Pacific Northwest Weather

[snow_wizzard]

Good Morning all!

By the way, I forgot to thank TT and Andy for welcoming me back. Thanks guys!

The models continue to show a remarkably dirty weather pattern for our area for at least the next 10 days. The thing that strikes me is how we just cannot get to a solidly sunny and nice, or a solidly cool and wet pattern. Very splitty and incredibly unpredictable! Some runs show we could see a more consolidated jetstream effect us by the 12th or so, but it's too soon to tell. One thing for sure, the jetstream has to come north again. It would be impossible for it to stay in Cal for much longer.

I would also like to take this opportunity to put in a good word for Brennan. He is a nice kid, who just got a bit carried away. A bit too much passion for what he believes!

[AnthonyC]

I agree with Snow_Wizzard.

The overall jetstream across the country is sketchy at best. There are weak steering currents which is causing the problem. This is sometimes typical in summer...but usually not this early.

As for this morning, we have mostly cloudy skies in Mukilteo. Temperature is fairly mild. And tonight? A weak shortwave is moving up from the south, but it's shearing off the coast. Will we see any precip? Probably, particularly over the southwest interior. But nothing substantial.

And the upcoming week is confusing at best. Like Snow_Wizzard stated, not one particular pattern is developing...no sunny/warm weather but no cool/wet weather. The general theme of partly/mostly cloudy will be present with seasonal temperatures.

Anthony

[andycottle]

Your welcome, snow wizzard Would have to agree with the both of ya. Not much in way any good look`n organized systems anytime soon with in the next couple weeks. -- Andy

[W13]

Currently 71 F under Mostly Sunny skies! Just a spectacular day!

[snow_wizzard]

Yeah it is a nice day W13. Now that it's May, I can actually enjoy a sunny and warm day. Make no mistake about it though, below normal temps are always welcome! I would love to see a summer with nothing but sunshine but fall like temps. Believe it or not, we used to get those!

As for the weather over the next week, I think there wil be something for everyone! Perhaps, if we're lucky, we will even see a thunderstorm or two. Rahter surprisingly it got down to 41 at my place last night. Some May's never get that low for the entire month. I think the propensity for cool low temps has been clearly established this year. It kind of ticked me off how the warm nights the final week of April messed up our fabulous average low for the month...

[AnthonyC]

A nice day...a few high clouds, but mild temperatures...currently 66F.

As for this upcoming week, your guess is as good as mine. A split flow is prevalent across the Eastern Pacific, but it's not strong enough to divert all clouds/moisture our way. In particular, Tuesday night/Wednesday look to be the wettest periods.

Temperatures should remain seasonal for this time of year...highs in the lower, middle 60s...although Tuesday may approach the upper 60s, lower 70s as the upper level ridge amplifies before the next upper level low approaches from the south.

All in all, not a bad weather pattern but it could be better this time of year...and it also could be much worse!! lol.

Anthony

[snow_wizzard]

Wow! Some very intense cells are showing up on the radar over SW Washington. It will be interesting to see if any of those can work their way toward Seattle. Incredible how many days that thunderstorms have been showing up over SW Washington lately.

[TT-SEA]

I think the thunderstorms are indicative of warm air at the surface. Not as common with cold air aloft AND at the surface.

[andycottle]

Hey all! Just got home from work. Not a bad weather day at all! Started off sunny, but then became partly cloudy with some high clouds increasing through the afternoon hours. My high today was 70 with a low of 43. Right I have light overcast skies. -- Andy

PS: Maybe some of thoes thunder showers will hold togeather and make there way toward us.

[snow_wizzard]

Well, well, well! It seems that the MJO is promising another pattern shift soon!

http://www.cpc.ncep.noaa.gov/products/p ... index.html

The reading at 20 degrees east longitude is the lowest that has been observed in quite some time. A few weeks ago the reading at that longitude was profoundly positive and ultimately resulted in Alaska having some monthly record highs for April, a few days ago. The MJO has been nothing short of amazing at foretelling pattern shifts this year. It went strongly positive about 10 - 14 days before our shift from below to above normal temps last month. If it continues to be the "crystal ball' that it has been so far this year, look for a period of well below normal temps again by mid month.

[andycottle]

Good evening all. Latest 12z and 18z GFS this evening is showing a few showers here and there through this week and into next week, but also some partly to mostly sunny days mixed in. No real organized systems affecting us in the next two to three weeks due to a split in the jet. On the flip side, temps should reamain fairly mild and in the 60`s to low 70`s.

-- Andy

[TT-SEA]

Awesome.

Just so you know... I am going to be cheering for anything that can bring us rain this summer. We need to get some rainy periods throughout the summer or its going to be a bad fire season.

I think temperatures from May - July will be below normal with above normal rainfall. This seems to be common after a warm, dry winter.

[andycottle]

Hey guess what! Just came back in from my garden and found out that a rabbit or something has eaten the tops off about three of my strawberries plants. Gosh darnet!!! It never fails, I tell ya. Never! I plant one certain thing or two...and days later, something has eaten it. Grrrrrr!

Ok...I`m done venting. On to weather. I think Tim is right. If we don`t get LOTS of rain this summer, there are going to some major wild fires, not to mention fires near our firendly and wilderness park areas/hiking spots. Though I hope we have a nice summer with some nice T-Storms! That would be cool!
-- Andy

[snow_wizzard]

It does indeed look like the 0z GFS is beginning to catch on to a pattern shift by hour 288 or 300. The trough which has been plaguing Cal is progged to shift northward. Besides that it shows the offshore ridge could amplify and force some cool air down from the Bering Sea, just like the first 2/3 of April. I am not convinced this will happen, but it sure seems reasonable. It would appear that the entire country is on the cold and then warm roller coaster!

By the way, I have looked up some of the anlogs from the CDC site and the similarity to patterns from the 50s and from 1972 is remarkable! The pattern the GFS is showing for hour 252 is a dead ringer for May 7, 1972. I mean the similarity is spooky! The most important trend in the analogs right now is that they are almost all from before 1975. That is why the current patterns look so foreign to us. We are going back in time! Enjoy the ride!

[TT-SEA]

Question for Snow_Wizzard...

The cold phase of our climate is tied to the cold (negative) phase of the PDO... correct??

I have read extensive research on "atmospheric lag" where the weather patterns are slow to respond to environmental changes. This happens seasonally (i.e. the hottest weather is at the end of July... 30 days after the longest day of the year) and in response to major shifts in global indexes.

The PDO is still positive.

So why would we be seeing changes in weather patterns already... resulting from a switch to the PDO cold phase?

I think you might be putting the cart before the horse.

I saw some major similarities to 1993 as well... and that was in the warm cycle.

[snow_wizzard]

TT...that is a good question. I can only answer that by saying, that we did get a nice negative PDO a few years ago and it never gave us anything. on the other hand we did get some very harsh winters in the 1930s and other years with positve PDO. You are correct that there is often a lag with such things. While I would like to see the PDO come into line, there is some debate as to how impostant it is for us to get cold winters. The tropical SST's are very important, and next winter looks pretty good in that regard. It would appear there is a chance that the atmosphere is changing before the PDO this time. In fact the experts are unclear which one is the cart and which one is the horse. Time will tell.

[george_r_1961]

His IP is now banned for being a troll.

Marshall thats a definite step in the right direction but many trolls change IP addys more often than I change my socks. Its not that hard either. Hopefully if we ignore them and dont respond to their moronic posts they will just go away

[TT-SEA]

Just some thoughts here...

I believe the negative PDO recently was far too short in duration to change the weather patterns. It went back to positive before that could happen.

Clearly a long-term negative (cold phase) PDO is an important factor overall. The are a few exceptions. Historically though it definitely seems like the weather patterns are effected by these "regime changes" in the Pacific Ocean.

So... without a negative PDO established for a period of 2-3 years... I think we will just have to get lucky with a cold, snowy winter. We are not yet in a cold phase.

[donsutherland1]

TT-SEA,

Among other things, you wrote, "Clearly a long-term negative (cold phase) PDO is an important factor overall." That's what the Pacific Northwest needs to enjoy, on average, colder and snowier winters than average.

There is much debate as to where things stand. Some have proclaimed that a new PDO- cycle had commenced in 1999. Others, including me, argue that we're probably in a transitional phase but not there, just yet. Certainly, aiding my point of view, is the fact that the PDO has experience significantly fewer PDO- months over the first 60 months (using the 1999 date) then occurred in the last PDO- cycle and substantially more +1.50 or above months, too, thus I remain skeptical of the idea that we're in a cool phase right now.

1947-52 PDO vs. 1999-Present PDO:

• First 63 months of the 1947-76 PDO- Cycle: 52/63 (83%) PDO-
• 63 Months since January 1999: 39/63 (62%) PDO-

• Number of Months with PDO+ during the 1947-76 PDO- Cycle: 97
• Number of Months with PDO+ 1999-Present: 24 (would extrapolate to 137 for a similar duration event as the 1947-76 cycle)

• Longest PDO+ stretch during the 1947-76 PDO- Cycle: 10 months
• Longest PDO+ stretch since 1999: 26 months

• Frequency of PDO +1.00 or above: 1947-76: 5%; 1999-Present: 11%
• Frequency of PDO +1.75 or above: 1947-76: 0.3%; 1999-Present: 5%

Finally, research by JPL (NASA's Jet Propulsion Lab) has suggested that there are actually two embedded PDO cycles--a shorter-term one, which is usually referenced, and a longer-term one that can last up to 70 years.

Clearly, there's much still to be learned about the PDO and I strongly believe that the body of existing knowledge is not sufficient for one to declare with any degree of certainty that a new PDO- regime has begun.

[weather girl]

Thought this was interesting regarding the fading El Nino. I thought when this event started it wouldn't be necessarily strong, but would be a slow fader. Maybe the negative PDO will be back after all???? I'm not much of a hot weather fan, so I'm all about anything that might point to a cooler summer:

Dynamic Predictables Meteorologist Al Peterlin said, "The nearly two-year old, mild El Nino will finish with an upsurge in May, and then Eastern Pacific Sea Surface temperatures bow to Christmas lows with broad global impact implications."


After the May 2005 peak, Nino3 Eastern Pacific region sea surface temperatures will fall to mild to moderately cool La Nina levels (range -0.3 to -1.0 degree C) by Christmas 2005.