C$$$  MAIN PROGRAM DOCUMENTATION BLOCK
C                .      .    .                                       .
C MAIN PROGRAM: ETAFCST      EARLY ETA MODEL FORECAST DRIVER
C   PRGMMR: JANJIC           ORG: NP22        DATE: 99-01-20  
C
C ABSTRACT: EBU3 CONTAINS THE PRIMARY RUNSTREAM FOR THE EARLY ETA
C   FORECAST MODEL.  AFTER AN INITIAL CALL TO SUBROUTINE INIT, CALLS
C   ARE MADE TO SUBROUTINES WHICH COMPUTE THE VARIOUS DYNAMICAL AND
C   PHYSICAL PROCESSES IN THE MODEL.  THE VARIABLE 'NTSD' IS THE
C   FUNDAMENTAL TIMESTEP COUNTER AND THUS ITS VALUE DETERMINES WHEN
C   THE SUBROUTINES ARE CALLED.  INFORMATION PERTAINING TO THE SCHEMES
C   USED IN THE MODEL AS WELL AS ADDITIONAL REFERENCES MAY BE FOUND
C   IN "THE STEP-MOUNTAIN ETA COORDINATE REGIONAL MODEL:  A DOCUMEN-
C   TATION" (BLACK 1988; DEVELOPMENT DIVISION) AND "THE NEW NMC MESO-
C   SCALE ETA MODEL:  DESCRIPTION AND FORECAST EXAMPLES (BLACK 1994;
C   WEATHER AND FORECASTING).
C
C PROGRAM HISTORY LOG:
C   87-08-??  JANJIC,     ORIGINATOR
C             BLACK
C   93-05-12  TREADON     DOCBLOCK INSERTED
C   93-10-25  BLACK       DOCBLOCK UPDATED
C   97-03-15  MESINGER    SPLITTING MODIFIED, TO SEPARATE THE
C                         ADJUSTMENT AND THE ADVECTION STEP
C   97-11-19  BLACK       MODIFIED FOR DISTRIBUTED MEMORY
C   98-10-20  BLACK       DISTRIBUTED MEMORY FORM FOR 
C                         CURRENT OPERATIONAL CODE
C   00-02-25 TUCCILLO     INCORPORATED ASYNCHRONOUS I/O SERVERS
C   12-01-13  EBISUZAKI   IF BAD PRECIP READ, SET TO PRECIP TO UNDEFINED
C   17-06-01  EBISUZAKI   CHANGED PARMETA - use 24 CPUS in 4x5 config
C
C
C USAGE:  MAIN PROGRAM
C
C   INPUT FILES:  NONE (SEE SUBROUTINE INIT)
C
C   OUTPUT FILES:  NONE (SEE SUBROUTINE CHKOUT)
C
C   SUBPROGRAMS CALLED:
C     UNIQUE:
C       INIT     - INITIALIZE VARIABLES AT START OF INTEGRATION
C       DIVHOA   - DIVERGENCE, AND HORIZONTAL PART OF THE OMEGA-ALPHA
C                  TERM
C       PGCOR    - PRESSURE GRADIENT AND CORIOLIS FORCE
C       PDTE     - UPDATE SURFACE PRESSURE TENDENCY AND ETADOT
C       VTADV    - VERTICAL ADVECTION
C       HZADV    - HORIZONTAL ADVECTION OF T,U,V, AND TKE
C       HZADV2   - HORIZONTAL ADVECTION OF Q AND CLOUD WATER
C       DDAMP    - APPLY DIVERGENCE DAMPING
C       PDNEW    - UPDATE SURFACE PRESSURE
C       HDIFF    - LATERAL DIFFUSION
C       BOCOH    - UPDATE H POINTS ON THE BOUNDARIES
C       BOCOV    - UPDATE V POINTS ON THE BOUNDARIES
C       RADTN    - RADIATION DRIVER
C       RDTEMP   - APPLY TEMPERATURE TENDENCY DUE TO RADIATION
C       TURBL    - PERFORM THE VERTICAL TURBULENT EXCHANGE
C       SURFACE  - UPDATE SURFACE TEMPERATURE, MOISTURE, AND OTHER
C                  GROUND HYDROLOGY
C       GSCOND   - CLOUD WATER/ICE PHYSICS PARAMETERIZATION
C       CUCNVC   - CONVECTIVE ADJUSTMENT FOR DEEP OR SHALLOW CONVECTION
C       PRECPD   - GRID SCALE PRECIPITATION
C       CHKOUT   - POST PROFILE DATA.  FOR INTERNAL POST,
C                  POSTS MODEL OUTPUT.  FOR EXTERNAL POST,
C                  WRITES TEMPORARY FILE CONTAINING ALL MODEL
C                  ARRAYS.
C
C   EXIT STATES:
C     COND =   1 - NORMAL EXIT
C
C ATTRIBUTES:
C   LANGUAGE: FORTRAN 90
C   MACHINE : IBM SP
C
C$$$