(6 intermediate revisions by the same user not shown)

Line 24:

''

''

==R-Checks Monthly Highlights==

==R-Checks Monthly Highlights==

+

=== April 2026 ===

+

'''CHIRPS v3: Final versus Prelim''' This [https://data.chc.ucsb.edu/products/CHIRPS/v3.0/diagnostics/chirps_minus_prelim/archive/Difference_global_202604.png map] shows the difference between Prelim data and Final data, for April 2026 CHIRPS v3. This [https://data.chc.ucsb.edu/products/CHIRPS/v3.0/diagnostics/chirps_minus_prelim/archive/PercentDifference_global_202604.png map] shows the ratio of values.

+

'''CHIRPS v2: Final versus Prelim''' This [https://data.chc.ucsb.edu/products/CHIRPS/v3.0/diagnostics/chirps_minus_prelim/v2/archive/Difference_global_202604.png map] shows the difference between Prelim data and Final data, for April 2026 CHIRPS v2. This [https://data.chc.ucsb.edu/products/CHIRPS/v3.0/diagnostics/chirps_minus_prelim/v2/archive/PercentDifference_global_202604.png map] shows the ratio of values.

+

''' Data notes: New SSOD station archive''' This month CHIRPS began blending station reports from the Synoptic Summary of the Day (SSOD), a new source that is intended to replace the Global Summary of the Day (GSOD). The GSOD archive ended in August 2025. Like other global sources, and some regional sources, we put SSOD through an automated quality control step that screens for false zeros, then we blend the QCed data (fSSOD) into CHIRPS v3 Final. Currently, for April 2026 CHIRPS v3 data, the SSOD reports are in eleven countries, and this number is expected to increase.

+

'''Data notes: Eurasia''' CHIRP v3 and CHIRPS v3 again underestimated precipitation in the region around eastern Europe to central Asia, including in western Russia, Ukraine, northern Turkiye, Kazakhastan, based on stations. The very low CHIRP values and blending algorithm resulted in the stations, though included, having little ability to raise CHIRPS v3 values. This is an issue that has been seen before during this time of year in CHIRP/S v3. e.g. December 2025.

+

'''Cambodia''' This month, with the inclusion of the new SSOD station dataset in the CHIRPS v3 blending process, Cambodia gained four new stations in CHIRPS v3 Final. This is helpful as this is the oblu source with stations located in Cambodia. In the SSOD archive there is metadata for 23 stations, though only these 4 stations had available reports to blend into CHIRPS. 

+

'''South Africa''' April rainfall was well above average in western Cape, South Africa, with heavy rainfall and associated flooding. This is reflected in CHIRPSv3 and CHIRPS v2.

+

'''Europe''' CHIRP (without stations) indicated fairly above-average conditions for April. However, stations (and several news reports) indicate April conditions were actually quite dry. The contrast between CHIRP and CHIRPS is notably in Germany, where extensive station reporting is available. A similar, albeit less dramatic, example can be seen in Portugal and Spain.

+

'''United States''' CHIRP v3 (satellite-only subset of CHIRPS) outperfromed IMERG Late in rainfall estimation over the central United States, across the region from Illinois to Arkansas. IMERG underestimated rainfall, while the CHIRP estimates closely matched station reports. Over the northern Sierra Nevada mountain range in California, CHIRP v3 underestimated precipitation, and the blending of stations brought CHIRPS v3 values close to reported values in that area.

+

'''New Zealand''' CHIRP v2 and v3 are pretty different for NZ's South Island, for April 2026 totals. CHIRP v3 is more accurate, based on the station reports. 

+

'''Rchecks plots''' This was one of the top two wettest Aprils on record for Haiti, South America, and the Great Lakes region. There were notable differences this month between CHIRP (satellite-only) and CHIRPS (with station data), particularly across Europe. Consistent with this, the global-average CHIRP–CHIRPS difference ranked among the three largest April discrepancies in the historical record. See the 'Data notes: Eurasia' entry above for more information on this. Plots are available [https://data.chc.ucsb.edu/products/CHIRPS/v3.0/diagnostics/rchecks/monthly_compares/?C=M&O=D here].

+

=== March 2026 ===

=== March 2026 ===

CHG-Wiki - Recent changes [en]

CHIRPS Reality Checks