October 2021 Forecasts and Discussion

[Catnip]

You are getting sleeeeeeeeeeeepy

bomb1022anim.gif

[VanCitySouth]

Euro's trended the Sunday bomb eastward every run for 4 runs. I find that mildly concerning.

[AbbyJr]

Euro trend is concerning for those who don't want a damaging windstorm. Significant SE trend on the 12Z versus the 00Z.

00Z:

ecmwf-deterministic-nw-mslp_anom-5166800.png

12Z:

ecmwf-deterministic-nw-mslp_anom-5188400.png

[Typeing3]

Big difference in the track of the low on UW MM5 12km NAM versus the regular 12km NAM:

UWMM5NAM.gif

nam-218-all-nw-mslp-5163200.png

North Island landfall is more realistic. Deep lows usually curve north.

[PortKells]

North Island landfall is more realistic. Deep lows usually curve north.

Is that good for avoiding major impacts?

[AbbyJr]

North Island landfall is more realistic. Deep lows usually curve north.

I agree but the Euro has trended SE with the track of the low on the 12Z today.

[Typeing3]

Is that good for avoiding major impacts?

I'd say 50/50 because it does depend on a couple of factors, at least for impacts to the lower mainland.

#1 is whether the low is weakening or intensifying as it approaches the coast and #2 is track (SW to NE is most conducive to a big windstorm for our region, based on historical events).

As an example for both, here is an image showing the strength and track of low that caused the the December 2018 windstorm:

coquitlamwx_lowcentertrack_stormtrack_20122018_12202018_20dec2018_nvilow_22dec2018_18in_72dpi.jpg

[VanCitySouth]

I agree but the Euro has trended SE with the track of the low on the 12Z today.

NAM 18z also south and east of 12z. 12z missed the Island completely and this one makes landfall.

Funny how the mm5 version is so much closer to the GFS track (south Island). I wonder if it's because UW initialises both the mm5 NAM and WRF with the same inputs.

[John]

Gfs 18z update? Yes

[Weather101]

[PortKells]

Gfs 18z update? Yes

Lol thank you for the update about the update.

[Abby_wx]

Gfs 18z update? Yes

Low fills and pretty much dissipates before moving across Northern Vancouver Island... non event for the Lower Mainland.

[PortKells]

He's back

[AbbyJr]

Here is a comparison of the December 20th, 2018 storm versus this upcoming storm as shown on the 12Z Euro for Sunday/Monday.

Based on what I can I see, there are some similarities but also some differences.

The December 20th, 2018 storm was less deep than this upcoming storm but it continued to deepen as it approached land. This upcoming storm, on the contrary, is deeper but it weakens as it approaches land. However, since it's significantly deeper than the 2018 storm, it ends up deeper when it reaches land despite weakening on approach. As for the track, this upcoming storm looks to be slightly further northwest than the 2018 storm.

December 20th, 2018:

EuroReanalysis2018.png

Upcoming storm:

12ZEuro2021.png

[PortKells]

Low fills and weakens before moving across Northern Vancouver Island... non event for the Lower Mainland.