Friday, December 30, 2011

Full Winter Update, Snowstorm Predictions, Long Range Predictions

We are seeing a major stratospheric warming event take place in the last several days. We are seeing some big temperature anomalies from the 30mb level up to the 1mb level. The big part is that the warming is occurring over Alaska. Because the warming is occurring over Alaska, we might be seeing the semi-permanent low pressure system over Alaska weaken as the warming may progress down into the troposphere. If this warming continues, the pattern change would definitely be helped along. The warmth may be able to propagate into the North Pole, where a disruption in the Polar Vortex could break the stubborn +AO/+NAO regime which has been producing a snow drought over the East US.
Here we have the 0z ECMWF 500mb analysis over the far North Hemisphere. We see the strong low pressure systems right over the North Pole. We can see the strong low pressure system over Alaska, where we are seeing warming occurring. Now let's skip ahead to hour 168.
At hour 168, we are seeing a ridge from Asia pump north into the polar vortex and interrupt it for a little bit. This ridge will be pulled north into the main polar vortex and disrupt the vortex. Essentially, the NAO and AO will also be disrupted. The AO, which is based in the North Pole, is the biggest piece that will be affected. If the vortex breaks, the extremely cold air that has been locked up may flow southward as the vortex breaks. Moving ahead to hour 240 is seeing the low pressure system over Alaska take a big weakening hit, which may bring some active weather into the US. However, no model does well at 10 days out, so take this as something to watch.
But let's say that this disruption does happen. Well, what would happen to the all-important NAO?
OLD 0z ECMWF
The old 0z ECMWF shows the point of when the expected break in the polar vortex is, as well as the effects of the polar vortex break. The new 12z ECMWF does now show the downward trend, but an up-and-down pattern similar to what we have outlined as the time when the vortex breaks. We are still seeing a more persistent ridge break into the polar vortex, however, so the NAO image above should not be discounted.

The NAO has been wildly swinging. With stronger systems bringing stronger positive NAO values, this means the potential for lower NAO values, going off of Newton's laws: With every action there is an equal and opposite reaction. If we use that law, it can be determined that a strong +NAO value will eventually lead into a strong -NAO sometime this winter.

SNOWSTORM PREDICTIONS---
Pre note: Confidence is low on these predictions. It is entirely possible that these snowstorms will not happen. In other words, don't hold me to these.

January 6-11: An active period is already setting up that should lead into the first couple weeks of January, if not longer. Among those possibly affected include the North Plains and the Northeast.

January 14-18: A couple shots of low pressure systems into the Southwest could make for a good snow somewhere in the Plains or Midwest.

LONG RANGE PREDICTIONS---
A quick start to January will continue as the deep low pressure system over Alaska weakens as the ridge interrupts the polar vortex in the early new year. Late January may bring a deep chill to much of the country as the Arctic Oscillation dips far enough into negative territory to unleash pure Arctic air. Using Newton's Laws mentioned above, we can expect a BIG snowstorm for the Northeast sometime this winter when the NAO goes negative in response to a very positive NAO so far this winter.

15 comments:

Mike Paulocsak said...

Hello Andrew.Great work on the update.Do any of these storms if they do come to life,have the potential of bringing snow to my area in Ohio,just a guess.

Mike Paulocsak said...

Hello Andrew.I was wondering if you see any developing storms Jan.2-6.There will be enough cold air to support snow.You would think there would be some developement of some sorts.

Andrew said...

Jan 2-6 looks to be dry for the time being.
It's too far out to tell if Ohio will be affected.

Mike Paulocsak said...

Hello Andrew.I'm HAPPY to report i'm getting a THUNDERSTORM right now.This sounds CRAZY doesn't it.It was never predicted by the weather forecast for my area.Go figure.You should hear the thunder.It's rattling the house a little.

Andrew said...

Ah yes- it looks like the clipper is hitting you with sue thunderstorms!

Mike Paulocsak said...

Hello Andrew.Too bad it wasn't snow,heavy snow.It's also pouring down rain/gusty winds to go with it.I can never remember a winter like this in the recent years.

Mike Paulocsak said...

Hello Andrew.On the instantweathermaps site on hour 384 it shows alot of snow around Ohio & surrounding states.I realize it's not an accurate model,but the way i figure it's hope.

Anonymous said...

Pardon my asking, but what is a sue thunderstorm?

Andrew said...

Mike: It seems like the GFS is hooking onto the pattern. Big snows are not out of the question.

Anonymous: 'sue' is 'some'. Autocorrect error.

Mike Paulocsak said...

Hello Andrrew.Do you see or think the big snows could hit my area in Ohio?Holmes county.I sure hope so.You probably figured i was going to ask this.Maybe the snows will replace all the rain i have been recieving.Do you think so?Thanks.

Andrew said...

Too far out to tell.

Mike Paulocsak said...

Hey Andrew.I just listened to my NOAA weather radio,and they're calling for above normal temps.& precip.for the 6-10 outlook.It looks like more mild rainy weather is on tap.I'm beginning to wonder if the pattern will change or not.I sure hope it does.

Anonymous said...

Are you sure that Newton's third law can be related to the NAO? It just kind of seems a little sketchy, considering these are Newton's laws of MOTION, not the NAO.

Andrew said...

Anonymous: That is true, but in the physical world, everything tries to reach balance. That said, if there is too much of a +NAO, it would seem logical that a -NAO will eventually prevail.

Anonymous said...

Then again, one might figure that this positives in response to the negative we had.