October 2020 Forecasts and Discussions

[SouthSardiswx]

1985.


/s

How much snow did Chilliwack receive back in Nov/85, can someone look it up.

[stuffradio]

The 12Z is continuing to forecast a chilly blast...

[Typeing3]

How much snow did Chilliwack receive back in Nov/85, can someone look it up.

The 85 event was more notable for extreme cold rather than snow. Totals were light/moderate overall.

[Rubus_Leucodermis]

The 85 event was more notable for extreme cold rather than snow. Totals were light/moderate overall.

Wasn’t living there at the time but I believe Seattle got a fair amount of snow out of it, so it sounds like one of those situations where we’re far enough north to get plenty of cold air but too far north to get much moisture.

[Typeing3]

Forget 1985, November 1911 is a better match with the timeframe! Models don't look nearly as cold though.

[Typeing3]

Wasn’t living there at the time but I believe Seattle got a fair amount of snow out of it, so it sounds like one of those situations where we’re far enough north to get plenty of cold air but too far north to get much moisture.

Our region saw 2-8cm heading into the blast on the 19th/20th, followed by a few cold and clear days. Another bout of snow on the 25/26/27th dropped a general 8-20cm. Another stretch of clear/cold days before the overrunning event on Dec 2nd/3rd with 8-15cm.

The cold was incredibly persistent though - ignoring the high of 0.1C on the 24th, YVR had an 11-day stretch with temps below freezing. The stretch included a high/low of -8.7c/-14.3c on the 27th.

Cold was even more impressive at YXX with 14 straight days below freezing including -10.5c/-16.7c on the 27th.

[stuffradio]

Here's the updated 12Z map

2020102912_054@007_E1_north@america_I_NAEFS@TEMPERATURE_anomaly@probability@combined@week2_186.png

[AbbyJr]

Here's the updated 12Z map

2020102912_054@007_E1_north@america_I_NAEFS@TEMPERATURE_anomaly@probability@combined@week2_186.png

What I find insane in the sudden model shift and how all the models jumped on board at once. Its crazy to see such high confidence so far in advance. That said, the cold doesn't look all that impressive at this point. Chilly modified outflow event likely though.

[stuffradio]

What I find insane in the sudden model shift and how all the models jumped on board at once. Its crazy to see such high confidence so far in advance. That said, the cold doesn't look all that impressive at this point. Chilly modified outflow event likely though.

It doesn't have to be impressive to be decent. The 12Z GFS drops to almost -5C in the long range though for YXX.

[PortKells]

What I find insane in the sudden model shift and how all the models jumped on board at once. Its crazy to see such high confidence so far in advance. That said, the cold doesn't look all that impressive at this point. Chilly modified outflow event likely though.

Yep. Lots of time to turn into something or fade into nothing.

[AbbyJr]

It doesn't have to be impressive to be decent. The 12Z GFS drops to almost -5C in the long range though for YXX.

Low though not high but still decent.

[Catnip]

D84816E3-3858-440A-884E-C8A7BD752BE2.png

[Rubus_Leucodermis]

What I find insane in the sudden model shift and how all the models jumped on board at once. Its crazy to see such high confidence so far in advance. That said, the cold doesn't look all that impressive at this point. Chilly modified outflow event likely though.

The model agreement is such that I am going to be willing to considerably relax my standard three-day rule. If there is still model (and run to run) agreement on cold and snowy solutions a week out from the event, I will find it exciting. The models were like this in December 2008 and they ended up verifying.

[AbbyJr]

The model agreement is such that I am going to be willing to considerably relax my standard three-day rule. If there is still model (and run to run) agreement on cold and snowy solutions a week out from the event, I will find it exciting. The models were like this in December 2008 and they ended up verifying.

February 2017 was like that too. A sudden model shift from mild SW flow to arctic air and heavy snow. The cold and snowy solutions verified.

[Typeing3]

February 2017 was like that too. A sudden model shift from mild SW flow to arctic air and heavy snow. The cold and snowy solutions verified.

That shift was only about 72-96hrs out too. You almost never see the models radically shift cooler in that timeframe which made it even more special.