National Climatic Data Center, 13 January 2005

Regional Overview

The December precipitation pattern at the primary stations in Alaska was mixed but mostly wetter than normal. The pattern was also mixed in Hawaii, but most of the stations were drier than normal. In Puerto Rico, the southeast and parts of the northern and western areas were drier than normal, based on National Weather Service radar estimates of precipitation and on Cooperative station precipitation reports for the last 4 weeks and 8 weeks. December streamflow averaged near normal for Hawaii and Puerto Rico.

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Long-term moisture deficits persisted in many areas. Much of the central and northern Rockies were dry at the 12 to 24 month timescales. Many Alaska stations, especially in the central and eastern interior regions, were drier than normal at the 12 month timescale. Severe moisture deficits were evident at the 36 to 60 month timescales across much of the West into the northern High Plains and central Plains. These long-term hydrological drought conditions are reflected in the January 4 United States Drought Monitor map.

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Some regional highlights:

• End-of-month and monthly averaged soil moisture conditions were drier than normal across parts of the central and northern Rockies and High Plains, the Pacific Northwest, eastern Alaska, and near the surface and at depth across parts of the central Plains to the Great Lakes, based on model computations (CPC-1, CPC-2, MRCC).
• Streamflow levels were below seasonal norms across a few parts of the Pacific Northwest, and central and northern Rockies and Great Plains, both as computed by models and based on USGS observations.
• Snow water content of the western mountain snowpack contrasted sharply from south to north. End-of-December snowpacks in parts of Arizona, Nevada, central California and Utah were above average, while snowpacks in Oregon, Washington, Idaho, Montana and the east slopes of the northern Rockies were significantly below average. This pattern, which is also apparent in water-year-to-date precipitation anomalies, reflected a southerly track of winter storms across the region for the last three months.
• Reservoir levels in most of the western states continued well below seasonal normals. Although long-term (out to 5-years) moisture conditions remained dry across much of the West, drought conditions have improved in recent months. The percent area of the western U.S. (Rockies westward) experiencing moderate to extreme drought (as defined by the Palmer Drought Index) decreased to about 10%.

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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 Mexico - Oklahoma-1 - Oklahoma-2 - 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

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