February 8, 1999
I admit, I was caught off-guard yesterday as we received a brief period of light snow.
Upper air temps did not look like they would be cold enough to bring snowfall, but they
were. Anyway, we received a trace of measureable snowfall here to add to our grand total
of 5 inches this winter so far. This week is going to be one of those periods of transition as
we go from chilly (today) to nice (tomorrow) to mild Thursday and most of Friday and then
the bottom drops out and we will see temperatures close to normal or even below normal
by the time Saturday rolls around. Needless to say, the cold air late in the week will be a
shock to most people as compared to the unseasonable weather we have experienced. The
mechanism responsible for the return to winter will be a powerful storm system moving
into Canada through the Great Lakes region. The trailing cold front will usher in the cold
air behind it, and as it becomes stationary just off the coast, there is the chance that an
area of low pressure may try to form and move up the front. Still too early to call, but the
models are split 50/50. The MRF and NOGAPS swing the trough through rather quickly
and the front never really becomes stationary. Therefore, if any wave were to develop
according to these models, it would be well out to sea. Regardless, these two models do
indicate a return to colder weather this weekend. Now, on the other hand, there is the EC
and the Canadian models. Both models are in agreement that the front will become
stationary, at or just off the coast, and will form a wave of low pressure along it. The
Canadian version isn't all that impressive, but does show the chance for a period of light
snow Friday night. The EC paints a much more intense picture. Needless to say, this is
just one of the possibilities, not a forecast by any means. By Saturday morning, the front
has passed through and has made it off the coast. Meanwhile, an area of low pressure
(1008mb) is beginning to develop along the front around the VA capes. At this time, the
atmosphere is continuing to cool and any moisture associated with THIS low would turn
frozen rather quickly according to the EC. By Sunday morning, the EC show the area of
low pressure in virtually the same area, but a bit stonger (1002mb). At this time, the EC
shows the Mid Atlantic still getting snow. Unfortunately, there is no QPF chart for the EC
so there is no saying just how much precip it drops. If the EC scenario were to pan out,
many metro area in the mid-Atlantic would be seeing snow for close to a 24 hour period.
By Monday morning, the EC has the low going negative and moving up through NY state.
By that point, the damage is already done and we would be digging out from a fairly
significant storm. However, I believe that the EC scenario is overdone. As deep as the
500mb trough is sweeping through, I'm surprised that the EC didn't follow along with the
MRF or NOGAPS tonight and send the front well off the coast. Tonight's run of the
Canadian model and tomorrow morning's run of the MRF should prove quite interesting
and will help to determine whether the EC is on to something or not. That's all for now. In
short, temps will be on the rise through Friday but will drop sharply as a cold front passes
through late in the week. Timing is still a bit uncertain, but it will be colder by the weekend
and a chance for some snow too. Check back tomorrow night and I'll let you know how I
see things.
