were also mentioned. It was very well handled by the SPC (although the PDS Tornado Watch on the morning of May 2 was probably overkill), the Southern Regional headquarters and the other offices.