January 28-29, 2007 Event

[donsutherland1]

In a "no dog" winter (at least so far), this little system could lead one to believe it is a "big dog," especially as its "bite" dramatically increases the depressed seasonal snowfall at such cities as Newark and New York. However, by the time it departs, the reality of its more diminutive nature will be recognized, and its light snowfall will quickly be forgotten.

By 6z, the NAM had finally come into better alignment with the GFS in terms of qpf. Given that we're nearing the end of what I believed would ultimately be a relatively dry period, I place greater weight on the operational GFS. An area of enhanced snow will likely form as the storm begins to develop, but that area could be yanked quickly offshore as the system begins to deepen fairly rapidly.

In general, an area that includes Philadelphia, Newark, New York City, Islip, and New Haven will likely see a coating to an inch of snow. Some snow that could accumulate to a coating might occur in Baltimore and Washington, DC to the south of that area and Providence and possibly Boston to the north. However, it is entirely possible that those four cities might pick up no accumulations of any kind. At Norfolk, light rain will likely end as a period of snow. Nonetheless, a light accumulation of less than an inch is likely there.

If any cities were to exceed an inch of snowfall, the more likely candidates would be New York City, Newark, and Islip. None of these cities are likely to exceed 2" (in spite of some of the NAM's earlier exertions).

[donsutherland1]

Over the day, the focus of heaviest snowfall--if one can actually describe it as "heaviest"--has shifted south and east. Following tomorrow's 12z guidance, I'll make my final estimates. I still believe a coating to an inch seems most likely where the snow falls, with very few locations seeing a little more.

[donsutherland1]

After yesterday's guidance pushed the area of more meaningful snowfall to the south and east, this morning's guidance has returned it pretty much to where it was prior to the 1/27 12z model runs.

In the end, my final thoughts are essentially unchanged from my initial thinking yesterday. I believe an area that includes Philadelphia, Newark, New York City, Islip, and New Haven will likely see a coating to an inch of snow. Some snow that could accumulate to a coating might occur in Baltimore and Washington, DC to the south of that area and Providence and possibly Boston to the north. However, it is entirely possible that those four cities might pick up no accumulations of any kind.

If any cities were to exceed an inch of snowfall, the more likely candidates would be New York City, Newark, and Islip. None of these cities are likely to exceed 2".

Final Estimates:

Baltimore: 0.5" or less
Islip: 2" or less
New York City: Coating to 1"
Newark: Coating to 1"
Philadelphia: Coating to 1"
Providence: 0.5" or less

[donsutherland1]

Verification:

From January 28:

In the end, my final thoughts are essentially unchanged from my initial thinking yesterday. I believe an area that includes Philadelphia, Newark, New York City, Islip, and New Haven will likely see a coating to an inch of snow. Some snow that could accumulate to a coating might occur in Baltimore and Washington, DC to the south of that area and Providence and possibly Boston to the north. However, it is entirely possible that those four cities might pick up no accumulations of any kind.

If any cities were to exceed an inch of snowfall, the more likely candidates would be New York City, Newark, and Islip. None of these cities are likely to exceed 2".

Baltimore: 0.5" or less; Actual: Trace: Within range
Islip: 2" or less; Actual: Trace: Within range
New York City: Coating to 1"; Actual: 0.5"; Within range
Newark: Coating to 1"; Actual: 2.0": Error: 1.0"
Philadelphia: Coating to 1"; Actual: 1.2"; Error: 0.2"
Providence: 0.5" or less; Actual: None; Within range

[roebear]

Good job Don, you've really been doing good this winter.

Any thoughts on Thursday-Friday Mid-Atlantic/NE? Joe Bastardi is talking a chance for 3-6 inches snow, but probably rain coastal areas .

Best,
Roebear

[donsutherland1]

Roebear,

I'll post my thoughts on the February 1-2 system a little later today. I'm thinking a weakening primary system could head into the Ohio Valley and a secondary will develop rapidly, moving off the Delmarva Peninsula and then just east of Cape Cod (preferring the ECMWF 1/30 0z and 1/29 12z idea over the 1/30 0z GFS, as I'm not sure the trough will sharpen so much that an inland track is likely). It does look like the kind of system that can bring at least several inches of snow to a region bounded by PHL-ABE-BDL-BOS even where a changeover is possible along the coast and somewhat inland. The clipper might deepen sufficiently as it heads past New England to promote some confluence ahead of the 2/1-2 event. In short, I don't agree with the 0z GFS's mostly rain idea for such cities as PHL.

Still, there's enough uncertainty for me to wait until I see the 12z guidance (including the ECMWF) before making some estimates.