We asked two weather experts from the Pacific Northwest 10 questions about the weather ahead in our area. From what mobile app is a must have to the urban myth that Portland is the wettest place in the country. What followed was a mix of vital information and interesting factoids from two weather aficionados that report on the Northwest area daily.
Q&A with KOIN Meteorologist Sally ShowmanKOIN 6 on weekday mornings.
OPB: Where is the wettest place in Oregon? What about the driest?
Sally Showman: Oregon is an amazing state; we have both desert and temperate rainforest. The wettest place in the state is Laurel Mountain, one of the highest peaks in the Coast Range. It averages 121 inches of rain per year. The driest place in Oregon is the Alvord Desert in the southeast corner of the state. It averages just 7 inches of rain per year.
OPB: What causes hurricane force winds at the west end of the gorge?
Showman: It’s a little technical, but let me try to break it down.
Big pressure differences drive the wind. When there is cold air and high pressure east of the Cascades and mild air and lower pressure west of the Cascades, the atmosphere wants to even itself out. The only sea level passageway for that cold, dense air to travel is through the narrow gap of the Columbia River Gorge. Air accelerates from high to low pressure, and the western mouth of (the) Gorge becomes a wind tunnel. I’ve been up at the Vista House when winds are gusting to 90 mph. It’s an incredible experience. The wind is strong enough to knock you off your feet, or break the hinge on your car door!
OPB: How many tornadoes does Oregon see on the average year?
Showman: Both Oregon and Washington average three tornadoes per year. Texas averages 155! The vast majority of tornadoes are EF0 or EF1 (the weakest). In 1972, a rare F3 tornado moved through Portland and Vancouver. It claimed six lives and caused $3-5 million in damage.
OPB: What is a pineapple express and why is it called that?
Showman: A pineapple express is a stream of very moist air that has roots in the subtropics near Hawaii. These events often trigger very heavy rain and can cause flooding. In addition, the pineapple express transports warm air into the region, so it can cause rapid snow melt off in the Cascades.
OPB: Portland has a wet reputation. Is it really one of the wettest cities in the country?
Showman: It rains a lot here but when it comes to quantity, Portland isn’t anywhere near the top of the charts. PDX averages 36.03” per year. The wettest metropolitan city in the country is Mobile, Alabama with an average 67” per year. On the average year, there are 155 days with measurable rain at PDX. Mobile averages just 59 days with rain. The bottom line; Portland outranks most cities when it comes to number of rainy days. However, torrential downpours and severe weather mean a lot more rain in the south and Gulf Coast.
Q&A with KGW Meteorologist Rod Hill
OPB: First off, the “Blob,” should we be scared?
Rod Hill: The “Blob” has shrunk, I think for now, the answer is no.OPB: Is Portland the most difficult place you have worked to forecast the weather?
Hill: For our local weather — Yes! PortlandWeather.com app for iPhone or PortlandWeather.com/mobile for android
OPB: Other than Portland of course, what would be the best and worst place to be a meteorologist?
Hill: Worst place is easy, a very boring San Diego. For best place, I pick Hood River, Oregon. Living in and studying the gorge on a daily basis would be beyond fascinating!
OPB: Lastly, in one sentence, can you describe what the rest of Oregon’s winter will look like?
Hill: I expect rainfall to be normal or above through March. The big question is the snow level, will it stay near 4,000 feet or go high like last winter?