National Climatic Data Center, 10 August 2005

Regional Overview

Some regional highlights:

• Four states had the tenth driest, or drier, July in the 111-year record.
• New Mexico had the second driest June-July.
• Three states had the tenth driest, or drier, May-July on record.
• Two states (Arkansas and Illinois) had the tenth driest, or drier, April-July.
• Three states (Arkansas, Illinois, Missouri) had the tenth driest, or drier, March-July.
• Two states had the tenth driest, or drier, February-July on record.
• Arkansas had the tenth driest December-July.
• By the middle of the month, more than half (59%) of Wisconsin's pasture and range land was in poor to very poor condition. On July 15, Wisconsin Governor Jim Doyle declared a statewide drought emergency to expedite irrigation relief for farmers (Wisconsin Ag Connection, 07/18).
• By the end of the month, 60% of the pasture and range land was in poor to very poor condition in Arizona (61%) and Arkansas (60%), with three-fourths in Missouri (78%) and Illinois (74%). In response to a request by Illinois Governor Rod Blagojevich, U.S. Department of Agriculture Secretary Mike Johanns designated nearly all of Illinois' counties drought disaster areas (Brownfield Network, 7/27). Burn bans were in effect in several Arkansas counties (NWS, 7/21).
• End-of-month and month-averaged soil moisture conditions were drier than normal across a broad swath from the southern Plains to the western Great Lakes, and parts of the Pacific Northwest, northern and central Rockies, Ohio Valley, and Northeast, based on model computations (CPC-1, CPC-2, MRCC). The models also indicated dry soil moisture conditions in east central and southeastern Alaska, parts of Hawaii, and near the surface and at depth from the western Great Lakes to Ohio Valley.
• According to end-of-July USDA observations, more than 50 percent of the topsoil moisture was rated short to very short (dry to very dry) in most of the Pacific Northwest, Rocky Mountain, and Great Plains states, spreading into the Ohio Valley and western Great Lakes. This is drier than the 5-year and 10-year averages across much of the area.
• Streamflow levels were below seasonal norms across parts of the Pacific Northwest, Rocky Mountain states, central Plains, Great Lakes, Mississippi and Ohio valleys, both as computed by models and based on USGS observations.

These overall conditions are evident in the following indicators:

• Palmer Drought Indices,
• Standardized Precipitation Index,
• long-term (36 to 60 month) percent of normal precipitation maps,
• airport station percent of normal precipitation maps,
• statewide precipitation rank maps,
• Cooperative station percent of normal precipitation maps,
• percent of average maps for the SNOTEL stations in the western mountains provided by the Western Regional Climate Center
  • hydrologic year precipitation,
• satellite-based observations of vegetative health,
• National Weather Service model calculations of
  • soil moisture,
  • runoff,
  • evaporation,
• National Weather Service model calculations of soil moisture using the Leaky Bucket Model,
• Midwest Regional Climate Center model calculations of soil moisture,
• topsoil moisture conditions observed by the USDA and mapped by the Climate Prediction Center,
• pasture and range land conditions observed by the USDA and mapped by the Climate Prediction Center,
• streamflow maps maintained by the USGS.

A detailed review of drought and moisture conditions is available for all contiguous U.S. states and the nine climatological regions:

REGIONS:

• Several large wildfires burned across the West during the month. By mid-July, most of the fires were concentrated in the Southwest, where unusually heavy precipitation during late fall to spring resulted in rapid and extensive undergrowth which provides abundant fuel for the fires. The dry July weather was exacerbated by unusually hot temperatures. By early August, many of the Southwest fires had abated, but several new fires had started in Alaska and the Pacific Northwest.
• Reservoir levels in the West reflected the long-term precipitation deficits in many states. The percent area of the western U.S. (Rockies westward) experiencing moderate to extreme drought (as defined by the Palmer Drought Index) decreased from about 67% in July 2004 to under 10% by October. Intensification of drought in the Pacific Northwest during winter and early spring (Nov., Dec., Jan., Feb., Mar., Apr.) resulted in an expansion of the western drought area to about 28% by the end of February. Above-normal precipitation from storms during late spring to early summer in the Pacific Northwest brought the western area coverage down to near 11% by the end of June. A dry July increased the western drought area to about 17%.

Additional Contacts:

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:

• Weekly, Monthly, 3-Month, 12-Month Monitoring
• El Nino, Drought, Snow Cover, and Degree Day Monitoring
• Weekly Drought Monitoring
• Soil Moisture Monitoring

Precipitation and modeled soil moisture anomaly maps for the Midwest U.S. can be found at the Midwest Regional Climate Center's monitoring page.

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