Nov 27-29th MidAtl/NE Storm

CPC NAO/AO/PNA/AAO indices

GFS ensembles show a storm in this period, it is late 15 days out, but the system in question impacts the flow across the US within three days time. The breakdown of the polar vortex over the Gulf of Alaska into two or three pieces of shortwave energy will determine our next major winter storm across the eastern US. Although this is in the extreme long range, there is enough model consensus within the GFS long range family of models to suggest that the PNA will soon become positive and the NAO/AO will become negative in this period. Individual ensemble members show a storm in this late period around hour 372 and beyond. THis could be a doozy of a storm for the Eastern US.

Nov 17-19th MidAtl/NE Storm

18z GFS this evening shows a potential storm developing off of the NC coastline with a large 1030mb+ strength high pressure system to the north of the low pressure system. Potential exists for snow as there is cold air to the north over western New England and Canada present. However it will likely change to all rain as the large cutoff H5 low will bring in too much warm air aloft and at the surface as its position is too far southwest for snow lovers to dream. This is the pre Thanksgiving storm.

November 3-4 2012 Northeast Storm

The 00z model suite suggests that there is potential for a storm off the New England coast this upcoming Saturday and Sunday, however current models suggest this system stays offshore. We are still three days away and there is a lot of upper level energy to be handled. I think this storm will be closer to the coast to give SNE some possible rain/snow. 6z GFS and 6z NAM are currently offshore with this system. -NAO and +PNA suggests a more amplified pattern would lead to a storm closer to the coastline, it will be interesting to see this unfold as anything can happen with the weather. Again this is quite the energetic setup and its possible the models could bring this system closer to the coastline. I will continue to monitor the progress of this system.

June 1-2nd MidAtl/NE Severe Weather

A potent mid level shortwave will enter the PAC NW US over the next several days as a large western US trough carves its way southward. As this happens a large build up of heights will occur across the eastern US, allowing temperatures to soar up into the upper 70s across most of New England, while areas further south have temperatures in the 80s to upper 90s. A large flow of moisture will come out of the south as a large surface cyclone enters the Canadian province of Ontario. Southerly flow ahead of the vort max will allow veering wind profiles and larger tha 90 degrees of clockwise turning in the atmosphere. Atmospheric enviroment will be one with intense instability and potentially strong northwesterly shear as the vortiticity max dives southeastward across the Northeastern US. A NW to SE outbreak of supercellular storms and line segments could encourage a large outbreak of tornadoes, along with the potential for damaging winds and large hail. Still model timing issues remain a problem especially about 4-5 days away from the potential outbreak, but nonetheless, this is a potential we need to continue to monitor. I will have more tomorrow, after 12z model cycle.

Jan 4-5 MidAtl/NE Clipper

18z NAM and 12z GFS are more robust with the potential clipper Tuesday and Wednesday. However models as a whole are quite weak, and really showing a frontal passage as the parent low tracks too far north of the region. However the 18z NAM is south with the vort max, and in this set ups, history shows that these setups produce at least light snows for the region. NAM wants to develop the clipper and coastal low redevelopment a little faster than most models and it won't take much for this system to produce. A little more digging of the vort max and we are in business. 12z EURO is just too far north with the surface low. potential for a few rain/snow shower mix if the frontal passage occurs. All I know is that it will get cold behind this system. Problem is during LA Ninas there are no sustained Quebec, canada surface highs present. So it can't stay cold for a prolonged period of time along the coastline. In any case it will get cold. Perhaps snowy for SNE.