October 2019 Weather Discussion for the PNW

[ShawniganLake]

Near sea level? That’s pretty ridiculous for this early.

Yea. 500ft.

[TigerWoodsLibido]

No significant temp drop here. Been in the mid 50s all night.

[TT-SEA]

Gfs looks really wet starting around the middle of next week. Firehose season is in full effect if that verifies.

 

 

Not really.   I ran the 6-hour precip loop for the entire run and it shows a few systems coming through for 5 or 6 days and then it dries out again.    I was expecting much worse based on your post.  

[ShawniganLake]

Not really. I ran the 6-hour precip loop for the entire run and it shows a few systems coming through for 5 or 6 days and then it dries out again. I was expecting much worse based on your post.

A lot of warm front hell in the long range

[TT-SEA]

A lot of warm front hell in the long range

 

 

Actually... that lasts for about 2 days on this run (10/21 and 10/22).

[MossMan]

Ice pellets!!

[GHweatherChris]

Ice pellets!!

We had some hail accumulation a little bit ago.

[MossMan]

Mixed with chunky snow!

[TT-SEA]

Mixed with chunky snow!

Wow.

 

Dry and 48 here.

[TacomaWaWx]

Mixed with chunky snow!

wow.

[TacomaWaWx]

Not really. I ran the 6-hour precip loop for the entire run and it shows a few systems coming through for 5 or 6 days and then it dries out again. I was expecting much worse based on your post.

haha well it looks fairly wet with some decent precipitation totals in BC especially along with the north coast and north cascades. Either way, it’s all theoretical at this point still a lot of time for it to change. looks like some nice weather this week!

[TT-SEA]

haha well it looks fairly wet with some decent precipitation totals in BC especially along with the north coast and north cascades. Either way, it’s all theoretical at this point still a lot of time for it to change. looks like some nice weather this week!

 

 

Devil is in the details... there is only 3 or 4 days on the 12Z GFS run with significant precip for the Seattle area. 

 

Of course those details will change many times, but this run does not show and endlessly wet, fire hose type of situation.

[TacomaWaWx]

Looks like it’s snowing at longmire on their webcam which is at 2700’ roughly.

[TacomaWaWx]

Devil is in the details... there is only 3 or 4 days on the 12Z GFS run with significant precip for the Seattle area. 

 

Of course those details will change many times, but this run does not show and endlessly wet, fire hose type of situation.

Yeah firehose May not have been the correct wording for the situation. “Wet” is a better word for it.

[Kayla]

Arctic front must be having a hard time reaching the border. Still a SW wind all the way up the Fraser Valley to Hope.

 

Actually even Lytton, way up the Canyon, has switched back to a South wind

 

It's progressing quickly through Montana. Already through Great Falls.

 

[MossMan]

All rain now. Temp pummeled all the way to 39 with that very intense ice pellet/snow shower!

[Kayla]

Pretty sad airmass. We did better in September. 

 

This airmass is actually colder but tracking further east rather than right over you like the last one.

[seattleweatherguy]

steady rain here

 

edit correction some ice pellets

[Front Ranger]

Balmy morning in Bend. An astonishing 55 degrees.

 

[Deweydog]

Euro!!!

[Phil]

Wow..up to +1.95 now. Third strongest +IOD on record.

 

[Phil]

For reference..the circulation associated with the +IOD enhances convection in the W-IO/Africa and reduces convection over Australia and the Maritime Continent.

 

Hence the phase diagrams for MJO appearing to “loop” in phases 8/1. In reality that’s not an MJO, it’s the IOD cell.

 

[Front Ranger]

That 1926 event is pretty far removed from anything else around this time. Records for 1 week centered on today are all in the 30-32F range with the exception of a 29F from 1930 and a 28F from 1985

 

From what I can tell, it was very north-focused. Doesn't look like it set many benchmark records south of the border.

[Phil]

Another perspective:

 

[Omegaraptor]

For reference..the circulation associated with the +IOD enhances convection in the W-IO/Africa and reduces convection over Australia and the Maritime Continent.

Hence the phase diagrams for MJO appearing to “loop” in phases 8/1. In reality that’s not an MJO, it’s the IOD cell.

What does this mean for the weather in this part of the world? Big ridges and troughs thanks to MJO?

[Phil]

And yes, an anomaly of this magnitude is relevant to the fall/winter pattern evolution across the NH, since it’s the strongest low frequency component in the structure of the tropical forcing(s) outside QBO, for the time being.

[ShawniganLake]

From what I can tell, it was very north-focused. Doesn't look like it set many benchmark records south of the border.

Must have been a decent Fraser River event. Probably very low dew points. The wind sheltered stations were in the 20s here will the wind prone locations stayed in the 40s.

[Front Ranger]

Tomorrow's record low at Silver Falls is 22 from 1985. Thursday's is 26 from 1946.

 

For OLM, tomorrow is 28 from 1985, Thursday is 27 from 1972, and Friday is 28 from 2009.

 

I would bet at least two out of three fall.

[TacomaWaWx]

D**n 1350’!

[ShawniganLake]

Looking fairly impressive for the BC interior right now. Clinton is down to 24F on the 11am obs with light snow, a 30mph N wind, and a wind chill of 10F.

[TacomaWaWx]

Convergence zone taking aim right at Seattle now. Looks like it’s been producing hail accumulations in many spots.

[Phil]

What does this mean for the weather in this part of the world? Big ridges and troughs thanks to MJO?

Varies by season, and more importantly it’s hard to dissociate from ENSO (since many of the strongest IOD events occurred with potent ENSO, unlike 2019 even though it’s behaving otherwise). But the +IOD could be considered a prolonged WHEM type MJO boundary condition, which favors western troughing in Sep/Oct, especially during +PMM.

 

While potent +IOD events aren’t usually long lived beyond three months or so, we’ve had a clear +SIOD tendency for several years now (including a doozy in 2017/18) and now the more classic +IOD of +IOD in S/O/N seems to have arisen out of that +SIOD. Very intriguing.

[Rubus Leucodermis]

Localized wind shifts don’t really mean that much, the cold airmass is still dropping south. It isn’t like this was ever forecast to be raging low level arctic outflow pattern anyway. It’s early October.

 

NWS is still calling for outflow winds to 25 mph in Whatcom County starting sometime this afternoon.

[Jesse]

Euro!!!

Uh oh...

[ShawniganLake]

[ShawniganLake]

Uh oh...

Looks like it’s gonna get wet next week

[Deweydog]

Thanksgiving.

[Deweydog]

Getting BREEZY out!

[High Desert Mat?]

Balmy morning in Bend. An astonishing 55 degrees.

Winds just switched to a brisk northerly one in Redmond.

[TacomaWaWx]

Looks like the convergence zone is trying to slide a bit farther south. Appears to be pretty strong. Wind is out of the north just around Lynwood north of Seattle.