Good morning weather folks! It’s time to talk tropics and Hurricane Henri. As of 8am, Henri is looking better organized. It’s currently located 525 miles south of Montauk Point with 70mph winds (and higher gusts), and minimum pressure of 993mb. Its moving NNE at 12mph and will continue to accelerate and strengthen to a Hurricane later today, as Henri will be traveling over very warm water (fuel for hurricanes). As it approaches Long Island it will weaken rapidly yet decelerate. Over the past 48 hours since my last post, the forecasted landfall has tracked approximately 100 miles west, a “slight” jog. While we are only 24 hours or so from landfall, and additional adjustments are indeed possible, it appears as though Henri will be making landfall over southern Long Island versus the Cape. As mentioned, a slight jog will have a significant impact where Southeast New England gets sparred the worst, yet Long Island, CT, RI, W MA, Hudson Valley on North to VT and NH/ME receive the brunt of Henri’s wrath. As you can see, this is a very complex and difficult forecast. Regardless, I hope you heeded my advice to prep in advance. If you haven’t yet you still have time this morning into the early afternoon before conditions go downhill quite fast. I’ll go over just a few suggestions (most of course are common sense and dependent on your location relative to impact areas).
Before I go into various impact scenarios, let’s review the 3 main hazards. Storm surge will be a big problem along southern exposed coasts of Long Island (Manhattan Beach to Montauk) CT south shore (Stanford to Stonington), and from Watchhill to Chatham. As Henri moves due North and spinning counterclockwise (southern hemisphere cyclones spin clockwise), its constantly pushing all that ocean water into those areas. And to make matters worse, conditions are exacerbated by astronomical high tides (it’s a full moon tonight). Strong to damaging winds will be a major problem, especially on the east side of Henri. Given how saturated the soil is throughout the Northeast (record rainfall in July plus Fred added to the totals), the roots of many trees are prone to snapping. This will lead to widespread power outages that may last for days and perhaps weeks in some neighborhoods. Lastly, drenching and excessive tropical downpours totaling 3-6”, up to 10” in isolated spots will lead to major flooding (don’t be that car stuck or floating down the street on the news). It doesn’t matter how big your SUV is.
Ok, lets go over 3 different tracks from the GFS, the European and the NAM. All 3 as of their latest runs make landfall on Long Island, yet the subtle differences and track post landfall result in vastly different outcomes. While we’re nearly 24 hours away, slight adjustments are still possible, but I do think it’s fair to say an out to sea recurve, a swing and miss scenario is off the table. As of its latest run, the GFS reversed trend and moved East with landfall right up the Narragansett Bay. Not sure I buy this but we’ll watch the next few runs. This puts SE New England in the high wind zones, especially E CT, RI (especially Narragansett Bay) and the Vineyard with 60-80mph gusts, and still strong but less severe on the Cape, Boston up to the Seacoast (30-50mph). Fortunately rainfall amounts will be manageable. The most significant rainfall would take place in C/E LI, up through C/E CT on up to W/C MA, then up to S VT and NH. On that track, NYC and NJ are spared the worst on both rainfall (an 1” or less) and wind gusts of 25-35mph. See GFS below for details for your area.
Scenario 2: The latest European takes the center of Henri near Southampton but continues more of a NW track than the GFS. This leads to more significant rainfall to C and W LI, NYC, NE NJ, SW CT up to the Berkshires, Hudson Valley, then up to S VT, S/C NH and coastal ME. As mentioned earlier, the strongest wind gusts are usually on the east of side of a tropical system. So, in this instance, E LI, southern CT from Greenwich to Mystic, and most of the state see 50-80mph winds (higher gusts will be along the coast). Similar to Irene in 2011, nearly 700,000 lost power in CT. W MA and Hudson Valley could see 30-50mph, strong enough to knock down trees. NJ and NYC would be limited to 25-40mph.
Scenario 3: The NAM 12km is the most western track which takes Henri near Patchogue but once over land, sticks around the tri-state area before weakening, makes a loop and travels due NE. The strongest wind gusts would be limited to LI (50-70mph), CT and MA (40mph), but NJ and lower Hudson Valley get into the game (35-45mph). Highest rainfall totals would be in NJ which could see 3-6”, and up to 9” in isolated spots. The lower Hudson Valley, LI, most of CT and MA are the 2-3” range, and S NH and SE ME could print 2-4”. With respect to the NJ shore on up to the Seacoast, expect high surf, strong rip currents, spill overs, and moderate beach erosion.
Approximate Timing
Exact timing is a bit of a challenge. There are model runs that have Henri loop around the tri-state area before moving NE. The basic thought is this, conditions along the coastal sections of Long Island go down hill after sundown tonight as winds start picking up throughout the night. Rain bands start moving in before or near dawn Sunday becoming heavier throughout the day. Conditions improve later Sunday night along Long Island but heavy rains move to upstate NY, MA, VT and NH on Monday, and finally exiting Maine on Tuesday. I added multiple forecast loops so you can get a visual on how complex this storm is.
Bottom Line
Bottom line, its better to prepare and assume the worst, and hope for the best. If you haven’t yet, do your shopping early today. Check your sump pumps, remove important items and boxes from flood prone basements, DON’T park your cars near trees, make sure you have your prescriptions filled, buy enough dry food to last a few days to a week if you live in areas known to lose power. Bring in loose items around the yard. At this point, if had to go with one of the 3 scenarios, the European scenario 2 would be my choice. But as you can see, while SE New England appears to have avoided a very bad situation, as well as NJ/NYC (sections of NE NJ including Middlesex and Monmouth could see stronger gusts), the brunt of Henri appears to be LI, CT, MA, and RI. That said, this is very fluid (pun intended) situation with lots of moving parts. Avoid traveling tomorrow and Monday if possible and plan for lengthy delays and cancellations at the airports tomorrow into Monday. I may post brief updates throughout the weekend here, including on my Twitter page, updates every 3 hours of the National Hurricane Center’s advisories of Henri’s location and other data points. I tweet those out at 8am, 11am, 2pm, 5pm 8pm, and 11pm. Btw, it’s only August 21st. Hurricane season is far from over. Please pay attention to your local weather outlets. If you have questions and/or thoughts, please comment in the comment section at the end of all my posts. Please feel free to pass along my post and tell others to subscribe to my site. Time for a brief snooze so I can keep up with the weather because weather never sleeps!
Above is Buoy 41001, located 172 miles East of Cape Hatteras is reporting significant wave height of over 15 feet!