Superstorm Sandy

  • Blizzard Warnings have been issued for the Central Virginia mountains including Skyline Drive
  • One Foot of rain will fall by the time this storm winds down on Tuesday
  • Hurricane Force Wind Gusts will occur in the Washington & Baltimore Metropolitan Areas late this evening through the overnight
  • Widespread sustained winds of 30 to 50 mph will be common with gusts to 70 mph across the entire region
  • A historic “Special Weather Statement” continues for the National Capital Region from the folks at the National Weather Service Office:  Conditions Will Deteriorate Rapidly now through the overnight!  Widespread power outages will occur across the DC Region.
  • Winds will continue to increase between 35 and 55 mph across the Washington Region tonight with gusts to Hurricane Force as Sandy gets wrapped up into a deepening trough.

As Sandy moves west over the Maryland-Pennsylvania border conditions will rapidly deteriorate across the Baltimore and Washington Region.  Peak wind gusts of 75 mph are likely with widespread damage to trees and widespread power outages! (Image courtesy: Weatherunderground.com)

6 to 12 inches of Rain will Cause Widespread Flooding of creeks, streams, rivers, basements, underpasses and low-lying areas.

Snow:  1 to 3 Feet in the mountains in elevations above 2000 feet.

Batten Down the Hatches… the winds are going to occasionally gust to Hurricane Force late this evening!


Sandy will Rival the March 1993 Storm of the Century

Consensus among the forecast models continues that the center of Sandy may make landfall between the Delaware Beaches and central New Jersey (Very Bad News for the Washington Area) Image courtesy: weatherunderground.com

My Latest Thoughts:

  • The Washington Region is under a High Wind Warning and should be prepared for 24 to 36 hours of sustained tropical storm force winds with gusts over 65 mph.
  • A Hurricane Force Wind Warning has been issued for the Chesapeake Bay.
  • Higher elevations (Blue Ridge Parkway) and locations along the Tidal Potomac could also experience wind gusts over 65 mph.
  • A landfall between Delaware & New Jersey places the Washington & Baltimore Areas in the prime zone for the heaviest rainfall.

Sandy will Transition into an Extratropical cyclone that will rival The March 1993 Storm of the Century

Current Infrared Satellite Image of massive, Hurricane Sandy (Image courtesy NOAA)

How Historic Could this Storm Be?

  • On March 14th, 1993 The “Storm of the Century” was located over the Chesapeake Bay with a central pressure of 960 millibars.
  • As of the 11 AM National Hurricane Center update, Hurricane Sandy’s central pressure is 951 millibars, or 9 millibars lower than the March Super-Storm.
  • Depending upon which model you look at, as Sandy becomes extratropical and engulfed into a massive inverted trough over the Mid-Atlantic, the central pressure with this Super Storm could drop into the low 930s as she wobbles over the Mid-Atlantic states!

HWRF Model depicts the center of Sandy moving into the southern NJ coastline with a central pressure of 928 millibars!  (Image Courtesy: NOAA)

Rainfall: 

  • Based on the current forecast track from the National Hurricane Center, 5 to 10 inches of rain is likely to fall across the Washington Region & Chesapeake Bay.
  • 2012 has been incredibly dry and may help to prevent what would have been a set up for catastrophic river flooding.  However, with that said, 5 to 10 inches of rain falling over 48 hours will be enough to cause flooding along area rivers with widespread flooding problems in low-lying areas, streams, creeks, underpasses, and basements.

The Heaviest rainfall with Sandy will fall on the southwest quadrant of her landfall. A landfall into the Delaware beaches or New Jersey places the DC Region into the zone of heaviest rainfall totals.               Image Courtesy: HPC

Damaging Winds & Widespread Power Outages

  • Sustained, high winds with gusts over 65 mph (or higher depending upon your location) during a 24 to 36 hour window is a scenario that could produce widespread  damage to trees and some minor structural damage to homes.   The Washington Area is in fact, one of the most wooded metropolitan areas in the Nation.

Sustained winds (in knots) according to the European Forecast Model – Hurricane Force winds along the Bay with Tropical Storm force winds in inland locations (Image Courtesy: Weatherunderground.com)

  • If you live in a neighborhood with beautiful, older, trees, please heed the National Weather Service’s High Wind Warning and plan to sleep on the lowest level of your home or make plans to possibly ride this out with friends and family.

Snowfall:

  • Elevations above 2,500 feet in the mountains of MD, WV, and VA can expect blizzard conditions with one to three feet of heavy, wet, snow. 
  • With a mild influx of air wrapping into the circulation of “Sandy” the heaviest accumulations will be across the central and southern mountains of West Virginia and southwestern Virginia
  • You better believe someone will pick up 3 feet of snow!  My heart goes out to anyone who gets snow as the high water content and high winds will produce catastrophic tree damage and widespread power outages that could last a week or more. 

Timing:

  • Expect Rapidly Deteriorating Conditions throughout the afternoon on Monday.
  • The highest sustained winds (averaging 30 to 50 mph) with gusts to Hurricane Force (74 mph) will occur Monday evening.

HRW-NMM-EUS Model simulating what the radar will look like on Monday morning at 6 AM

  • Rainfall will be most intense over the National Capital Area due to convergence and a strong Jet Stream.

HRW-NMM-EUS Model simulating what the radar will look like on Monday at 6 PM

  • Conditions will begin to relax Tuesday with significant improvement on Halloween.

I have added quick links to the top of my web page that will take you directly to:

  • OPM’s Government Status
  • WTOP’s school closings & delays
  • Latest Warnings and Advisories issued by the National Weather Service
  • NOAA/NCEP’s Forecast Models
  • Traffic Cameras from TrafficLand.com

Sandy Bombogenesis & Incredible Wind Field

As expected, Hurricane Sandy weakened last night into a Tropical Storm as she continues to take on extra-tropical characteristics.  As Sandy moves into the warm Gulf Stream waters on Sunday and Monday she will strengthen and her wind field will expand

In a warm core, tropical, system the highest winds are usually located around the eye wall.  However, this storm will be transitioning into a mid-latitude cyclone and as her central pressure rapidly drops, a term sometimes referred to in meteorology as bombogenesis, the wind field will increase in size.  *This is why tropical storm status versus hurricane status isn’t important in regards to the widespread damaging wind gusts that this system will contain.

The models seem to be converging on the idea that Sandy will possibly make landfall between Ocean City, Maryland and the central New Jersey coastline.  A land fall anywhere between Northern Virginia and Long Island remains possible as well. (image courtesy: weatherundeground.com)

The Wind Field (in knots – which are higher than mph): 

European forecast model’s depiction of the massive wind field (in knots which are higher than mph) associated with Sandy on Monday.  Image courtesy: weatherunderground.com

In the immediate DC Area, I would be preparing for the potential of tropical storm force winds of 40 to 60 mph with higher gusts.

Latest Forecast of Rainfall Potential  (Image courtesy NOAA, hpc.ncep.noaa.gov)