Max 5-Day Precipitation RX5day Extractor
Extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation.
Description
Maximum five-day precipitation measures the largest accumulated rainfall over a consecutive five-day interval.
Maximum five-day precipitation measures the largest accumulated rainfall over a consecutive five-day interval. Overlapping windows help capture a multi-day event even when its start does not align with a calendar week.1, 2
Extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation.
When to use Max 5-Day Precipitation RX5day Extractor
Use this tool to extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation.
Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.
How to use Max 5-Day Precipitation RX5day Extractor and understand its results
- Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.
- Enter dailyPrecipitationMm using the field table and calculation rules, then run the tool.
- Read rx5dayMm, firstMaximumWindowStartIndex, completeFiveDayWindowTotalsMm. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| dailyPrecipitationMm | Daily precipitation mm | list of number | Required |
Supply at least five nonnegative daily precipitation values in mm. The tool sums each complete overlapping five-sample window independently, returns all window totals, and selects the largest total and the zero-based start index of its first occurrence. Independent summation avoids cancellation from repeatedly subtracting old rainfall from a rolling total.
S_i = P_i + P_(i+1) + P_(i+2) + P_(i+3) + P_(i+4); Rx5day = max S_i Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| rx5dayMm | Rx5day mm | number |
| firstMaximumWindowStartIndex | First maximum window start index | number |
| completeFiveDayWindowTotalsMm | Complete five day window totals mm | list of number |
{
"input": {
"dailyPrecipitationMm": [
1,
2,
3,
4,
5,
0
]
},
"output": {
"rx5dayMm": 15,
"firstMaximumWindowStartIndex": 0,
"completeFiveDayWindowTotalsMm": [
15,
14
]
}
}Limitations and assumptions
The input must be a gap-free daily series; five samples are treated as five consecutive days. Windows can cross calendar boundaries within the supplied list. The tool does not choose annual reporting periods or estimate a return period or flood discharge.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Max 1-Day Precipitation RX1day Extractor: Extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series. For a complementary task, use Simple Daily Intensity Index SDII: Compute SDII using observed precipitation only on wet days at caller inclusive threshold; zero observed wet days is undefined rather than inventing a daily intensity.
Further background: Climate extreme index definitions.
References
-
Max 5-Day Precipitation RX5day Extractor — tool.io
-
Climate extreme index definitions — Climdex
Similar or alternative tools
- Max 1-Day Precipitation RX1day Extractor
Extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series.
- Simple Daily Intensity Index SDII
Compute SDII using observed precipitation only on wet days at caller inclusive threshold; zero observed wet days is undefined rather than inventing a daily intensity.