# Presentation: 657322

-              Naomi Surgi

- NCEP/Environmental Modeling Center

**WHERE  AMERICA’S  CLIMATE  AND  WEATHER  SERVICES  BEGIN**

- Advanced Hurricane Modeling
- at EMC:   The HWRF

**                      ****Hurricane Program Leader **

**Notes:**
Some of the season highlights include
 12 tropical storms of which 8 became hurricanes
 5 major hurricanes, all Category 4...an all-time record
 5 year total of 41 hurricanes...an all-time record
 3 hurricanes (Bret, Floyd, Irene) and 2 tropical storms (Dennis and Harvey) made landfall in the mainland U.S.

## Overview

**HWRF implementation strategy**
**HWRF development**
**Results:  HWRF vs. GFDL**
**HWRF for the future**

## HWRF

**    ****02-03**                **03-04           05                06                     07**

-       **Mesoscale Data Assimilation for Hurricane Core**

**         ****Prelim. Testing grid, hurricane physics**

**HWRF**

**Final GFDL upgrades      **
**   **

**          ****TRANSITIONING TO HURRICANE WRF**

**Begin R&D**

**Continue     upgrades**

**T&E**

**Begin Physics upgrades**

** ****IOC**

**GFDL**

## Pre-Implementation Strategy for  HWRF

- <date/time>

_**Pre-Implementation Strategy for  HWRF**_
**FOR THE HWRF OPERATIONAL IMPLEMENTATION:**_**   **_
_** **__**HWRF MUST PERFORM AT LEAST AS WELL AS THE GFDL MODEL**_
**  **_**UPGRADE  GFDL SYSTEM / Establish GFDL as benchmark**_
**  ****-  ****UPGRADE GFDL PHYSICS WITH GFS PHYSICS ****(’04)****  **
**           ****(GFS  SAS and PBL schemes)**
**  ****-   INCREASE RESOLUTION  ****(’05)****  **
**           ****(inner nest from 18 to 9km.)  **
**  ****-  IMPLEMENT EMC Ferrier MICROPHYSICS to GFDL **
**  ****-  Upgrade AIR-SEA PHYSICS  (reduced drag)                ****‘06**
**  ****-  IMPROVE OCEAN INITIALIZATION**
**  **
** ****TRANSITION GFDL UPGRADES TO HWRF  **

##          HWRF Development

**CONDUCTED 25+  EXPERIMENTS,  e.g. 25 versions of the HWRF**
**Tested each upgrade (numerics, physics, coupling) for clean comparisons  -  ****comprehensive testing >200 cases**
**Next 2-3 weeks:  FINALIZE HWRF (ocean coupling for hi-res nest,  vortex initialization, cumulus momentum mixing)**
**PERFORM EXTENSIVE COMPARISONS BETWEEN GFDL AND HWRF FOR MULTIPLE SEASONS AND STORMS  **
** ****(‘04, ’05, ’06)**

## Other upgrades for ‘07

_**Other upgrades for ‘07**_
**GFDL T&E already underway for new global system:  **
**GFS (Hybrid) – 382/64L;  SIGMA/P  (in trop)**
**New Data Assimilation System, e.g. GRID POINT STATISTICAL INTERPOLATION  (GSI)  **

##           THE HURRICANE  WRF (HWRF) 

**          **_**THE HURRICANE  WRF (HWRF) **_
**                   **_**PREDICTION  SYSTEM**_
**  ****H****WRF began development 2002  **
**  ****Operational this season;  GFDL will run in parallel**
**  ****Non-hydrostatic hurricane model; movable, inner nest**
**  ****Coupled air-sea-land prediction system**
** ****Advanced data assimilation for hurricane core (make use of airborne doppler radar obs and land based radar)**

## HWRF continued.....  

**   ****Assimilation of ocean observations**
**  ****Advanced physics for high resolution and air-sea**
** ****Coupling with wave model**
** ****Land surface coupled to hydrology/inundation**
** ****Coupling with dynamic storm surge**

## HWRF SYSTEM 

**High resolution **
**Coastal, Bay & **
**Estuarine **
**hydrodynamic model**

**Atmosphere/oceanic Boundary Layer**

**HYCOM**
**3D ocean circulation**
**model**

**WAVEWATCH III**
**Spectral wave model**

**NOAH LSM**

**NOS**
**land and coastal waters**

**NCEP/****Environmental Modeling Center**
**Atmosphere- Ocean-Wave-Land**

**runoff**

**fluxes**

- wave fluxes

-                    wave
-                  spectra

- winds
- air temp.

- SST
- currents

- elevations
-        currents
- 3D   salinities
-         temperatures

- other fluxes

**surge**
**inundation**

- radiative
- fluxes

**HWRF SYSTEM **

**NMM hurricane atmosphere**

## THE  Coupled HWRF SYSTEM      

_**THE  Coupled HWRF SYSTEM      **_
_**2007:    **__**Initial Operating Capability**_
**  ****Movable, 2- way nested grid   (9km; 27km/42L;  ~75X75)**
**  ****Advanced Physics (atmosphere-waves-ocean)  **
**  ****Coupled to Ocean  (POM)  **
**  ****Advanced vortex initialization (3-D var)**** – parallel run w/radar data**
**  ****Multi-grid wave model - (static multi-grids, some shallow water physics)   **

**                       **

## Wave model development

**’****07 -****  operational implementation of multi-grid wave model with static grids and initial surf-zone physics.**
**‘****08**** - development of re-locatable grids.**
**‘****08+ - **** incorporation in HWRF with relocatable grids, advanced stress computation and expanded shallow water physics.**

## The multi-grid wave model

**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**

**This is the 2003 vision; In 2007 areas will mimic areas of NWS forecast responsibility**

## Wave model resolution in minutes for operational implementation in FY2007-Q4, mirroring WFO NDFD responsibilities.

**Wave model resolution in minutes for operational implementation in FY2007-Q4, mirroring WFO NDFD responsibilities.**

## HWRF Results–  4X daily throughout ’04, ’05, ‘06 hurricane season for all storms – system very stable and reliable 

**Over two hundred cases with prelimary HWRF system **
**Results from a subset of these**

## HWRF (coupled- parent domain)

**HWRF (coupled- parent domain)**

**TRACK**

## Intensity

**Intensity**

## HWRF

**HWRF**
**DENNIS**

## HURRICANE EMILY 

**HURRICANE EMILY **

## HWRF 

**HWRF **
**Hurricane **
**Katrina**

## HWRF 

**HWRF **
**Hurricane Wilma**

## Forecast Spread: Katrina 2005

- HWRF

- GFDL

## Forecast Spread: Wilma 2005

- HWRF

- GFDL

## Forecast Spread: Ernesto 2006

**HWRF**

**GFDL**

## WHAT’s NEXT ????

## THE  Coupled HWRF SYSTEM      

_**THE  Coupled HWRF SYSTEM      **_
**Couple to HYCOM, WAVEWATCH III    (’08)**
**Improve data assimilation of airborne and land based radars for hurricane core initialization (continuing)**
**        **
**Advance Physics – sea spray (’08-’09)  (collaboration with ESRL, URI) , improved stress, cloud/radiation**
**Waves up to the coastline (Non-linear interactions, surf-  zone shallow-water physics)   (collaboration w/USA, HRD) **
** **
**Land surface coupling to streamflow and inundation  **
**       ****(collaboration w/USA, HRD)   **
**Development of HWRF ensembles  **
**Coupling to dynamic storm surge model  (w/NOS)**

##    Atm/ocean boundary layer:  wave drag,   enthalpy fluxes  (sea spray)      

**    ****08                  09**                10                 11                     12

** ****Radial vel./ reflectivity        Adv. DA**
**                                                ****SDBE**

**Mesoscale Data**** ****Assimilation for Hurricane Core**

**  **

** **

**  **

**          ****Advancing  HURRICANE System**

- Atm. Model  physics and resolution upgrades (continuous)

**   ****Atm/ocean boundary layer:  wave drag,   enthalpy fluxes  (sea spray)      **
**     ****Microphysics, Radiation  **

**Incr. resolution    **
**   ****(6km/>64L)****   **

** **

**   ****Waves****:   surf-zone physics           implement  **
**    ****Ocean:****  4km.    - continuous upgrades in  RTOFS **

**  **
**ENSEMBLES???**

**     ****Prototype **
**     ****Ens w/Navy**

**    ****Land coupling****                              Implement****     **

**Storm surge???**

##  Development of Advanced Probabilistic Guidance   for Intensity/structure  (in progress)

** ****HWRF Ensembles****     **
**    ****Configuration **
**        ****initial conditions, resolution, members???**
**   ****OR**
**     ****Use of multi model ensembles (MME)  **
**     ****(Explore shared MME w/Navy -  Demo ’07, ’08...) **
**(Value of very hi-resolution deterministic forecasts vs. ensembles?)   ****(LES studies in progress - PSU)**

## Aircraft in Hurricanes

**Need to develop flight strategies for GIV and P-3’s for core missions**
**Two mission profiles:     Environment & Core**
**Observations:                  GPS, Radar, AXBT’s**
**Large**** increase in request for flight hours for core missions – ****HWRF requirement 4X/day for assimilation problem**** **
**Working on operational requirement for AXBT’s**

## THANK YOU 

**FOR  YOUR**
**ATTENTION... **

**Many thanks:  Gopal S, Qingfu, Bob T,  Bill O, Vijay T, Young-Kwon,  Isaac G.,  Morris B**
** ****Scott Carter for ****$$$$$$$$   ****     **

## Extra slides

## Slide 31

## Slide 32

## Slide 33

## HWRF

**HWRF**
**DENNIS**

## HYCOM  T&E - Dennis

**HYCOM  T&E - Dennis**

## HURRICANE EMILY 

**HURRICANE EMILY **

## HWRF 

**HWRF **
**Hurricane **
**Katrina**

## HYCOM T&E     Katrina

**HYCOM T&E     Katrina**

## Slide 39

## Slide 40

## Wavewatch model at Landfall

- The eye positions are nearly identical, but the difference in spatial scales has a huge impact on the coastal wind fields.

**Driven by GFS winds**

**Driven by GFDL/GFS winds**

## Two Weather Research and Forecasting (WRF) Model dynamical cores:   (noted here to avoid further WRF confusion)  

● 	NCEP Nonhydrostatic Mesoscale Model (NMM)
		Janjic, Gerrity and Nickovic, 2001, MWR		Janjic, 2003, MAP
		Black, Tucillo, Parallelization, Optimization, WRF standards

● 	NCAR Explicit Mass Core (EMC or ARM)
		Klemp, Skamarock, Dudhia, 2000, Online
		Wicker and Skamarock, 2002, MWR
		Klemp, Skamarock, Fuhrer, 2003, MWR
		Michalakes, 2002  

- ● 	_**NCEP Nonhydrostatic Mesoscale Model (NMM)**_
- 		**Janjic, Gerrity and Nickovic, 2001, *****MWR*****	****	****Janjic, 2003, *****MAP***
**	****	****Black, Tucillo, Parallelization, Optimization, WRF standards**
- ● 	_**NCAR Explicit Mass Core (EMC or ARM)**_
- 		**Klemp, Skamarock, Dudhia, 2000, Online**
**	****	****Wicker and Skamarock, 2002, *****MWR***
**	****	****Klemp, Skamarock, Fuhrer, 2003, *****MWR***
**	****	****Michalakes, 2002  **

## Single digit resolutions affordable for NWP

●	Nonhydrostatic mesoscale NWP models needed.

●	How do we build a true mesoscale NWP model?
	-	Extend a cloud model to synoptic scales and beyond?

	-	Build on NWP experience and extend NWP models to mesoscales?

●	What should a successful nonhydrostatic mesoscale NWP model be able to do?
	-	Reproduce classical nonhydrostatic solutions at high resolutions;
	-	Competitive with mature NWP models at transitional resolutions. 

- ●	**Nonhydrostatic mesoscale NWP models needed.**
- ●	**How do we build a true mesoscale NWP model?**
- 	-	Extend a cloud model to synoptic scales and beyond?
- 	-	Build on NWP experience and extend NWP models to mesoscales?
- ●	**What should a successful nonhydrostatic mesoscale NWP model be able to do?**
- 	-	Reproduce classical nonhydrostatic solutions at high resolutions;
- 	-	Competitive with mature NWP models at transitional resolutions.

## Cloud models, conventional approach 

- (**Klemp and Wilhelmson, 1978a,b, ) MM5,**
** ****DWD LM, Nonhydrostatic Eta (Gallus and Rancic, 1996, QJ)...**

**Pressure tendency Eq.**

**Thermodynamic Eq. **
**sigma-z (Gal-Chen, Somerville, MWR), z-sigma-z hybrid (**
- ●	**Often nonconservative, higher order, discretization**
**●****	****NWP dealing with much larger range of spatial and temporal scales**
**●****	****Specific difficulties:**
**	****-****	****How to introduce diabatic forcing?**
**	****-****	****3D divergence typically does not sum-up to zero, mass (etc.) conservation?**
**	****-****	****Rigid lid on top**
**	****-****	****Computational boundary condition on top in NWP applications**

** ****Three Momentum  Eqns****	**

## The NCEP NMM
●	 Instead of extending cloud models to larger spatial and temporal scales, NMM built on experiences of NWP (Janjic et al., 2001; Janjic, 2003), i.e.,
       -	Relaxing the hydrostatic approximation, while
	-	Using modeling principles (Janjic, 1977, 1979, 1984)
		proven in NWP and regional climate applications.

	Nonhydrostatic equations split into two parts:
	-	Hydrostatic part, except for higher order terms due to vertical    acceleration, 
	-	The part that allows computation of the corrections in the first part,
	-	Convenient for unified systems

**●****	**** ****Instead ****of extending cloud models to larger spatial and temporal scales****, NMM built on experiences of NWP ****(Janjic et al., 2001; Janjic, 2003), i.e.,**
**       ****-****	****Relaxing the hydrostatic approximation, while**
**	****-****	****Using modeling principles (Janjic, 1977, 1979, 1984)**
**	****	****proven in NWP and regional climate applications.**
**	****Nonhydrostatic equations split into two parts:**
**	****-****	****Hydrostatic part, except for higher order terms due to vertical    acceleration, **
**	****-****	****The part that allows computation of the corrections in the first part,**
**	****-****	****Convenient for unified systems**

##  Continued.....
●	No linearizations or additional approximations required, fully compressible system
●	The nonhydrostatic effects as an add–on nonhydrostatic module:
	-	Easy comparison of hydrostatic and nonhydrostatic solutions;
	-	Reduced computational effort at lower resolutions.
●	Pressure based vertical coordinate.
	-	Exact mass (etc.) conservation,
	-	Nondivergent flow on coordinate surfaces (often forgotten),
	-	No problems with weak stability,
	-	Sigma-z system problems shifted to stratosphere and upper troposphere.
●	 “Competitive with mature hydrostatic NWP models ...” 

- ●	No linearizations or additional approximations required, fully compressible system
- ●	The nonhydrostatic effects as an add–on nonhydrostatic module:
- 	-	Easy comparison of hydrostatic and nonhydrostatic solutions;
- 	-	Reduced computational effort at lower resolutions.
- ●	Pressure based vertical coordinate.
- 	-	Exact mass (etc.) conservation,
- 	-	Nondivergent flow on coordinate surfaces (often forgotten),
- 	-	No problems with weak stability,
- 	-	Sigma-z system problems shifted to stratosphere and upper troposphere.
- ●	 “Competitive with mature hydrostatic NWP models ...”

## ☞ 	Nonhydrostatic model equations; for simplicity, inviscid, adiabatic, sigma:

- ●	Φ, w and ε not independent, watch for overspecification!

## Coordinate system

● 	 Rotated lat-lon

- ● 	 Rotated lat-lon

- Rotated lon

- Rotated lat

- ●	More regular grid, longer time step

**This allows a transformation of the central coordinates at the equator to a specified location**

## ●	NMM/HWRF  

- 		**Janjic, Gerrity and Nickovic, 2001, *****MWR*****	****	****Janjic, 2003, *****MAP***
**Non-hydrostatic dynamics**
- ●	NMM Computationally robust, reliable in operations;  many tests
-        NWP, convective cloud runs, PBL LES, with resolutions from 50 km to 100 m;
- ●	THREE TIMES faster than most established NH models
- ●	_**NMM/HWRF  **_
**Simplified Arakawa Shubert  (Pan and Wu, 1994)**
**GFS PBL/Surface physics  (Troen, Mahrt, 1986; Hong and Pan, 1996)**
**Radiation (Yu-Tai Hou, 2002; Mlawer (AER), 97)**
**Microphysics (Ferrier et al., 2002)**
**●****	****HWRF prototype ran during ’04, ’05, ‘06 hurricane season **

##  Science Issues  

_**Fundamental questions (process/sensitivity studies):**_
**Relative role of vortex vs. environment in influencing intensity.    **
**Role of ocean.  Role of Oceanic heat content.     **
**Processes within atmosphere-ocean boundary layer on  intensity/structure changes.    **
**Determinants of structure and relationship with preexisting wave disturbance.  Relationship between structure and intensity.      **

## Role of inner core processes for intensification/weakening, e.g. eyewall replacement cycles, mixing.  

**Relative role of physics, e.g. Air-sea, microphysics, convection etc. on intensity change in various  environments (sheared vs. non-shear) ****    **

## Some Model Related Issues

_**Data Assimilation**_
**  ****Assimilation of satellite radiances   ****               **
**  **_**Vortex Initialization**_** **
**                 ****definition of hurricane “core” circulation  **
**                  ****where to take obs?  difficult for mature storms; more elusive               weaker circulations.   (obs taken during RAINEX?) **
_**Physics**_** **
**role of radiation?   complexity of microphysics and interaction of microphysics with radiation **
**atmosphere/oceanic boundary layer for coupled air-sea-wave  problem.  Momentum (wave induced drag)  and enthalpy fluxes (sea spray complexity?)**

##  Resolution -   

**  ****relative importance of horizontal vs. vertical resolution for modeling intensity/structure (important consideration for ops)**
**  ****Coupled Ocean -  **
**  ****advancements to support  **
**   ****initialization  **
**  ****vertical mixing     **
**  ****Obs to support effort data assimilation for improved ocean state (discussed at 2003 Air-Sea workshop at EMC)  **
** ****Land Surface Coupling**_** **_**-   **
** ****Complexity of coupling w/HWRF?     **
** ****Sensitivity of LSM for track, structure/intensity, rainfall?    **
**  ****Future coupling with hydrology/inundation models****. **

##  Validation/Verification/Diagnostics – 

**initialization  **
**requirement for development of  verification techniques **
**all stages of storm evolution; varying atmos/ocean environment  **
**required obs to support model diagnoistics and verification, **
**                  ****e.g   IFEX effort led by HRD  **
**particularly  deficient in ocean obs. **
**temporal and spatial scales?       **
**  **

##  Development of Advanced Probabilistic Guidance   for Intensity/structure 

** ****HWRF Ensembles****     **
**    ****Configuration **
**        ****initial conditions, resolution, members???**
**   ****OR**
**     ****Use of multi model ensembles (MME)  **
**           ****(Share w/Navy?  COAMPS, GFDL **
**           ****NCEP:  HWRF,  NAM)  **
**(Value of very hi-resolution deterministic forecasts vs. ensembles?)  **

## HWRF TEAM

**Gopal S. ;  Qingfu Liu;  Bob T,  Veejay   T. ;    Y. Kwon  (soon)**

## HWRF atmosphere-ocean coupling

**Sea surface temperature to Atmosphere  from:**
**Regional ocean (HYCOM)  dx~ 8-14(km)**
**SST analyses (GFS)          dx~ 30(km)**
**Radiative/turbulence fluxes to Ocean from:**
**Atmosphere model (HWRF) dx~ 27(km) & 9(km)**
**Boundary layer model uses surface wave information from:**
**Wave model (Wavewatch 3) dx~ 30(km)**
**   **

## Ocean initialization and assimilation

**Initial conditions from operational Atlantic forecast model (RTOFS):**
**Data is assimilated during the nowcast cycle of RTOFS**
**Boundary conditions are derived from RTOFS:**
**Five day forecasts are sample for volume data twice daily and for the external velocity and surface elevations three hourly.**
**Data Assimilation in RTOFS:**
**2D/3D Var**
**Data assimilated includes**
**SST**
**SSH**
**CTD, XBT....**
**   **

## Wave model development at EMC

**WAVEWATCH III  -  pre-operational and operational at NCEP for nearly a decade (hurricane wave models with GFS-GFDL winds since 2001)**
**Recent developments in wave modeling are largely driven by the hurricane (wave) forecast problem**
**Coupling of wind and wave models:**
**  ****New parameterizations of wind stresses over                         waves in high wind regimes.**
** ****Development of a multi-grid wave model to mimic the grid layout of HWRF (use of high-res wind data, coupling)**

## Multi-grid wave model 

**Virtually all present wave models consider one-way nesting only, with low resolution providing boundary data for high resolution models. **
**Hurricanes require high resolution in generation area, but their swells are covering full basins. Hurricanes therefore require two-way nesting and relocatable nests.**
**Coupling with hurricane models for the atmosphere benefit from identical grids.**
**NCEP:   Build upon the present operations: design as multiple grids in a single model.**

## Additional benefits of a multi-grid wave model

**Consolidation of global and regional models into a single model**
**Maximum consistency between global and regional models**
**Natural way of reducing resolution for ensembles by removing highest resolution coastal grids**
**Additional benefits / applications for relocatable nests**
**On demand high resolution hazard models (plane crashes, oil spills etc.)**
**Navy: On demand high resolution coupled modeling**

## The multi-grid wave model

- Hurricane described with Rankin vortex with maximum wind 45 m/s at radius of 50km. Hurricane moves to the right at 5 m/s.
- Telescoping grids with 50, 15 and 5 km resolution.
- Circular outline of domains.

## The multi-grid wave model

- Individual models with different resolution give inconsistent results.
- Running as a single model gives consistent results with variable resolution.

- Tolman and Alves, *Ocean Modelling* 2005.

##           THE HURRICANE  WRF (HWRF) 

**          **_**THE HURRICANE  WRF (HWRF) **_
**                   **_**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**
**  ****Coupling with wave model**
**  ****Land surface coupled to hydrology/inundation **
**  ****Coupling with dynamic storm surge**

## Development of Collaborations

** ****HWRF WORKSHOP – JUNE 2002   (EMC)**
**   ****(45 attendees – estab. hurricane community)**
** ****1****st**** HWRF TUTORIAL –  Oct. 2004   (EMC)**
**   ****(26 attendees –  precocious hurr. modeling types)**
** ****AIR-SEA WORKSHOP – MAY 2005  (EMC)**
**    ****(35 attendees – introduction of ocean community)**
** ****WRF/NMM Tutorial – Sept 2005   (JMT/Boulder)**
**      ****the beginning of “formal” training  **

## Pre-Implementation Strategy for  HWRF

_**Pre-Implementation Strategy for  HWRF**_
_**Upgrade GFDL as the benchmark for the HWRF**_
**UPGRADE GFDL PHYSICS WITH GFS PHYSICS ****(’04)****  **
**           ****(GFS  SAS and PBL schemes)**
**INCREASE GFDL RESOLUTION  ****(’05)****  **
**           ****(inner nest from 18 to 9km.)  **
**IMPLEMENT EMC Ferrier MICROPHYSICS (in HWRF)**
** ****UPGRADE AIR-SEA PHYSICS  (reduced drag)       ****‘06**
** ****IMPROVE OCEAN INITIALIZATION    **

## Next 2-3  weeks:

**Next 2-3  weeks:**
**  ****FINALIZE HWRF (ocean coupling for hi-res nest,  vortex initialization, cumulus momentum mixing)**
** ****PERFORM EXTENSIVE COMPARISONS BETWEEN GFDL AND HWRF FOR MULTIPLE SEASONS AND STORMS – ’04, 05, 06 – compare to GFDL results **

**CONTINUED:   PRE-IMP HWRF STRATEGY**

## Evolution of HWRF Development

**HWRF**	**First moving nest NMM HWRF**
*                     ****GFDL Initialization; 2005 Hurricane Season; Dennis***
***H001******	******	******HWRF Runs with GFS Initialization; 2005 Hurricane Season; Atlantic ******and East Pac, Near Real Time runs.***
***H002******	******	******HWRF Runs with New GFDL Surface Physics; Wilma, Rita and        Emily***
***H003******	******	******HWRF Runs with GFDL Slab Model***
***H004******	******	******HWRF Runs with Two-Way Interactive Moving Nest (with feedbacks)***
***H005/******	******HWRF Runs with Varying physics time steps (1 min. and 5 min.)***
***H006***

## Evolution of HWRF Development     

**H007****	**	HWRF Runs with *Varying Radiation Calls*
***H008******	******	******HWRF Runs using Initialization from Uncoupled GFDL; ***
***     ******Dennis, Katrina, Rita and Wilma***
***H009******	******	******HWRF Runs with Varying Physics and Convection time steps***
***H010/11******	******HWRF Runs with QingFu's New Initialization Procedure (3DVAR) based on GFS analysis and GSI***
***H012******	******	******HWRF Runs with New Random Number Code for SAS Convection***
***H013******	******	******HWRF Runs with Upgraded Physics and Microphysics; Katrina, Philippe, Rita, Wilma and Beryl (2006)***

## Evolution of HWRF Development

**H014****	****          **HWRF Runs with ***QingFu's modified initialization that includes a bogus vortex specification***
***H015/016******	******HWRF Runs using QingFu's modified initialization package ***
***H017******	******	******HWRF Runs with New Surface Physics (Bob Tuleya) and inclusion of  Dissipative Heating***
***H018/******	******HWRF Runs with QingFu's modified initialization package (III)***
***H019******	******	***
***H020******	******	******HWRF Runs with Cloud Momentum Mixing Coefficient Introduced (kept ***
***                     ******at 0.5)***

## Evolution of HWRF Development

**H021****	**	**HWRF Runs with *****QingFu's revised 3DVAR that uses 10 m winds (instead of level 1 winds) for initialization***
***H022******	******	******HWRF Runs using QingFu's modified initialization package (IV) that  includes adjustment to Sea Level Pressure***
***H023******	******	******First Comprehensive Testing of the end-to-end HWRF Modeling System.   Conducted 218 experiments that include Atlantic Hurricanes from 2004,****** ******2005 and 2006 seasons.  Results are presented at***
***    ***_***http://www.emc.ncep.noaa.gov/gc_wmb/vxt/***_
***H024******	******	******HWRF Runs with new Surface Enthalpy Flux Coefficient***
**HCBS/****	****HWRF Coupled Model Configuration, Initialization with High Resolution GFS Sigma & Hybrid Data – work in progress**