Monday, February 11, 2013

Update On Wednesday Night's Snow

We continue to keep an eye on Wednesday afternoon and evening's system -- the models have come into some agreement (for now) on a more "active" and phased solution that brings snow to a fair chunk of the Delaware Valley on Wednesday PM.    There are still differences in the computer models in timing and details a few takeaways are available as of this point in the day:

1) The slower the system is, the more likely it is to be a bit stronger.  It will be able to phase and combine its southern moisture with the northern energy that had been separated out in prior models.  The slower timed (Wednesday night) systems are modeling out to be a bit stronger, more robust, although with more rain southeast of the city and more snow northwest.  The run of the GFS below from late this afternoon shows a slower timed system (generally after PM rush hour) with a stronger surface low, more precipitation, and snow along and northwest of the NJ Turnpike (although it will be rain ending as snow east of it).

This yields a healthy swath of snow, perhaps several inches, across the city and northern burbs, potentially extending into South Jersey.  Lesser totals farther to the city's south where temperatures will be milder.

2) On the flip side, a faster moving event such as the midday Euro and GFS run showed today will yield less snow but no issues with precipitation type or rain/snow line. The Euro paints a general 1-3, perhaps a 2-4, type event through the Delaware Valley, moving through during Wednesday afternoon and evening.  A bit faster, a bit less precipitation, but snowstarved will rejoice.

3) These types of events, because of the dynamics involved, are bound to surprise or disappoint.  A weaker, faster system produces less snow but most get in on it.  A slower mover will produce more snow farther northwest but it's going to lead to rain/snow line setup and a number of folks will merely get rain and not get much else.  It does look more promising for snowlovers that we will see some snow in or close to the area on Wednesday afternoon or evening but modeling is still struggling on timing and details.  That said, the consensus from the midday runs showed a couple of inches seems like a reasonable prediction as a starting point.  However, given the dynamic nature of this storm system, it is very much subject to change...and we will keep an eye on it.