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Hey Everyone! The calender has finally caught up with the unseasonable weather Seattle has been experiencing these last few weeks, and I want to welcome you into the first official week of Spring. This week we will continue to see a mixed bag of weather, with the forecast showing the possibility of warm and clear conditions on the approach.
This weekend we saw one of our first upper level low pressure systems, which are notorious for bringing the sun-breaks and heavy showers during springtime. These systems usually carry a pool of very cold air in the upper levels of the atmosphere. When this cold air moves over rising warm air from the ground, combined with moisture and sunlight, you have the basic ingredients for thunderstorms.
That’s what the forecast is calling for on Monday. A large suspended pool of cold air associated with an upper level low can be seen off the Oregon coast over the water, and is defined by the spotty white cumulus clouds and storms within it.
This system will move into the region on Monday afternoon, and will result in an unstable atmosphere (where warm rising air moves into colder air above). The instability and the apparent sunshine that will be available should be enough to spark thunderstorms. These storms may be capable of producing small hail, heavy downpours, thunder, and lightning. Keep updated here for short term forecast information.
Following this storm producing system, mostly dry weather will resume on Tuesday accompanied by more comfortable temperatures in the upper 50s. A less potent disturbance arrives during the mid-week which will make for a decently soggy Wednesday.
Afterwards, a strong hill of high pressure will possibly build warm and clear weather across the region on Thursday and Friday. However, the National Weather Service seem to be suspicious of this, as shown in their forecast discussion:
“THE MODELS ARE NOT OUR FRIENDS…RATHER THEY ARE MOTHER NATURES TOOLS USED TO MAKE WEATHER FORECASTERS LOOK FOOLISH. I WILL TAKE A CAUTIOUS STEP TOWARD A DRIER FORECAST…”
This weekend I took a mini-vacation to Vancouver BC, and was unable to update the blog. Upon my departure, the weather in Seattle was forecast to be rainy on Saturday, with a transition period on Sunday; a reasonably straightforward situation that we’ve seen numerous times this season, or so I thought.
When I checked the radar on Sunday, it became obvious that Mother Nature had thrown a curve-ball at the Northwest, and even the forecasters had been duped. By the end of the day on Sunday, the rain totals at Sea-Tac Airport topped out at 2.20″ which broke the previous record for March 15th (1.20″ back in 1972.
There were a combination of factors that came into play that made this rain event particularly impactful and unpredictable. The weather models run on Friday were certain that an atmospheric river (a river of suspended water transported over thousands of miles, usually from sub-tropical regions) would form over the weekend and drop rain in the Northwest.
What the weather models had a tougher time figuring out was how the embedded surface low pressure (circulating area of low pressure at the surface which usually causes strong winds in their paths) was going to behave. On Friday, the forecast models predicted the low pressure to hit central/southern Oregon with moderate rain and winds; nothing extraordinary.
However, what actually happened on Sunday was vastly different from Friday’s forecast. The low pressure system, combined with the atmospheric river strengthened significantly, and smacked into western Washington, and Oregon hard. Rain poured relentlessly for nearly ten hours, while the low pressure pounded Portland and other areas with damaging high winds.
As if this wasn’t overwhelming enough, an epic 19″ of snow fell on Hurricane Ridge in the Olympic Peninsula in 24 hours.
In conclusion, this event highlights the weaknesses that are involved in current weather forecasting. There are many situations that the weather models handle very well, but we must be wary of the vulnerabilities of the current computer systems, and observation data. The atmosphere is a very delicate and complex system, and the best thing humans can do in these situations is to learn from our mistakes and improve the art and science of forecasting.
Looking ahead, a mixed variety bag of weather is in the works for the region. A weak system is traversing through with clouds and a few spot showers on Tuesday, setting up for a pleasant transitional period on Wednesday with highs in the 60s.
Rain returns on Thursday as we tap into another little atmospheric river and gear up for a rainy Friday and a showery Saturday. Clearing is expected by Sunday.
Enjoy your week, and happy St. Patricks Day!
My claim of the ” the return of winter” in my last article may have been slightly premature or unwarranted. After a few chilly nighttime lows dipping into the 30s, it appears that for the foreseeable future, cold weather is long gone from the Pacific Northwest.
This weekend has been the pinnacle of an unseasonable warm and dry spell.
Tee-shirt weather has been in full effect this weekend, but temperatures will gradually decrease as our dream weather starts to deteriorate. A soppy system will drop some rain towards the middle of the week, and then again next weekend. However, temperatures will still remain comfortable.
Stronger Spring Storms Due to Warmer Temps?
As we approach springtime, we also approach spring storm time. You may remember in one of my articles last year, I referenced one of UW Professor Cliff Mass’ articles about how springtime around here is the most atmospherically unstable. This is due to the coldest air in the upper levels of the atmosphere during this time of year.
This will be interesting because while we are forecast to have below normal precipitation in the coming weeks and months, the forecast of above average temperatures might make for some stronger thunderstorms this spring season in the Northwest.
All we need is an upper level low pressure system to drift onshore combined with some accompanying moisture, and above average surface temperatures to spark some strong storms. While this formula isn’t exactly common up here, I’ll certainly be watching for it.
Have a good weekend, and enjoy the lovely weather!
This article, I’m going to briefly describe the forecast for the next few days, and then go over the topics discussed during the Pacific Northwest Weather Workshop.
The weather patterns are beginning to shift, and Winter is returning with a vengeance.
An upper level low pressure system traversed the region from the north on Thursday (2-26) which not only led to some heavier rain showers throughout the night, but will also lead to the onset of a rather potent cold spell in the days to come.
Cold air will come spilling through the Frasier River Valley and the gaps in the Cascade mountains in the weekend. Near freezing temperatures will rapidly begin to take hold during the nights, while the daytime highs will reach the upper 40s. Lows in the 20s are even possible by the middle of the week.
Pacific Northwest Weather Workshop 2015
This was the first time I’ve been to the Northwest Weather Workshop. I didn’t know much about it other than that Cliff Mass had been advertising it on his blog for the last month or so.
I arrived and was pleasantly surprised by the amount of people who came from every walk of life from all over the western US. I met lawyers, retail executives, chemists, medical doctors, and of course meteorologists and atmospheric scientists; all enthusiasts who love the weather.
The talks were 12 minutes each, and very diverse in the range of topics that they covered. Some talks were emotional in nature, and some talks focused purely on the science involved. Here is a description of some the topics that popped out to me the most! The National Weather Service will be releasing the full video of the talks and when that is rendered, I will post the link to it for all to see!
The first topic that was introduced was obviously the SR-530 Oso, WA Landslide. This catastrophic and tragic event was covered in detail from multiple angles. Ted Buehner and Brent Bower (NWS Meteorologists) went in depth into the heavy rain events before the slide, and the Geology and Hydrology that came together to create the conditions that caused the slide to occur. Then, the event was described from the response and recovery perspective from Incident Meteorologist Andy Haner, Emergency Manager Heather Kelly, and Emergency Director John Pennington.
The next big topic discussed in length was models, models…and more models. The computer generated forecast models that forecasters and researchers use to simulate the atmosphere on high powered super computers were the primary discussion by many scientists, forecasters and students throughout the event. Cliff Mass discussed the upgrades and changes to the UW WRF-MM5 model that I use frequently use when looking at the short term and long range forecasts. There were a number of upgrades that have already been initiated that will make huge differences in forecast accuracy. Such changes will be: new computer components, upgraded land-surface models (essentially, how the model simulates the interaction between different features on the surface such as snow and vegetation with the atmosphere) as well as a future plan to improve the graphics of the model, and integrate it with Google Maps. This is exciting stuff for me!!
Scientists from the University of British Columbia talked about their in-house weather models that they’ve upgraded. There were several talks that went into researching different effects when various parameters are changed or fabricated to experiment with different results from the model outputs.
There was a session dedicated to Fire Weather that included talks about forecasting smoke plumes in Canada, and the thunderstorms that sparked the large and destructive Carlton Complex Fire in 2014.
My most favorite part of the Workshop was the “Year in Review” time lapse compilation that was captured and presented by Greg Johnson from Skunkbayweather.com. This video in my opinion, perfectly portrays the passion that all of us weather enthusiasts have. Research and data is immensely important for the understanding and future of weather and climate forecasting, but nothing can intrigue and captivate as much as seeing the beauty and wonder of nature in action…especially when set to music! Here’s a link to the video!
Over all, the Workshop was an enlightening experience, and I can’t wait to go again next year!
You may have noticed that this Winter has been wet and well above the normal temperatures. You may have even given up all hope for a normal Winter and accepted that Winter is already over. Well, not so fast!
Spring doesn’t officially start until March 20th and Nature is here to remind us that. The computer models are finally signaling a shift in the weather pattern coming soon. By this weekend a cold air mass will begin intruding towards western Washington, butting up against the eastern Cascade peaks.
The result will still be milder than usual with highs in the mid 50s. Night-time lows will drop down into the 30s through the weekend, giving us a little taste of winter. The snow level will drop enough that some ski areas in our mountains might make up a little bit of snow, however likely not enough to replenish the historical lack of snow this season.
Next week will be mostly dry, maintaining mild temperatures.
If you’re interested in learning about the weather or meeting others interested in weather in our region, be sure to check out the Pacific Northwest Weather Workshop being held at the National Weather Service in Sandpoint on Feb. 27-28! If you can’t visit, then you can catch up on all the topics discussed when I write up an article about it when it’s over.
There seems to be nothing Winter-like about this Winter! I suppose we’ve skipped Winter and jumped straight into Spring because there’s hardly any snow in the mountains (15″ on Snoqualmie) and we’ve hit multiple high temperature records this season. Continue reading
It’s pretty stormy out there! Heavy rain and winds peaking in the low 40mph occurred Friday morning and more heavy rain and wind has been the story for Saturday as well. The cause is yet another strong atmospheric river setup bringing in loads of warm tropical moisture. Continue reading
Happy Friday evening everyone! Thick fog is blanketing the region right now, and the KOMO Air 4 Helicopter captured some AMAZING images from above Seattle as the sun set. Continue reading
Hey there! We’re going to start going through some fairly dramatic weather changes in the next few days so I’ll fill you in on the details. Continue reading