1. Advanced Hurricane Prediction A plan for research and development
Naomi Surgi
February, 2005

2. Requirements Process Societal Impacts:
More people living along coastal areas – takes longer to evacuate
Evacuations are costly: ~$1M per mile of coastline evacuated
Evacuation numbers depend on hurricane size and intensity
More hurricane related fatalities now due to inland flooding

3. Stakeholder Requirements
Improved track forecast skill – where and when?
Extend track forecasts out to 5 days
Improved hurricane intensity forecasts
intensity at landfall – how strong?
onset of gale force winds at coastline (structure) – how big & when?
Skillful heavy rainfall forecasts out to 3 days in advance

4. Operational TC Forecast Issues:
Continued advancement of TC track forecasts
Improved TC intensity prediction (genesis and rapid intensification)
Improved prediction of TC surface wind distribution (structure)
Improved rainfall forecasts
TC waves, storm surge

5. TPC Atlantic 72-hr Track Forecast Errors
With the exception of “erratically” moving storms, while hurricane track prediction has shown remarkable progress, skill in predicting intensity/ structure changes is still poor. It is expected that high resolution, advanced NWP modeling systems may continue to improve track as well as intensity, structure predictions. Hurricane WRF is the next step towards this goal.

7. Lowest track errors on record for GFS, GFDL models and TPC!

8. How NOAA Improved Track Forecasts
Three components of modeling system:
HIGH QUALITY OBSERVATIONS (large scale environment surrounding hurricane, e.g. satellite, aircraft)
MADE BETTER USE OF OBSERVATIONS IN HURRICANE MODELS (advances in data assimilation)
IMPROVED HURRICANE MODELS (improved numerical techniques and representation of physical processes)

9. Advanced Data Platforms for Hurricanes
Environment: (Winds, Moisture, Temperature) – to define steering currents
Satellite: Advanced Satellite Instruments
(AMSU, GOES, NPOESS etc.)
In-situ: Aircraft (dropsondes)

10. NCEP Global Forecast System 6 hr Forecast and WV Imagery

11. Jung and
Zapotocny
JCSDA
Funded by
NPOESS IPO
Satellite data
~ 10-15% impact

12. Synoptic Surveillance Pattern

13. Impact Of Dropsondes On NCEP Global Model Track Forecasts
Note: Improved skill at all forecast times in 2002 and 2003

14. Intensity Guidance
Most skill

15. Charley deepened
From 964 mb to 941 mb
in 4 h 35 min near
landfall – NIGHTMARE!

16. Science Issues to address Intensity/Structure
ENVIRONMENTAL FORCING
“good vs. bad” trough interactions
SST changes (including ocean subsurface)
CONVECTIVE SCALE PROCESSES
total rainfall – organization of convection, eyewall vs. Stratiform
MICROPHYSICS – LIQUID VS. ICE
INNER CORE REGION
scale interaction – feedback between vortex dynamics, convective physics and environment
triggering and adjustment processes – eyewall replacement cycles, eyewall mixing

17. Science Issues – con’t
AIR SEA INTERACTION: OCEANIC/ATMOSPHERE BOUNDARY LAYER)
Air sea fluxes under disturbed conditions (sea spray)
Turbulence and subgrid scale mixing
Coupled atm/ocean model; coupled wind-wave model
UPPER OCEAN PROCESSES
SST changes – depth of warm layer (accounts for turbulent mixing, horizontal advection) e.g. Gulf Stream and loop currents, warm core eddies, cold wakes
LAND SURFACE PROCESSES
PBL fluxes – storm structure -- coupling to hydrologic processes

18. To advance TRACK forecasts AND improve INTENSITY, STRUCTURE and RAIN Forecasts:
Need high quality hurricane core* and environmental observations
Need advanced data assimilation techniques for environment and hurricane core
Need advanced modeling system
Need a “disciplined” approach for transition from research to operations, e.g. JHT, JCSDA
* critical observations for intensity/structure and rain problem

19. Advanced Observation Platforms for Hurricanes
Environment (Winds, Moisture, Temp.)
In-situ: G-IV, UAV’s, Driftsondes
Satellite: ADVANCED MICROWAVE INSTRUMENTS
Hurricane Core (Winds from 12 km to surface)
G-IV, WP-3D airborne Doppler radars
88-D Level II data
Upper Ocean (SST’s, wave height, mixed layer info)
AXBTs, Altimeter, ARGOS, Current Meter, Buoys

20. Required Data Assimilation Development
Advanced Data Assimilation Techniques
Environmental flow – in progress (some success)
Hurricane Interior substantial R&D necessary*
Ocean data assimilation – new effort (GODAS)
* EMC is developing scale-dependent covariances

21. Hurricane WRF (HWRF) Prediction System
Community based next generation hurricane prediction system
Will replace the GFDL in 2007
Coupled air-sea-land prediction system
Advanced data assimilation for hurricane vortex
Advanced physics for high resolution
Land surface coupled to hydrology/inundation
Nested wave prediction
Coupling to dynamic storm surge (in planning)

22. Preliminary Test HWRF physics
TRANSITIONING TO HURRICANE WRF
Mesoscale Data Assimilation for Hurricane Core
GFDL frozen
HWRF T&E
Continue upgrades
GFDL
Begin Physics Upgrades
Transition to HWRF
HWRF Operational
MM5
HWRF
T&E
Preliminary Test HWRF physics
HWRF
Begin R&D

23. Pre-Implementation Strategy for HWRF
INCREASE RESOLUTION
UPGRADE GFDL PHYSICS WITH GFS PHYSICS
IMPLEMENT MICROPHYSICS, SFC. PHYSICS
PUT PHYSICS IN WRF FRAMEWORK
MIGRATE ALL PHYSICS TO NMM, e.g. HWRF
CARRY OUT TEST & EVALUATION ON UPGRADED GFDL SYSTEM (GFDL FROZEN ’05-06)
PERFORM EXTENSIVE COMPARISONS BETWEEN GFDL AND HWRF FOR MULTIPLE SEASONS AND STORMS

24. DEVELOPMENT OF THE HWRF SYSTEM
Movable, nested grid (configuration, domain)
Advancement of physics (wheel of pain)
Initialization (development of DA for hurricane vortex) (LONG TERM EFFORT)
Coupling to HYCOM
Coupling to WAVEWATCH III (+ multi-scale model)
Coupling to LSM
Development/Upgrade of hurricane verification system (PPT, STRUCTURE)
Coupling to storm surge-wave coupled model (planning stage)
HWRF ensembles

25. “THE PHYSICS WHEEL OF PAIN”
Compliments of Dr. Jaiyu Zhou (NOAA/OST)
Direct Physical
Interaction of Clouds
- Hydrometeor type (phase)
- Cloud optical properties
- Cloud overlap (merging Cu, grid-scale cloudiness)
- Cloud fractions
- Precipitation
- Sfc energy fluxes
Convection, PBL evolution, precipitation
Radiation
Cu Scheme
Sfc & PBL
Grid Scale Microphysics

26. Hurricane-Wave-Ocean-Surge-Inundation Coupled Models HWRF
NCEP
Atmosphere and Ocean
NOS
land and coastal waters
HWRF
NOAH LSM
runoff
High resolution
Coastal, Bay &
Estuarine
hydrodynamic model
surge
inundation
fluxes
Atmosphere/oceanic Boundary Layer
radiative
fluxes
winds
air temp.
other fluxes
elevations
currents
3D salinities
temperatures
SST
currents
HYCOM
3D ocean circulation
model
wave
spectra
WAVEWATCH III
Spectral wave model
wave fluxes

27. HYCOM Expt – Hurricane Isabel
MODEL:
HYCOM Mercator North Atlantic 1/12 degrees (∆x ≈ 7 km).
26 vertical coordinates.
Vertical viscosity and mixing: GISS.
FORCING: 6-h NCEP (GFS analysis).
INITIAL CONDITIONS: from near-real time North Atlantic system (NRL & RSMAS) (O.M. Smedstad).
PERIOD: Sept. 3-30, 2003
Put here the region of analysis and mention that the two sings are different from NRF

28. SSH and cross section positioning
∆H~30 cm

29. Temperature cross sections for Sept 11, 15-21, 30
What are they looking at at position

30. GFDL Coupled Model

31. C-BLAST BUOYS DURING FRANCES

32. Hurricane Frances – impact of coupling
Blue- GFDL operational coupled model
Red- GFDL uncoupled model

33. The Future Deep ocean model resolution dictated by GFS model
Higher coastal model resolution dictated by model economy
Highest model resolution in areas of special interest
Hurricane nests moving with storm(s) like GFDL and HWRF

34. Technology Infusion Joint Hurricane Testbed Mission Statement:
The mission of the JHT is to transfer more rapidly and smoothly new technology, research results, observational and model advances into improved tropical cyclone analyses and prediction at operational hurricane forecast centers.