WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Ophelia departing, TD 17 arriving?

By: Dr. Jeff Masters, 4:15 PM GMT on September 15, 2005

Storm surge levels observed last night in Bogue Sound, which is the bay between Morehead City and its barrier island, reached seven feet--near the record levels set there from Category 3 Hurricane Hazel in 1954. The storm surge reached 10 feet in some of the smaller creeks in the Neuse River and may have reached 12 feet, a remarkably high storm surge for what was a tropical storm for that area. High storm surges can result from just tropical storm force winds, if they blow over a large area for a really long time, like Ophelia's did.

Figure 1. Storm Surge heights measured in Ophelia.

For those of you who can handle a 1.6Mb animation, the radar loop from Morehead City, NC during the time Ophelia's northern eyewall passed over the city is fascinating. The turbulence created by having part of the eyewall over land and part over water created some smaller vorticies along the inside edge of the eyewall.

While Ophelia did dump it share of heavy rain--around 5 - 7 inches near Wilmington, and over 10 inches around Cape Fear, south of Wilmington--the rain was mostly confined to the coast, and did not cause widespread flooding problems. Ophelia's winds also did relatively light damage--sustained hurricane force winds (74 mph) were only observed at one location, on Cape Lookout near the Outer Banks. The storm surge was what caused the main havoc with Ophelia.

Figure 2. Estimated rainfall from the Morehead City radar for Ophelia's passage.

Ophelia is very slowly lumbering out to sea, and is a mere shell of her former self. The eyewall has disintegrated, and the latest hurricane hunter flight found a rising pressure (987 mb) and winds at flight level (78 knots) that may support downgrading Ophelia to a tropical storm this afternoon. Cooler waters, dry air, and wind shear are all taking their toll on Ophelia, and by the time she races past Cape Cod on Saturday, the worst she will be able to do there is generate wind gusts of 40 mph.

TD 17?
A well-organized tropical wave 900 miles east of the Windward Islands is slowly improving in organization and may become Tropical Depression 17 by tommorow. The wave, located near 9N 47W, is a little too far south to develop quickly, but is moving WNW towards higher latitudes. The shear over the wave is marginal for development, about 10 - 15 knots, but is expected to drop by this evening. Wind measurements from the QuikSCAT satellite show that an elongated surface circulation has already formed, but winds around the disturbance are below 20 knots. The upper level environment is favorable--an anticyclone has formed on top of it, which should provide very favorable outflow for any deep convection that fires up. The disturbance is expected to continue moving west-northwest at 10-15 mph the next few days, then possibly slow down and turn more northwest under the steering influence of a large mid-Atlantic trough.

Figure 4. Early track model runs for the disturbance that may turn into Tropical Depression 17. The 2am GFDL run disippated the disturbance immediately.

Elsewhere in the tropics
No other tropical storm developent is expected elsewhere in tropics through tomorrow. However, conditions for development are expected to improve over much of the tropical Atlantic over the coming week, including the Caribbean and Gulf of Mexico.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Firsties says, "Bring on 17!"
This is a visible sat. loop. Can anyone tell me what the "line" moving northwest to southeast is? Actually, it appears to be moving clockwise against the rotation of the storm. It is north of the storm.
could be out-flo in anticyclonic rotation above the storm or just caucht in the normal west to east flo which the storm will soon follow
Cajun, The line is so straight it looks strange. I'll be you're right.
okay, now Ophelia will move out and Phillipe is beginning a nice brew, should be a good next week, lots to talk about, getting excited! :-)
I noticed that convection NE of Puerto Rico...its been persistantly there for a couple of days...any chance that could be tropical?
Dr. Masters(or anyone else who wants to put two cents in) what about the area of disturbed weather near Puerto Rico? Is that supposed develop into anything?
saymo, its mother nature slapping Ophelia for taking so long. lol...no probably just windshear, moving one of her bands away from her instead of allowing it to circle back in...Ive been seeing a lot of those on the i.r. satellite lately....there was one yesterday, and look at this Link, you'll see lots of tails out there.
The latest few runs of the GFS have shown some development North of P.R. with that area moving to the west and into the Gulf as a large High pressure to the north steers it west.
the area to the ne of Puerto Rico is coming off a trough that has been lingering there for awhile, heck with this tropical season, anything is possible...I just don't know if its beginning to rotate and I am not sure the windshear in that area. So far, no one is talking about it except us, it seems...
thanks 03, that was what we wanted to know. SO, maybe two storms soon....well, its still peak season...so we'll watch wait and see...
Dr. Masters, or someone who really does know what they are talking about, can you please explain why the formation of an anticyclone in the upper level is favorable for outflow? Do all organized tropical systems have anticyclone rotation in the upper level?

You a trip stormydee. Glad to know other people like storms too. On the radar you posted it looked like to me the ne/PR blob had outflow... Then again I'm just a rookie.
The tide is dropping in Oriental

See the time & date stamp on each frame!
Yeah stormy. thats funny..i made mention of it about four days ago as i saw some of the GFS runs showing it..Also you get troughs lingering around there this time of year as we saw with Ophelia it can generate something, but we will see, dont see any circulation there yet..it would be something that would slowly evolve.
afternoon to all

I'm trying to get a location where all of our blogers live want to then make a directory that I will post on my blog
just looking for city (and maybe location in that city if it is large) and state..no other info needed or wanted..Thanks to all who will participate in this endevor..
tks...please make post on the first thread of my blog.
would like to include all that live outside of the states
also..will be interesting to see how wide spread our blogers are in the world..

please, if you can give the gift of life (blood),please contact your local Red Cross and make an appointment..the pint of blood you give my save 3 lives..and blood is really needed in the gulf coast..they lost their supply
of blood because of Katrina..and donors due to displacement..
I noticed that our local weather service office in So Fl has persisted in calling for "breezy" conditions for Sunday night and Monday. I am familiar with their usual forecast reasoning, and they are usually VERY conservative about bringing specific coditions like that into the forecast this far out based on a "developing system". It will be interesting to see if we do in fact see "breezy" conditions here in So Fl.
Hey all im back power was restored here on Ocracoke 15 minutes ago"at least in my area".We have wind gusts to at least 70mph recently and so far have not had any measurable flooding but that may be in the works later when the wind goes to the NW.A few trees down and minor shingle damage but thats about it.In the Cedar Island area i have heard that the flooding is the worst they have ever seen.From Hatteras village this morning i had reports that water has been sucked out of the sound and left boats almost high and dry in the marinas, it could get really bad up there depending on haw fast the water comes back.I hope everyone is safe and will post conditions here as warrented.
Here is latest GFS run...Link..it shows weak low trying to develop near Bahamas and track south of Fla. into the Gulf..something just to watch for now...This has alot of frames so if you have dial-up it will take forever...Also shows other system east of the leewards hooking east of the US.
whitewabit, I live in Baton Rouge, looks like Ophelia is moving almost due south
Afternoon all....
Glad you are safe OBX..Good luck the rest of the way...Hopefully your power stays on.
Here is the UKMET 5 days out

I would say stationary right now...Link..thankfully the western eye wall has weakened.
As for that low near Puetro Rico, I heard somewhere this morning (can't remember where) that there was a large high-pressure system over the central US now that would keep it away from the eastern gulf (N.O to Florida) and bring it across to Texas or Mexico.

any verification of that?
Any more reportds from Hatteras Village? Any flooding from Ocean side?
Looks like once O moves out, high pressure will build back to the west along the gulf coast.
Hatteras no reports of ocean flooding a little bit of overwash just north of the village but not bad.Power still out in hatteras so we must be on the generator.Ill let you know if i find out anymore.
just talked to my cousin in wilmington,said power still out at his dad's house on the waterway near figure 8. was on his way to get a crane to move someones boat off of their lawn.
I bet lefty is mad lol,oh well we told him he wouldn't get much in virginia beach.
Thanks OBXER. Any reports of home damages e.g. roof, cedar siding etc windows you hear about please let me know. Thanks again.
there is outflow with both disturbances...just a matter of the windshear and the ability to start spinning into our little lows that could...
Ophelia developed from a cluster of presistent thunderstors at the end of an old trough over the bahamas so if conditions are right,something could form off that cluster near PR.
I wish I could justify what I read this a.m. on the discussion, cause it changed with the 8:05 update, but it stated that the disturbance by the islands actually had two low level circulations...considering how big the blob is, I wouldn't put anything past it...wouldn't that be crazy, though, to get two t.s. out of one blob?!? Oh, I know one would weaken and/or destroy the other, but it would make for an even MORE rememberable season!!!!!
I'm waiting till we have TS Alpha....that would certainly sound strange..and it would be storm 22..if it happened.
Hfmy check out new GFS run, i have link below..it does show that possible system moving more towards Mexico..Large high pressure should dominate East Coast after Ophelia departs.
lets just hope that if our PR blob becomes a T.S. that it moves way quicker than Ophelia...those trough tropical storms seem to meander, not sure what they want to do and of course, if the blob by the islands gets named 1st, the PR one will be another woman.....go figure!
Weatherguy.. where's your link?
Speaking of blobs, what's with the enormous cluter of storm that's trailing right behind what could become TD17?

Will that cluster simply dissipate with time?
Here ya go..Link..Has alot of frames so if you have dial-up will take awhile..lol...
Latest animated GFS (850mb) Link
thx ; )
Fine,I think in five days Ophelia will still be some where between Virginai and NY.
Willjax, that has some dust with it, so its hard to say what that will do, surely take its time with the dust in the way...
afternonn, ya'll...any port orange, florida folks in here?
It does look like O is drifting a little southeast... what's left of her anyway. Looks like stormydee's going to have to put up with that old woman a little bit longer. Any thoughts on her doing another loop and heading south.
the area further behind is supposed to be td #17.. not sure about the blob near PR... locals (I'm in South FL) didn't say much... where are you Subtropic?
Stormydee- Joe Bastardi is talking about the PR disturbance, he thinks it may be over South Florida on Sunday/Monday.. he didn't say as what though, wave, depression. TS, hurricane... and then into the Gulf
gulf don't need more action...my offer still stands, send a cat3 my way just to keep it outta the gulf.
they stated O would hug the coast throughout the day, then pull off NE late tonight into tomorrow...I think that trough coming off the US will push her NE, however, anything is possible...but I don't think she'll come back south, besides, I am tired of her...I am ready for Phillipe and Rita and Stan...maybe they will all be friends out there at the same time. lol
i can almost see a rotation in the PR disturbance. But, I don't think it has all the conditions favorable for a quick development right now. Seems to have a lot of westerly shear (or nw shear). So, depending on how fast it moves (which the past few days, its been sitting there)...if they say maybe sun/mon it will effect so. FL, well, I think it will be very weak if it is a storm at all...but if it moves into the gulf...well, I just don't know, no computer models here, just guessing and observing.
maybe we'll have some good news today....
east coast florida
well, I gotta go, Im sure more bloggers will be on to answer any questions. I hope I wake up tomorrow and have a TD out there...or maybe two...or three! :-) goodnight.
i have a blog about the tropics.
Looks like O's starting to do a loop and head back into Hatteras.
Good Afternoon. I have been reading you all for about 2wks now. Heading to the OBX sunday, hopefully. Always interested in damage anyone hears about.
billsfaninsofla: Sure, another hurricane, just what I need. I came down to Ft. Lauderdale in a 15 foot travel trailer for a software contract just before Katrina breezed through. I had to evacuate for a couple of days since the trailer won't handle a hurricane. If another one comes this way, I'm outa here for a few.
Looks like Ophelia is going to be a Nor'easter.

Pretty impressive flare up east of PR..
Anyone know if they have power in Emerald Isle?

What part of the Outer Banks?
am910 where u from?
NJ SHore...hoping to get some Ophelia. Mabye next time around.
Bastardi is calling for you to get some of TD 17..
were gonna get rain, but only 10 mph winds ( according to Accuweather), I've haven't been through anything since Floyd.(Charley was to weak when it came our way)
NWS says were getting heavy rain and 15-mph winds on Friday and Saturday.
Mia NWS has now removed the "breezy" wording from the So Fl extended forecast. Based on the discussion, they have backed off of the assumption that the system near P.R. is going to develope and move west until the models get more of a concensus going. Now THAT'S more like them!
Avon area
Hi I just got a phone call from friend in Hatteras Village...I have a home by the ferry docks up a few streets...so far no damage...all is dry....the water has not come up yet...but its not dry in the marinas either..so hopefully the water will not rush back in...I am praying too!
nothing showing up on PR radar.......yet

sorry about that

I've come to OBX several times, but this is the first with a hurricane. Been glad for this blog so I get some idea of what's happening.
goodenough what street are you on in Hatteras Village?
Avon is probably OK right now. But the flooding could come from the sound side tonight or whenever O decides to move northward.
OMG that is strange,the are where jeff morrow was took quite a beating to category 1 ophelia,there were at least 3 homes destroyed and quite a few with significant damage,and no they were not mobile homes eather!It seemed that it was the combination of surge winds and waves did this damage,there is also extensive heavy rain flooding where as much as 12 to 15 inches fell near and along the NC coast.
On TWC is where I saw this at.
where is your house?
I have family near Teach's Lair, oceanside.
might be able to give you an idea of your street condition tomorrow after things settle down.
MyamuhNative its off of Woodall across from Teachs Lair on Sand Road. Where is your house? Thanks!
Shoals here...finally just got power back. whew what a day! Its still a blowing North 45-50 with gusts in the 60's easily rain off and on. When it switches to the NW tomorrow is when we will get it from the sound. No major damage, one trailer flipped in Hatteras...minor ocean overwash and no soundside flooding...let me rephrase that, NO soundside water as you can see from the photo I got earlier today at Hatteras Harbor Marina-the charter boats were high and dry! I know I have never seen it this low.

We never got a break today and probably won't until late friday.

woodall and empire gem.
she has been down to teach's Lair three times today and every thing is fine.
water hasn't come up yet that is noticeable.
she said she will go back down and take another look.
will let you know...
Stormdee - "I hope I wake up and have a TD or two or three tomorrow" Stormdee - let me guess --- age 15, residence Indiana, experience with mortality zero. We want no more TDs. And, I don't care what anyone says about me.
email me when you get a chance.
info in my blog

and MuffinAnne,
I heartily support you!
I am still cleaning up from Katrina's damage to my yard in South Dade and don't need any more damage.
MyamuhNative Many thanks just emailed you. Any info you have please send