blizzard Watches Upgraded to Warnings as Storm Approaches

Areas previously under a Blizzard Watch saw an upgrade to "Warning" status around 6:00am this morning amid continuing confidence in Jonas' impact.  Snow total forecasts haven't changed much over the last 24 hours, with a large swath of the Philadelphia Area still slated to get 12-18" with lesser amounts as you move towards the Lehigh Valley or towards the shore.

In Eastern Montgomery County, local weather outlets are predicting 10-14" and the National Weather Service has us in the "most likely" 12-18" range with a "maximum possible" of 25".

The arrival of snow to Philly and points northwest will be after 8pm.  The heaviest snow is expected during the early morning hours on Saturday with moderate to heavy snow throughout the daytime hours.  There may be a mid-day lull, but steady snow is expected to re-appear during the late afternoon and early evening.

Blizzard Watch Issued, Snow Totals Topping 1 Foot Forecasted

We are less than 36 hours from the anticipated arrival of the winter storm (named "Jonas" by the Weather Channel), and much of Southeastern PA including Lower Montco, Lower Bucks, Philadelphia, Chester and Delaware counties have been converted to a Blizzard Watch until 10:00AM Sunday.  North and West areas remain under a Winter Storm watch until 7:00AM Sunday.  The criteria for a Blizzard include sustained winds of 35MPH along with heavy snowfall.

The National Weather Service in Mt Holly, Nj released the following map of anticipated snow Totals through Sunday morning about an hour ago:

With the Lansdale area in the 12-18" zone, expect to do quite a bit of shoveling this weekend!

Stay tuned for updates.

Few Snowfall Predictions Published as Weather Models Diverge on Track of Storm

The consensus held by numerous weather models earlier in the week has begun to deteriorate as we approach the arrival of this storm.  There are two possible tracks for the storm:  One shows the storm tracking slightly more inland, which would bring in more warm air from offshore, meaning a higher likelihood of a wintry mix in Philadelphia and moderate snowfall North and West.  The other pushes the storm center further out to sea, bringing more snow to Philadelphia and potentially very heavy snow North and West.  Most local meteorologists seem to be waiting for models to settle out and reach more of a consensus before posting snow totals.  However, the National Weather Service in Mt. Holly, NJ has the following "Most Likely" snowfall map posted, showing 4-6" for upper and central Montgomery County, with 6-8" for lower Montgomery and points South.  These totals only include snowfall totals through 8:00AM Saturday Morning, 

The Weather Channel has also posted a map, albeit with a less precise, wider-area view showing the Philadelphia area in either the 8-12" or 12-18" range:

Stay tuned to NPWA for more exiting updates!

Early Snow Total Predictions Begin

Fox 5 in Washington, DC posted their "first call" snow totals, showing 6-12" for the Philadelphia area and some more impressive predictions for Virginia and the DC Metro area:

This prediction is based on a composite of the GFS and EURO models, and should be taken with a grain of salt this far in advance of the storm.

Big Storm to Pummel the PA/NJ/DE Area?

Most news outlets are stating with a high degree of confidence that Friday late afternoon/evening will bring a significant snowstorm to our area, likely lasting through the day on Saturday.

With approximately 72 hours to go until the anticipated arrival of the system, snowfall totals have not been widely published.  However, the following was posted to the National Weather Service's Extended Forecast Discussion page for their College Park, MD office:

“To put this system in context… the potential snowfall distribution has similarities to several major East Coast storms in recent past including the 5-6 February 2010 snowstorm/the January 1996 Blizzard of 1996 and the President’s Day of February 2003.  January 1996 is likely to be more widespread/heavy but only time will tell.  The mechanisms coming together for a major snowfall are textbook.”

Furthermore, the NWS Philadelphia forecast page says "Based on the anticipated storm track, as much as 1 to 2 feet of snow is possible near and northwest of I-95."

Stay tuned for more updates on this developing weather event!