1. Storm Surge Products John Cole Warning Coordination Meteorologist NWS Morehead City/Newport NC Acknowledgements: Jamie Rhome and Rick Knabb (NHC), Mark Willis (WFO MHX),

2. Outline SLOSH (MOM’s and MEOW’s) Operational SLOSH (Deterministic Runs) Probability Surge (P Surge) Surge Product Timeline

3. The Storm Surge Threat An abnormal rise in water generated by a storm, over and above the astronomical tide A temporary rise in sea level that, in effect, moves the coastline inland Caused primarily by force of wind blowing across water surface Contribution by low pressure within center of storm is minimal Influenced greatly by track, RMW, size, coastline characteristics.

5. MEOW’s and MOM’s Maximum Envelope of Water Composite of maximum storm surge heights at each grid cell using hypothetical hurricanes run with the same: –Category –Forward Speed –Landfall Direction –Initial Tide Levels Composite achieved by reviewing parallel tracks that make landfall at different locations Over 80 MEOWs have been generated for some basins Maximum of MEOWs Composite of the maximum storm surge height for all hurricanes of a given category Disregards forward speed, landfall direction, landfall location, etc. Only 5 MOMs per basin, i.e. one per storm category

6. CAT 3 MEOW SurgeInundation

7. SLOSH Tides

8. Maximum Storm Surge Potential for Cat 3 Storm (worst case scenario of all motions, sizes, etc) Little Washington: We have a Hurricane Problem.

9. Deterministic Runs and SLOSH SLOSH will be run approximately 36 hours prior to arrival of TS winds –Why only 36 hours? NHC track/intensity errors Run every 6 hours coinciding with full advisory package –Animated gifs –Still images of Envelope of High Water (EOHW) –Rexfiles –Shapefiles (GIS) Output placed on FTP site: –ftp.nhc.noaa.gov –www.nhc.noaa.gov/ftpwww.nhc.noaa.gov/ftp New SLOSH display program that incorporates GIS layer capabilities, the ability to show inundation (which will also be mentioned in the advisories), more control over fonts/colors, and better briefing capabilities.

10. Deterministic SLOSH Run Rmax=25 mi (forecast) Surge Based on NHC - 12 hr. Advisory

11. Actual Hurricane Track 30 mi. E of 12 hr. Advisory Forecast Track TRACK FORECAST ACTUAL TRACK 133 mph, 933 mb.

12. Rmax=40 mi Surge Based on NHC Storm Best Track

13. Probabilistic Storm Surge takes this error into account Use an ensemble of SLOSH runs to create probabilistic storm surge (p-surge) Atlas of pre-computed surge maps based on: –Different directions of motion –Different landfall locations –Different intensities –Different storm sizes –Different forward speeds Based on statistics of NHC error including: along track error (timing), cross track (location), intensity, and Rmax error.

14. PSURGE for IVAN Similar probabilities near Mobile Bay as around Pensacola

15. Beginning when the NHC issues a hurricane watch or warning for the continental US Available approx. 1-2 hours after the advisory release time When and Where is P-Surge Available? http://www.weather.gov/mdl/psurge/active.php P-Surge Available in 1 foot increments from 2 to 25 feet.

17. Thank you… More details and products available at: http://slosh.nws.noaa.gov/sloshPub/ (SLOSH)http://slosh.nws.noaa.gov/sloshPub/ www.hurricanes.gov (National Hurricane Center)www.hurricanes.gov www.weather.gov (NWS homepage )www.weather.gov John Cole 252-223-5122 ext 223 John.Cole@noaa.gov