Pacific Northwest Weather

[TT-SEA]

Yes... the El Nino of 1940-41 was a little stronger than this one. But less than half the strength of 1982-83 and 1997-98. The El Nino of 1992-93 was a perfect match with the same results as 2005.

1940-41 was a moderate event at best.


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[TT-SEA]

Our El Nino did not disappear. It has recently made a resurgence.

The MEI value increased from .298 to .742 last month. So it is already showing signs of returning.

[TT-SEA]

A general pattern of ridging and split flow is certain now.

It should be dry and warm the rest of April.

Here is the latest GFS for 12 days out... still looking nice!!

[TT-SEA]

That should push us well into the 70's towards the end of the month.

[TT-SEA]

Actually... a very pleasant afternoon now. Temperatures in the mid to upper 50's. Not cold at all.

This is in the middle of a cold trough!!

A ridge will mean 70's.

[Guest]

WEll I don't know where your warm temps are coming from... I have had 2.0 inches of rain in the past 40 hours and besides the warm up before the front passed last night, it hasn't gotten above 47 degrees today... IT peeked at i think 54 this morning at about 3 AM and after it dropped to about 45 at 8 this morning it hasn't been above 47.

I am enjoying the debate between TT and Snow Wizzard. I have some opinions but I think I'll keep them to myself. Whenever i get involved things seem to get a little over the scale of a calm debate...

1 think i want to say is, TT you may not be finding many matches of global patterns that lead to cold winters so you are saying that by just having the Dry February, Warm March and Below Normal April isn't enough if just looking at Seattle... Well even though the other years that had similar stats in seattle may not have been caused by the overall global pattern, MAYBE that type of weather in this area during those months SOMEHOW leads to a colder and snowier following winter, despite the global pattern.

[TT-SEA]

I disagree.

We are not an island of weather. We are directly effected by the overall global pattern. You cannot just look at Seattle. If you do... you will not be very accurate in predicting future weather for Western Washington because one result here can be caused by many global patterns.

So picking one result here will lead to many different results in the future based on the overall patten.

The best scenario is to find a match locally AND with the overall pattern.

The great thing about 1993 is that we did have a dry February... a warm March... and an April just like this one.

And the overall pattern was identical. If that is not a match... I am not sure what is!!

A total of 1.30 inches of rain here and now it is sunny with calm winds and a temperature of 53 degrees and still rising. Looks like North Bend is in a prime postion tomorrow to get slammed by the PSCZ. It should align itself with I-90 as is common with the predicted wind flow.

[TT-SEA]

Approaching 60 degrees at Bellevue High School. The high there was 59.6 degrees. I think we can round that up.

Not bad with such a cold air mass!! Gotta love that strong April sun. It can turn a cold, rainy morning into a very pleasant afternoon.

I cannot wait for the 70-degree weather coming next week and beyond.

[snow_wizzard]

TT...I love how you choose to ignore every other GFS run and the ensemble mean which shows another trough developing the final 4 or 5 days of the month. I agree we will get some warmer weather, but I think you guys are gettinga bit carried away with intensity and duration. Quite frankly, I will enjoy a couple of warm days. Our monthly average is SO FAR BELOW normal, I think we can spare a few. I don't know how everyone is getting these fantastic high temps today...I have only hit 52 here.

[snow_wizzard]

Statistics for the first half of April 2005, in Covington.

Avg high - 54.0 (much lower than the March average high)

Avg low - 36.7 (very cold for April)

Monthly avg to date - 45.3 (3.2 degrees below normal).

Total Precip (through the 15th) - 2.56

I'm telling you guys, we will get at least 6 or 7 more below normal days this month. This will almost certainly eliminate any chance of Seattle averaging 50 or higher this month.

[TT-SEA]

Most places were in the mid to upper 50's at 4 p.m. which is about 15 degrees higher than they were at 10 a.m... so it is happening.

I reached 54 degrees so thats only 2 degrees warmer than you.

Here is the deal on the pattern change. I just have a sense about pattern changes and model nuances. I tracked the change from warm and dry to cold and wet without wavering with every run of the GFS that showed something different. I knew what was coming. And it came with full force.

I know we are heading into a dry, warm period that will last into May. I am not going to get excited about every run of the GFS because I know what is coming. If it supports the theory then its coming to terms with reality. If it does not... then its slow with the pattern change.

The fact is... starting Wednesday it will be mostly dry and warm through the rest of April. The GFS model will come around eventually. The 18Z run is a good start.

I have a good track record on this stuff. You guys thought the cold pattern was coming in February. I always insisted March. The pattern change arrived on March 16th.

Since then I have received 13.80 inches of rain at my house!!

[snow_wizzard]

TT...Thanks for telling me how to post the pix correctly!

I don't know about the 1941 El Nino...I have an official looking sheet right here that says it was strong.

Also...the 18z shows a decent trough effecting our weather around day 6 and then another one at day 10. That does not bode well for any kind of extensive warm weather. The day 10 trough shows very strong onshore flow, and thickness values dropping to 534. That would equal highs at least 5 degrees below normal. It then takes about 2 days for the temperatures to recover from a trough like that, so you are talking about 3 more days in the below noraml column form that trough alone! The trough at day 6 and 7 is much stornger in this run, but is slightly too far west to really make us cool. If it comes right over us, we could see one well below normal day out of that....

[TT-SEA]

The GFS is just playing catch up with reality.

Ridging and split flow = WARM in Seattle.

I ran some numbers. Counting today... Sea-Tac is averaging 46.6 degrees for the month of April.

I believe it will end up around 49.5 degrees for the month assuming a relatively warm, dry end of April. Which it will be. Regardless of what the GFS shows!!

That is slightly below normal... but nothing extreme. Just 1 degree lower than April of 1993. That is not statistically significant.

We cannot focus so intently on one location.

[TT-SEA]

Ran some more numbers and it appears that Olympia will average ABOVE normal for April. They are less than 1 degree below normal right now.

Just goes to show... you cannot focus on one location.

Places in Western Washington will average above normal for April. You cannot say this April was so terribly cold for our region!!

[snow_wizzard]

I am very confident that you are wrong about us not getting a trough in here later in the month. You taking a huge chance on this! You are good at predicting pattern changes, but the change in March did come slower than you expected. Also...I have the MJO on my side. It is still favorable for us to have cool weather. The MJO has been a huge player in our weather this year.

I think the reason Olympia has not been so cold this month is beacuse they normally have very low minimums this time of year. That has been squelched by the heavy cloud cover.

I am more excited for the month to average below normal, than how much below normal it may be. Once again....out of the last two years, we have only had a very few months average below normal. The more below normal months we get (regardless of when they come) the better our chances of getting on a tangent of below normal. The past is clear...above normal months and below normal months come in bunches. I can prove that very easily.

[snow_wizzard]

The El Nino is actually in a weakening phase right now. Region 4.0 is lower than it's been in months.

http://www.cpc.ncep.noaa.gov/data/indices/wksst.for

[snow_wizzard]

This is a test post



This doesn't exactly help my case!

Anyways...I finally got a picture to post so it opens!

I think I agree that the 6 - 10 day period will end up above normal collectively, but after that...BELOW!!!!

[TT-SEA]

Not taking that big of a chance... the theme will be a ridge and split flow.

The GFS always shows troughs breaking through a split flow in the medium range and is almost always wrong. You should have learned that from this winter!! You cling too tightly to troughs on a particular run and miss the big picture. I ignored ridging on some runs of the GFS in the middle of March and I will ignore most troughs now. The GFS will catch up to reality eventually.

Also... the MJO loses its influence on U.S weather outside of the winter season.

I know that above normal and below normal periods come in groups... but they also can go into an alternating pattern. Overall... the average temperatures have been rising (not always evenly but definitely over the long-term) for the last 100 years so it would make sense to have more above normal months in the recent past.

Sea-Tac slightly below normal for April... Olympia slightly above normal for April.

As a region... it will end up being a pretty normal April. I think in general... the entire summer will end up below normal and the winter will be above normal. Similar to a number of years I looked at... including 1993.

[TT-SEA]

The El Nino is actually in a weakening phase right now. Region 4.0 is lower than it's been in months.

This is true. Something to watch.

[snow_wizzard]

I hope you will be willing to amend your predictions as needed as more data comes in later in the year. It's too soon to be so certain.

The MJO was not in this phase when the GFS had problems before. I think it still influences our weather to some degree in the spring.