Daily Archives: February 13, 2014

Nor’easter Update – 7PM Feb 13, 2014

Noreaster, NYC, Snow, Storms, Weather Update, , , , , , , ,

We’ve enjoyed a period of relative calm as the dry slot (orange outlined in purple below) mentioned earlier pushed in over the area, leading to a lull in heavy precipitation and more of misty drizzle. However, these conditions will not last as the nor’easter will gain strength overnight.

The mid-upper level low that is responsible for bringing in this dry slot will gradually move over the surface low pressure center currently located offshore of central NJ. Once the low pressure systems stack up, the surface low will rapidly deepen. As this occurs, the warm front extending from the nor’easter’s core will rotate to the NW of the storm center.

This frontal boundary will push moist air (greens and yellows in this image below) ahead of it, leading to the formation of a new heavy band of snow – technically a “frontogenetically induced deformation band”. Within this band, snowfall rates may hit 1-2″ per hour, and an additional 4-8″ could accumulate across the region (except eastern Long Island). Interior areas where temps have remained cold could see an additional 8-12″ overnight.
Screen shot 2014-02-13 at 7.03You can already see in the radar image below that precipitation is already filling back in across southern NJ and the WAS-BAL-PHL corridor.

Screen shot 2014-02-13 at 7.03.52 PM

Nor’easter Update – 12PM, Feb 13, 2014

Noreaster, NYC, Snow, Storms, Weather Update, , , , ,

Satellite water vapor imagery clearly shows an area of drier air (in orange), known as a dry slot, working its way into the nor’easter currently impacting the NYC area. Intense bands of snow continue to push into the interior areas north and west of the city.

However, radar imagery from Mount Holly, NJ NWS office is already beginning to show a break in precipitation associated with this drier air. As this dry air works its way north, we can expect a break with lighter snow/rain for the area. This could work to lower overall snowfall totals in areas that see this break. At the surface, snow has transitioned to rain/sleet for most areas in NYC, Long Island, coastal NJ and southeastern CT. The rain/snow line should remain stable in its current position for the remainder of the afternoon.

Precipitation should transition back to all snow during the evening and overnight. Additional accumulation is expected with more large-scale banding features forecast to form on the backside of the nor’easter low pressure center as it intensifies and exits to the northeast. Another 3-5″ is possible overnight in the city. Snowfall totals in areas north and west should easily top 12″ by the end of this event.

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