# Presentation: 918838

## HWRF: AN INTRODUCTION TO THE NMM-WRF MODELING SYSTEM

- S.G.Gopalakrishnanand
- The HWRF team at EMC

## , Matthew Pyle

*, Matthew Pyle*

## Tuesday October 26, 2004

- Introduction
- WRFSI
- REAL
- WRF

## Error (nautical miles)

- <date/time>

**Error (nautical miles)**

**    ****1970                          1980                    1990                    2000**
**                                              ****Year**

**72 h  TPC Atlantic Track Forecast Errors**

**1970-1986 trendline**

**1987-2003 trendline**

-   **700**

-  **600**

**500**

-  **400**

-  **300**

**200**

-   **100**

-    ** ****0**

** ****Major Upgrades in Global and**
** ****Hurricane Numerical models**

**With the exception of “stalling and looping storms”, while hurricane track prediction has shown remarkable progress, skill in predicting intensity changes is still poor. It is expected that ocean-coupled, high resolution, advanced  mesoscale modeling system may improve track  as well as intensity predictions. Hurricane WRF is the next step towards this goal.  **

## ----->

- <date/time>

**----->**

**----->**

**----->**

**<-----**

**----->**

**---->**

**----->**

**----->**

**---->**

**<----**

**---->**

**---->**

**----->**

**Upper Level Divergence**

**PBL Moisture Convergence over warm ocean**** **

**Weak subsiding motion**

**---->**

**<----**

**---->**

**<---****-**

**<----**

**<----**

**Latent Heat - Cooling by W = Warm Core Vortex**

*--------- >*
*mean motion*

- MULTI-SCALE INTERACTION

**Gopalakrishnan et al, 2002, MWR**

- While convection within the organized circulation occurs at the cloud scale, boundary layer convergence and subsidence, for instance, takes place in the warm core system over larger scales. In order to create the right scale interactions, a large domain as well as high resolution are pivotal requirements of a hurricane forecasting system.

## The Modeling Framework

- Real cases:
- Standard
- Initialization
- (WRFSI/NMMSI)

- Ideal Cases

**Wrfv1**
**./Registry ./inc**
**./Main**

- Post Processor:
- Netcdf (ii) Binary

**./phys**
**./frame**
**./share **
**./external **

**./dyn_nmm**
**or**
**./dyn_em**
**or**
**...****.**

## Adopted from http://wrf-model.org/PRESENTATIONS/2000_06_23_schultz/sld003.htm

## NMM SI

- Directory structure of WRFSI
- Static Data from SI
- Dynamic Data
- wrfsi.nl and script to run that
- Output from SI
- 	        Grid configuration is created here
-             wrf_real_input_nm.d01.2003-09-15_12:00:00

## Directory Structure of NMMSI

- This is what you will see when you set up your SI
- directory !
- [/emc2/wx20gk/WRFEMC/HWRF/NMMSI] % ls
-     install.scr   wrfsigeog  gribdata  srcroot ONESIXTH   PARX18 readme

- setup

## install.scr

- /usr/bin/perl ./srcroot/install_wrfsi.pl  \
- --srcroot="/emc2/wx20gk/WRFEMC/HWRF/NMMSI/srcroot"  \
- --installroot="/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup"  \
- --dataroot="/emc2/wx20gk/WRFEMC/HWRF/NMMSI/gribdata"  \
- --path_to_netcdf="/emc2/wx20gk/WRFEMC/netcdf/netcdf-3.5.0"  \
- --geog_dataroot="/emc2/wx20py/wrfsigeog" \
-  --machine="ibm"

## Static SI Data Directory Structure

-     [/emc2/wx20py/wrfsigeog] % lsalbedo_ncep          Islope                   pctland_10m       soiltype_top_30s   greenfrac              landuse_30s       soiltemp_1deg       topo_10m             greenfrac_10m     maxsnowalb          soiltype_bot_30s  topo_30s

## Description of the WRFSI Static Data

- topo_30s              :  FIS/9.8
- landuse_30s         : IVGTYP, LANDUSEF and SM
- albedo_ncep        :  ALBASE  (monthly changes)
- soiltype_top_30s :  ISLTYP   (1-16)
- soiltype_bot_30s :  fixed
- soiltemp_1deg     :                   (1 layer deep soil temperature)
- maxsnowalb         : fixed
- greenfrac              : from 0 1 (0 is no cannopy)
- islope                   :  used in run off computation (not used in NMM)
- pctland_10m        :  not used in NMM
- topo_10m             :  not used in NMM
- greenfrac_10m     :  not used in NMM

## Meteorological Input Grib Data

- Handles pressure level data only!!!
- GFS grib files ( ex:  gblav.t00z.pgrbf84)
- _[ftp://](ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/avn/prod)__[ftpprd.ncep.noaa.gov/pub/data/nccf/com/avn/prod](ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/avn/prod)_
- GFDL grib files (ex: frances06l.2004083100.grib3rd.f66)

## Basic grib data requirement

- Description     Units           Output Name
- -------------------------------------------
- Temperature      K                 T
- U-wind comp     m s{-1}       U
- V-wind comp     m s{-1}       V
- Rel. Humidity     %                RH
- Geo. Height       m                 HGT
- Surface Press     Pa                PSFC
- Terrain Hgt        m                 SOILHGT
- Skin temp           K                 SKINTEMP
- SST                    K                 SST

## Source and Set up for WRFSI

- [/emc2/wx20gk/WRFEMC/HWRF/NMMSI/srcroot/src] % ls
- grib_prep   hinterp     io_netcdf   mod   vinterp   grid     include    lib    util
- [/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup] % ls
- bin   data   extdata    templates config_paths  domains    etc

## Grid Structure of the WRF-NMM

## NAMELIST: wrfsi.nl

- &project_id
-  SIMULATION_NAME = 'HWRF     '
-  USER_DESC = 'NOAA/NCEP/EMC'
- /

## wrfsi.scr (date and time)

- &filetimespec
-  START_YEAR = 2003,
-  START_MONTH = 09,
-  START_DAY = 15,
-  START_HOUR = 12,
-  START_MINUTE = 00,
-  START_SECOND = 00,
-  END_YEAR = 2003,
-  END_MONTH = 09,
-  END_DAY = 16,
-  END_HOUR = 12,
-  END_MINUTE = 00,
-  END_SECOND = 00,
-  INTERVAL = 21600
- /

## Wrfsi.nl (domain info)

- &hgridspec
-  NUM_DOMAINS = 1,
-  XDIM = 103,100,200
-  YDIM = 217,100,200
-  PARENT_ID = 1,1,2
-  RATIO_TO_PARENT = 1,4,4
-  DOMAIN_ORIGIN_PARENT_X = 1,36,36
-  DOMAIN_ORIGIN_PARENT_Y = 1,36,36
-  MAP_PROJ_NAME = 'rotlat',
-  MOAD_KNOWN_LAT = 35.0,
-  MOAD_KNOWN_LON = -75.0,
-  MOAD_KNOWN_LOC = 'center'
-  MOAD_STAND_LATS = 35.0, 0.0,
-  MOAD_STAND_LONS = -75.0,
-  MOAD_DELTA_X = 0.07716066390
-  MOAD_DELTA_Y = 0.08169933408
-  SILAVWT_PARM_WRF = 0.
-  TOPTWVL_PARM_WRF = 2.
- /

## wrfsi.nl  (static files)

- &sfcfiles
-  TOPO_30S = '/emc2/wx20py/wrfsigeog/topo_30s',
-  LANDUSE_30S = '/emc2/wx20py/wrfsigeog/landuse_30s',
-  SOILTYPE_TOP_30S = '/emc2/wx20py/wrfsigeog/soiltype_top_30s',
-  SOILTYPE_BOT_30S = '/emc2/wx20py/wrfsigeog/soiltype_bot_30s',
-  GREENFRAC = '/emc2/wx20py/wrfsigeog/greenfrac',
-  SOILTEMP_1DEG = '/emc2/wx20py/wrfsigeog/soiltemp_1deg',
-  ALBEDO_NCEP = '/emc2/wx20py/wrfsigeog/albedo_ncep',
-  MAXSNOWALB = '/emc2/wx20py/wrfsigeog/maxsnowalb',
-  ISLOPE = '/emc2/wx20py/wrfsigeog/islope',
- /

- &interp_control
-  NUM_DOMAINS = 1,
-  DOMAIN_ID_LIST = 1,
-  PTOP_PA = 5000,
-  HINTERP_METHOD = 1,
-  LSM_HINTERP_METHOD = 0,
-  NUM_INIT_TIMES = 1,
-  INIT_ROOT = 'AVN',
-  LBC_ROOT = 'AVN',
-  LSM_ROOT = 'AVN',
-  CONSTANTS_FULL_NAME = 'SSTDATA','SNOWDATA',
-  VERBOSE_LOG = .false.,
-  OUTPUT_COORD = 'NMMH',
-  LEVELS = 1.0, .9919699, .9827400, .9721600, .9600599, .9462600,
-  .9306099,     .9129300, .8930600, .8708600, .8462000, .8190300,
-  .7893100,     .7570800, .7224600, .6856500, .6469100, .6066099,
-  .5651600,     .5230500, .4807700, .4388600, .3978000, .3580500,
-  .3200099,     .2840100, .2502900, .2190100, .1902600, .1640600,
-  .1403600,     .1190600, .1000500, .0831600, .0682400, .0551200,
-  .0436200,     .0335700, .0248200, .0172200, .0106300, .0049200,
-  .0000000,
- OUTPUT_VARS = 2,
-  OUTPUT_FILE_TYPE = 'BOTH',
- /

## wrfsi.nl (Paths) 

- &si_paths
-  ANALPATH = '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup/extdata/extprd',
-  LBCPATH = '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup/extdata/extprd',
-  LSMPATH = '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup/extdata/extprd',
-  CONSTANTS_PATH = '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/setup/extdata/extprd',
- /

## ../setup/extdata/static/grib_prep.nl

- &filetimespec
-  START_YEAR = 2003
-  START_MONTH =12
-  START_DAY =12
-  START_HOUR =00
-  START_MINUTE = 00
-  START_SECOND = 00
-  END_YEAR = 2003
-  END_MONTH =12
-  END_DAY =12
-  END_HOUR =00
-  END_MINUTE = 00
-  END_SECOND = 00
-  INTERVAL = 10800
- /

## ../setup/extdata/static/grib_prep.nl

- &gpinput_defs
- ! modified for GFDL vortex. See Vtable.GFDLX for details.. Gopal
-  SRCNAME = 'GFDL','ETA','GFDLX','AVN'
-  SRCVTAB = 'GFDL','ETA','GFDLX','AVN'
-  SRCPATH = '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/gribdata/GFDL',
-                       '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/gribdata/ETA',
-                      '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/gribdata/AVN‘
-                     '/emc2/wx20gk/WRFEMC/HWRF/NMMSI/gribdata/AVN',
-  SRCCYCLE =  6,6,6,6,12,12,24,
-  SRCDELAY =  3,4,4,3, 0, 0,36,
- /

## WRFSI OPERATION

- Domain localization (creation of a new domain)
-     /setup/etc/window_domain_rt.pl
-    uses /setup/gridgen_model.exe
- Grib data preparation
-      /setup/etc/grib_prep.pl
-      uses /setup/bin/grib_prep.exe
- Interpolate on to the created grid and produce SI outputs
-    /setup/etc/wrfsi.pl
-     uses /setup/bin/hinterp.exe and vinterp.exe

## REMEMBER!

- OUTPUT FROM WRFSI IS ONLY AN INPUT TO THE REAL CODE AND NOT AN INPUT TO WRF MODEL.
- YOU CANNOT RUN THE WRF MODEL WITH  OUT PUT FILES FROM THE SI,  wrf_real_input_nm.d01.yy-mm-dd_hh:mm:ss
- YOU NEED TO RUN THE REAL CODE NEXT!!!!

## PROGRAM  REAL

- The real suite of code provides initial and boundary conditions for the WRF model (wrf.exe) derived from wrfsi.
- Nevertheless, inputs required for the wrf model is not restricted to wrfsi alone. For instance, NMM core does not use Coriolis defined in wrfsi. Also, several variables are defined/re-defined using the real suite of routines.
- Separating  real code from the wrf model code provides an advantage in terms of run time requirements.
- The real code provides yet another opportunity for developing I/O for model initialization  (scope for ideal cases!)

## The Real Code

- Includes:
- ./main/real.F
- (2) ./dyn_nmm/module_initialize_real.F    real.exe
- (3) ./dyn_nmm/start_nmm.F
- (4) ./share/module_soil_pre.F
- Products:
- wrfinput_d01 and wrfbdy_d01

## In a nut shell

-                       wrfsi
- wrf_real_input_nm.d01.yy-mm-dd_hh:mm:ss
-                                       real.exe
-                                          (+ namelist.input etc..)
-                 wrfinput_d01 & wrfbdy_d01
-                                         wrf.exe
-                                           (+ namelist.input etc..)
-                        wrfout_d01_yy-mm-dd_hh:mm:ss

## I picked this one up from Dave Gill @ NCAR!

- _[http://www.mmm.ucar.edu/wrf/tutorial/2003/WRF_Tutorial/Initialization_for_Real_Data_Cases/Slide2.html](http://www.mmm.ucar.edu/wrf/tutorial/2003/WRF_Tutorial/Initialization_for_Real_Data_Cases/Slide2.html)_

## The Modeling Framework

- Real cases:
- Standard
- Initialization
- (WRFSI/NMMSI)

**Wrfv1**
**./Registry ./inc**
**./Main**

- Post Processor:
- Netcdf (ii) Binary

**./phys**
**./frame**
**./share **
**./external **

**./dyn_eh**
**or**
**./dyn_em**
**or**
**./dyn_slt**

## Quick walk thru’ of the real programme

- _[file:///C:/Documents%20and%20Settings/emc_user/gopal/html_code/](file:///C:/Documents%20and%20Settings/emc_user/Desktop/gopal/tutorial/tutorial2004.PPT)_

## Welcome To the Inaugural Meeting of the WRF Software Training and Documentation TeamJan. 26-28, 2004NCAR, MMM Division 

- _[http://box.mmm.ucar.edu/wrf/WG2/Tigers/](http://box.mmm.ucar.edu/wrf/WG2/Tigers/)_
- _[http://www.mmm.ucar.edu/wrf/tutorial/2003/WRF_Tutorial/Tutorial_2003_03/](http://www.mmm.ucar.edu/wrf/tutorial/2003/WRF_Tutorial/Tutorial_2003_03)_

## Is this a Jig-Saw Puzzle ??

- [/emc2/wx20gk/WRFEMC/HWRFV1/WRFV1] % ls
- CVS           configure         dyn_slt                phys
- Makefile     configure.wrf  external               run
- README   dyn_eh            frame                  set_core
- Registry      dyn_em           inc                       share
- arch             dyn_exp          install_nmm.scr   test
- clean           dyn_graps        main                    tools
- compile
-                     dyn_nmm

## Directory Structure

## WRF Model Directory Structure

**Notes:**
As a handout

## Slide 38

- #<Table> <Type> <Sym>   <Dims>   <Use>   <NumTLev> <Stagger>
- #<IO>     <DNAME> <DESCRIP>     <UNITS>
- state  real   t       ikj    dyn_nmm    1  -   i01rh  "T"       "TEMPERATURE IN KELVIN"        -
- state  real   pd    ij      dyn_nmm    1  -   i01rh  “PD"     " PRESSURE DEPTH IN PASCALS"  -
- state  real   f       ij     dyn_nmm     1  -   irh      "F"        "CORIOLIS PARAMETER "               -
- state  real   pint  ikj   dyn_nmm     1  Z  irh      "PINT " “INTERFACE HSTATIC PRES“        -

## # Exchange in the NMM core

- halo    HALO_NMM_C                           dyn_nmm 8:u,v
- halo    HALO_NMM_INTERP_DOWN  dyn_nmm  120:sm,fis,t,u,v,q,pd

## Boundary Arrays in the Registry

- state  real    pd_b       ivjb    dyn_nmm     1      -      b    "PDB"
- state  real    pd_bt      ivjb    dyn_nmm     1      -      b    "PDBT"
- state  real    t_b          ikjb    dyn_nmm     1      -      b    "TB"
- state  real    t_bt         ikjb    dyn_nmm     1      -      b    "TBT"
- state  real    q_b         ikjb    dyn_nmm     1      -      b    "QB"
- state  real    q_bt        ikjb    dyn_nmm     1      -      b    "QBT"
- state  real    u_b         ikjb    dyn_nmm     1      -      b    "UB"
- state  real    u_bt        ikjb    dyn_nmm     1      -      b    "UBT"
- state  real    v_b         ikjb    dyn_nmm     1      -      b    "VB"
- state  real    v_bt        ikjb    dyn_nmm     1      -      b    "VBT"
- state  real    q2_b       ikjb    dyn_nmm     1      -      b    "Q2"
- state  real    q2_bt      ikjb    dyn_nmm     1      -      b    "Q2T"
- state  real   cwm_b    ikjb    dyn_nmm     1      -      b    "CWM"
- state  real   cwm_bt   ikjb    dyn_nmm     1      -      b    "CWMT"

## Boundary Conditions

- The lateral boundaries for real cases are stored as, and read from special four  dimensional arrays. These arrays are specified in the Registry as follows: the state variable, say for instance U, has its boundary values stored in U_b and the boundary tencied in U_bt. The “_b” and “_bt” arrays are four dimensional (max(ide,jde),kde,spec_bdy_width,4).
- As indicated by the fourth dimensional index, the data is stored in the form of four strips, P_XSB (western), P_XEB (eastern), P_YSB (southern) and P_YEB  (northern), each denoting a boundary of specified width, spec_bdy_width that is controlled by the namelist file.
- While the second dimension index of these array denotes the maximum vertical dimension, the first index denotes maximum of x and y dimension. Figure below illustrates this array for a case where ide > jde
- _[http://www.mmm.ucar.edu/wrf/WG2/software_2.0/LBC_Documentation.pdf](http://www.mmm.ucar.edu/wrf/WG2/software_2.0/LBC_Documentation.pdf)_

## LBC Arrays

- unused

- P_YEB

- P_YSB

- A Given Domain

- P_XSB

- P_XEB

- jds

- jde

- ids

- ide

- spec_bdy_width

## rconfig entries

- # some examples of rconfig entries
- # NAMELIST 01
- rconfig  integer  time_step  namelist,namelist_01  1     -   ih   "time_step“
- # NAMELIST 02
- rconfig   integer start_year   namelist,namelist_02    max_domains 1993 irh   "start_year"   "4 DIGIT  START  YR"  “YR"
- # NAMELIST 03
- rconfig   real    dx  namelist,namelist_03  max_domains  200    h     "dx"   "X HORIZONTAL RES” “M”
- rconfig   real    dy namelist,namelist_03   max_domains  200    h     "dy"   “Y HORIZONTAL RES” “M”
- # NAMELIST 04
- rconfig   integer nphs  namelist,namelist_04  max_domains   12   irh   "nmm input " " "

## Example of derived data type

- # following  added for nesting purpose  (gopal's doing)
- rconfig   real  wbd0   derived  max_domains    0  -   "wbd0"   “domain western boundary “
- rconfig   real  sbd0    derived  max_domains    0  -   "wbd0"   “domain western boundary “
- !   grid configuration in mediation_integrate.F
- parent%wbd0 = -(IDE -2)*parent%dx
- parent%sbd0 = -((JDE-1)/2)*parent%dy

## package entries

- # Package entries within the Registry
- package   rrtmscheme    ra_lw_physics==1             -             -
- package   gfdllwscheme  ra_lw_physics==99            -             -
- package   swradscheme   ra_sw_physics==1             -             -
- package   gsfcswscheme  ra_sw_physics==2             -             -
- package   gfdlswscheme  ra_sw_physics==99
- package   sfclayscheme   bl_sfclay_physics==1        -             -
- package   myjsfcscheme   bl_sfclay_physics==2        -             -
- package   slabscheme     bl_surface_physics==1       -             -
- package   lsmscheme      bl_surface_physics==2       -             -
- package   ruclsmscheme   bl_surface_physics==3       -             -
- package   nmmlsmscheme   bl_surface_physics==99      -             -
- package   ysuscheme      bl_pbl_physics==1           -             -
- package   myjpblscheme   bl_pbl_physics==2           -             -
- package   gfsscheme      bl_pbl_physics==3           -             -
- package   mrfscheme      bl_pbl_physics==99          -             -
- package   kfetascheme    cu_physics==1               -             -
- package   bmjscheme      cu_physics==2               -             -
- package   gdscheme       cu_physics==3               -             -
- package   sasscheme      cu_physics==4
- package   kfscheme       cu_physics==99

## namelist.input

- &namelist_01
- time_step                           = 30,
- time_step_fract_num         =  0,   related to fractional time steps
- time_step_fract_den           =  1,   related to fractional time steps
- restart                                  = .false.,
- max_dom                            =  1,
- dyn_opt                               =  4,
- ifsnow                                  = 1,   snow-cover effects
- icloud                                   = 1,   cloud effect to the optical depth in radiation
- num_soil_layers                   = 4,
- spec_bdy_width                   = 5,
- spec_zone                             = 1,
- relax_zone                            = 4,
- tile_sz_x                                      = 0,     number of points in tile x direction
- tile_sz_y                                      = 0,     number of points in tile y direction
- numtiles                                       = 1,     number of tiles per patch
- debug_level                          = 1,/

## namelist.input

- &namelist_02
- grid_id                           = 1,
- level                               = 1, domain level (leave as is)
- s_we                               = 1,
- e_we                               = 288,
- s_sn                                = 1,
- e_sn                                = 638,
- s_vert                              = 1,
- e_vert                              = 43,
- start_year                        = 2004
- start_month                     = 10
- start_day                         = 22
- start_hour                        = 00
- start_minute                    = 00,
- start_second                    = 00,
- end_year                         = 2004
- end_month                      = 10
- end_day                           = 26
- history_interval               = 360,
- restart_interval                = 00,
- frames_per_outfile          = 1,
- interval_seconds             = 21600,/

## namelist.input

-  &namelist_03
-  dx                                  = 0.132867,   in degrees
-  dy                                  = 0.119497, /  in degrees

## namelist.input

-  &namelist_04
- specified                          = .true.,
- top_radiation                   = .false.,
-  cu_physics                      = 2,
-  mp_physics                     = 5,
-  bl_pbl_physics                = 2,
-  bl_sfclay_physics            = 2,
-  bl_surface_physics          = 99,
-  ra_sw_physics                 = 99,
-  ra_lw_physics                  = 99,
-  io_form_history               = 2,
-  io_form_restart                 = 2,
-  io_form_input                   = 2,
-  io_form_boundary            = 2,
-  idtad                                  = 2,
-  nsoil                                  = 4,
-  nphs                                  = 20,
-  ncnvc                                = 20,
-  nrads                                = 180,
-  nradl                                = 180,
-  sigma                               = 1/

## Slide 52

## The solver

- Quick walk thru’ of
- (1) WRF.F
- (2) module_integrate.F
- (3) solve_em.F

## How to run the wrf model

- [/emc2/wx20gk/WRFEMC/BHWRFV1/WRFV1/test/nmm_real] % ls
- ETAMPNEW_DATA             namelist_nmm.input
- GENPARM.TBL                    namelist_nmm.input.new_physics
- LANDUSE.TBL                     real.exe
- README.namelist                 real_nmm.scr
- RRTM_DATA                        tr49t67    !
- SOILPARM.TBL                    tr49t85    !  GAKT )))-
- VEGPARM.TBL                     tr67t85   !
- co2_trans                                  wrf.exe
- eta_micro_lookup.dat              wrf_nmm.scr
- emc2/wx20gk/WRFEMC/BHWRFV1/WRFV1/README_NMM

## A note on nesting

- WRF-NMM: An operational Multiscale Hurricane Forecasting System by S.G.Gopalakrishnan, Robert Tuleya, Naomi Surgi, Thomas Black, Z.I.Janjic , Geoff Dimego and  John Michalakes
-  _[http://www.mmm.ucar.edu/mm5/workshop/ws04/Session7/Gopalakrishnan.pdf](http://www.mmm.ucar.edu/mm5/workshop/ws04/Session7/Gopalakrishnan.pdf)_
- Nesting in WRF 2.0  by David Gill John Michalakes Jimy Dudhia William Skamarock and S.G. Gopalakrishnan_[http://www.mmm.ucar.edu/mm5/workshop/ws04/Session6/Gill.Dave.pdf](http://www.mmm.ucar.edu/mm5/workshop/ws04/Session6/Gill.Dave.pdf)_

## E-grid configuration for 1:3 ratio

## Hurricane Floyd

- Thanks to Nashat Ahmad