PDSI is Palmer Drought Severity Index, an indirect measure of soil moisture, relative to local baseline climate. SC means self-calibrating.
"The index is the difference between the amount of precipitation required to retain a normal water-balance level and the amount of actual precipitation."
Light blue (-4.0 to -5.0) is extremely wet, red (+4.0 to +5.0) is extremely dry.
These 10-year averages did not occur in the model results before 2000,
Baseline climate period is probably a 30-year period before 1965.
The maps display soil moisture, not precipitation. With the same amount of rain and more evaporation, soil moisture decreases.
Note that southern Europe is extremely dry by the 2060s and especially the 2090s, perhaps Saharan.
The USA is a lesser case of such dryness.
So are the much of the Amazon basin and the Andes, central America, southern Africa, and Australia.
Note also the increasing soil moisture around the Acrtic.
Extremely wet conditions prevail in Indonesia, India, equatorial east Africa, Ecuador, and southern New Zealand.
Aiguo Dai, Kevin Trenberth et al.
The two maps below are from IPCC 5, Technical Assessment (2013).
Multi-Year Droughts Are Worsening. Here’s Where They Have the Most Effects. 0125.rtf
Climate Crisis ‘Wreaking Havoc’ on Earth’s Water Cycle 0125.rtf
3:4 of Earth’s Land Got Drier in Recent Decades - UN 1224.rtf
Why Hydropower Is Failing This Nation — and Could Fail Others 1124.rtf
Why Future Droughts Will Not Be about Rain 1124.rtf
Extreme Drought Areas Tripled in Size since 1980s 1024.rtf
Drought Touches 1:4 of Humanity, Disrupting Lives Globally 0124.rtf
UN Drought Report Highlights ‘Silent’ Threat to Warming Planet 1223.rtf
Extreme Droughts by 2030 - Dai 0111 2.pdf
Extreme Droughts by 2030 - Dai 0111.pdf
Very Hot and Very Dry Conditions Have Doubled Worldwide 1118.rtf
No Rain for Decades - Stand by for the ‘Megadroughts’, Scientists Warn 0914.rtf
Global Drought Threatens Water, Food Supplies. Get Used to It. 0914.rtf
Shrinking Aquifers in Drought-Stricken Areas 0613.rtf
Global Drought a New Normal 1012.rtf
Extreme Droughts by 2030 1010.rtf - This is a summary of the above study.
50-Year Droughts Plague World's Breadbaskets 0309.rtf
Climate Change Drives Water Shortages for Half the World 1108.rtf
Also available at https://journals.ametsoc.org/view/journals/hydr/5/6/jhm-386_1.xml for "A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming" in Journal of Hydrometeorology, December 1, 2004, pp. 1117-1130.
Two key figures are excerpted below, with Dr. Fry's annotations.
The slide below summarizes what has been happening with water tables, as groundwater is used ever more to cope with droughts and supply irrigation water for the Green Revolution.
Section Map: Droughts, Deserts & Fires