diff --git a/src/Microphysics/Microphysics.jl b/src/Microphysics/Microphysics.jl
new file mode 100644
index 00000000..980cc294
--- /dev/null
+++ b/src/Microphysics/Microphysics.jl
@@ -0,0 +1,21 @@
+module Microphysics
+
+import CloudMicrophysics
+
+using Oceananigans.Grids: Center, xnode, ynode, znode
+using Oceananigans.Fields: ZeroField
+
+import Oceananigans.Fields: CenterField
+
+const CM1 = CloudMicrophysics.Microphysics1M
+const CMNe = CloudMicrophysics.MicrophysicsNonEq
+const CMP = CloudMicrophysics.Parameters
+
+export AbstractMicrophysics,
+       
+include("interface.jl")
+include("process_rates.jl")
+include("sedimentation_velocities.jl")
+include("microphysics_1m.jl")
+
+end # module
diff --git a/src/Microphysics/interface.jl b/src/Microphysics/interface.jl
new file mode 100644
index 00000000..231cd624
--- /dev/null
+++ b/src/Microphysics/interface.jl
@@ -0,0 +1,131 @@
+#####
+##### Generic fallbacks for microphysics
+#####
+
+@inline microphysics_rhs(i, j, k, grid, ::Nothing, val_tracer_name, clock, fields) = zero(grid)
+
+"""
+    update_tendencies!(mp, model)
+
+Update prognostic tendencies after they have been computed.
+"""
+update_tendencies!(mp, model) = nothing
+
+"""
+    update_microphysics_state!(mp, model)
+
+Update microphysics state variables. Called at the end of update_state!.
+"""
+update_microphysics_state!(mp, model) = nothing
+
+@inline microphysics_drift_velocity(mp, val_tracer_name) = nothing
+@inline microphysics_auxiliary_fields(mp) = NamedTuple()
+
+
+"""
+    AbstractMicrophysics
+
+Abstract type for microphysics models with continuous form microphysics reaction
+functions. To define a microphysial relaionship the following functions must have methods
+defined where `Microphysics` is a subtype of `AbstractMicrophysics`:
+
+ - `(mp::Microphysics)(i, j, k, grid, ::Val{:tracer_name}, clock, fields)` which
+     returns the microphysics reaction for for each tracer.
+
+  - `required_microphysics_tracers(::Microphysics)` which returns a tuple of
+     required `tracer_names`.
+
+  - `required_microphysics_auxiliary_fields(::Microphysics)` which returns
+     a tuple of required auxiliary fields.
+
+  - `microphysics_auxiliary_fields(mp::Microphysics)` which returns a `NamedTuple`
+     of the models auxiliary fields.
+
+  - `microphysics_drift_velocity(mp::Microphysics, ::Val{:tracer_name})` which
+     returns a velocity fields (i.e. a `NamedTuple` of fields with keys `u`, `v` & `w`)
+     for each tracer.
+
+  - `update_microphysics_state!(mp::Microphysics, model)` (optional) to update the
+      model state.
+"""
+
+abstract type AbstractMicrophysics end
+
+# Required for when a model is defined but not for all tracers
+@inline (mp::AbstractMicrophysics)(i, j, k, grid, val_tracer_name, clock, fields) = zero(grid)
+
+@inline extract_microphysics_fields(i, j, k, grid, fields, names::NTuple{1}) =
+    @inbounds tuple(fields[names[1]][i, j, k])
+
+@inline extract_microphysics_fields(i, j, k, grid, fields, names::NTuple{2}) =
+    @inbounds (fields[names[1]][i, j, k],
+               fields[names[2]][i, j, k])
+
+@inline extract_microphysics_fields(i, j, k, grid, fields, names::NTuple{N}) where N =
+    @inbounds ntuple(n -> fields[names[n]][i, j, k], Val(N))
+
+@inline function microphysics_transition(i, j, k, grid, mp::AbstractMicrophysics,
+                                           val_tracer_name, clock, fields)
+
+    names_to_extract = tuple(required_microphysics_tracers(mp)...,
+                             required_microphysics_auxiliary_fields(mp)...)
+
+    fields_ijk = extract_microphysics_fields(i, j, k, grid, fields, names_to_extract)
+
+    x = xnode(i, j, k, grid, Center(), Center(), Center())
+    y = ynode(i, j, k, grid, Center(), Center(), Center())
+    z = znode(i, j, k, grid, Center(), Center(), Center())
+
+    return mp(val_tracer_name, x, y, z, clock.time, fields_ijk...)
+end
+
+@inline (mp::AbstractMicrophysics)(val_tracer_name, x, y, z, t, fields...) = zero(t)
+
+microphysics_tracernames(tracers) = keys(tracers)
+microphysics_tracernames(tracers::Tuple) = tracers
+
+add_microphysics_tracer(tracers::Tuple, name, grid) = tuple(tracers..., name)
+add_microphysics_tracer(tracers::NamedTuple, name, grid) = merge(tracers, (; name => CenterField(grid)))
+
+@inline function has_microphysics_tracers(fields, required_fields, grid)
+    user_specified_tracers = [name in microphysics_tracernames(fields) for name in required_fields]
+
+    if !all(user_specified_tracers) && any(user_specified_tracers)
+        throw(ArgumentError("The microphysics model you have selected requires $required_fields.\n" *
+                            "You have specified some but not all of these as tracers so may be attempting\n" *
+                            "to use them for a different purpose. Please either specify all of the required\n" *
+                            "fields, or none and allow them to be automatically added."))
+
+    elseif !any(user_specified_tracers)
+        for field_name in required_fields
+            fields = add_microphysics_tracer(fields, field_name, grid)
+        end
+    else
+        fields = fields
+    end
+
+    return fields
+end
+
+"""
+    validate_microphysics(tracers, auxiliary_fields, mp, grid, clock)
+
+Ensure that `tracers` contains microphysics tracers and `auxiliary_fields`
+contains microphysics auxiliary fields.
+"""
+@inline function validate_microphysics(tracers, auxiliary_fields, mp, grid, clock)
+    req_tracers = required_microphysics_tracers(mp)
+    tracers = has_microphysics_tracers(tracers, req_tracers, grid)
+    req_auxiliary_fields = required_microphysics_auxiliary_fields(mp)
+
+    all(field ∈ tracernames(auxiliary_fields) for field in req_auxiliary_fields) ||
+        error("$(req_auxiliary_fields) must be among the list of auxiliary fields to use $(typeof(mp).name.wrapper)")
+
+    # Return tracers and aux fields so that users may overload and
+    # define their own special auxiliary fields
+    return tracers, auxiliary_fields
+end
+
+const AbstractMicrophysicsOrNothing = Union{Nothing, AbstractMicrophysics}
+required_microphysics_tracers(::AbstractMicrophysicsOrNothing) = ()
+required_microphysics_auxiliary_fields(::AbstractMicrophysicsOrNothing) = ()
diff --git a/src/Microphysics/microphysics_1m.jl b/src/Microphysics/microphysics_1m.jl
new file mode 100644
index 00000000..ec627d45
--- /dev/null
+++ b/src/Microphysics/microphysics_1m.jl
@@ -0,0 +1,155 @@
+struct Microphysics1M{TH, SV, PAR} <: AbstractMicrophysics
+    thermodynamics::TH
+    sedimentation_velocities:: SV
+    parameters:: PAR
+end
+
+function Microphysics1M(grid; thermodynamics, parameters)
+    sedimentation_velocities = (; ρq_rai = ZFaceField(grid), ρq_sno = ZFaceField(grid))
+    Microphysics1M(thermodynamics, sedimentation_velocities, parameters)
+end
+
+required_microphysics_tracers(::Microphysics1M) = (:ρq_tot, :ρq_liq, :ρq_ice, :ρq_rai, :ρq_sno, :ρe_tot)
+required_microphysics_auxiliary_fields(::Microphysics1M) = (:rho, :PAR)
+
+@inline specific(ρ, values...) = (value/ρ for value in values)
+
+@inline function (mp::Microphysics1M)(::Val{:ρq_liq}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dt = PAR.dt
+    q_tot, q_liq, q_ice, q_rain, q_snow = specific(ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    T = air_temperature(mp.thermodynamics, ρe_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    
+    cond_vapor_liquid = cloud_liquid_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    auto_liquid_rain = autoconversion_liquid_to_rain_rate(mp, q_liq, ρ, dt)
+    acc_cloud_rain = accretion_cloud_rain_rate(mp, q_liq, q_rain, ρ, dt)
+    acc_cloud_snow = accretion_cloud_snow_rate(mp, q_liq, q_snow, ρ, T, dt)
+
+    return ρ * (cond_vapor_liquid.liq + auto_liquid_rain.liq + acc_cloud_rain.liq + acc_cloud_snow.liq)
+end
+
+@inline function (mp::Microphysics1M)(::Val{:ρq_ice}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dt = PAR.dt
+    q_tot, q_liq, q_ice, q_rain, q_snow = specific(ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    T = air_temperature(mp.thermodynamics, ρe_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+
+    cond_vapor_ice = cloud_ice_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    auto_ice_snow = autoconversion_ice_to_snow_rate(mp, q_ice, dt)
+    acc_ice_snow = accretion_ice_snow_rate(mp, q_ice, q_snow, ρ, dt)
+    acc_ice_rain_snow = accretion_ice_rain_to_snow_rate(mp, q_ice, q_rain, ρ, dt)
+
+    return ρ * (cond_vapor_ice.ice + auto_ice_snow.ice + acc_ice_snow.ice + acc_ice_rain_snow.ice)
+end
+
+@inline function (mp::Microphysics1M)(::Val{:ρq_rai}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dt = PAR.dt
+    q_tot, q_liq, q_ice, q_rain, q_snow = specific(ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    T = air_temperature(mp.thermodynamics, ρe_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+
+    auto_liquid_rain = autoconversion_liquid_to_rain_rate(mp, q_liq, ρ, dt)
+    acc_cloud_rain = accretion_cloud_rain_rate(mp, q_liq, q_rain, ρ, dt)
+    acc_snow_rain = accretion_snow_rain_rate(mp, q_rain, q_snow, ρ, T, dt)
+    acc_cloud_snow = accretion_cloud_snow_rate(mp, q_liq, q_snow, ρ, T, dt)
+    sink_ice_rain = rain_sink_from_ice_rate(mp, q_ice, q_rain, ρ, dt)
+    evaporation_rain = rain_evaporation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    melt_snow_rain = snow_melt_rate(mp, q_snow, ρ, T, dt)
+
+    return ρ * (auto_liquid_rain.rain + acc_cloud_rain.rain + acc_cloud_snow.rain + acc_ice_rain_snow.rain + acc_snow_rain.rain + sink_ice_rain.rain + evaporation_rain.rain + melt_snow_rain.rain)
+end
+
+@inline function (mp::Microphysics1M)(::Val{:ρq_sno}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR) 
+    dt = PAR.dt
+    q_tot, q_liq, q_ice, q_rain, q_snow = specific(ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    T = air_temperature(mp.thermodynamics, ρe_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+
+    auto_ice_snow = autoconversion_ice_to_snow_rate(microphysics, q_ice, dt_ft)
+    acc_ice_snow = accretion_ice_snow_rate(microphysics, q_ice, q_snow, ρi, dt_ft)
+    acc_cloud = accretion_cloud_snow_rate(microphysics, q_liq, q_snow, ρi, Ti, dt_ft)
+    acc_ice_rain_snow = accretion_ice_rain_to_snow_rate(microphysics, q_ice, q_rain, ρi, dt_ft)
+    acc_snow_rain = accretion_snow_rain_rate(microphysics, q_rain, q_snow, ρi, Ti, dt_ft)
+    melt_snow_rain = snow_melt_rate(microphysics, q_snow, ρi, Ti, dt_ft)
+    deposition_vapor_snow = snow_deposition_rate(microphysics, q_tot, q_liq, q_ice, q_rain, q_snow, ρi, Ti, dt_ft)
+
+    return ρ * (auto_ice_snow.snow + acc_ice_snow.snow + acc_cloud.snow + acc_ice_rain_snow.snow + acc_snow_rain.snow + melt_snow_rain.snow + deposition_vapor_snow.snow)
+end
+
+@inline function (mp::Microphysics1M)(::Val{:ρq_tot}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dρ_liq = mp(:ρq_liq, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dρ_ice = mp(:ρq_ice, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dρ_rai = mp(:ρq_rai, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dρ_sno = mp(:ρq_sno, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    return dq_liq + dq_ice + dq_rai + dq_sno
+end
+
+@inline function (mp::Microphysics1M)(::Val{:ρe_tot}, x, y, z, t, ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno, ρe_tot, PAR)
+    dt = PAR.dt
+    q_tot, q_liq, q_ice, q_rain, q_snow = specific(ρ, ρq_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    T = air_temperature(mp.thermodynamics, ρe_tot, ρq_liq, ρq_ice, ρq_rai, ρq_sno)
+    Lv = latent_heat_vapor(mp.thermodynamics, T)
+    Ls = latent_heat_sublimation(mp.thermodynamics, T)
+    Lf = latent_heat_fusion(mp.thermodynamics, T)
+
+    cond_vapor_liquid = cloud_liquid_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    cond_vapor_ice = cloud_ice_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    acc_cloud_snow = accretion_cloud_snow_rate(mp, q_liq, q_snow, ρ, T, dt)
+    rain_sink_ice = rain_sink_from_ice_rate(mp, q_ice, q_rain, ρ, T, dt)
+    acc_snow_rain = accretion_snow_rain_rate(mp, q_rain, q_snow, ρ, T, dt)
+    rain_evap = rain_evaporation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+    snow_melt = snow_melt_rate(mp, q_snow, ρ, T, dt)
+    snow_dep = snow_deposition_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+
+    l_vapor_liquid = Lv * cond_vapor_liquid.liq
+    l_cond_ice = Ls * cond_vapor_ice.ice
+    l_acc_cloud_snow = Lf * acc_cloud_snow.snow
+    l_rain_sink_ice = Lf * rain_sink_ice.snow
+    l_acc_snow_rain = Lf * acc_snow_rain.snow
+    l_rain_evap = Lv * rain_evap.rain
+    l_snow_melt = Lf * snow_melt.snow
+    l_snow_dep = Ls * snow_dep.snow
+
+    return ρ * (l_vapor_liquid + l_cond_ice + l_acc_cloud_snow + l_rain_sink_ice + l_acc_snow_rain + l_rain_evap + l_snow_melt + l_snow_dep)
+end
+
+@inline microphysics_sedimentation_velocity(mp::Microphysics1M, ::Val{:ρq_rai}) =
+    (; u = ZeroField(), v = ZeroField(), w = mp.sedimentation_velocities.ρq_rai)
+
+@inline microphysics_sedimentation_velocity(mp::Microphysics1M, ::Val{:ρq_sno}) =
+    (; u = ZeroField(), v = ZeroField(), w = mp.sedimentation_velocities.ρq_sno)
+
+function update_microphysics_state!(mp::Microphysics1M, model, kernel_parameters; active_cells_map = nothing)
+    w_velocities             = mp.sedimentation_velocities
+    arch                     = architecture(model.grid)
+    grid                     = model.grid
+    density                  = model.density
+    parameters               = mp.parameters
+
+    exclude_periphery = true
+    for tracer_name in sedimenting_tracers(mp)
+        tracer_field = model.tracers[tracer_name]
+        #tracer_w_velocity_bc = mp.sedimentation_velocities[tracer_name].boundary_conditions.immersed
+        w_kernel_args = tuple(Val(tracer_name), density, tracer_field, parameters)
+        #w_kernel_args = tuple(Val(tracer_name), density, tracer_field, parameters, tracer_w_velocity_bc)
+        launch!(arch, grid, kernel_parameters, compute_sedimentation_velocity!, 
+                w_velocities[tracer_name], grid, w_kernel_args;
+                active_cells_map, exclude_periphery)
+        fill_halo_regions!(w_velocities[tracer_name])
+    end
+
+    return nothing
+end
+
+@kernel function compute_sedimentation_velocity!(w_sed, grid, args) 
+    i, j, k = @index(Global, NTuple)
+    @inbounds w_sed[i, j, k] = w_sedimentation_velocity(i, j, k, grid, args...)
+end
+
+@inline function w_sedimentation_velocity(i, j, k, grid, microphysics::Microphysics1M, ::Val{:ρq_rai}, ρ, ρq_rai)
+    ρᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρ)
+    ρq_raiᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρq_rai)
+    return CM1.terminal_velocity(microphysics.parameters.pr, microphysics.parameters.tv.rain, ρᶜᶜᶠ, ρq_raiᶜᶜᶠ/ ρᶜᶜᶠ)
+end
+
+@inline function w_sedimentation_velocity(i, j, k, grid, microphysics::Microphysics1M, ::Val{:ρq_sno}, ρ, ρq_sno)
+    ρᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρ)
+    ρq_snoᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρq_sno)
+    return CM1.terminal_velocity(microphysics.parameters.ps, microphysics.parameters.tv.snow, ρᶜᶜᶠ, ρq_snoᶜᶜᶠ/ ρᶜᶜᶠ)
+end
diff --git a/src/Microphysics/process_rates.jl b/src/Microphysics/process_rates.jl
new file mode 100644
index 00000000..9e571bc8
--- /dev/null
+++ b/src/Microphysics/process_rates.jl
@@ -0,0 +1,303 @@
+
+const CM1 = CloudMicrophysics.Microphysics1M
+const CMNe = CloudMicrophysics.MicrophysicsNonEq
+const CMP = CloudMicrophysics.Parameters
+
+# ------------------------------------------------------------------
+# Microphysical process rates
+# ------------------------------------------------------------------
+
+"""
+    cloud_liquid_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+
+Return the net tendency (kg kg⁻¹ s⁻¹) for cloud liquid water produced by
+supersaturation-driven condensation/evaporation. Positive values indicate vapor
+condensing into cloud droplets; negative values correspond to evaporation.
+"""
+@inline function cloud_liquid_condensation_rate(
+    mp::Microphysics1M{FT},
+    q_tot::FT,
+    q_liq::FT,
+    q_ice::FT,
+    q_rain::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    qv = q_vapor(q_tot, q_liq, q_ice, q_rain, q_snow)
+    q_sat = convert(FT, saturation_specific_humidity(T, ρ, mp.thermodynamics, mp.thermodynamics.liquid))
+
+    raw = qv + q_liq > FT(0) ?
+        CMNe.conv_q_vap_to_q_liq_ice_MM2015(
+            mp.parameters.cl,
+            mp.thermodynamics,
+            q_tot,
+            q_liq,
+            q_ice,
+            q_rain,
+            q_snow,
+            ρ,
+            T,
+        ) :
+        FT(0)
+
+    return (; liq = raw > FT(0) ?
+        triangle_inequality_limiter(raw, limit_available(qv - q_sat, dt, 2)) :
+        -triangle_inequality_limiter(-raw, limit_available(q_liq, dt, 2)))
+end
+
+"""
+    cloud_ice_condensation_rate(mp, q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T, dt)
+
+Return the net tendency (kg kg⁻¹ s⁻¹) for cloud ice resulting from deposition
+or sublimation. Supersaturation relative to ice yields positive tendencies;
+evaporation produces negative values. Ice formation is suppressed above the
+snow freezing temperature.
+"""
+@inline function cloud_ice_condensation_rate(
+    mp::Microphysics1M{FT},
+    q_tot::FT,
+    q_liq::FT,
+    q_ice::FT,
+    q_rain::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    qv = q_vapor(q_tot, q_liq, q_ice, q_rain, q_snow)
+    q_sat = convert(FT, saturation_specific_humidity(T, ρ, mp.thermodynamics, mp.thermodynamics.solid))
+
+    raw = qv + q_ice > FT(0) ?
+        CMNe.conv_q_vap_to_q_liq_ice_MM2015(
+            mp.parameters.ci,
+            mp.thermodynamics,
+            q_tot,
+            q_liq,
+            q_ice,
+            q_rain,
+            q_snow,
+            ρ,
+            T,
+        ) :
+        FT(0)
+
+    if T > mp.parameters.ps.T_freeze && raw > FT(0)
+        raw = FT(0)
+    end
+
+    return (; ice = raw > FT(0) ?
+        triangle_inequality_limiter(raw, limit_available(qv - q_sat, dt, 2)) :
+        -triangle_inequality_limiter(-raw, limit_available(q_ice, dt, 2)))
+end
+
+"""
+    autoconversion_liquid_to_rain_rate(mp, q_liq, ρ, dt)
+
+One-moment warm-rain autoconversion mass flux transferring cloud liquid water
+into rain water. Returns a `NamedTuple(liq=-S, rain=S)` suitable for direct
+accumulation into tracer tendencies.
+"""
+@inline function autoconversion_liquid_to_rain_rate(
+    mp::Microphysics1M{FT},
+    q_liq::FT,
+    ρ::FT,
+    dt::FT,
+) where {FT}
+
+    raw = mp.parameters.Ndp <= FT(0) ?
+        CM1.conv_q_liq_to_q_rai(mp.parameters.pr.acnv1M, q_liq, true) :
+        CM2.conv_q_liq_to_q_rai(mp.parameters.var, q_liq, ρ, mp.parameters.Ndp)
+
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_liq, dt, 5))
+    return (; liq = -rate, rain = rate)
+end
+
+"""
+    autoconversion_ice_to_snow_rate(mp, q_ice, dt)
+
+Cold-phase autoconversion mapping cloud ice onto the snow category. Returns
+`NamedTuple(ice=-S, snow=S)`.
+"""
+@inline function autoconversion_ice_to_snow_rate(
+    mp::Microphysics1M{FT},
+    q_ice::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.conv_q_ice_to_q_sno_no_supersat(mp.parameters.ps.acnv1M, q_ice, true)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_ice, dt, 5))
+    return (; ice = -rate, snow = rate)
+end
+
+@inline function accretion_cloud_rain_rate(
+    mp::Microphysics1M{FT},
+    q_liq::FT,
+    q_rain::FT,
+    ρ::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.accretion(mp.parameters.cl, mp.parameters.pr, mp.parameters.tv.rain, mp.parameters.ce, q_liq, q_rain, ρ)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_liq, dt, 5))
+    return (; liq = -rate, rain = rate)
+end
+
+@inline function accretion_ice_snow_rate(
+    mp::Microphysics1M{FT},
+    q_ice::FT,
+    q_snow::FT,
+    ρ::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.accretion(mp.parameters.ci, mp.parameters.ps, mp.parameters.tv.snow, mp.parameters.ce, q_ice, q_snow, ρ)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_ice, dt, 5))
+    return (; ice = -rate, snow = rate)
+end
+
+@inline function accretion_cloud_snow_rate(
+    mp::Microphysics1M{FT},
+    q_liq::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.accretion(mp.parameters.cl, mp.parameters.ps, mp.parameters.tv.snow, mp.parameters.ce, q_liq, q_snow, ρ)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_liq, dt, 5))
+
+    if T < mp.parameters.ps.T_freeze
+        snow_rate = rate
+        rain_rate = zero(FT)
+    else
+        α = max(zero(FT), fusion_factor(mp, T))
+        snow_rate = -triangle_inequality_limiter(rate * α, limit_available(q_snow, dt, 5))
+        rain_rate = rate - snow_rate
+    end
+
+    return (; liq = -rate, snow = snow_rate, rain = rain_rate)
+end
+
+@inline function accretion_ice_rain_to_snow_rate(
+    mp::Microphysics1M{FT},
+    q_ice::FT,
+    q_rain::FT,
+    ρ::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.accretion(mp.parameters.ci, mp.parameters.pr, mp.parameters.tv.rain, mp.parameters.ce, q_ice, q_rain, ρ)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_ice, dt, 5))
+    return (; ice = -rate, snow = rate)
+end
+
+@inline function rain_sink_from_ice_rate(
+    mp::Microphysics1M{FT},
+    q_ice::FT,
+    q_rain::FT,
+    ρ::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.accretion_rain_sink(mp.parameters.pr, mp.parameters.ci, mp.parameters.tv.rain, mp.parameters.ce, q_ice, q_rain, ρ)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_rain, dt, 5))
+    return (; rain = -rate, snow = rate)
+end
+
+@inline function accretion_snow_rain_rate(
+    mp::Microphysics1M{FT},
+    q_rain::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    if T < mp.parameters.ps.T_freeze
+        raw = CM1.accretion_snow_rain(
+            mp.parameters.ps,
+            mp.parameters.pr,
+            mp.parameters.tv.rain,
+            mp.parameters.tv.snow,
+            mp.parameters.ce,
+            q_snow,
+            q_rain,
+            ρ,
+        )
+        rate = triangle_inequality_limiter(clip(raw), limit_available(q_rain, dt, 5))
+    else
+        raw = CM1.accretion_snow_rain(
+            mp.parameters.pr,
+            mp.parameters.ps,
+            mp.parameters.tv.snow,
+            mp.parameters.tv.rain,
+            mp.parameters.ce,
+            q_rain,
+            q_snow,
+            ρ,
+        )
+        rate = -triangle_inequality_limiter(clip(raw), limit_available(q_snow, dt, 5))
+    end
+
+    return (; snow = rate, rain = -rate)
+end
+
+@inline function rain_evaporation_rate(
+    mp::Microphysics1M{FT},
+    q_tot::FT,
+    q_liq::FT,
+    q_ice::FT,
+    q_rain::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    rps = (mp.parameters.pr, mp.parameters.tv.rain, mp.parameters.aps, mp.thermodynamics)
+    raw = CM1.evaporation_sublimation(rps..., q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T)
+    rate = -triangle_inequality_limiter(-raw, limit_available(q_rain, dt, 5))
+    return (; rain = rate)
+end
+
+@inline function snow_melt_rate(
+    mp::Microphysics1M{FT},
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    raw = CM1.snow_melt(mp.parameters.ps, mp.parameters.tv.snow, mp.parameters.aps, mp.thermodynamics, q_snow, ρ, T)
+    rate = triangle_inequality_limiter(clip(raw), limit_available(q_snow, dt, 5))
+    return (; snow = -rate, rain = rate)
+end
+
+@inline function snow_deposition_rate(
+    mp::Microphysics1M{FT},
+    q_tot::FT,
+    q_liq::FT,
+    q_ice::FT,
+    q_rain::FT,
+    q_snow::FT,
+    ρ::FT,
+    T::FT,
+    dt::FT,
+) where {FT}
+
+    sps = (mp.parameters.ps, mp.parameters.tv.snow, mp.parameters.aps, mp.thermodynamics)
+    raw = CM1.evaporation_sublimation(sps..., q_tot, q_liq, q_ice, q_rain, q_snow, ρ, T)
+
+    if raw > FT(0)
+        rate = triangle_inequality_limiter(raw, limit_available(q_vapor(q_tot, q_liq, q_ice, q_rain, q_snow), dt, 5))
+    else
+        rate = -triangle_inequality_limiter(-raw, limit_available(q_snow, dt, 5))
+    end
+
+    return (; snow = rate)
+end
\ No newline at end of file
diff --git a/src/Microphysics/sedimentation_velocities.jl b/src/Microphysics/sedimentation_velocities.jl
new file mode 100644
index 00000000..d0e0e1d1
--- /dev/null
+++ b/src/Microphysics/sedimentation_velocities.jl
@@ -0,0 +1,11 @@
+@inline function w_sedimentation_velocity(i, j, k, grid, microphysics::Microphysics1M, ::Val{:ρq_rai}, ρ, ρq_rai)
+    ρᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρ)
+    ρq_raiᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρq_rai)
+    return CM1.terminal_velocity(microphysics.parameters.pr, microphysics.parameters.tv.rain, ρᶜᶜᶠ, ρq_raiᶜᶜᶠ/ ρᶜᶜᶠ)
+end
+
+@inline function w_sedimentation_velocity(i, j, k, grid, microphysics::Microphysics1M, ::Val{:ρq_sno}, ρ, ρq_sno)
+    ρᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρ)
+    ρq_snoᶜᶜᶠ = ℑzᵃᵃᶠ(i, j, k, grid, ρq_sno)
+    return CM1.terminal_velocity(microphysics.parameters.ps, microphysics.parameters.tv.snow, ρᶜᶜᶠ, ρq_snoᶜᶜᶠ/ ρᶜᶜᶠ)
+end