Saturday, July 26, 2014
Inquirer Daily News

Bolaris: Old Man Winter to drop bombogenesis

Ready for the cold, a man scurries down the 1600 block of Spruce Street on Thursday, Jan. 16, 2014, dodging snowflakes while carrying a hot beverage and wearing a polar bear hat. (Ed Hille/Staff)
Ready for the cold, a man scurries down the 1600 block of Spruce Street on Thursday, Jan. 16, 2014, dodging snowflakes while carrying a hot beverage and wearing a polar bear hat. (Ed Hille/Staff)
Ready for the cold, a man scurries down the 1600 block of Spruce Street on Thursday, Jan. 16, 2014, dodging snowflakes while carrying a hot beverage and wearing a polar bear hat. (Ed Hille/Staff) Gallery: Snow storm hits Philly region

BOMBOGENESIS (a rapidly intensifying storm) will take place Tuesday afternoon off the Virginia coast.

Computer models had an extreme reversal on the intensity and track of this storm over the last 24-36 hours, and that's why snow amounts were jacked up Monday as computer models came late to the snow party.

Hinting started to take place late Sunday as my forecast called for a significant storm for some with 4+ inches of snow possible across parts of New Jersey. But a big uptick in moisture being fed into the storm combined with a piece of the polar vortex sending another package of severe cold. This time, it gets pulled into the storm's circulation leading to rapid intensification and high snow ratios.

Normally we receive a 10-1 ratio, with one inch of liquid equaling 10 inches of snow, but in this case we have an overall ratio of 13-1, to as much as 15-1, meaning more snow with less liquid.

More coverage
  • Today, 2 p.m.-midnight: John Bolaris live-chats the snowstorm
  • Snow's falling; a Philly record also?
  • Snow emergency issued; city schools closed Wed.
  • The set-up

    A weak storm will move into the Tennessee Valley Tuesday morning, marking the leading edge of the arctic outbreak. As that one weakens, another storm develops and intensifies rapidly off the Virginia coast, spreading snow, heavy at times with increasing wind and falling temperatures. Temperatures by Wednesday morning will be in the single numbers with wind chills 10-15 below zero. Plenty of blowing and drifting of snow. Dangerous cold.

    Timing

    Snow will overspread the region shortly after the morning rush.

    Noon-3 p.m.: It starts to accumulate, including roadways.

    3-8 p.m.: The brunt of accumulating snow, heavy at times, blowing and drifting. The impact? Hazardous driving and major travel troubles, including in the air, railways and any form of mass transit.

    8 p.m.-midnight: The heaviest of snow is moving out, but still snowing and accumulating.

    Midnight-3 a.m.: The snow is moving out, but severe cold, blowing and drifting will make for extreme travel conditions. Stay home!

    Potential snow totals

    Philly, 7-11 inches

    Camden, 7-11 inches

    Delaware County, 7-11 inches

    Chester, Montgomery and Bucks counties, generally 6-10 inches

    Berks County, 4-6 inches

    Lancaster County, 6-10 inches east/4-8 inches western side

    Salem County, 7-11

    Jersey Shore, 6-10 inches

    Northern Ocean and Monmouth counties -  8-12 inches

    Northern Delaware - 7-11 inches

    Central and southern Delaware, 6-8 inches

    Lehigh Valley, 4-6 inches

    Poconos, 2-4 inches

    Baltimore, 6-8 inches

    Washington, D.C., 5-8 inches

    New York City, 6-9 inches

    Eastern Long Island, 8-12 inches

    Boston, 6-9 inches

    Capes of southeast Massachusetts, 10-14 inches

    Shores of Connecticut, 6-9 inches

    John Bolaris

    John Bolaris PHILLY.COM
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