A Hurricane Warning remains in effect for eastern areas. Some of the heavy tropical rain squalls with Irene are spreading across the area this evening and winds are slowly starting to pick up. The center of Irene is currently re-emerging in the Atlantic Ocean near the Virginia/North Carolina border as a minimal Category 1 hurricane with 80 mph maximum sustained winds. As mentioned yesterday though, it is not the maximum sustained winds that are impressive but rather the immense size of the storm itself. Tropical storm force winds spread out up to 300 miles from the center, and as I also alluded to yesterday, the storm surge/coastal flooding threat with this storm is much more severe as a result. The eye of the storm will slowly move northward overnight with strong winds gradually increasing and extremely intense rains of 1-2 inches per hour into Sunday. By 8AM Sunday morning the center of Irene will be located on top of the Jersey shore about to push into eastern NYC by midday. The exact track and timing is on the map to the left, and is the most feared track. Thankfully Irene’s winds weakened a good bit before making landfall in NC, but that is not to take away from the ensuing damage. Here is how each aspect of the storm breaks down for the area.
First off as conditions deteriorate tonight, embedded supercell thunderstorms will move quickly inland and can drop weak tornadoes at any time causing isolated areas of damage. A tornado watch is in effect for eastern areas of NJ through the overnight period as a result. Stay alert as Tornado Warnings may be issued at any time.
Storm Surge/Coastal Flooding
The forecasted track is as bad as it gets for producing storm surge/coastal flooding up and down the Jersey shore and into the NYC back bays. With the center hugging the shore and tracking along the Garden State Parkway early tomorrow morning, the strongest northeastern part of the storm with powerful onshore winds will hug the coast for the most part and pile a storm surge inland. We are expecting a 3-6 foot tidal surge up the entire coastline, and this is on top of the 7-8AM astronomical high tide cycle which is timing extremely poorly with Irene’s passage. 15-20 foot waves will be crashing ashore on top of this tidal surge. I absolutely fear the amount of destruction this may cause to the coast and hope it turns out for the better.
Further north, this track is also terrible for the low-lying areas of New York City, Jersey City, Hoboken and the Raritan Bay. Easterly winds will funnel water directly into the New York Bight, and as a result these susceptible areas could see a 4-8+ foot tidal surge Sunday morning.
A 63 mph wind gust has already been reported at Cape May, NJ at 7:30 tonight well out ahead of the center. As Irene moves north tonight hugging the Atlantic coast, I expect her to either maintain her current strength or weaken slowly down to 70-75 mph maximum sustained winds by 8AM Sunday. This is minimal hurricane/strong tropical storm strength. With the track expected, the immediate Jersey shore may see a period of sustained winds between 50-70 mph with gusts possibly as high as 75-85 mph Sunday morning. In general I expect the peak wind gusts from Irene to be in the 60-80 mph range within 10-20 miles of the shore. Further inland the winds may drop off significantly, especially since the western side of a tropical storm often has the weaker winds. Still though I anticipate wind gusts between 40 – 65 mph being common across inland New Jersey. With the very saturated ground and leaves on the trees, these winds can easily uproot large trees and cause massive power outages. Hopefully you are prepared with your flashlights or generators by now because there is a great chance you will need them.
On the back side of the storm tomorrow afternoon, additional powerful wind gusts from the opposite direction may cause further tree damage and power outages. So just because the rain ends tomorrow, this does not necessarily mean the storm is over. Things wind down by Sunday evening.
As of this morning, New York’s Central Park had already broken the all-time August monthly record for rainfall. Needless to say it has been extremely wet across the entire area over the past few weeks and the ground is completely saturated. Amazingly, Irene’s rains may double the monthly total in the area with another 6-12 inches easily on the way. This will not only cause widespread flash flooding, but the excessive runoff will force large area rivers to extreme flood stages over the next couple of days. Flood Warnings have already been issued well in advance for most of the state. Folks along the Raritan and Passaic River basins should prepare for a top 3 historic flooding event carrying over into early next week.