Hi everyone, it's John Manetta, or John M. as some of you know me. To those that don't know me, I look forward to having some great discussions with you. I've been absent for some time, which is a long story, but I'm glad to be back.
There is a threat of a warning criteria event in the 8/9/10th time frame, (likely the latter part). At this point there is a fairly wide range of possible outcomes. I am currently using the ECMWF and GFS for guidance into this period, (of course with a close look at the UKMET, EPS and other ensembles etc.). Both models, (at this time), are predicting a situation that would be favorable for significant cold air damming during the event. This means that the cold air at the low levels will likely remain cold while warm air floods the mid levels as waves of low pressure enter the region and finally a coastal develops and locks the surface cold in. This would favor a significant period of freezing rain for a portion of the region.
Of course, the global models have not yet had a good sampling of data to ingest into their initialization because the systems have not yet reached the the upper air network, (the weather balloons that are launched from around the world to collect data are very sparse over the oceans). This is why 00z and 12z predictions are usually more accurate, because the balloons are launched twice per day and the data is used at those times, (sometimes more in exceptional circumstances).
As we can get a handle on this in the coming days, I will get more specific. At this point I suspect that the high pressure system will be in an optimal position for a while, but with the Atlantic not helping with a -NAO it's going to be close. The timing of the second wave and where the high is before and during the development of the coastal means everything from significant snow, to an icing event to a mix, (I'm confident about the coastal development, but it's placement and the column temperatures are debatable at this time).