Hurricane Sandy Discussion 1

You have probably heard much about an upcoming massive storm.  You would be right.

ECMWF Surface Pressure and Average Temperature (Thickness) forecast valid for 8am Monday, 10/29. Forecast initialized at 8am Wednesday 10/24.

Over the last few days, meteorologists have been following the computer simulations, each with widely varying ideas of how this storm will play out.  It now appears a consensus is starting to gather, with the biggest concern being the northeastern coast of the United States.

The primary medium range American forecast model (GFS) is beginning to follow the lead set by the ECMWF model. Image courtesy of Weather Underground.

This starts with Hurricane Sandy, which, as of Wednesday evening, is exiting the north coast of Jamaica.  It is a Category One storm.  The storm will continue to move north across Cuba and The Bahamas into Thursday evening.

Hurricane Sandy at 5:45pm ET, Wednesday, 10/24. Note the dark spot in the center of the clouds, which is an eye feature emerging from the north coast of Jamaica.

Already, winds are gusting to 30 mph in South Florida, so it is important not to focus on the category of this storm.  As it moves north, a large disturbance will dive in from the Northern Plains, further strengthening the storm despite its transition to an extratropical cyclone (e.g. a nor’easter).

Again, do not think that because Sandy loses tropical characteristics that it will be weaker.  That will not be the case.  If anything, the area of damaging winds around the center of the storm will grow when the storm becomes extratropical.

Once the storm moves north of The Bahamas, our best guess is a track with a center about 100-200 miles east of North Carolina and Virginia’s Eastern Shore, then making a turn into the Northeast.  When and where that turn happens can still be hotly debated, but I would argue the area from Cape May, NJ to Cape Cod, MA is most at risk. Time frame would be Sunday through Tuesday.

Impacts: Coastal flooding and erosion. Torrential rain with flooding of streams. Widespread tree damage with corresponding power outages over several states.  Huge disruptions in air travel.  Sustained winds in excess of 40 mph with gusts to 80 mph, with those levels of winds persisting for several hours in any one particular place.

Now, in Virginia, it does not appear it will be as bad as the Northeast.  However, areas along and east of I-95 will be closer to the storm and will have the potential for some wind damage and very heavy rain.  Scattered to moderate power outages and tree damage are possible in those locations.  For Virginia, comparisons to Irene (2011) are not out of place.

From Charlottesville, Lynchburg, Danville, and areas to the west, the conditions appear more muted.  Showers are likely and it will certainly be breezy… if not windy for a spell (15-30 mph), but at this time, it does not appear that much damage will result in this part of the state.

Time frame for Virginia impacts is from late Sunday through most of Monday.  This does have repercussions for the Sprint Cup Race in Martinsville on Sunday.  The western edge of the rain shield appears to be a sharp one, so it is possible that no rain falls during the race.  However, that is not the most likely situation.  If you are going to the race, prepare for a cool and breezy period with a few showers.  Temperatures are likely to hold in the 60s.

There has been some buzz about snow, but in our part of the state, that is not likely.  Having said that, on the back side of the storm, cold air will rush in, and some snow showers are likely Tuesday in Virgina’s Western Highlands and New River Valley, but accumulating snow is expected to hold in the state of West Virginia.  Ski resorts in the Mountaineer State must be getting excited, but they will also deal with winds nearing 60 mph in some of that snowfall.

Tweaks in the storm track are expected in the next couple of days; some timing and effects will also need to be updated and refined.  A quick dodge to the west would set our part of Virginia up for a much more devastating hit.

Please follow this storm closely over the next few days, especially if you have interests in the Northeast.

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And for interests in the Northeast, you can also check out State of Occlusion, a blog run by a colleague of mine, Matt Lanza, a meteorologist who originally hails from South Jersey. He has more first hand experience with the detailed geography of the Garden State.

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Update.  This storm has caught the attention of meteorologists on the West Coast.  Cliff Mass at the University of Washington describes how the computer simulations have taken us to this point.

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About seansublette

Meteorologist at Climate Central. Broadcast meteorologist in Virginia from 1995 to 2015. Born and raised in Richmond, VA. Penn State alumnus. Loves baseball and the rock band Rush. Views are independent of my employer. Past performance does not guarantee future results.
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