Out with a cold myself but wanted to let you know that Rufus at the WxCafé ® is going polar. Robin
Monday December 5
Potentially, there's a lot of serious winter weather on the way which may make this week's "almost winter" weather just a tease. Your host is about to board for Chicago & Wisconsin, so forgive the brief (for our team) format in this forecast. A thorough, detailed update will be posted here Friday.
The Current Event
The arrival of the coldest shot of air has been a bit delayed this morning. There remains a reasonable chance for some surface snow from Salem north to Vancouver Is later today/tonight. The biggest "winter" impact will be the sub-freezing temps and transition period on late Wed/Thu. Patrons above that magic 1,000 foot line should see plenty of White to set the holiday mode. There are indications that portions of the Puget Sound will also be under a heavier snow (3"-7") issue early this week (think Convergence Zone) as the cold modified Arctic air powers out of the Fraser Gap. Also, by Tue/Wed, the easterly wind out of the Columbia Gorge is likely to kick-up to a higher mph than expected in our last report. This will create perfect conditions for SNOW to FREEZING RAIN to RAIN when the warmer system moves in late Wed into Thur. Local forecasters will work this system hard, as will the Nat'l Wx Service, so please pay attention.
The coming weekend will be wet and have plenty of mountain snow. Models have been holding the freezing level much lower than expected earlier, so anywhere above 2,500-3,000 ft could get hammered. As we turn the Sunday corner into next week, the situation could become truly one of those Events to Remember (think December 2008 as the closest comparison).
While timing & position are always everything for the PNW to get a major Arctic Outbreak combined with multiple rounds of sea level snow that doesn't melt away in 27 seconds, there have been repeated model runs indicating that, indeed, sometime next week the PNW & CA could be Going Polar. The event may start as early as Monday Dec 12 or as late as Thursday Dec 15. Either way the coldest air mass in years - direct from the North Pole - will power south, briefly move out over the eastern Pacific pick up moisture, and slam into the west coast. Several lows may join in on the Going Polar Program, ushering multiple rounds of snow in various surface locations, even potentially all the way south into CA. What a news maker, should this develop. An alternative pattern would be for a battle between a Polar front and a warmer, southern front to take place right over the southern portion of the PNW, with on/off threats for surface snow, super cold nights. IF so, snow to the north, heavy surface rain to the south and mountain snow measured in FEET. Where that "line of demarcation" sets up is the unknown today.
Your WxCafe (TM) ponders the possibilities here whenever wx models repeatedly present a solution. Such is the case today. On Friday we'll have a better grasp of what could happen. Let's get through this week first. Then, on Friday we'll peek at just how cold, how long, etc the Polar Blanket will impact the PNW.
Off to the Windy City on my last trip as a full time employee. Oh the Joy.
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Snow-ish . . . forecast from Rufus at the WxCafé ®. Robin
Friday December 2
Across the PNW, Wx Geeks are focused on the chance for SNOW at the surface (sea level, essentially). There are several reasons why the simple mention of that possibility brings out the child in so many. Primarily, surface snow is a relatively rare event on the west side of the Cascades. Not to disappoint, but the coming event is looking to be more of a 'close encounter' than a major snow storm pattern. Still, there remains the chance for an inch or two at the surface, so mug up, Patron, and read on.
A damp start to the weekend begins today, with most of the rain falling north of Eugene. Showers letting up early Saturday before the leading edge of the coldest air mass of the season begins moving into the PNW after sunset. Moderate rain will drape across the region, north to south. Cold air behind the front will rapidly drop the freezing level low enough to bring on The White above 500-1,000 feet late afternoon on Sunday (mainly from Eugene/Salem north to Vancouver Is). As is typical with these type of events, the cold air needed for snow at the surface arrives when most of the moisture has passed. That said, it is likely for 1-2" of snow to dust the ground before midnight Sunday. Keep in mind, since roads, etc will be relatively warm, the snow will melt rapidly.
Monday & Tuesday: secondary band of moisture may move into the PNW with plenty of cold air aloft to set off additional snow showers. Maybe another inch or two of snow, esp from Eugene/Salem north. Much of this depends on the placement of the onshore flow of air -- but it should be noted that for patrons in the Puget Sound area, esp north of Everett - the "convergence zone" in WxSpeak - snow showers on Monday into the evening are highly probable. Tuesday should be the driest day, and coldest, of this event. Morning temps will be sub-freezing (low 20s west side, if sky clears and no wind); colder east, of course. Patrons that are typically under the influence of the Fraser Gap outflow during Arctic events will be getting some wind, but not as strong as previous events. Not this time. The center of the high pressure dome over northern Alaska & the Yukon is modeled to reach the 1048-1052 mb range, but it will remain far enough north and drift east in a manner that limits the strong NE winds through the Gaps (Fraser & Columbia). We do get Arctic or modified Arctic air events whenever a 1040-1050 mb 'Dome' forms; such is the case this time.
Wednesday: Transition day. A warm front from the west will bring moisture up and over the cold air trapped at the surface, so SNOW is possible early on, turning to freezing rain, then plain rain later Wednesday. Wind from the south will clean out the low level cold, as we see frequently in these Arctic patterns. Moderate-to-heavy rain Thu into Fri.
The first weekend of December looks wet and cool, with plenty of mountain snow. Some solutions build a high pressure ridge over much of the PNW for a dry weekend, but that has been inconsistent.
Bottom Line: Snow at the surface cannot be ruled out, although it will be a fairly minor event, with a couple inches total over a 24-36 hr period. Still, this will be the first Close Encounter of the holiday season. FEET of snow in the mountains over the next several days. We will be watching the chance for another round of this type of action later in December. That has been trending away in the latest model solutions, but we often see the shift back, so stay tuned.
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Great news from the Oregon Department of Agriculture! Robin
Asian gypsy moth efforts produce big decline
After checking approximately 19,000 traps statewide, and about 3,000 specifically in the north Portland area, the Oregon Department of Agriculture is happy to report no detections of Asian gypsy moth following an 8,800 acre eradication project this spring. The good results indicate there will be no need for ODA to come back next year with additional treatment for the invasive, plant-eating pest.
“In Forest Park and the north Portland area where gypsy moths were trapped in 2015, all our traps came up empty, “ says Clint Burfitt, manager of ODA’s Insect Pest Prevention and Management Program. “We will do two more years of high density trapping in the area before we can officially declare gypsy moth eradicated, but right now, it looks like our treatments were successful.”
Last year, ODA found 14 gypsy moths statewide, five in the greater Portland area. Two of the moths were trapped in or near Portland’s Forest Park, another two in the St. Johns area and the Port of Portland’s Terminal 6. The most significant was the detection of Asian gypsy moth– one in Forest Park, the other near St. Johns. Additionally, an Asian gypsy moth was trapped across the Columbia River near the Port of Vancouver in Washington.
Trapping results appear to show that three aerial applications of the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) not only eradicated an existing population of gypsy moths in the area, but that there are no new introductions of the exotic insect this year.
“It looks like the pest pressure from Asia has decreased and inspections by US Customs and Border Protection and USDA-APHIS (Animal Plant Health Inspection Service) of vessels coming into from infested areas of Asia have been effective,” says Burfitt.
Oregon is more familiar with the European gypsy moth, which is usually introduced when new residents or travelers from areas of high gypsy moth populations in the eastern US unwittingly bring the pest with them on outdoor household furniture or other items that may harbor gypsy moth eggs. Asian gypsy moth is potentially a much more dangerous insect. Unlike its European cousin, the female Asian gypsy moth has the ability to fly, which can lead to a more rapid infestation and subsequent spread. The Asian gypsy moth also has a larger appetite for what grows in Oregon, including a taste for conifers.
There have been just three Asian gypsy moths detected in Oregon prior to last year– a single catch in North Portland in 1991, one caught in Portland’s Forest Park in 2000, and one caught in St. Helens in 2006. It’s notable that two of the three Asian gypsy moths trapped in Oregon were relatively in the same locations as the 2015 detections. It’s not surprising since infested cargo from Asia runs the risk of coming into Portland via ship along the Columbia River.
“We receive shipments into our ports from Russia, Korea, China, and Japan,” says Burfitt. “Those Asian ports are well lit and near forested areas. The Asian gypsy moths are attracted to the lights. Female moths fly onto the ships, then lay their eggs on containers and commodities. Based on the high population of moths at these Asian ports and the egg masses that have been recovered from the ships the past couple of years, there has been a heightened alert nationally to be on the lookout for Asian gypsy moth.”
Reports that Asian gypsy moth populations in the Pacific Rim are down is welcome news to Oregon and Washington– two states that conducted large eradication projects this past spring. Oregon’s neighbor to the north caught 10 Asian gypsy moths last year.
This year’s scorecard is not perfect, but close to it. There were six European gypsy moths trapped in Oregon over the summer– 4 in the Grants Pass area and 2 east of Springfield in Lane County. Neither locations are being considered for an eradication project next spring, even though gypsy moth detections in Grants Pass have taken place for the past couple of years.
“Despite increasing the number of traps in that area, we are catching fewer moths each year and it looks like the population of moths in Grants Pass is not succeeding long term, based on some environmental limitations for the pest,” says Burfitt. “It might be that the area is not as good a habitat for gypsy moth as other places in Oregon.”
Next spring, additional high density trapping will take place in areas where gypsy moth was detected this year, along with the heavy trapping in north Portland.
“Residents in the areas we treated this spring will see an increased number of traps in those areas once again,” says Burfitt. “They can be helpful by allowing our traps to be placed on their properties in 2017.”
Since new introductions of gypsy moth– both Asian and European varieties– can occur any year, Oregon is probably never going to be out of the woods when it comes to the threat of the invader. That’s why it’s so important to put up the traps. Early detection allows for a rapid response in the form of treatment to eradicate gypsy moth populations.
“Had Forest Park, north Portland, and the port area not been treated this spring, it would have been a different story,” says Burfitt. “I would expect there would have been an increased number of Asian gypsy moth detections and it would have made it far more difficult to achieve eradication of this invasive species.”
All the outreach efforts prior to spraying in the Portland area this spring were well worth it, says Burfitt.
“The amount of cooperation between the different agencies and various community groups within the treatment zone was unprecedented. It just shows that when we have a difficult issue and something that will negatively impact the community, like Asian gypsy moth, everyone can come together and be part of the solution.”
With no plans for gypsy moth eradication in 2017, Oregon can return to a quieter spring.
For more information, contact Clint Burfitt at (503) 986-4663.
Rufus at the WxCafé ® is making a lot of bold statements. I've learned to pay attention to that. Robin
Monday November 21
Weather with an Impact is on the way, from windy & wet to dry & COLD. The upcoming weather will be complex, so Mug Up.
The region is between storms today with calm & mostly dry conditions leading into the evening. The first in a series of increasingly stronger storms will arrive overnight/Tue morning. Cold air behind the system will drop snow down to pass level, with plenty of rain (0.5" - 1.0") at the lower elevations. The next storm is on track to develop into a 'double low' type pattern - which slows down arrival, but also increases the impact - for arrival later Wed into Thanksgiving Day. Snow level will drop to 2,500 ft by later Thu. WIND in western WA (western OR to a lesser degree) will pick up considerably Thanksgiving Day as the first low tracks over Abbotsford. This hold the freezing level up high enough to threaten passes for holiday travel, before it drops to the 2,500 ft mark, post-passage. Note: should the low track inland farther south, there will be less wind NW OR & WA, but snow could be a story for areas above 500-1,000 ft, as well as in the Columbia River Gorge.
Black Friday will be intense inside & outside the shopping malls. In fact, there's a high likelihood for power outages to be in play because of WIND generated from a rapidly deepening low that could track WIND will be an issue as the second low is currently modeled a tad south of the first. Barometric pressure difference from Brookings to Vanc Is may be 20+ mb. Cold air support behind the front will bring plenty of powder snow to the Ski Resorts late day Fri on through Sat.
Homeward Day, Sunday Nov 27, promises to be another stormy day with plenty of rain & piles of mountain snow. The Kodiak Chill. WIND will again come into the picture, similar to what develops on Black Friday but this time more of an impact on western OR. Travel will be slow & arduous, so allow for the extra time.
As the post-holiday work/school week gets underway, conditions will settle down, with potential for some fog in the usual morning locations. Another weak, cold system is progged for Wed night into Thu, Nov 29,30. Snow level will be below the passes. Here's where we transition into another Impact Pattern.
The possibility for the first Arctic type COLD SNAP of the season is in the works as December kicks into gear. Current model charts indicate a high pressure dome will form over Alberta Canada and retrograde into the PNW behind the last wet system of November. Right now, expect dry and COLD weather to be in play across the entire PNW and California starting late Thu Dec 1 through Sun Dec 4. East-to-NE winds will become strong out of the Columbia River Gorge and mountain passes from OR down into California. Sub-freezing temperatures will push single digits east side, low 20s west in wind sheltered areas. Patrons should be get their freeze-protection program completed beforehand. NW WA will not get quite as cold as areas in OR because the cold air will be centered SE, and not over BC. A resultant storm over the desert SW will bring plenty of winter weather into the region and up into the Rocky Mtn states. Southern CA mountains could get slammed with low elevation snow. A news maker, should this all verify. For the PNW, the lack of any notable cold weather thus far this fall will obviously bring on discussions of potential crop damage should the sudden sub-freezing weather arrive. We simply have not had 'hardening off' type of weather. Keep that morning beverage handy.
The week of Dec 5-9 should start out dry with a warming trend for western valley locations, as high pressure centered over the Pacific should help moderate the cold snap. Dry conditions should hold through that first full week of December.
Summary: strong storms, with heavy valley rain and plenty of mountain snow is on tap for the next week, then dry and COLD to start the last month of 2016. Be ready, be safe, have an enjoyable Thanksgiving. Update here on Black Friday.
"A Hard Rain's A Gonna Fall" - Bob Dylan 1965
Rufus at the WxCafé ® warns of storms ahead. Let the tempests begin. Robin
Friday November 18
A decent mix of weather is on the way, so too is the holiday season. Similar to summer vacations, weddings and harvest, weather plays a key 'impact role' during the holiday season. The primary premise of The WxCafe™ is to meld planning life's activities with a reasonable foreknowledge of just what may be coming to a sky near you. Hey, many of you have bravely sipped through these diatribes for decades and continue to still step up to the virtual morning beverage counter with mug in hand. Awesome!
An upper level trough will spin surface systems into the PNW for the next few days. Expect the weekend to present as WET and notably warmer than the days ahead. It will turn rather breezy Sunday, as a surface low spins onshore over Vancouver Is. California will get a notable rain event from this storm. Good news.
The holiday week will continue wet, with colder systems tracking into the PNW. A short break in the action is possible late Mon into early Tue. The mid-week storm will not be as intense as we discussed earlier, however, it will pull in colder air aloft, so mountain snow at and below pass level will be an issue for holiday travelers in the 'over the river and through the woods' mode.
THANKSGIVING HOLIDAY - wet, chilly, seasonal weather with lots of great food. Skiers & snowboarders should find enough snow accumulation, esp by late Friday, to clear out all that political anxiety on a downhill rush. One twist to all of this is that recent model solutions keep the center low pressure far enough north early on in the 4 day holiday to hold up the snow level vs earlier charts; if it tracks farther south, plenty of below pass level snowfall. All in all, there remains a good chance for The White in areas enjoyed by snow lovers at some point during the long weekend. The Black Friday storm continues to promise blustery conditions and run-for-the-door heavy rainfall, along with another shot of rain for northern CA. Some shoppers may need a towel to dry off packages.
The Kodiak Chill: travel home late Sunday Nov 27 could be seriously dicey as the strongest storm of the holiday week/weekend - coined here this morning as The Kodiak Chill - powers its way into the PNW. The upper level wind will stream from over Kodiak Island area directly down into the PNW. This will tie into a a cold air mass and a surface wave that will tighten up and slam into our area starting sometime on Sunday. WIND & heavy rain, along with a rapidly dropping snow level, will combine to remind all of us that winter is coming. The key issue will be for patrons returning home over the passes. An early return home may be an easier, safer drive than late day/evening. We will update details next week, but plan ahead, just in case. CA will get in on the action, as well. Another storm, tracking from just south of Kodiak Is. will bring on more rain late Tue into Wed, Nov 29,30. Not quite as cold as the Kodiak Chill system.
Wet to end the week after Thanksgiving. The 'jet stream' is modeled to shift from a chilly NW finger to a direct across-the-Pacific type pattern, aiming right at the west coast as the last month of 2016 gets under way. Expect snow above the passes, and plenty of additional precip across most of the west during the first week of December.
"It is said to be the age of first person singular." -Ralph Waldo Emerson
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