Wednesday, October 24, 2012

A Stormy Pattern Ahead?
Increasing likelihood of coastal and inland impacts to the 
Mid-Atlantic and Northeast from a significant storm next week

Several model projections have been showing a mean-looking 

6:00 AM EDT 10/25 (Mid-Atlantic Team) You know the saying, "When it rains, it pours." In the weather forecasting business, we prefer to say, "When it rains, it's a monsoon." Even though Hurricane Sandy may over a thousand miles away, changes in the large scale atmospheric pattern are already beginning to take shape. The indicators our Long Range Team and meteorologists are watching suggest the Mid-Atlantic and Northeast may be increasingly facing very stormy weather in the 5-10 day period ahead. 

WHAT ARE THE SCENARIOS? For the Mid-Atlantic, we have outlined two possible outcomes for the period Sunday into Monday of next week. There are still many factors at play which could keep either scenario from being realized. If you need an alternate look on what NOAA meteorologists are saying about this at the federal level, just glance at the first line of this link. For additional detailed analysis of our confidence interval and other specifics, please visit our STORM section.  

  • Scenario A: Significant impacts both inland and along the coast. The European model as shown to the left is our representative sample of other models depicting more extreme solutions. In this scenario, Hurricane Sandy transitions to extra-Tropical and begins tracking toward the coast. A deepening upper level trough in the Midwest begins to "tilt" negative, or have it's axis be oriented more southeast to northwest. As the coastal begin interacting with the upper level trough, it explosively develops into a very large and extremely strong hurricane-like system. Winds of tropical storm to near hurricane force would impact a large area of the Eastern seaboard from southern New England to the Mid-Atlantic, including the I-95 corridor. 
  • Scenario B: Stormy along the coast, windy & rainy inland. This scenario is generally what the US Global Forecast System (GFS) has been showing, denoted in the second image. Some remnants of a post-Tropical Sandy interact with the approaching upper level trough, pulling the energy toward the coast. Cold air working in from the trough, combined with tropical moisture, fuels the rapid development of a large coastal Low. Some beach erosion and tidal flooding would occur, but limited to the Atlantic coast.
NEXT STEPS? Our Mid-Atlantic Leadership Team has conducted an assessment of the scenarios and will be adding a third option outlining possible impacts in New England. 

Contributors to this report: 
Mid-Atlantic Director Greg Jackson at California Univ of Pennsylvania 
Pennsylvania State Leader Andrew Barney at Penn State University
Central Maryland Lead Forecaster Mike Natoli at Univ of Maryland, College Park
Central Maryland Lead Forecaster Connor Meehan at Howard Community College
U.S. Team Spokesperson Aaron Salter at Univ of Maryland, Baltimore County
Tropical Coordinator Jason Mitchell at College of Southern Maryland
North Carolina Forecaster Ross Harris, Wilmington NC
Meteorologist Alex Davies at University of Delaware
Meteorologist & Tropical Team Leader Daniel Ross at Georgia Tech, Atlanta
North Georgia Forecaster Jason Isaacs, Gwinnett County Schools, GA
CEO & Lead Advisor Rich Foot in Dundalk, MD

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