Quentin 01/03/2019: backup from commit 7d17f6da: the TINY function added on...

Quentin 01/03/2019: backup from commit 7d17f6da: the TINY function added on PURS lead to non-zero values to other variables such as convective precip. and snow variables such as T%TSNOW_ROOF%WSNOW in urban_snow_evol.F90 which lead to activate the snow cover 1layer model even if snow is not present

src/MNH/convect_updraft.f90

@@ -144,7 +144,6 @@ END MODULE MODI_CONVECT_UPDRAFT
 !!      Original    07/11/95 
 !!   Last modified  10/12/97
 !!   V.Masson, C.Lac, Sept. 2010 : Correction of a loop for reproducibility
-!  P. Wautelet 12/02/2019: bugfix: PURR/PURS were sometimes =-0. -> problems later
 !-------------------------------------------------------------------------------
 !
 !*       0.    DECLARATIONS
@@ -380,9 +379,7 @@ DO JK = MAX( IKB + 1, JKMIN ), IKE - 1
     PUTPR(:)    = PUTPR(:) + PUPR(:,JKP)   ! total precipitation rate
     ZWORK2(:)   = PURR(:,JKP) / MAX( 1.E-8, PURC(:,JKP) + PURI(:,JKP) )
     PURR(:,JKP) = ZWORK2(:) * PURC(:,JKP)          ! liquid precipitation
-    PURR(:,JKP)=MAX(TINY(0.),PURR(:,JKP)) !To prevent problems when =-0. (occur sometimes)
     PURS(:,JKP) = ZWORK2(:) * PURI(:,JKP)          ! solid precipitation
-    PURS(:,JKP)=MAX(TINY(0.),PURS(:,JKP)) !To prevent problems when =-0. (occur sometimes)
 !
 !
 !*       7.     Update r_c, r_i, enthalpy, r_w  for precipitation