Note that the only *official* information is what you hear from local emergency management and the National Weather Service/National Hurricane Center. I’m just offering you my own opinion on how this may shake out.
If you are ordered to evacuate, do so…this storm isn’t a drill. There’s always a chance it “might not be that bad,” but ALL indications are that it will be that bad. This forecast is not hyped…this is simply what we’re seeing right now from the computer models. Breaking this down region by region….note that the timing could change by 3-6 hours in any given location depending on how fast Irene ultimately tracks.
NC Outer Banks: Should see the brunt of the storm with sustained cat 1-2 hurricane winds and gusts perhaps to cat 3 intensity. Conditions deteriorate Friday afternoon, with the brunt of the storm late Fri night and into early afternoon Saturday. Major wind/flooding from Hatteras north. Models have indicated some increase in rainfall intensity near landfall, so 10″ or more of rain is possible on top of storm surge flooding. Conditions will improve Saturday night.
Norfolk/VA Beach: Area could see substantial Cat 2-3 gusts and some Cat 1, maybe low end 2 sustained winds. In addition to piling of water into the harbor there, rain amount of up to 10″ or more will likely exacerbate flooding there. Height of the storm will be Saturday morning through Saturday evening.
Richmond to Raleigh Breezy conditions, with tropical storm force gusts (40-50 mph) likely in Richmond. Any further west track of the storm will increase the risk of strong tropical storm force wind gusts (60 mph or more). Raleigh will see perhaps a low end tropical storm force gust or two, along with minimal rain (probably an inch or less). Richmond could see substantially more rain depending on the exact track…likely 2-5″, but potential for more. Height of the storm will be Saturday morning through Saturday evening.
Delmarva: You will get hit very hard with storm surge flooding, sustained tropical storm to category 1 hurricane force winds and gusts easily into the category 2 hurricane range (> 90 mph). Very heavy rainfall to the tune of 6-10″ is likely. Height of the storm is mid to late morning Saturday into early Sunday morning.
Southeast NJ (Cape May/Atlantic/Cumberland) and the Delaware Beaches: Storm surge flooding is likely at times of high tide, especially Sunday morning…possibly Sunday evening as well if this slows down further. Wind gusts of 80-90 mph. Sustained tropical storm force winds. 6-10″ of rain likely, but any shift further west would knock you down to 4-8″, but increase the storm surge/wind/isolated tornado potential. Barrier Islands will be impossible to get to, and will likely be impossible to get around on Sunday. The brunt of the storm will hit late Saturday afternoon to early afternoon Sunday.
DC-Baltimore: Heavy rain and flooding will be the major stories. Any further shift west will exacerbate rain totals, which should be 3-6″. Also, any further shift west will allow for more storm surge up the Chesapeake. This would cause substantial tidal flooding…but that is not the main concern right now. Winds should be sustained at least low end tropical storm, with some strong TS gusts likely. Rain will drop off substantially west of the cities. Worst of the storm will be late Saturday afternoon into Sunday morning.
Philly/SW Jersey/Trenton: The current forecast track keeps you in the solid 3-6″ rainfall band, with higher amounts possible with a shift to the west. Significant to record flooding on some rivers is possible. Winds will be tropical storm force, with the potential for a few hurricane force gusts, especially in NJ. Height of the storm will be Saturday evening through mid afternoon Sunday. Also note that tidal Delaware River and Delaware Bay flooding is likely with this storm, especially if the track shifts any further west.
Metro New York City/North Jersey/Long Island: Same story here… heavy rain, up to 6-10″ with locally higher amounts, dropping off west of I-81 in Pennsylvania. Storm surge flooding is a distinct possibility in Manhattan, as well as from LBI to Sandy Hook and obviously on Long Island. Current projections would be Cat 2 storm surge flooding potential from Cape May to Sandy Hook. Strong winds, mostly tropical storm force, but could be hurricane force at times in Ocean and Monmouth Counties. Gusts to hurricane force/80 mph or so in Ocean/Monmouth/NYC/Long Island likely, gusts to tropical storm force in inland Jersey/NY. Height of the storm will be Saturday night into late Sunday afternoon or evening.
Upstate NY (Syracuse-Albany): Heavy rain in the Hudson Valley… 6-10″ south, 4-8″ north. Any shift west will push amounts into the widespread 6-12″ zone. Rain will drop off steadily west of Albany (1″ every 5 miles or so to just some squalls Syracuse/Utica) Winds will gust to tropical storm force, especially at higher elevations, mostly in the Hudson Valley. Wind gusts should edge back to 20-30 mph between Syracuse and Utica. Height of the storm will be from mid to late Sunday morning into Sunday evening or night.
Connecticut/RI/Mass (incl Cape Cod and Boston): Heavy rain likely, especially along and west of I-91…any shift west or east will shift that axis. Rain amounts of 6-10″ west and 3-7″ east. Again, any shift in track shifts that. Winds will gust to hurricane force as you will be on the eastern, or stronger side of the storm. Some sustained category 1 hurricane winds will be possible on the Connecticut shore, southern RI, Block Island, the Cape, and the Islands. Rain may be more squally or sporadic and the potential does exist for brief weak, but damaging tornadoes anywhere at any time. The height of the storm for you looks to be late Saturday night into Sunday night or early Monday morning.
Northern New England/Maine: Widespread tropical storm force wind gusts, with some isolated hurricane force gusts on the Maine/NH coasts. Rain of 6-10″ likely. Height of storm Sunday afternoon into Monday morning.
Some Q&A…
Can this forecast change? Yes. If the track of Irene is a little further west, the storm may weaken a little faster over land, causing less in the way of wind gusts, but it would also put different people on the eastern side of the storm for longer, creating more of a coastal flooding problem. Either way, someone is looking at substantial to serious flooding because of rainfall. It’s just a question of who. The forecast could also change if Irene makes any unexpected wobbles between the Bahamas and North Carolina. A shift in course of 25 miles in either direction will move people’s impacts around rather substantially because of the angle this storm is going up the coast at.
Could Irene go out to sea? Strongly doubt it. Most of the computer guidance has come into very good agreement now, and within 72 hours, such a dramatic change in the forecast would be almost unprecedented. It’s running out of time to make a move that would cause this.
Should I evacuate? I cannot tell you what to do or make that decision for you. Heed the advice of local emergency managers or law enforcement.
How bad will the aftermath be? The storm surge flooding should subside Sunday night and Monday from south to north. This is the type of storm that has the potential to permanently alter the coastal geography and it’s not impossible to think that new inlets could form or water may never recede from certain locations. Be prepared to find that in a few areas. The soaking wet record month in PA/NJ/DE has saturated the ground. Add even modest tropical storm force winds and an average of 6-10″ of rain, and fully leaved trees/power lines will be coming down by the hundreds. Expect widespread, potentially long duration power outages up to a week or longer over a VERY wide swath of the region impacted by Irene.
This has all the makings of an historic storm. Yes, there is the off chance that the storm is “not that bad,” but given all the information we currently have in front of us, it would be very difficult to say that that is a possibility. This is the most serious storm since Hurricane Gloria and possibly back further than that. Please heed all warnings and orders from the appropriate authorities. Hunker down, be strong, be safe, and life will go on!
State of Occlusion 