Let the chaos begin. Hurricane Sandy, now known as “Frankenstorm,” is currently located just north of the Bahamas moving North at 7 mph. It should start to turn toward the NE in a few hours, however It’s central pressure is 971 mb and maximum sustained winds are 75 mph. Sandy is expected to strengthen as she heads out of the “shearzone”. Everything in this scenario points to a “perfect storm.” We have a negative NAO, a hurricane, energy from a trough in the midwest, and a cold front… all phasing together into one huge storm. Here is a satellite image of Sandy (not live image, that will come later):

Part 1: Track

Most models are in consensus that Sandy will retrograde into the East Coast. Right now the uncertainty lies in where she will make landfall. At this point, it could be as far north as Long Island, or as far south as Ocean City, MD. Sandy, even though a weak hurricane is expected to rebuild and strengthen into a strong category 1 storm. She is also expected to become extratropical as she heads into cooler waters off the mid-atlantic coast.

Part 2 Model Analysis:

First, the GFS. The GFS has been consistently the northern outlier. A few days ago when I posted, I said that the GFS was showing an out to sea solution. But now, however, it has switched to an east coast hit. The 12z GFS shows hurricane Sandy taking the turn west a little later than the European. This would take Sandy into Long Island. The GFS then brings Sandy south over land, and eventually takes it out over New York state, where it fizzles out. This solution is the outlier out of all the forecast models. I will continue to track the upcoming runs of the GFS, especially as we get closer to the event.

The European model takes more of a south track, turning Sandy to the west much sooner than the GFS. This solution would be devastating to the Philadelphia region, as the proximity to the center and heavy rain will bring many trees down and knock out power for days in places.

Part 3: Timing and Strength:

Rain will start to fall on Sunday evening as we will get some interaction from the phasing cold front and Sandy out in the Atlantic. Monday should be a dreary day with drizzle as Sandy heads NE before the retrograde. By Monday late night, the rain should start picking up in intensity. By Tuesday morning into afternoon, the heaviest rain will affect the area.By Wednesday morning, things should start to calm down as Sandy weakens and heads north.

Here is the unofficial, arbitrary timeline forecast:

Sunday 5 PM – Monday 7 PM: Cloudy and Drizzly

Monday 7 PM- Tuesday 4 AM: Drizzle becoming moderate rain; some gusty winds

Tuesday 4 AM – Tuesday 5 PM: Heavy rain, heavy winds

Tuesday 5 PM – Wednesday: Rain calming down, Sandy moves out

The wind associated with Sandy will depend on the track she takes. The strongest wind field is expected to be southwest of her center. A track that projects Sandy making landfall on the NJ coastline could bring 80 mph wind gusts with 50 mph sustained at the surface. A more northerly track  (Long Island) will also bring strong winds. A southerly track , however, will bring lesser wind gusts.

Here is the European wind forecast. It is showing around 75-80 mph over Philadelphia 8 AM on Tuesday:

The rain forecast for this storm is pretty spectacular. Some models have been projecting 6-10 inches of rain falling in the Philadelphia region. I would not be surprised if some areas surpass this prediction.

Part 4: Effects

The effects of this storm will mostly be flooding and wind damage. Because there are many leaves on the ground, many water drainage grates will be blocked, causing widespread flooding. Many tree branches will also snap from the high wind. Some whole trees may even topple. Like Irene last year, there will be widespread power outages. Millions and millions of people will lose power at some point during this storm. Some households may not get it back for days or even a week.

Please start preparing now for this storm. Bring any furniture that has the risk of blowing away inside. Stock up on food and drinks; power outages will last for days in places. If you have a generator, make sure it is working correctly. Try not to drive during the storm as branches will be down on many roads.