I can not stress enough that if one follows the pattern that is in place then one can generally have an upper hand on what one can expect. Specifics are always going to be a bit more difficult compared to what one can expect when one recognizes and understands the pattern that is and has been in place for some time now.
So we are going to reflect back into what pattern has been in place for sometime now…
The AO is above…one can see that at the present time the AO is positive..expected to head towards neutral but then stay positive…
Whenever you have a positive AO the air mass involved is not supportive of deep cold or arctic air…
North Atlantic Oscillation is positive expected to stay that way in the near to medium term before heading towards neutral. Again when you have a positive NAO cold air is not as abundantly supplied if it were a negative NAO. Neutral NAO would be slightly more favorable cause it would allow colder air that is available to tap to bleed somewhat into the 40 N region.
What about the PNA folks? The PNA is neutral currently and forecasted to head into negative territories. Positive PNA indicates a trough along the east and a ridge along the west. We do not have a positive PNA but rather a neutral PNA. This neutral PNA can be compensated and made up for however by a negative EPO or Eastern Pacific Oscillation. We do have a negative EPO coming into play currently and for this time period ahead in reference to the 9-12th. However..there is also a catch 22 when it comes to a Negative EPO. While a negative EPO can send ridging into Canada and compensate for a neutral negative PNA in creating a trough along the east it also places what is known as a Bermuda High or a SE ridge along or off the SE coast. This is a strong area of high pressure located near bermuda that extends westwards to the coast.
Typically speaking a low pressure area unless it is a very deep area of low pressure can not shove into a Bermuda High or SE Ridge…so the low pressure will take the path of least resistance…Since there is a SE ridge in place (negative EPO) it will not head off to the south and east.
Folks the above explains the current pattern that we are in & also points out what one can expect. Here is a graphic representing what is talked about above:
So now lets look at the latest modeling from 12 Z today..
The above is the GFS/UKMET and GGEM. All three of these models generally take the low well east of the region,
the 12 Z Nogaps also takes the low well south and east of the region and this is pretty much to be expected with the models very progressive bias.
However…all these models essentially end up in approximately the same location as the 12 Z Nogaps or in the general vicinity! The problem is all these models are not recognizing the SE ridge and are taking this into and thru where the SE ridge would actually be do to the teleconnections that are in place.
They are also all showing a much colder air mass then what is representative by the teleconnectors. The ECM is somewhat recognizing things a little better ..
Its starting to realize that the SE ridge is stronger and it is starting to slow the system down and build higher heights along the east coast. It still ends up being quite east at 144 hrs.
Now lets just reflect back on past systems and how in this range they were all modeled to be south and east..and at that time we had more favorable connections but they managed to come back and track further to the NW and in most cases further NW then what models showed and suggested. Lets look at the current surface map for the current system..
This shows a strong primary over Western PA and a coastal beginning to deepen but this coastal is not the primary as the low to the west is deeper then the coastal. This storm as well was originally modeled to be a coastal and a colder solution to cause the region to receive several inches of snow but the pattern always suggested a further west solution. This is why i mentioned yesterday in the chat room that the NWS had this completely backwards and that we would have ice turning to snow if there is enough moisture left as the upper levels cool off. Currently on radar you can see the WAA (warm air advection ) from the southerly flow around the stronger primary causing precipitation all the way into Central New England to fall as either Ice or rain.
So..with recognizing the pattern that is in place we are not going to change our thoughts from a further west solution occurring as we get closer to the event. We feel that there is indeed the potential for a significant winter storm in this time period.We also feel that with the further west solution and the teleconnections in place and pointing the direction that things should transpire that the big cities along the east coast would end up being either a wintery mix or mainly rain.
If this storm does materialize it would be the inland locations that receive the snowfall. How far inland? Way to early to speculate on this at this point and time.
Thought to ponder is everyone has been talking about a pattern change. We do believe a pattern change is indeed coming and this storm will usher this pattern change in…However…when you look at the teleconnections that are currently in place and have been in place for some time…what pattern change would be coming? Though to ponder!
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