Redistribution of 24 hour precipitation

RR_24 is the precipitation collected over the last 24 hours. The Qc1 check precipcollected_flag identifies if an RR_24 value is valid (fd=1), erroneous (fd=3) or is the accumulation (fd=2) of a number (N) of consecutive 24 hour periods, where N>1. For the case fd=2, the accumulated value shall be distributed over the N 24 hours periods.

For each day the calculated

RR_24= model_value*observed_accumulation/sum_of_model_values

where the model values for the N missing values of RR_24 are calculated by an interpolation from the other stations making measurements at the same time and for which fd=1. At present, the interpolation uses an inverse 2-D squared distance weighting. Other weighting and interpolation techniques might be added later.

The calculated RR_24 updates the corrected value in the kvalobs database.

A warning is given if fmis=0 and original!=-1.

Configuration and Parameters

The standard configuration options detailed in the user guide also apply to Redistribution.

Further configuration options are:

Option	Default	Description
endpoint_cflags	fmis=[04]&fd=2&fhqc=0	specify the flags for accumulation endpoints. Endpoints not matching these flags will not be detected
endpoint_uflags	no constraints
missingpoint_cflags	fmis=3&fd=2	specify the flags for the missing points before the accumulation
missingpoint_uflags	no constraints
neighbor_cflags	fd=1	specify requirements for the neighbor stations used for the interpolations. Neighbor stations that do not match these flags will be ignored.
neighbor_uflags	U2=0
warn_and_stop_cflags	fhqc=)0(	define for which flags for the accumulation point or the missing points before the accumulation the only action should be to print a warning and stop
warn_and_stop_uflags	no constraints
update_flagchange	fd=7;fmis=3->fmis=1	flags to change for the accumulation endpoint and the missing points
ParamId	---	selects the parameter ids to use. The only value tested here is 110 (RR_24).
tids	---	accepted typeids
measurement_hour	6	specifies the hour at which the data are expected. Series containing data with other times will be rejected with a warning.
min_neighbors	1	specifies the minimum number of neighbor stations with good data
max_neighbors	5	specifies the maximum number of neighbor stations to use
InterpolationDistance	100	radius in km inside which to search neighbor stations
warning_distance_closest_neighbor	50	minimum neighbor distance to print an INFO message about not so good neighbors
days_before_no_neighbor_warning	14	specifies the number of days after which a WARN is written to the logfile if there are not enough neighbor data
days_before_redistributing_zeroes_warning	14	specifies the number of days after which a WARN is written to the logfile if a non-dry accumulation has only dry neighbors

Parameters

This algorithm has only been tested for paramid 110.