1. Hurricane Matthew Anatomy of a Flood
Impacts and Forecasts
Bill Sammler
Warning Coordination Meteorologist
National Weather Service – Wakefield, VA

2. Overview Third Significant Rainfall Event in 6 weeks
Interaction with Cold Front Enhanced Winds near the coast (SE VA/NE NC)
Matthew Not Truly Tropical
Storm Surge/Beach Erosion a Problem
Track Forecasts Were As Not Helpful in Assessing Potential Impacts As They Normally Are

3. Tropical Cyclone Rainfall
Hurricane Irene – 2011 vs. Floyd
Track

4. Tropical Cyclone Rainfall
Hurricane Irene – 2011 vs. Isabel
Track

5. Hurricane Matthew Track

6. Hurricane Matthew Rainfall
Track

7. The Anatomy of the Flood

8. Salient Points
Widespread Major Floods Rarely Result from a Single Heavy Rain Event
Antecedent Moisture Conditions Play a Critical Role
Heavy Rainfall in September Made Matthew’s Flooding Possible
Rainfall Pattern Resulted in Unusual Impacts

9. September Rainfall

10. Hurricane Matthew Rainfall

11. Max Rainfall September through Matthew
Where Does the Water Go?
Max Rainfall September through Matthew

12. Tidal vs. River Graphs

13. Tidal vs. River Graphs

14. 6 Days above “record” stage!!
Tidal vs. River Graphs
South Mills, NC - 9/15 to 10/18
Record Stage
6 Days above “record” stage!!

15. Now for a Discussion of the Impacts
The End!!
Now for a Discussion of the Impacts