18 Z Comments 3/12/09

Sometimes you have to look at the models and what they are showing and just laugh out loud. This is one of those times. The images above are pretty explanatory but the one shows the state of the NAO. As you can see a high pressure over Greenland is indicative of a negative NAO...
The other image you are looking at is the 18 Z GFS 84 hour 500 mb height depiction. As you can also see there is a High pressure centered over Greenland. So we have the 18 Z GFS at 84 hours showing a negative NAO...
What else do we see on this image? We see an upper level low to the south of Alaska. Notice that this upper level low is not over Alaska. If this upper level low was over Alaska then we would be looking at a positive EPO.
This is the consistent reason why I have been looking to the teleconnections to try and figure out what is happening.
Essentially you have the 18 Z GFS showing a negative NAO..and you have the 18 Z GFS showing a Neutral EPO. If the EPO was negative then there would be high pressure over Alaska. Again low pressure over Alaska would represent a Positive EPO.
What about the PNA? Above is an image that represents a positive PNA. So what is the 18 Z GFS showing here? Remember the low is to the south of Alaska and not to the Southwest of Alaska. We have a high pressure to the SW of Alaska. So this does not imply a postive PNA..nor does it imply a negative PNA... so this would also imply a neutral PNA...
So here we are seeing a Negative NAO portrayed and a Neutral PNA and a Neutral EPO...
There is also a 1037 high pressure to the north of NY... In a set up with these conditions in place...its my opinion that the temperatures should be alot colder then what is being modeled on the 18 Z GFS. A 1037 high pressure with a negative NAO and a neutral EPO would allow confluence to bleed into the colder levels.
To give you an example of this. The forecasted high temperature for today was suppose to be in the lower 40s. Of course this was dropped from the mid 40s. Todays high temperature just made it to 40 degrees here in KABE. Though the official high occurred after midnight last night at 42..I am simply referencing the daytime temperature during the daylight hours. This high temperature worked out to be 5 degrees below normal to give an over all departure of -2 on the day. This is the type of stuff that happens with the teleconnections that are in place. Colder air bleeds down into the lower levels and you end up with below normal temperatures. This is all thanks to Canadian high pressure which is in the process of moving into the area. If you look at the inverted surface map above you will also notice that this high pressure is dominating the country. Looking at the temperature map above you can see temperatures into the 30s in TX..This is March folks. This is unseasonably cold air.
So what about storms and no storms?
Well the 18 Z GFS suppresses the wave that is currently on the radar but it does bring it further to the north then earlier runs. This would be between the 13 and 15th. The current wave on the radar. The wave that was for the 17-19th has now turned into a non event, other then a cold front that now at 180 hours out has a wave that develops to the south along the front.
In other words we have a different solution on our hands once again.
So my thoughts at this point and time is that with such model mayhem and confusion but yet the operational runs continuing to show the teleconnections that offer a potential favorable setup..that we just watch the models, nowcast observations and keep an eye on those teleconnections and we should be able to determine the sensible weather for the time period between the 15-20th.
Thats all for now! Thanks for reading!