February 25-‐27th 2010 Nor`Easter

February 25-­‐27th 2010 Nor’Easter-­‐ The “Snowicane” Robert D’Arienzo Synoptic Meteorology December 8, 2011 Photo: NASA Earth Data Storm Overview •  NESIS (Northeast Snowfall Impact Scale): –  NESIS value of 5.46 (Range: 1-­‐10) –  Category 3 (“Major”) –  Ranked 15th all time •  Minimum pressure: 972 mb •  Maximum snowfall amount: 53.0” (Preston-­‐Potter Hollow, NY) •  Maximum peak wind gust: 91 mph (Portsmouth, NH) “Snowicane” Controversy •  Sustained winds >39; tropical storm strength –  Peak gusts exceeded 90 mph –  Equivalent to a category 1 hurricane? •  Minimum SLP of 972 mb –  Comparable to a category 2 hurricane? •  Accuweather forecasted “hurricane-­‐like” conditions classified storm as a “snowicane” •   “bad meteorology” Storm Diagnostics   Jet stream analysis   Vorticity   Temperatures   Surface analysis/precipitation   Vertical motion:   QG omega equation   Trenberth forcing   Q-­‐vectors/convergence   Frontogenesis   QGPV   Isallobars/height tendencies Storm Analysis 1.  2/25/10 at 00Z-­‐ Developing Stages 2.  2/25/10 at 12Z-­‐ Fuel for the Fire 3.  2/26/10 at 00Z-­‐ Bombogenesis 4.  2/26/10 at 12Z-­‐ Dissipating Stages Storm Analysis 1.  2/25/10 at 00Z-­‐ Developing Stages 2.  2/25/10 at 12Z-­‐ Fuel for the Fire 3.  2/26/10 at 00Z-­‐ Bombogenesis 4.  2/26/10 at 12Z-­‐ Dissipating Stages Storm Analysis 1.  2/25/10 at 00Z-­‐ Developing Stages 2.  2/25/10 at 12Z-­‐ Fuel for the Fire 3.  2/26/10 at 00Z-­‐ Bombogenesis 4.  2/26/10 at 12Z-­‐ Dissipating Stages Infrared 0000Z on 2/26/10 Minimum pressure: 978 mb Image: UCAR Image Archive Infrared 0415Z on 2/26/10 Minimum pressure: 972 mb Image: UCAR Image Archive Infrared 1045Z on 2/26/10 Minimum pressure: 973 mb Image: UCAR Image Archive Storm Analysis 1.  2/25/10 at 00Z-­‐ Developing Stages 2.  2/25/10 at 12Z-­‐ Fuel for the Fire 3.  2/26/10 at 00Z-­‐ Bombogenesis 4.  2/26/10 at 12Z-­‐ Dissipating Stages Image: NCDC; NESIS Storm Radar Loop NJ Storm Totals Image: NJ State Climatologist Forecasted Snowfall (23rd 00Z)
Forecasted Snowfall (23rd 12Z) Conclusion •  Storm represented prime examples of: –  Explosive cyclogenesis –  Explosive bombogenesis –  Shapiro-­‐Keyser cyclone model