weatherwiz

We should also watch the June - September timeframe for a potential cold front that could spark t'storms

expansion coming tonight

Beautiful out.

@HoarfrostHubb change title to reflect convection please

GOOD CALL!!!!!!!!!!!!!1

Placement of the warmest temperatures anomalies I think worked in our favor significantly as well: also the core of the westerlies surrounding the SPV were displaced towards the other side of the hemisphere But I think I am a little confused about something...this event in 2015 (since i don't remember off the top of my head is that referring to a strong PV or weakened PV? Based on what you posted and what i did I would assume the PV is pretty strong here (2015)...which is a good thing that it is displaced towards the other side of the globe. A strong PV displaced south into Canada would result in strong westerlies over the U.S.

I wish we could poke that ridging a bit more into the GoA...even with the crappy polar region perhaps that could displace some of the cold that's been in AK our way and at least we would have that nearby. That look isn't great...but would certainly take chances given the time of year

was it east-based? I thought the east-based events had the + height anomalies positioned east of Greenland which yielded a higher likelihood for -height anomalies across the east...while a west-based had the +height anomalies so far west (and during strong events) they even were displaced south and penetrated into our region? I may have this reversed though...trying to picture in my head

We can get away with having a crappy PAC I think...although depending on what you're expectations are. If you're expecting a pattern that is going to consistently deliver well that's difficult with a crappy PAC but if we can get a favorable polar domain and get an active storm track...chances are something will deliver...perhaps more ratters than not but I'll take the chances

Yeah I certainly agree there is definitely more to it than that. The biggest weight overall I think is structure and placement of these anomalies and synoptic features. This is that extra piece which makes the seasonal forecasting challenging...sure we can have an idea of how NAO/AO may evolve based on QBO projection and how the stratosphere may evolve but we really don't know how they will be structured...and that's the key piece...I think anyways. Do you remember way back I think his name was Allan (Raleighwx) did something with breaking the NAO into regions (similar to ENSO) with east-based and west-based +/- NAO events...he even had an index to measure it...but never heard of anything since and there is very little about this online. but doing the correlations to patterns by breaking down (say a negative NAO) between east/west based increased the correlation significantly.

This is a great site with stratosphere products stratobserve.com You can see that the PV does look to elongate by around 228-hr...but then towards the end of the run it becomes more compact..I would assume though we would want it to become more displaced on our side of the hemisphere I'm glad I have that notion correct about the PV taking hits. One thing noticeable too (wish I could do this in animation) but around 228-hr there is a reversal of the zonal winds aloft...they become westerly Quite a bit of heat flux too Again though...seems like all of this is happening on the wrong side of the globe? (Of course this is based off the GFS)

I agree...but I think we're talking about different aspects here...you're referring to long-term forecasting where I'm talking about medium-range signals. The PV has been quite strong all winter...and while perhaps from an evaluation of pre-season indicators you could assume weakening based on several factors (such as descending QBO as you mentioned)...we can also see models in the 10-15 day period just start to weaken the PV and then all of a sudden inside of D10 or D8 that signal vanishes...once it becomes apparent that there indeed be direct impacts on the PV the initial forecasts really mean nothing. My understanding is that one way to weaken it is to keep pelting it with Rossby wave after Rossby wave...and strong Rossby waves. Let's say you have a 4-5 week stretch of horrific winter weather...and you think it may never end...if there is a constant flux of Rossby waves pelting the PV...that can give you a very strong indication that within the next 3-4 weeks big changes will result. Anyways...perhaps through pre-season guidance you can put a wager on these changes happening...but until you actually spot those potential developments within guidance the preseason guidance doesn't hold a whole heck of alot of merit.

yup...could see some convective snow squalls with that!!!

decomposing chicken poop

We should see general t'storm line get into parts of New England with the new D2 I would think

This is something I'm trying to read up on and learn more about. What are good signals to focus on for this process? Is it escalated or driven by series of strong s/w's crashing into the vortex and strong heat flux transport from the tropics?

If there is one thing that seems to be going for next weekend it's the evolution of the pattern across the eastern PAC into the western U.S. The signal is there for not only somewhat substantial ridging across the western U.S. but the structure of the ridge doesn't look bad...would favor deep troughing in the east and they key here is where the trough axis becomes positioned. Even looks like some very weak but noticeable ridging (or at least higher heights) poking into the Arctic. As long as models aren't very off with the development of the ridge to the west we're in a good spot. As far as any worries about the airmass...as long as the track is off-shore the majority of the region should be fine. Looking at 850 temp anomalies can be very misleading given the time of year we're in...sure they may be above-average but we're still talking about -10C's 850's in southeast Canada.

I'll take...wish the MUCAPE was higher...but 17 J/KG of MLCAPE in January

the Euro is sooooooooo close with getting convection into here ughhhhh come on big boy

it is if you don't understand it

that's a good point...but yikes thats a bit of money

They should be banned from model output.

I bet haha. Much easier and more fun