21 August Thunderstorms in Okanogan County
Heavy rain occurred in Okanogan County on the evening of 21 August in the region of the Carlton Complex wildfire of earlier in the summer of 2014, leading to flash flooding and mudslides.
Read moreSkill in ENSO Model Prediction
We have previously discussed the skill of seasonal weather predictions for winter in this newsletter (March 2014 edition). One of the most important sources of information for these seasonal forecasts is the future state of El Niño-Southern Oscillation (ENSO).
Read moreThe Precipitation Winners and Losers in Major League Baseball
Seattle’s rainy reputation is difficult to combat, especially among those that have never lived in the Pacific Northwest. The dry Washington summers are often overlooked. In that context, OWSC was pleased to have recently heard a “rumor” that during the regular baseball season, Seattle is one of the driest cities of those that have a Major League Baseball team.
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The Blob: Warm Water off the Coast of the PNW and What it May Mean for Our Summer Weather
The Pacific Northwest experienced a period of seasonally quiet and dry weather from October 2013 into February 2014. This period also featured anomalously weak cooling of the upper ocean off our coast for the time of year.
Read moreExtreme Precipitation Events in Washington State
There has been a slight upward trend in mean precipitation for Washington state over the last century or so, but this change is marginal from the standpoint of statistical significance. Readers are encouraged to explore this for themselves using an application on the OWSC website: www.climate.washington.edu/trendanalysis.
Read moreA Review of Winter 2013-2014
The predictions for the winter of 2013-14 included little consensus among the seasonal forecast models in August and September, but were hinting at dry winter conditions by October 2013. However, neutral El Niño-Southern Oscillation (ENSO) conditions were projected for the upcoming winter, resulting in a lack of a strong statistical signal toward below or above average temperature or precipitation anomalies for the winter as a whole.
Read moreThe Quality of CFS Seasonal Winter Predictions for the Pacific Northwest
Seasonal weather predictions are based increasingly on global climate model output. They have been evaluated for the tropical Pacific and other very large (continental scale) regions, but less is known about the quality of these predictions for specific regions such as the Pacific Northwest.
Read moreRecent Precipitation near the Oso Landslide
A landslide occurred on Saturday, March 22 east of Oso, WA in Snohomish County that resulted in a tragic loss of life. At least a contributing factor related to this landslide was the anomalously heavy rainfall that occurred at the location during February and March 2014.
Read moreReview of 2013: Climatic Averages and the Top 6 Weather and Climate Events
With 2013 now in the books, we would like to review the year from a weather and climate perspective. First, the Washington State average temperature and precipitation during 2013 are presented, along with a comparison of this year to other years.
Read moreThe Arctic Oscillation and Pacific Northwest Weather
The Arctic Oscillation (AO), also known as the Northern Annular Mode (NAM), is an important element of the variability in the weather and climate of the Northern Hemisphere. It relates fundamentally to the state of the flow at northern latitudes, with the positive phase associated with a strong, axisymmetric polar vortex and the negative phase associated with a weak polar vortex, allowing for more prominent large-scale ridges and troughs for the whole hemisphere.
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