Thursday, February 02, 2012

Split Reality Yields Makes Sunday's Event Not So Super

What looked like a pretty decent storm on Sunday and Monday when we were first talked about what computer modeling was showing is shaping up as a super miss by both the GFS and Euro computer models for Sunday. While there will probably be type of event for Sunday, the presence of a stronger split flow in the jet stream and a weaker wave of energy in the southern stream have yielded a weakening and suppressing reality for snow lovers.

I've posted two mid level graphics of the GFS -- the first below is from yesterday's midday run, which brought a glancing shot of snow from the PA Turnpike on south.  You can see all the red up in the Northeast following along lines that track from north to south into the Great Lakes (that is the northern branch of the jet), with a blob of energy working across Illinois and Iowa (southern branch of jet).  These two branches begin to merge together over the Great Lakes, resulting in a slightly stronger, snowier scenario that brings a modest snow event to Philadelphia and the immediate southern suburbs on Sunday morning.

Contrast that to last night's run of the GFS -- the northern branch of the jet is a bit stronger (darker reds showing more energy) but it is also concentrated a bit north of its position from Wednesday afternoon's run, while the southern branch is weaker and a touch slower.  This lack of interaction between the two branches of energy results in a weak system that tracks south of the city for the most part and has much precipitation with it.   The southern (er, western) energy isn't able to tap into all of the goods that the northern energy gets depressed and suppressed to the south and doesn't get pulled a touch north for the ride with the northern energy.  The result is a non-event in the city.

Even if the two energy streams were to hook up, the result would not necessarily be a major storm.  The fast-moving nature of the split pattern we're entering was resulting in a modest to at best a moderate snow event (the GFS in yesterday's midday run was a minor 1-3/2-4 type event).

We spoke on twitter yesterday that we preferred some form of the GFS over the Euro, which in yesterday's run was showing nada for Sunday anywhere on the East Coast as it was keeping the energy with the western/southern jet much farther back.  The Euro as of this morning had caved somewhat to the GFS, sending out a wave of energy eastward but even more suppressed than last night's GFS run.

Putting all this together, the reality is the Super Bowl event is looking like some of those late 1980's and early 1990's Super Bowls that were over before the opening kickoff (like Super Bowl 24, Super Bowl 27) and the kind of Super Bowl where the Bud Bowl commercials were more entertaining.   In other words, a real non-event.  You can thank the split personality of the jet stream for that.