PNW November 2021 Wx Obs/Discussion

[TT-SEA]

1 minute ago, 1000'NorthBend said:

2.36" of rain so far today, add in the 2.51" yesterday and we're at 4.87" for the event. That puts us at 9.61" for the month (it's only the 12th!) and 80" YTD. We're making a run for 100"! The longer 

Snoqualmie River looks it will be about half of the predicted flow from 24 hours ago:

NOW:

YESTERDAY:

I wonder what

Even the current predicted peak flow seems way off, I wonder what went wrong?

Their probability graph did way better, where yesterday afternoon it said the most likely range of peak flow would be between ~20,000 cfs and ~42,000 cfs. Here is the max it predicts as of 7:30 AM:

Seems more reasonable.

It doesn't seem like either is concerned about flooding for early next week. 

This event was drawn out with pulses of rain rather than continuous heavy rain.   Makes a big difference.   We can get 2 inches a day forever and never have flooding issues on the Snoqualmie.  Also there was very little snow in the mountains to add to the flow.   Those extreme flow predictions never made sense to me given the situation. 

[Phil]

32 minutes ago, hawkstwelve said:

Is that a ridge setting up slightly offshore? Could it mean we finally dry out for longer than 12 hours?

Gotta be too good to be true. Not trusting the maps, even the trusty EPS. It will find a way to continue to rain for eternity.

That ridge will probably retrograde into the GOA next month, marking the inception of winter in the West.

Degree of amplification still questionable though. Could be a close call. Keep the vortex out of Alaska and I think it’ll work.

[Gradient Keeper]

1 minute ago, Phil said:

That ridge will probably retrograde into the GOA next month, marking the inception of winter in the West.

Degree of amplification still questionable though. Could be a close call.

I would say amplification is always uncertain Winter after Winter.

00z ECMWF in 9 hours 13 minutes. Who's staying up for the EURO!

[bainbridgekid]

Interesting how much drier the NAM is than the GFS, Euro and UKMET. It literally shows less than 1/6 as much rain for Seattle as any of the other three.

[SilverFallsAndrew]

7 minutes ago, Phil said:

That ridge will probably retrograde into the GOA next month, marking the inception of winter in the West.

Degree of amplification still questionable though. Could be a close call. Keep the vortex out of Alaska and I think it’ll work.

So basically you think it will be like January 2008 where it wasn’t super amplified?

[TT-SEA]

2 minutes ago, 1000'NorthBend said:

Right, but then why was it forecast that way? Were they anticipating more continuous heavy rain but that didn't end up happening? Seems like the rain forecasts weren't showing that and they knew how much mountain snow we had. Maybe the river forecasts are often quite wrong and I just haven't been paying enough attention. 

Not sure... if we got 5 inches in 12 hours then it would have been bad.     But 5 inches over 2 days with pulses of rain and lighter rain in between is typically not going to be a problem unless there massive snow melt involved.

[Phil]

5 minutes ago, SilverFallsAndrew said:

So basically you think it will be like January 2008 where it wasn’t super amplified?

I don’t know. Small differences in initial conditions could make a huge difference in the outcome.

[SilverFallsAndrew]

River is up, I have seen it much higher. 

[Joshua Lake Oswego]

36 minutes ago, bainbridgekid said:

Interesting how much drier the NAM is than the GFS, Euro and UKMET. It literally shows less than 1/6 as much rain for Seattle as any of the other three.

The NAM is garbage for QPF in my experience. I wouldn’t even look at it. The 3k NAM did nail the snow/ice line in the Portland area in February though.

[bainbridgekid]

3 minutes ago, Joshua Lake Oswego said:

The NAM is garbage for QPF in my experience. I wouldn’t even look at it. The 3k NAM did nail the snow/ice line in the Portland area in February though.

What's odd is it usually overestimates QPF.

[Phil]

29 minutes ago, 1000'NorthBend said:

The most annoying thing about my Ambient Weather Station is how it calculates the rainfall rate.

At the start of every hour it resets the rainfall rate to 0.00 in/hour and then it just ticks up as rain falls, eventually resetting at 0.00 in/hour at the start of the next hour. So if we get 0.25" between 1:00 and 1:15 and then 0.01" between 1:15 and 2:00, the rainfall rate at 1:59 (even though it's basically dry) is displayed as 0.26 in/hour. Pointless. 

It seems like instead it should be taking the rainfall amount from the most recent 1 minute and multiply it by 60 to get in/hour.  

You can’t switch to the alternative rain rate?

[SilverFallsAndrew]

8 minutes ago, bainbridgekid said:

What's odd is it usually overestimates QPF.

The 3KM NAM is actually a lot better than people give it credit for IMO. 

[TT-SEA]

SEA is at 1.92 inches for this event... PDX is at 2.63 inches.

[SilverFallsAndrew]

3 minutes ago, TT-SEA said:

SEA is at 1.92 inches for this event... PDX is at 2.63 inches.

Kool

[Omegaraptor]

13 minutes ago, TT-SEA said:

SEA is at 1.92 inches for this event... PDX is at 2.63 inches.

Gotta say, I did pick a good weekend to come home.

[Anti Marine Layer]

Looks to stay dry for the Ducks game.

[NWbyNW]

Hey, this is an invite for everyone.  I'm teaching swim lessons outside in the rain today.  Open invite. This atmospheric river is giving us some great swim lesson opportunities. ;D  All you have to do is step outside.

 

[Anti Marine Layer]

1 hour ago, TT-SEA said:

Totally agree.   

That's why some PNW people spend winters in California or Arizona. 

[Tyler Mode]

I'm trying to find more "normal" pictures for reference, but this is as high as I've ever seen the East Fork of the Lewis River.  I know 1996 was higher though.

[bainbridgekid]

Back edge of the rain should be through Seattle by around 3 PM. Looks like they will get very little in the next 24 hours before the next round starts late tomorrow afternoon/evening.

I'll be at the Husky game at 4 PM so holding out hope that round holds off as long as possible. WRF showed nothing in Seattle till 7 PM.

[Poulsbo Snowman]

40 minutes ago, NWbyNW said:

Hey, this is an invite for everyone.  I'm teaching swim lessons outside in the rain today.  Open invite. This atmospheric river is giving us some great swim lesson opportunities. ;D  All you have to do is step outside.

 

I only swim naked.  Not a good look anymore.

[Blizzard777]

41 minutes ago, Tyler Mode said:

I'm trying to find more "normal" pictures for reference, but this is as high as I've ever seen the East Fork of the Lewis River.  I know 1996 was higher though.

Looks like the chocolate river from Willy Wonka’s!

[Deweydog]

Tapering off just in time for rush hour.

[TacomaWaWx]

1 hour ago, TT-SEA said:

SEA is at 1.92 inches for this event... PDX is at 2.63 inches.

1.98” here with 0.66” today. 

[TacomaWaWx]

We’ve also hit 5.03” for the month. 14.52” in the last 60 days. 

[MossMan]

1.38” for the day, 7.32” for the month. 

[TT-SEA]

54 minutes ago, bainbridgekid said:

Back edge of the rain should be through Seattle by around 3 PM. Looks like they will get very little in the next 24 hours before the next round starts late tomorrow afternoon/evening.

I'll be at the Husky game at 4 PM so holding out hope that round holds off as long as possible. WRF showed nothing in Seattle till 7 PM.

It will be dumping during the Huskies game.   Count on it.    It will start right as they kick off.    

[Blizzard777]

2.29 AR event with .75 today

5.08 for the month 

[MossMan]

Heavy rain. 

[Skagit Weather]

26 minutes ago, MossMan said:

1.38” for the day, 7.32” for the month. 

You have almost twice as much as me for the month. 0.77" for the day, 1.5" in the last 2 days, 3.8" on the month.

[Gradient Keeper]

3 minutes ago, MossMan said:

Heavy rain. 

3:40 PM Radar Update

[TT-SEA]

Over 5 inches of rain the last 2 days... if we could keep up this pace our annual average would be close 1,000 inches.    

[Cloud]

The next AR coming in is gearing up riding directly behind of the previous one and is tapping in on subtropical elements just north of NW of Hawaii. Could be a juicy and warm one. 

[TacomaWaWx]

5 minutes ago, Cloud said:

The next AR coming in is gearing up riding directly behind of the previous one and is tapping in on subtropical elements just north of NW of Hawaii. Could be a juicy and warm one. 

Tims very happy about it 

[Anti Marine Layer]

9 minutes ago, Cloud said:

The next AR coming in is gearing up riding directly behind of the previous one and is tapping in on subtropical elements just north of NW of Hawaii. Could be a juicy and warm one. 

Oh baby

[Skagit Weather]

14 minutes ago, TT-SEA said:

Over 5 inches of rain the last 2 days... if we could keep up this pace our annual average would be close 1,000 inches.    

1,041" Aug 1, 1860 - July 31, 1861 in Cherrapunji, India which I believe is the world record for 365 days. 366" in July 1861 alone which is averaging more than 10" a day !

https://www.wunderground.com/blog/weatherhistorian/the-wettest-places-in-the-world.html

[snow_wizard]

Killer analogs today.  2008 has been making a huge showing lately.  Also seeing 1990 (no surprise), 1955, 1956, 1962, 1964, 1992, 1995, and some other decent ones.  2007 has been fairly scarce lately.

[snow_wizard]

7 minutes ago, Skagit Weather said:

1,041" Aug 1, 1860 - July 31, 1861 in Cherrapunji, India which I believe is the world record for 365 days. 366" in July 1861 alone which is averaging more than 10" a day !

https://www.wunderground.com/blog/weatherhistorian/the-wettest-places-in-the-world.html

Believe it or not I have seen that actual book at the University of Washington library many years ago now.  I also knew about the incredible monsoon that India had in 1861 thanks to a weather calendar I got for Christmas some years back.  No doubt in my mind that was somehow connected to the incredible summer (1861) and winter (1861-62) that we had here.  I'm impressed you found this stuff.

[snow_wizard]

I am so looking forward to this chilly / dry interlude coming up!

[snow_wizard]

31 minutes ago, Cloud said:

The next AR coming in is gearing up riding directly behind of the previous one and is tapping in on subtropical elements just north of NW of Hawaii. Could be a juicy and warm one. 

I'm getting to the point where I will be highly surprised if we don't get nailed sometime in the next 6 weeks.  December has been telegraphed for quite some time this year, but now even more so.