1. Warm Season Flash Flood Detection Performance at WFO Binghamton
Mike Evans
NOAA / NWS Binghamton, NY
NROW 2015

2. Previous local study on severe weather predictability

3. Method for examining flash flood predictability
Examine Hazardous Weather Outlooks issued on the midnight shift (April – October, ).
Compare to occurrence of flash flooding during the following 24 hours.
A detected event – Heavy rain or flooding in the HWO, at least one flash flood report.
A missed event – No mention of heavy rain or flooding in the HWO, at least one flash flood report.
A false alarm – Flooding mentioned in the HWO, no flash flood reports
Sounding parameters from the RAP (BUFKITS) composites from the NARR

4. POD and FAR for flash flooding (2011-2014)
27 out of 42 events were “detected”
27 out of 49 “warnings” were false alarms

5. POD and FAR by month
Weak forcing?
Tropical events

6. Number of floods

7. Number of severe events

8. 0-3 km shear

9. MBE Vectors

10. Precipitable water

11. Sea-level pressure anomalies
Detected
Missed
False Alarms

12. 500 mb height anomalies
Detected
Missed
False alarms

13. 850 mb total wind anamolies
Detected
Missed
False Alarm

14. 850 mb meridional wind anomalies
Detected
Missed
False alarm

15. 250 mb total wind anomaly
Detected
Missed
False alarm

16. Precipitable water anomaly
Detected
Missed
False alarm

17. Lifted index anomalies
Detected
Missed
False Alarm

18. Summary
Flash flood forecasting in central NY / northeast Pa is often difficult.
Sounding parameters associated with detected vs. missed vs. false alarms are often similar.
Composites for detected vs. missed vs. false alarms are similar.
Case studies indicate multiple patterns favorable for flash flooding.
Antecedent conditions are critical.