Seasonal to Interannual Forecasts
The Climate Impacts Group (CIG) translates global-scale climate forecasts and conditions into regional-scale climate forecasts for Pacific Northwest (PNW) resource managers and the general public. The El Niño/Southern Oscillation (ENSO) is the most important factor for seasonal forecasting, changing the odds for different types of winter and spring weather (e.g. warmer/drier, cooler/wetter) in the PNW. Another important climate variable for Pacific Northwest climate is the Pacific Decadal Oscillation (PDO). The climate outlook is now provided by the Office of the Washington State Climatologist on a quarterly basis with the CIG newsletter.
Recent PNW Climate
Updated 06 February 2013 (posted 06 February)
The 90 days ending on February 3 were warmer than normal throughout eastern WA and much of ID, as shown in the temperature departure from 1981-2010 normal map (Figure 1). The temperatures in that region mostly ranged between 1 and 2°F above normal when averaged over the last 90 days, but there are a few areas where average temperatures were between 2 and 4°F above normal. On the other hand, western WA and western OR were near-normal (within 1°F of normal), except for some areas (e.g., Puget Sound region in WA and coast range in OR) that were between 1 and 2°F below normal. Average temperatures in eastern OR were below normal when averaged over the last 90 days, ranging anywhere from 1 to 4°F below normal.
Precipitation during the last 90 days was near-normal (between 90 and 110% of normal) in western WA and northwestern OR, according to the precipitation percentages of normal shown in (Figure 2). Otherwise, the precipitation varied across the Pacific Northwest. The WA and OR Cascade Mountains, the Blue Mountains, southeastern OR, and southwestern ID all had below normal precipitation in the last 90 days, ranging from 50 to 90% of normal precipitation. Meanwhile, the Rocky Mountains in ID, northeastern WA, southwestern OR, and parts of south-central OR and areas of the Sawtooth Mountains in ID had above normal precipitation during this period (between 110 and 200% of normal). Despite the deficit of precipitation in some Pacific Northwest locations during the last 90 days, the snowpack (as of Feb 6) is normal throughout much of the region, and above normal in the WA Cascade Mountains, WA Olympic Mountains, northern OR Cascades, and the eastern Sawtooth Mountains in ID (Figure 3). Some regions do have below normal snow water equivalent, such as eastern OR, eastern WA, and parts of the ID Panhandle and the ID Sawtooth Mountains, with amounts ranging between 69 and 89% of normal.
For More Information
According to the Climate Prediction Center (CPC), neutral El Niņo-Southern Oscillation (ENSO) conditions are still present in the equatorial Pacific Ocean. Negative sea surface temperature anomalies in the equatorial Pacific Ocean have strengthened in the last 90 days, especially in the central and eastern Pacific, but the western Pacific is still warm, and in an overall sense, conditions remain neutral. There is a consensus among the model predictions that near-neutral conditions will continue through spring 2013.
What's next for the Pacific Northwest? Unfortunately, neutral ENSO conditions mean lower skill for our seasonal forecasts compared to when La Niņa or El Niņo is present. Still, the CPC three-class February-March April (FMA) temperature outlook (Figure 4) has chances of below normal temperatures exceeding 33% for WA, the western two-thirds of OR, and the ID panhandle. Southeastern OR and southern ID have equal chances of below, equal to, or above normal temperatures for FMA. Most of WA and northwestern OR have chances of below normal temperatures for the three-month period that exceed 40%. On the other hand, there is very little indication of precipitation for FMA (Figure 5) with equal chances of below, near-normal, or above normal amounts.
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Pacific Northwest Resource Outlooks
Climate Prediction Resources
The links below provide access to the latest information on the current state of global and regional climate, as well as links to global and regional climate predictions.
The Current State of the Tropical Pacific
- Real-time data from moored ocean buoys (NOAA’s TAO array)
- ENSO diagnostic discussion (NOAA’s Climate Prediction Center)
- Weekly ENSO update (NOAA’s Climate Prediction Center)
- ENSO Quick Look (International Research Institute for Climate and Society
- Monitoring El Niño/La Niña (NOAA’s Climate Prediction Center)
Predictions of Tropical Pacific and North Pacific Conditions
- Seasonal Niño3.4 sea surface temperature anomaly plume forecasts (European Center for Medium-Range Weather Forecasts)
- Statistical Probabilistic ENSO Predictions (International Research Institute for Climate and Society)
- Sea surface temperature forecasts (International Research Institute for Climate and Society)
- Experimental PDO and Pacific Seasonal Forecasts (NOAA's Earth System Research Laboratory)
The Current State of the Globe
- Climate diagnostics bulletin (NOAA’s Climate Prediction Center)
- The North Atlantic Oscillation (NAO) (NOAA’s Climate Prediction Center)
- Accumulated daily precipitation time series graphs (NOAA’s Climate Prediction Center)
- Daily global and regional precipitation analysis (NOAA’s Climate Prediction Center)
- Index of Climate Prediction Center’s climate monitoring activities and data
Current and Predicted U.S. Conditions
- Monthly to seasonal climate outlooks (NOAA’s Climate Prediction Center)
- State of the Climate report (National Climatic Data Center)
- Northern Hemisphere snow report (National Climatic Data Center)
- Spring and summer streamflow forecasts (USDA Natural Resources Conservation Service)
- Drought in the US
- Water supply forecasts and snowpack conditions for the Western U.S.
- Large fire incidents (National Interagency Fire Center)
- Experimental seasonal fire risk forecasts (U.S. Forest Service)
- Western U.S. climate conditions and forecasts (Western Regional Climate Center)
- Monthly temperature and precipitation maps (National Climatic Data Center)
Pacific Northwest Conditions
- Temperature and precipitation maps (Western Regional Climate Center)
- Temperature and precipitation maps (High Plains Regional Climate Center)
- Western Washington water and snowpack (Seattle City Light)
- Seattle water supply conditions and outlook (Seattle Public Utilities)
- Monthly snowpack maps for the region (National Resource Conservation Service)
- Snotel River Basin Snow Water Content (Western Regional Climate Center)
- River forecasts (NOAA Northwest River Forecast Center)
- Wildland fires (Incident Information System -- InciWeb)
- Oregon and Washington wildland fires (Northwest Interagency Coordination Center)
- Coastal conditions (NOAA’s CoastWatch)
State Climatologist Offices
- Drought in central and southwest Asia (International Research Institute for Climate and Society)