Thunderstorm Outbreak This Weekend?

Happy Friday the 13th everyone! As you may have heard, one or two of the local media outlets have mentioned a good chance of seeing a widespread thunderstorm outbreak Saturday afternoon across the Portland / Vancouver area. I have taken a long hard look at both the WRF and NAM and unless something changes dramatically in the next 12-24 hours I see almost ZERO chance for any thunderstorms west of the Cascades this weekend. This mornings slate of models clearly shows an upper level low headed south along the coast today and tonight. What stands out nice and clear to me is a moist return flow around the low pressure center that will feed quite a bit of precipitation back over the metro area from about dusk Saturday night through most of Sunday. Rather than t-storms, I would get ready for more of our famous Pacific Northwest rain. Maybe it is the curse of Friday the 13th? However, for all of you thunderstorm lovers out there, fear not, storms will most likely pay us a visit at some point this spring or summer.

Below are two frames from the 12z run of the WRF and the 12z NAM from the U of W. These maps are what is referred to as C.A.P.E. or Convective Available Potential Energy outputs for Saturday afternoon and evening. This indicates the areas around the Pacific Northwest that are most likely to see instability and the best chances for t-storms. As you can see, there is not much C.A.P.E. on the west side of the Cascades. In fact, none! Eastern Oregon looks like the best location for t-storms Saturday afternoon. With the orientation of the off-shore trough, time of the year and strength of the daytime heating (more like lack thereof), I see no reason to argue with these model outputs. Bottome line — t-storms stay over the Cascades and points east on Saturday.

Have a great weekend! I recommend getting all of that outdoor work done Saturday morning, as Saturday evening and Sunday look wet, as does most of next week. After temperatures near 70 today and mid-60’s tomorrow (Saturday) it looks like we will once again fall below normal for a few days beginning Sunday. It would sure be nice to see some “real” spring weather around here at some point. I guess the wait continues!

Stay tuned!

Steve Pierce


Steve Pierce

Steve Pierce

Steve Pierce is widely known as Oregon and Washington's "go-to-guy" when it comes to fast, accurate historical meteorological research and forecasts. Steve is currently the President of the Oregon Chapter of the American Meteorological Society (AMS). Steve is also recognized as a regional weather commentator and blogger who can be heard on local radio stations and seen in print media outlets across the Pacific Northwest. His Weather Blog is hosted by the Columbian Newspaper in Vancouver. Check it out! He is a third generation resident of Vancouver, Washington and holds a degree in Communications. Both sets of Steve's grandparents migrated to Vancouver during World War II. One set traveled from Lenox, Iowa to work in the Kaiser Shipyards supporting the war effort. The other set came to Vancouver from Olympia, Washington to work as educators for the rapidly expanding Vancouver School District. When the war was over, both sets of grandparents decided to stay in Vancouver and continue raising their families, as did thousands of other families at the time. Those who are most familiar with Steve can attest to the fact that weather is his true passion. His love for "all things weather" began at the age of 7 when Mt. St. Helens erupted in 1980. He was fascinated with which direction the ash plumes were headed. Then came the very powerful windstorm of Friday, November 13, 1981, also referred to as the "Friday the 13th" storm. This was the strongest storm to hit the Portland / Vancouver area since the great Columbus Day Storm of 1962! At age 11, he was asked to publish an extended weather forecast for his elementary school's weekly newsletter. In the 1980's, at age 14, Steve was the youngest of KGW-TV's local "weather watchers" and would phone in his daily Vancouver weather stats to then television meteorologist Jim Little for use on-air. Steve has lived through all of the major Pacific Northwest weather events of the past 30 years, and then some. The most notable events include; the bitterly cold winter of 1978-1979, the record setting snow storms of January 1980, the summer heat wave of August 1981, the windstorms of November 1981 and December 1995, the severe arctic blast of February 1989, the record flood of February 1996, the historic ice storm of January 2004, the Vancouver tornado of January 2008 and the record setting snow storm of Christmas 2008. Not to mention every Mt. St. Helens volcanic eruption in between. With access to the most extensive set of historical weather records available to date, Steve has personally designed and integrated a proprietary system that gives him the ability to quickly locate and manipulate weather data as far back as the 1800's. As one local Meteorologist put it, "Steve has fast access to historical weather data that is needed for media, agriculture, business, personal, historical and other climatological needs. He can quickly manipulate the data in many different ways. His forecasts are also quite accurate, especially at longer lead times." Steve also provides local storm assessments, narratives and weather presentations to the general public, as requested. In his spare time, Steve enjoys spending time with his family, the outdoors, vacationing at his family's coastal cabin and just relaxing! By the way, do you like your weather on the "extreme" side? So does Steve! Whether it is collecting damage assessment data & photos after record setting 125 mph winds at the coast in December 2007, being one of the first on the scene after the January 2008 Vancouver tornado, or feeling (literally) the awesome power of 100 mph wind gusts at Oregon's Crown Point in January 2010, Steve has experienced it all! As Steve says, "don't just love weather, live weather!" Check out Steve's personal weather website at:

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