Hurricane Irene – Saturday Morning Update

91 Comments

3:30AM

As of 3AM, Hurricane Irene’s top winds are down slightly to 90 MPH as it moves NNE along the North Carolina Coast.

What is hurting Irene? She felt some southwesterly wind sheer from a trough of low pressure over the Gulf of Mexico during the past 24 hours, but has now gotten beyond that. The circulation being partly over land interrupts the even inflow to the storm. Some dry air has also worked into the western part of the circulation, making it look irregular.

What will aid Irene? The center of the hurricane should remain mostly over water as it moves away from NC later Saturday. The water temperatures are quite warm right up to Long Island NY.

When is storm for the Boston area? Although tropical showers are possible today, the heaviest tropical rain will occur tonight and Sunday morning, and the strongest wind will occur Sunday afternoon and evening.

Tornadoes? As noted in the previous blog post, tropical cyclones can and do produce tornadoes when they come over land. This takes place because friction encountered by the storm over land lowers the wind speed there, while the winds just above remain stronger. This results in wind sheer, which can be explained as differences in wind speed and direction as you go from the ground up. These differences create the rotation that becomes tornadoes. These are usually embedded in some of the rain bands on the right front quadrant of the storm, or in this case, to the northeast of where the center is. Hurricane-produced tornadoes are weaker than their severe thunderstorm cousins, but can cause significant damage. Do not be surprised if a tornado watch is issued for at least the eastern half of MA including RI and southern NH by the National Weather Service on Sunday.

Where is the center of Irene going? I believe Long Island landfall will take place slightly earlier than I said on the previous post, by 6PM Sunday at the latest. I’m edging my forecast track east very slightly, based on the fact that the hurricane had already turned to the north northeast as of late Friday night and is not expected to turn back to north, but continue north northeast. The center will probably cross central Connecticut and Massachusetts, passing over or just west of Worcester by 8PM. One change in my thinking from earlier is that the air mass will be very tropical and with water temperatures quite warm right up to long island, it may take a little longer for Irene to start losing tropical characteristics. Once it gets into northern New England later Sunday night, it will start to transition into a regular storm, at which time the winds around the storm, though weakening, may expand and cover a larger area. How rapidly this takes place will determine how much wind lingers over southern New England after the storm leaves. Keep in mind that strong and gusty winds may continue into Monday, even though the storm will be long gone by then.

Wind? East of the center, expect tropical storm-force winds (39-73 MPH)with the potential for hurricane-force gusts (74 MPH or higher), strongest near the coast and over higher elevations. Winds will blow mostly from the south southeast to south in the big wind regions. West of the center, winds will be mostly east to northeast as the storm approaches, shifting to north and northwest as it passes, and may be strong and gusty at times, with possibly the strongest winds coming as the storm is departing Sunday night.

Rain? Tropical showers and possible thunderstorms, with some heavy rain bands, will result in around 1 to as much as 3 inches of rain in eastern areas, east of the center. Amounts will be much heavier to the west of the center, with 4 to 7 inches of rain common. Amounts of over 7 inches may occur in some up-sloping wind regions in western Massachusetts and then up into portions of northern New England.

Coastal storm surge & flooding? East-facing coastal areas will see splashover and flooding especially at high tide, but should not be any worse than during powerful winter storms.  South-facing areas, especially the bays of the South Coast, will see storm surge flooding as high as 4 to 8 feet. Significant flooding is likely in these areas.

I hope this breakdown of the storm covers just about everything. If you have any questions, do not hesitate to post them in the comments section below.

Beyond Irene? Well it looks like a great stretch of weather follows this storm for the first half of next week!

Updated Boston Area Forecast…

TODAY: Mostly cloudy to partly sunny, warm, and very humid. Isolated showers in the morning. Scattered showers in the afternoon, a few of which may be heavy. High 73-78. Wind S to SE 5-15 MPH.

TONIGHT: Cloudy. Episodes of tropical showers, heavy at times. Chance of thunderstorms. Areas of fog, possibly dense at times. Low 64-69. Wind SE to S 5-15 MPH.

SUNDAY: Overcast. Fog possible in the morning. Tropical showers most numerous in the morning, likely heavy at times with a chance of thunderstorms as well. Showers may become less numerous for a time in the afternoon, but a core of heavier rain is expected later in the afternoon.  Mild with tropical humidity. High 70-75. Wind SE to S 15-25 MPH increasing to 25-45 MPH with gusts 50 MPH or higher becoming quite common, possibly up to 75 MPH or slightly higher over coastal and higher elevations by late in the day. Isolated tornadoes are possible, but not likely.

SUNDAY NIGHT: Rain and showers ending from south to north with breaking clouds following. Still mild and very humid. Low 65-70. Wind SW to W 15-35 MPH with gusts 45-55 MPH.

MONDAY: Mostly sunny. Warm and humid. High 80-85. Wind W 15-30 MPH and gusty, diminishing slowly.

TUESDAY: Sunny. Low 58. High 79.

WEDNESDAY: Sunny. Low 56. High 78.

THURSDAY: Mostly sunny. Low 62. High 83.

FRIDAY: Partly sunny. Low 63. High 82.

91 thoughts on “Hurricane Irene – Saturday Morning Update”

  4. Can’t get a better explanation of Irene than that!
    I’ve been away in Ireland, and will be here until Thursday, so I’ll be missing out on whatever comes that way.
    Stay safe everyone!

    3. You should hear from the extratropical cyclone formerly known as Irene right about when you are getting ready to leave. Hopefully it doesn’t delay your departure. Let us know what you see.

  5. Thanks TK !!

    Currently in Cape Hatteras, NC…..

    Heavy Rain, winds SE sustained at 54 knots, gusting to 74, pressure 29.06 in and falling. I cant imagine how much water must be surging into Pamlico Sound.

  6. Most recent pressure is 951mb……one thing the models have been consistent with is to maintain whatever the pressure is from the NC Coast to landfall in southwestern most New England.

  8. Btw I was surprised to see that 00z nam last night, I guess it was off base. Again never thought it would be as west as the some of models showed.

  9. Thanks TK. I can’t remember the last time a category 1 storm had pressure this low. The clouds are already here. If anyone did not do preperations you still go today. I know yesterday I was running around getting stuff and helping my family move in any loose objects that could blow away. I will be doing the same thing at my place today and then hope for the best.
    The good news great weather once we get past Irene next week to clean up from whatever damage Irene causes.

  13. latest dropsonde : 951mb…

    took a ride down Rte 139 to ocean. Couple homeowners decided to board up and the town has one of those big highway dpw signs blinking : Caution : Rip Tides

    Very still and muggy out. For now, the ocean was calm (no swells) and nearing high tide.

    1. Tom many boarding up on end of Humarock we are on. Most have said they are leaving. All I can hear are hammers. Air is eerily quiet

      We went to dinner at ocean deck in green harbor last night. It was very good. Have you tried it.

      1. Yes we have. Enjoy it a lot. Havent been this year, it has been a hectic summer, but hope to return soon.

  15. Thanks again TK good reporting. My question is, during the last Hurricane I remember the wind aloft whooshing along all the time then the sound changed as it seemed closer and lower along with the sound of large branches falling and trees snapping in half. Is that a micro burst or something else? Not to worry Scott you may not have missed the storm as it’s headed your way later in the week. Best of luck to everyone stay safe!

    1. That’s a decent way to explain it. It’s not a classic micro burst, or created the same way as one in a thunderstorm would be. But just visualize the turbulent air moving along very fast above the ground where there is very little friction, and having to slow down and go over and around things at ground level due to friction and objects. You end up with a rolling and tumbling of air, almost like little vorticies upright, sideways, and every which way, and when it’s just right, some of these are going to come right down into a certain spot and cause a powerful gust. This goes on for quite sometime as the strongest circulation is moving over you.

  16. The ocean was like glass this morning but has some waves building now. Our neighbors are all heading out today and have advised us to do the same more for the cars than us. We will head home this afternoon and finish up securing stuff at our house that the kids haven’t already secured

      1. Thanks Tom. God willing we will return at the crack of dawn Monday do you still think wind here will BR strong enuf for massive power outages or more scattered now

        1. I expect to lose power. Hopefully not too long, but I think we are ready. Bought lots of ice to try to save the frozen foods in the freezer and have a propane grill.

  17. Starting to sprinkle a bit….radar seems to be showing showers breaking out in Connecticut…….I know the storm has landfalled, but its current satellite presentation is the best its looked in 24 hrs, its not too far away from water. I wonder if there’ll be a brief pressure drop into the high 940s.

  18. Hi Tom- Pete b said plan on a simple noreaster, do you agree. I still have stuff to put away, but am torn on what to do. What is your thinking for us Tom. I was thinking of taking a ride through the old neighborhood later down foster ave and brantrock.

    1. Pete B … wow.

      This will by no means be a catastrophic storm, nor will it be a “simple noreaster”.

    2. Hi John,

      Well yes, I agree with him in the sense that, especially at the immediate coast, we can go thru a several hour period of strong winds in a noreaster, except inland is going to get it too this time.

      Moderate rain shower now.

      1. as a disclaimer, I went to school with Pete, have him as a friend on facebook and we still, on rare occasion say hello and ask how our families are, so I tend not to get on him too much about his weather predictions. 🙂

  19. Ugh I have the sense we really don’t have to leave here except that even in a nor’easter the ocean and river can come up over. Is this thing going to fizzle cometely or will it still be strong enuf to cause problems.

    1. Hi Vicki.

      Of course, this is just an opinion……I think the southerly and southeasterly winds are going to be strong tomorrow. So, its not going to fizzle. The pressure on this thing is very, very low, so I dont think its going to unwind before it gets here. Also, now that its sped up slightly, it could put that 11am high tide into play. At 10.2 ft in Boston Harbor, even a 1 to 2 ft surge with increasing waves will have splashover and minor coastal flooding on east coastal facing beaches.

        1. I like TK’s timing of Sunday afternoon and evening for the strongest winds…….tonight and Sunday morning for the most rains.

    2. I feel the same way as you. I am so torn on what to do. You have all next week down here, and looks like a great week. With not knowing what this will do you should just head home, sleep in your own bed and be back on the beach first thing monday. If I get called into work tomorrow for nothing I will be pissed. I have a life outside of work, I’ve had enough OT this summer I do not need to keep padding my pocket like some do. Good luck Vicki It is a pleasure talking to you here. Go home and grab some takeout and hop back on line.

      1. John it’s a pleasure talking to you too. Your message made me smile. The bed here is miserable and our own plus takeout sounds great 🙂

  21. Sometimes I get so mad at people that just say we wont get more than some rain and a few gusty winds but what makes me the maddest is that they r usually right lol grrrr, and all these people always wanna make a bet, I’m totally afraid of just getting 30-40 mph winds

  22. Allow me to editorialize for a moment.

    I think the problem is pretty simple. TV stations, in the name of ratings, always want to go for the big story. The decisions to do this are made by people who don’t know much, if anything, about weather. So when it comes to weather being the story, you can already see the problems that are going to be created. The meteorologist working for these people has no choice but to hop on the hype wagon, unless they desire to be replaced.

    So it becomes all about telling us the details of what we’re going to have 5 days in advance and somehow they slip in that it will be from (example) “category 3 Hurricane Abercrombie” or whatever. They make it sound like WE will 100% be getting a CAT 3 on whatever day it is gonna be, so better prepare now! I’m not sure exactly when this became such a disease of media, but there you have it.

    Why not go back to the old style? Give the facts. Give the forecast. Give the caveats. Update. When you are not sure, SAY you are not sure. And for goodness sakes, stop giving details about things right down to how many branches might fall on your uncle’s favorite 1979 Subaru so you better call him up and tell him to move it now!

    This is why I try to keep a little bit of an old school feel to the blog. Sure we’ll utilize some nice graphics eventually, but we will do it in a way that will hopefully inform, not confuse, the user of the info.

    A combination of old school and today’s technology can do wonders for predicting weather and getting the word out, and then simply just talking about what is expected, what is going on, and what has happened.

    Keep it real, and leave the hype to the tabloid TV shows please.

    Thanks for letting me rant. 🙂

    1. I got a weird feeling were gonna be seeing just 30 or 40 mph winds, I feel like I just worked a full week for nothing

  23. Tk- I am sorry but this feeling I have is fizzle. I trust you more than Harvey. Is this thing going to continue to loose steam. In your oppinion could you give me your best shot at what to expect down here on the south shore. I just have so much more to put away here, but do I need to go that far now. After this maybe you can help me with learning how to read the maps, I have looked at them but just lines to me.

    1. If you were around for Gloria in 1985, prepare for something like that. I’m starting to think this thing may be like Gloria was on its front side and like Bob was on its back side. Lots of wind, but mostly below hurricane force even in gusts. It can’t hurt to get things moved out of the way, in case, and it’s a good exercise drill for a situation that looks a lot worse than this, which do happen, and will again.

      1. Thank’s TK- Yes I was in Marshfield and packed a good punch,I will continue with my plans. So you say gloria on the frontside. What is the timing on the frontside, and for how many hour on this front. And do you think the bigest concearn down here is the wind and storm surge. What is your guess on wind gusts and rain precip. And TK thank you for making me part of this site, I am hooked. I voted for you 5times again last night.

        1. Wind and storm surge biggest concern in that area, yes. Again, not catastrophic, but if you are in an area prone to damage, it’s concern enough.

          Timing of strongest wind and all of the front side activity is basically just during the day and very early evening tomorrow, winds building, peaking out from SE-S, before shifting more SW-W after the center gets deeper into New England. And strong wind gusts are going to occur regardless of the status of the storm (TS or Hurricane). These things take time to spin down even over land.

  24. 10 am ob from Cape Hatteras, NC

    T : 81F
    Td : 77F
    SE wind at 49, gusting to 77
    Pressure : 28.78 in and falling

  25. Pretty good line of showers setting up in southern RI……had one heavy shower roll through about 15 minutes ago and another one is just southwest of Marshfield. Now its very, very soupy out.

  26. Looking back at some the comments this will not be a simple Noreaster. This will not be the hurricane of 1938 but I think we could get something close to Gloria when all is said and done.
    Henry Margusity saying the eye is reforming. Will see what the new advisory and track say when it comes out shortly.

    1. Hi JJ.

      I wonder if we’ll get direct recon pressures anymore, since its over some land. I guess the flights stop over land. I think they can still fairly accurately estimate pressure based on land based readings. I think Henry is onto the idea that this thing looks really good on satellite and based on some of the sustained wind reports and gust reports, I personally think this thing has intensified some this morning.

      1. Hey Tom…. Latest advisory still has Irene with 85mpn winds. There looks to be more convection around the center.

  27. Good morning all.

    I must say, so far I am not impressed. The only thing that has me concerned, is that the progged pressure remains seriously low all the way to NE. I think TK described the expected conditions perfectly with no HYPE. Great job TK.

  28. Is it just me or does anyone think this is going to take an inland track the entire way up the coast?

  31. The track has shifted to the west a little bit come across western Long Island and into western CT. It will be very close to the Jersey shore so that could zap some energy which could make Irene a strong tropical storm when she makes a landfall in CT instead of a category 1 hurricane.
    Tornado Watch box now up to Southern NJ and got some bands of showers and Rhode Island and CT right now.

  32. Pressures r coming up and it’s on land and could be on land all the way up, my latest thinking is a weak noreaster is on it’s way

    2. It will be a rainstorm only im jumping off the wagon, for all of us I think we get occasional showers today and Sun with 15-25mph gust to 35mph, along the coast they could get a few gust to 50mph

  35. Charlie,

    I agree with you. I have not yet taken in Lawn furniture etc.
    Now, I am NOT sure I will even bother. I’ll see how things look after I run some errands after lunch.

  36. Just pondering future track based on what looks like a due north current movement. Most of the winds at 11am on the Virginia coast, are currently from the Northeast. I’d imagine its quite possible they can veer to the east and southeast, however, all those northeast winds make me think the center is going to go slightly SE of Norfolk, VA….

    Pressure at 28.75in and falling at Cape Hatteras, NC and near 29.00 in at many other reporting stations. My opinion is, over land or not, Irene is going to take a while to unwind.

    1. checking and see that Elizabeth City, NC is also Northeast at 45 gusting to 56…so, I’m going to guess and say the center goes just southeast of Elizabeth City and the center emerges out back into the Atlantic Ocean and parallels the Virginia and Maryland Coastland 20 to 40 miles offshore.

    2. Large systems tend to weaken slowly. Until the tropical storm and hurricane warnings get dropped I am not letting my guard down. Will see what happens with the 5pm advisory with the warnings.

  37. How long will it maintain hurricane status over all of that land?
    10mph to go. I think it is under hurricane force by the time it exits NC.

  41. This is the kind of hype from TWC that is unfounded:

    The threat level is “EXTREME” along the East Coast from eastern North Carolina to New England.

    It may be close to extreme in NC, but for NE? Give me a break.

  42. There is no way this storm maintains 70 MPH winds over N. New Hampshire as the cone represents, if it stays over land which it will. It is frustrating as can be that the Weather Channel and others mis-represent things. If this comes up over land we will have 20-40MPH winds and a lot of rain; but Pete B. is correct.

  44. Here is what Pete has on his blog:

    For some parts of Massachusetts, this will be a long duration nor’easter. Nothing more, nothing less.

    Still don’t want to let your guard down completely. The steady, occasionally gusty wind will still bring down some trees and create isolated power outages. Beach erosion and a storm tide will cause coastal flooding in Buzzards Bay and south-facing beaches and shore roads from Southern Rhode Island to the Cape/Islands.

    Heaviest rain falls from late tonight through early afternoon tomorrow.
    Wind will run the entire compass direction starting from the northeast and ending from the northwest
    Strongest winds will be from mid morning through 10pm Sunday night. Expect max gusts from 40-50 mph along the coast/Cape/Islands

    Sun’s out Monday, and the rest of the week is looking mild, calm, and bright.

    Pete

    Read more: http://www1.whdh.com/weather/blog/posts/BO146358/#ixzz1WFFSo5Ld

  46. The fact that Pete has even used the term “long duration northeaster” already throws the credibility of that entry out the window.

    A decaying tropical cyclone accelerating through the middle of New England is not nearly the same thing as a long duration northeaster. I’m not saying its worse, better, or the same with the statement. I’m just saying it’s a bad comparison.

    1. ….despite my disclaimer above, I will respectfully disagree with Pete’s 40-50 mph gusts along the Coast, Cape and Islands. Two reasons, the low pressures being currently reported in the mid-atlantic make me think it will not unwind quickly and as I used Elizabeth City, NC ob above and its northeast wind, I think the center will reemerge over the Atlantic later this afternoon.

    1. Only partially. Signs of the center traveling over water for several hundred miles before landfall, while accelerating, still means some powerful wind gusts (not sustained) for the South Coast. There are a lot of weak trees from last winter and the fact we haven’t had a strong tropical in some time, along with wet ground from previous rain. I’m not saying widespread devastation, but some places will take a bit of a beating down there.

      He’s also missing the fact that some very strong wind gusts may occur on the back side of this (like Bob) due to dry air entrainment which allows strong winds aloft to mix down to the surface in big gusts. Those winds being from another direction could just put more stress on some trees.

  48. With the latest forecast from the NHC having Irene near N.Y.C. at 8:00 am tomorrow, does this mean an earlier arrival for N.E. and (hopefully) departure?

  49. That is also what I meant. The conditions will be no worse than a noreaster. In fact I think Pete is overdoing it a bit. There will be a storm surge on the south coast but an inland track will decay this storm quickly. This one will go down as a near miss.

  50. I even think that the track will be so far West now, that I think we will be spared
    the tornado watch box. That and it will be weaker than previously thought.

  51. Is it my imagination or does it look this thing has stalled on radar or even moving a bit northwest?

    1. You are witnessing the end of the northward wobble and it should start an east then north northeast turn in the next couple hours.

    2. Hi haterain,

      I was thinking the same thing as far as speed, it really has slowed down.

      Direction, I was thinking the last 2 or 3 radar images had shown a return to a North-Northeast jog.

      Awaiting 12pm obs for Norfolk, VA and Elizabeth City, NC wind directions to see if they are maintaining the Northeast wind direction (sign that the center will stay to their south and east) or if they are veering around to the east and southeast (sign the center will go over or west of them)

      1. At 12 pm, Norfolk, VA has a Northeast wind and Elizabeth City, NC has an East wind…..4 reporting stations have pressures under 29.00 inches.

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