Mar 5, 2013 Noon Update

12:00 PM: Models Trending Weaker With Storm

The forecast for the mid-late week storm continues to become complicated with several new trends on today’s models. Last night’s update noted that the GFS was significantly north with the storm while the rest of the models were south. With the other model runs last night and this morning, the rest of the models failed to add support to the GFS; instead, the GFS trended south, especially with its 12z run, no longer supporting a major precipitation event for the NYC area, although the Mid Atlantic and New England still receive moderate to heavy snow.

Model trends have been inconsistent this year, and this sudden change in the GFS needs to be approached  with caution, as with yesterday’s GFS runs which were significantly north of the rest of the models, and from what current indications suggest were likely too far north. Yesterday’s forecast sided with a compromise of the GFS/ECM, which would have resulted in at least 1/2 to 1 inch of liquid equivalent precipitation across the area with over 1 inch towards parts of Long Island. For the afternoon update, I am lowering forecast precipitation totals, which shows the potential for light snow accumulations from NYC and north/west, with strong winds still expected. I will continue to monitor today’s trends, and additional changes will be posted with this evening’s update. Precipitation amounts may be lowered further with the next update, and the original solution of light rain/snow showers remains a valid possibility, although the possibility is there for an inverted trough on Thursday night to increase precipitation totals for at least parts of the area.

Regardless of the track, however, strong winds and coastal flooding are still expected for the coast. A strong NE to NNE wind of 20-30 mph across the area, up to 35 mph in Long Island, with gusts generally up to/over 40 mph, perhaps up to 45-50 mph in Long Island. Minor to moderate coastal flooding is also likely for coastal areas, with a storm surge up to 2-4 feet possible. More information on this will be posted tonight.



Leave a Reply