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U.S. Regional Drought Watch

National Climatic Data Center, 17 June 2002

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Global Analysis / Global Hazards / United States / U.S. Drought / Extreme Events
Use these links to access detailed analyses of Global and U.S. data.

Regional Drought Overview / Western U.S. / Central U.S. / Eastern U.S. / Additional Contacts / Questions

Click here to go to Top of Page Regional Overview

May was very dry across much of the western U.S. and adjoining Great Plains, the Gulf Coast, and parts of the mid-Atlantic states. Near-normal precipitation fell across part of the Pacific Northwest, mainly Washington and the extreme northern Rockies. Beneficial rains continued for a third month bringing drought relief to a good part of the Northeast. May was wet at the primary stations in Hawaii, dry at many stations in Puerto Rico, and showed a mixed pattern across Alaska.

These overall conditions are evident in the following indicators:

Two other drought-related monitoring tools are the Vegetation Health Index and the Keetch-Byram Drought Index:

  • NOAA satellite observations of vegetation health from early June revealed stress on vegetation across much of the southwestern U.S. and in parts of the Plains and northern and central Rockies.
  • The USDA Forest Service uses a satellite-based vegetation health index tool to monitor the risk of wildfires. This Greenness Index for mid-May revealed above-average stress on vegetation across much of the West and Great Plains, extending into the Great Lakes region.
  • The Keetch-Byram Drought Index (KBDI) is used by the Wildland Fire Assessment System to monitor the risk of wildfires. The early June KBDI showed dry conditions in the Desert Southwest, parts of the central and northern Rockies, and from the southern Plains to the mid-Atlantic coast. The Forest Service fire danger analysis indicated a high risk of wildfires in the Southwest, across much of the Great Plains, and in parts of the southern Great Lakes and New England. The fire threat conditions can change rapidly from week to week.


Click here to go to Top of Page Western U.S. Drought

While beneficial rain and snow fell across part of the Pacific Northwest, mainly Washington and the extreme northern Rockies, short-term drought characterized the conditions across much of the western U.S. during May. Water year (October 2001-present) precipitation totals were above average in the northwest, but totals dropped precipitously toward the Rockies and the Southwest. Snowpacks were essentially melted for this water year except for the higher elevations of the northern Rockies, northern Cascades, and Canada.

A detailed discussion of drought conditions in the western U.S. can be found for the following regions:

Dry conditions in the western U.S. stretched from the Canadian border to the Mexican border. As illustrated in the North America vegetation health index map to the right below, the drought did not stop at the borders. According to news reports (Reuters),

  • several stations in the Canadian prairie provinces of Saskatchewan and Alberta had a record or near-record dry May this year
  • forest and grass fires, dust storms, and drying water holes have accompanied the dry weather
  • with dryness throughout the central and southern areas of the plains provinces of Manitoba, Saskatchewan and Alberta, some experts now believe between one half to two thirds of Canada's western grainbelt is suffering from a moisture deficit
  • five counties in eastern Alberta, along the border with Saskatchewan, have already declared an agricultural disaster
  • for many farmers, this is the third, or even fourth year of drought.
Click here for map showing June 2, 2002, North America Vegetation Health Index
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The drought in the western U.S. extended into the adjoining portions of the Great Plains. The precipitation deficits across this entire region, stretching from the High Plains to the West Coast, have ranked in the top ten driest category (out of 107-108 years) for all seasons from May back to June-May (see table below). The deficits have persisted, in some cases, for three years (see table, and top graph below right). This region experienced a rapid intensification of the Palmer Hydrological Drought Index (PHDI) in 2000 (see bottom graph below right), which was compounded by numerous wildfires that summer. The regional PHDI has reached levels this May comparable to those of summer 2000.
Precipitation Ranks for the
High Plains to West Coast Region, 2001-2002
Period Rank
May 3rd driest
Apr-May 5th driest
Mar-May 5th driest
Feb-May 3rd driest
Jan-May 4th driest
Dec-May 6th driest
Nov-May 9th driest
Oct-May 6th driest
Sep-May 3rd driest
Aug-May 2nd driest
Jul-May 3rd driest
Jun-May 3rd driest
Click here for graphic showing High Plains to West Coast Region Precipitation Anomalies, January 1998 - present
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Click here for graphic showing High Plains to West Coast Region Palmer Hydrological Drought Index, 1895-2002
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Click here to go to Top of Page Central U.S. Drought

May 2002 was unusually dry across much of the central U.S., from the High Plains of Montana and the Dakotas to southern Texas. This month was a continuation of dryness which extended back for a year or longer for some of these areas.

The West North Central region, which consists of the western states Montana and Wyoming and the Great Plains states North and South Dakota and Nebraska, has had six consecutive months of near to below-normal precipitation (see top graph below). Dryness during most of the last ten months has given the region a rank of second driest August-May (see bottom graph below).

Precipitation Ranks for the
West North Central Region, 2001-2002
Period Rank
May 9th driest
Apr-May 10th driest
Mar-May 10th driest
Feb-May 6th driest
Jan-May 6th driest
Dec-May 3rd driest
Nov-May 5th driest
Oct-May 3rd driest
Sep-May 3rd driest
Aug-May 2nd driest
Jul-May 9th driest
Jun-May 10th driest
Click here for graphic showing West North Central region precipitation departures, January 1998 - present
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Click here for graphic showing West North Central region precipitation, August-May, 1895-2002
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Some Montana drought impacts:
  • Up to 400,000 acres of winter wheat, which relies on snow and rain, rather than irrigation, that were seeded last autumn were written off. National winter wheat levels are at their lowest point since 1978 (The Arizona Republic).
  • As noted by the USDA, Montana farmers were forced to abandon more than 20 percent of the state's winter wheat for the second consecutive year in 2002, which is the first such occurrence since 1935-36 and 1936-37.
  • The USDA will provide the state's agricultural producers with payments for cover crops and no-till farming in an effort to control wind erosion and prevent dust storms (Reuters 5/29).
  • By the first week of June, conditions for at least 40 percent of the range and pastures in the state were rated poor to very poor according to the U.S. Department of Agriculture.

May marked the second consecutive dry month, regionwide, for the South region. There has been considerable variability within this region, with the western and southern portions of the South region being hardest hit by drought (see map to right for short-term soil moisture conditions). Some drought impacts:
  • According to the USDA, winter wheat, pastures, and summer crops across the Southern Plains are being hurt by hot and dry weather.
  • In early June, the USDA NASS reported that wheat conditions in Kansas, Oklahoma, and Texas were rated as 45, 33, and 53 percent poor to very poor.
  • In Kansas, agricultural extension agents are saying a million acres of agricultural land may have to be abandoned this year because of the drought (The Arizona Republic).
Click here for graphic showing Southern Plains soil moisture, April 1, 2002
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Precipitation Ranks for the
South Region, 2001-2002
Period Rank
May 28th driest
Apr-May 20th driest
Mar-May 38th driest
Feb-May 27th driest
Jan-May 27th driest
Dec-May 42nd driest
Nov-May 53rd wettest
( 55th driest)
Oct-May 52nd driest
Sep-May 51st wettest
( 57th driest)
Aug-May 46th wettest
( 62nd driest)
Jul-May 52nd driest
Jun-May 53rd wettest
( 55th driest)
Click here for graphic showing South region precipitation departures, January 1998 - present
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Click here for graphic showing South region precipitation, April-May, 1895-2002
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Click here to go to Top of Page Eastern U.S. Drought

May marked the third consecutive wet month across much of the Northeast region, bringing drought relief to much of the area. However, long-term deficits remain, with June 2001-May 2002 ranking as the 21st driest June-May on record. In the Southeast, this was the second consecutive month with dry conditions averaged across the region. May dryness was especially acute across the Gulf coast and in North Carolina.

Precipitation Ranks for the
Southeast Region, 2001-2002
Period Rank
May 30th driest
Apr-May 12th driest
Mar-May 28th driest
Feb-May 18th driest
Jan-May 22nd driest
Dec-May 15th driest
Nov-May 12th driest
Oct-May 7th driest
Sep-May 11th driest
Aug-May 10th driest
Jul-May 10th driest
Jun-May 21st driest
Click here for graphic showing Southeast region precipitation departures, January 1998 - present
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Click here for graphic showing Southeast region precipitation, October-May, 1895-2002
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Click here to go to Top of Page Additional Contacts:

Damage due to the drought has been summarized by NOAA and the Office of Global Programs in the Climatological Impacts section of the Climate Information Project. Crop impact information can be found at the USDA NASS (National Agricultural Statistics Service) and Weekly Weather and Crop Bulletin pages. Drought statements by local National Weather Service Offices can be found at the NWS Hydrologic Information Center. Drought threat assessments and other information can be found at NOAA's Drought Information Center. Additional drought information can be found at the National Drought Mitigation Center, the USDA's National Agricultural Library, the interim National Drought Council, and the NOAA Paleoclimatology Program. The following states have set up web pages detailing current drought conditions and/or their plans to handle drought emergencies:
Colorado - Delaware - Delaware River Basin (DE-NJ-NY-PA) - Florida Panhandle - Georgia - Hawaii - Idaho - Kentucky - Maine - Maryland - Missouri - Montana-1 - Montana-2 - Nebraska - New Jersey-1 - New Jersey-2 - New Jersey-3 - New Mexico - North Carolina - Oklahoma-1 - Oklahoma-2 - Oklahoma-3 - Oregon-1 - Oregon-2 - Pennsylvania-1 - Pennsylvania-2 - Pennsylvania-3 - South Carolina - Texas - Vermont - Virginia - Washington - Wyoming

For additional information on current and past wildfire seasons please see the National Interagency Fire Center web site or the U.S. Forest Service Fire and Aviation web site.

NCDC's Drought Recovery Page shows the precipitation required to end or ameliorate droughts and the probability of receiving the required precipitation.

Additional climate monitoring graphics can be found at the Climate Prediction Center's monitoring pages:

Drought conditions on the Canadian prairies can be found at the Agriculture and Agri-Food Canada Drought Watch page.

Click here to go to Top of Page For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:

Climate Services Division
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4876
phone: 828-271-4800
email: ncdc.info@noaa.gov
For further information on the historical climate perspective presented in this report, contact:

Richard Heim
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: Richard.Heim@noaa.gov
-or-
Jay Lawrimore
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: Jay.Lawrimore@noaa.gov
Click here to go to Top of Page
Graphic showing NOAA logo NCDC / Climate Monitoring / Climate of 2002 / May / Search / Help

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