National Climatic Data Center, 14 October 2004

Regional Overview

In between these two September wet bands was a large swath of very dry conditions which stretched from the Great Lakes to the Lower Mississippi Valley and southern Plains. The southwestern quarter of the country and parts of the northern Rockies and High Plains were also dry.

The precipitation pattern at the primary stations in Alaska and Hawaii was mixed, although most Alaska stations were wetter than normal. September was generally wet to near normal in Puerto Rico, based on both the primary station precipitation reports and on streamflow.

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Long-term moisture deficits (last 6 to 24 to 60 months) persisted across parts of the mid-Mississippi Valley, central Great Plains, and northern High Plains, and most of the West. In spite of the record heavy tropical rainfall during September, the Southeast over the last 5 years was so dry that slight deficits still appear on the 48-month and 60-month precipitation anomaly maps.

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Some regional highlights:

• Several states had the tenth driest, or drier, month or season for:
  • September (Arkansas-2nd, Indiana-2nd, Michigan-2nd, Illinois-4th, Louisiana-6th, Missouri-6th)
  • July-September (Louisiana-5th)
  • April-September (California-3rd)
  • March-September (California-driest)
• Maine was the only east coast state that received below-normal rainfall in September, ranking 24th driest
• Soil moisture conditions:
  • End-of-month soil moisture conditions were drier than normal in parts of the Lower and Mid-Mississippi Valley, Upper Midwest, northern High Plains, and Alaska, and drier than normal across much of the West, based on model computations (CPC-1, CPC-2, MRCC).
  • late September USDA topsoil moisture observations were dry to very dry (also compared to 5-year and 10-year climatologies) in states in the central and southern Great Plains, northern Rockies and northern High Plains, and especially along the Mississippi Valley to Great Lakes.
• According to early October USDA reports, more than 30 percent of the pasture and range land was in poor or very poor condition (higher than seasonal norms) in several states in the West, central and northern Plains, and along the Lower Mississippi Valley and Great Lakes. The most rapid 4-week deterioration in pasture conditions occurred along the Mississippi Valley to Great Lakes.
• The month began with several large wildfires burning in Alaska and the western U.S., but by month end the fires were largely put out or under control (wildfire loop).
• Much of the western U.S. has experienced dry conditions for the last five to six years.
  • Reservoirs in the western states were still low or depleted.
  • Streamflow levels were below seasonal norms across much of the West, both as computed by models and based on USGS observations. Below-normal monthly streamflows were also observed in parts of the central Plains, Great Lakes, and Mississippi Valley.
  • The percent area of the western U.S. (Rockies westward) experiencing moderate to extreme drought (as defined by the Palmer Drought Index) decreased during September to about 64%. While this is not near record historical levels, it is still comparable to the major droughts of the 20th Century.

Additional Contacts:

Colorado - Delaware - Delaware River Basin (DE-NJ-NY-PA) - Florida Panhandle - Georgia - Idaho - Kentucky - Maine - Maryland - Missouri-1 - Missouri-2 - Montana - New Jersey-1 - New Jersey-2 - New Jersey-3 - New Mexico - Oklahoma-1 - Oklahoma-2 - Oklahoma-3 - Oregon - Pennsylvania-1 - Pennsylvania-2 - South Carolina - Texas - Vermont - Virginia - 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:

• 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.

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

Richard Heim
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: Richard.Heim@noaa.gov