Daily Archives: February 11, 2014

NYC Storm Update – Feb 11, 2014

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There is increasing confidence that NYC will be seeing a high-impact snow storm Wednesday night into Thursday night. However, there are still discrepancies between different forecast models that are leading forecasters to not place too much confidence in overall snowfall totals. There are two main scenarios that could unfold: 1) the storm center takes a track closer to the coast, or 2) the storm center tracks further offshore.

In the first scenario, warmer air would be able to enter into coastal areas and lead to more rain, thus cutting down snowfall totals in NYC, Long Island, and coastal NJ, CT. In the second scenario, warmer air does not flow in as much. This would lead to higher snowfall totals for all areas of the NYC metro. With snow:water ratios about 8:1, and as much as .75-1.5″ inches of precipitable water available (moisture that can fall as snow, rain, ice, etc.), any small change in forecast track and temperature could lead to significant changes in the forecast total snowfall.

Current forecast:

Timing: accumulating snow will begin falling over the area, spreading from south to north, beginning Wednesday night. During the overnight hours into early Thursday morning, widespread totals of 4-6″ are possible. If the track producing a warmer temps verifies, then snow will mix in with rain along coastal areas during the day Thursday, while remaining all snow inland. A return to all snow will occur Thursday night as temps drop below freezing and the storm system exits to the northeast.

Impact: NWS is forecasting 6-8″ total snowfall for areas along the coast including NYC, with 8-10″+ in areas immediately north and west of the city. This is a total for Wednesday night into Thursday night. Thursday morning commute will be messy, with accumulating snow transitioning to rain making for a slushy mess in coastal areas, and all snow in the interior.

Screen shot 2014-02-11 at 6.27

Historic Ice Storm to Hit GA, SC

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Screen shot 2014-02-11 at 6.11.11 PM

The storm system set to impact the Northeast will make its impact felt in the Southeast Wednesday and Thursday. An historic ice storm/winter storm is set to take shape and impact areas of the Atlanta metro, hard hit by the January 28th storm.

To quote National Weather Service in Atlanta:

HAVE GONE WITH THE MORE DIRE PREDICTIONS OF A HALF AND INCHOF ICE TO CLOSE TO AN INCH FOR EAST CENTRAL PORTIONS OF THE STATE.BIGGEST CHANGE PERHAPS IS THE SNOWFALL ACCUMULATIONS WITH NOW 4 TO 8 INCHES ACROSS THE NORTHERN TIER WITH 10 INCHES TO PERHAPS A FOOT POSSIBLE IN THE NE MOUNTAINS. WE ALSO INCREASE THE TOTALS FOR THE NORTH ATLANTA METRO WITH AN INCREDIBLY DANGEROUS COMBINATION OF OVER A QUARTER INCH OF ICE AND 2 TO 5 INCHES OF SNOW.

Ice accumulation on top of snow of this magnitude will almost certainly lead to widespread power outages from downed tree limbs and power lines, as well as deadly travel conditions. The governor of Georgia, Nathan Deal, wisely declared a state of emergency and shut down non-essential services across the state.

The areas of greatest impact for icing will lie along the I-20 corridor east of Atlanta, curving into central South Carolina, although ice storm warnings have not been posted yet in some areas of South Carolina. If you are living in this area, avoid any unnecessary travel, and make any necessary preparations immediately.

NYC Snowstorm Update – Feb 11, 2014

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UntitledSignificant winter storm is already underway for large parts of the southeast. Snow, and ice accumulation up to 5″+ in some areas before this storm moves in on the northeast.

Still a decent amount of uncertainty as to final track of this storm. If the storm takes a track closer to land, there will be more rain and less snow. If the center of the storm passes south of NYC near what is referred to as the 40°N 70°W benchmark, this will become an all snow or mostly snow event area wide.

With snow to liquid ratios between 10 and 15:1, even a slight deviation could mean dramatically different outcomes. The city has been consistently forecast to be on the cusp of the rain/snow line so final track adjustments are worth keeping an eye. Current NWS forecast thinking is for accumulating snow to begin falling overnight Wed through late Thurs morning. A changeover to rain is currently expected in NYC and coastal areas which would keep overall snowfall totals down. A change back to all snow would occur as temps drop later Thurs as bands of precip wrap around the center of the low departing east.

Temps today will remain chilly in the upper 20s, with sunny conditions. Overnight lows in the teens, and a similar day weather-wise Wed. Overnight lows Wed in the mid 20s, and hi temps Thurs (critically) just above freezing in this forecast. Warmer on Fri w temps nearing 40.

Details:
All reliable models point to a rapidly deepening low pressure center, with central pressure dropping from 992mb to 970mb in this Navy model forecast as the low moves from our area into New England. A mesoscale banding feature also develops, but final placement is uncertain. Right now, hpc is forecasting axis of heaviest snow from NE PA, northeast through NE NJ, western MA and into down east ME. 6-12″ could easily accumulate under this banding feature.

Details:

All reliable models point to a rapidly deepening low pressure center, with central pressure dropping from 992mb to 970mb in this Navy model forecast as the low moves from our area into New England. A mesoscale banding feature also develops, but final placement is uncertain. Right now, hpc is forecasting axis of heaviest snow from NE PA, northeast through NE NJ, western MA and into down east ME. 6-12″ could easily accumulate under this banding feature.