January 19, 2005
Lots to discuss, but no certain solution on the potential weekend storm system.
Continued clear and very cold tonight. High cirrus and mid level clouds beginning to stream into the region ahead of an Alberta Clipper which will race through during the second part of the day on Wednesday. Lows tonight around 5F. Wednesday will be cloudy with a chance for snow showers developing around midday. Snow may accumulate up to an inch. High temperature around 23F.
Snow flurries end Wednesday night under mostly cloudy skies. Lows will be in the upper teens.
It will be mostly cloudy again on Thursday with the chance for more scattered flurries and snow showers as yet another piece of upper level energy comes spinning through. High temperature around freezing. Partly cloudy Thursday night and cold, with lows in the low to mid teens.
Things get ugly as we approach the weekend. To put it quite simply, yes, there will be a MECS this weekend (Major East Coast Storm). The problem at the moment, is fine tuning all of the little details that go into putting out an accurate forecast. I believe that up to this point, the majority of computer guidance has done an outstanding job in predicting the fact that a MECS will take place during the Jan 22-24 period. However, small fluctuations and missing details from model to model make it virtually impossible to get an exact handle on the precise track of this storm.
As we head into Friday, there will be 4 (actually closer to 7) pieces of upper level energy that will play an immense role in the development of this storm. Perhaps the most important piece of the puzzle for our area in terms of track and precip type will be dependent upon what happens with the remnants of the Alberta Clipper which will swing through the region on Wednesday. Folks, the key with the upper energy (if in fact you are pulling for a large frozen storm this weekend) is that as it pulls away into Northeastern Canada, it needs to close off and develop an upper level low near the 50 latitude / 50 longitude position (the famous 50/50 low). This is possibly the most important key when forecasting a winter MECS. The benefits of this feature are that it aids in developing a good confluence zone in the Northeast, develops blocking signatures downstream of the low, and most importantly, it locks / funnels cold air into the Northeastern US.
That all being said, guidance has shifted from strongly favoring the development of the 50/50 low towards just barely developing the 50/50 low at all as it gets pulled around the huge Polar Vortex over Hudson Bay. Suffice to say, this does not mean we wont see any nasty weather but our chances at receiving a HECS (Historic East Coast Storm) are much lower than they were 48 hours ago. Now keep in mind, we still have 3.5 days to go before this storm develops, so things WILL change and trends will take shape, but as we enter the short and medium range for this forecast, we will be closer to having exact details on the storm system.
For now, expect upper energy (3 pieces respectively) from the SW, the NW, and Northen Canada to join forces and phase somewhere over the Ohio Valley on Friday night or early Saturday. At the surface, low pressure in the form of a quasi-Alberta Clipper will dive out of Canada and into the plains. As the upper energy forms a closed upper low Saturday afternoon and night, the surface storm reflection will head ENE towards the Ohio Valley. Snow should move into our area during the day on Saturday and could become heavy at night. While all this is happening, a huge dome of high pressure will be nosing into the Northeast and will help keep cold air in place at the surface. Meanwhile, a secondary area of low pressue will form right along the Carolina/VA coastline and will intensify Saturday night and during the day on Sunday to become the new primary low pressure system. From there, the storm is expected to move NNE and should pull away from the Mid-Atlantic by Monday at some point.
There are hints now that because the 50/50 low may NOT develop, warmer air *may* win out for a period here and turn snow over to a mix or just plain rain to a while. Again, there is not enough detail this far out in advance to tell for sure exactly what will happen, so keep all options open at this time. Am very confident though at this time that this system WILL bring snow here to at least start the event some time on Saturday. Finer details, duration, accums, etc to come with later discussion.
For now, keep in the back of your mind that there is the likelihood that parts of the East including our area will be hit rather hard by a winter storm over the weekend. More details to come. Take care.
S.B.
