National Weather Service United States Department of Commerce

Heat Across the Center of the Nation; Severe Thunderstorms Across the Great Lakes and Ohio Valley

Heat expands across the Desert Southwest, Plains, Mississippi Valley and Midwest into Monday. Fire weather concerns continue for portions of the Intermountain West. Active monsoonal moisture fuels thunderstorms over the Southwest with possible flash flooding. Tropical cyclone Fausto in the Pacific, should weaken as it approaches Hawaii; Dangerous surf, swells and rip currents are expected. Read More >

 

  Drought Severity Classifications

 

Ranges

Category

Description

Possible Impacts

Palmer Drought Index

CPC Soil
Moisture Model
(Percentiles)

USGS Weekly Streamflow
(Percentiles)

Standardized Precipitation Index (SPI)

Objective Short and Long-term Drought Indicator Blends (Percentiles)

D0

Abnormally
Dry

Going into drought: short-term dryness slowing planting, growth of crops or pastures. Coming out of drought: some lingering water deficits;  pastures or crops not fully recovered

-1.0 to -1.9

21-30

21-30

-0.5 to -0.7

21-30

D1

Moderate Drought

Some damage to crops, pastures; streams, reservoirs, or wells low, some water shortages developing or imminent; voluntary water-use restrictions requested

-2.0 to -2.9

11-20

11-20

-0.8 to -1.2

11-20

D2

Severe
Drought

Crop or pasture losses likely;  water shortages common; water restrictions imposed

-3.0 to -3.9

6-10

6-10

-1.3 to -1.5

6-10

D3

Extreme Drought

Major crop/pasture losses;  widespread water shortages or restrictions

-4.0 to -4.9

3-5

3-5

-1.6 to -1.9

3-5

D4

Exceptional Drought

Exceptional and widespread crop/pasture losses; shortages of water in reservoirs, streams, and wells creating water emergencies

-5.0 or less

0-2

0-2

-2.0 or less

0-2