# Presentation: 546622

## Hurricane Model Transitions to Operations at NCEP/EMC

*2005 IHC Conference, Jacksonville, FL*
- Robert  Tuleya, Weixing Shen,
- S. Gopalkrishnan, N. Surgi, and H.Pan

*JHT sponsored*

## Project Goals and Emphasis 

- EMC interested in upgrading the GFDL model through implementing GFS physics packages.
- Establish baseline of skill for WRF development
- Begin transition of Hurricane model from GFDL to WRF
*EMC, GFDL and URI collaborate and rely on one another for their respective areas of expertise*

## JHT tasks at EMC/NCEP

- Implement NOAH Land Surface model
- Install and Implement bulk microphysics packages into the GFDL model (Ferrier scheme)
-  Develop proto-type Hurricane WRF

## Coupled GFDL-LSM ran for ~30 historic cases and ~40 cases in 2004 with ocean couplingLSM coupled to GFDL leads to track degradation

- LSM worse

## Breakdown in ridge leads to increased anomalous northward movement of Jeanne in coupled GFDL-LSM

- heights too low

- GFDL moves Jeanne north!!

## Coupled GFDL-LSM appears to have more accurate thermal field ....but ???

- Improvements with LSM

## Installation & evaluation of bulk microphysics

- Code implemented with options for Ferrier or Lin schemes
- Several cases run
- Weaker storms
- Track degradation??
- High computational overhead
- Chose to increase GFDL resolution instead for 2005
- Run microphysics with new proposed high resolution model in parallel this season

## Development of the Hurricane WRF prototype System at EMC

- <date/time>

**Development of the Hurricane WRF prototype System at EMC**

- Design of the prototype system for HWRF
- 2004 preliminary HWRF forecasts
- Future plans

##       Hurricane Forecast System

- Storm information

- Model integration

- Model hurricane output products

-       Hurricane Forecast System

- Wrf si
- Wrf real
- Wrf model

- NHC storm message
- Position domain

- Synoptic fields for many variables
- Create file for track, intensity, etc

## HWRF features

- Uses WRF NMM dynamic core
- Initial condition options
- Current or historical cases
- GFS or GFDL initial conditions
- HWRF forecast/analysis cycle
- Physics options
- Eta model physics
- Transitioning to GFDL(GFS) physics

## GFS..............GFDL

## Additional HWRF features

- Requires grib input of initial conditions
-   replaced by analysis cycle
- Uses wrf binary and netcdf files
- Rotated-E NMM grid ... a bit awkward
- WRF SI...a slow, big, generalized interpolator
- Netcdf WRF output on native model grid
- HWRF post
- Uses EMC post utilities to interpolate to ‘A’ grid on pressure levels
- Creates synoptic fields at ~ model resolution
- EMC post output grids in grib format
- Creates ‘atcf_unix’ file to track storm location, intensity, and extent
- More output products to be developed
- Tracker software to create storm temporal forecast information
- May be part of model run or done in post in/out of house
- ‘tracker’ becoming a misnomer since intensity and storm structure also analyzed
- Usually requires temporal data near surface, 850mb and 500mb
- Usually multi-variable analysis...vorticity, U, V, T, etc.
- EMC uses scheme by Tim Marchok (GFDL)

## 2004 preliminary HWRF forecasts

- Run at least one storm per day (00utc)
- >120 uniform resolution cases
- ~20km resolution with 42 GFDL levels
- System found to be quite robust with few if any non-user failures
- Started with eta-physics, GFS initial condition
- A work in progress !!

## Preliminary HWRF results 

## HWRF Track Verification

## HWRF Agenda

- An active start for HWRF !
- Migrate to improved initial condition
- Migrate to GFDL-type physics + microphysics
- Begin forecast verification & analysis
- Initiate moveable, nested HWRF
- Upcoming season ..nested runs
- Upcoming season ... Forecast/analysis cycle

## HWRF idealized nested caseparent              nested

## Additional HWRF products      Sfc Wind & Rainfall Requires wrf output at shorter time intervalPuts strains on distributed software designNew products needed??

## Summary & PlansGFDL..............HWRF

- Collaborate with GDFL and URI to upgrade GFDL physics... microphysics, lsm, surface layer
- Can physics upgrades be made without degrading track while improving intensity and structure ???

- Upgrade and evaluate physics....surface layer, lsm, microphysics, radiation
- Continue parallel HWRF runs.... forecast/analysis cycle ....initiate moveable, nested HWRF
- Compare with GFDL and other models