Half way there

By: Dr. Jeff Masters , 4:05 PM GMT on September 10, 2005

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We're half way there. That's right, today is September 10, and that marks the half way point of hurricane season in the Atlantic. On average, half of all hurricanes and tropical storms occur after September 10. We still have a long way to go in what has already been the most destructive hurricane season on record.

What does the second half of hurricane season have in store for us? Well, after Ophelia departs, there is nothing brewing to take her place. The entire tropical Atlantic between Africa and the Lesser Antilles is covered with dry, dust-laden Saharan air that should suppress hurricane activity there. However, according to the September 2nd forecast issued by Dr. Bill Gray of Colorado State, tropical cyclone activity for the remainer of this hurricane season will be over 50% above average. The September-only forecast calls for five named storms and four hurricanes, with two of them major hurricanes. The October-only forecast calls for three named storms and two hurricanes with one of them a major hurricane. Normal activity for September-October is five named storms and 3.5 hurricanes, with one or two of them a major hurricane. So if you live on the coast, stock up on your hurricane supplies, review your evacuation options, and hang on for the second half of this unbelievable hurricane season of 2005.

Ophelia weakened to a tropical storm last night as the trough carrying it northeastward dumped dry air into her northwest side and attacked the west side with 20 knots of shearing winds. The trough has moved ahead of Ophelia this morning, and she is now slowing down and strengthening in response. The shear has fallen back to the 10 - 15 knots she has lived with most of her life, and the dry air is starting to mix out. The 10am EDT Air Force hurricane hunter flight found Ophelia's lowest pressure and strongest winds yet, 976 mb and 80 mph, repsectively. Long range radar out of Wilmington, NC is showing little change in what it can see of the northwestern portion of the storm, and little motion of the center.

Track forecast
Most of the major computer models show a track into South Carolina by Tuesday. The exceptions are the Canadian model, which calls for a Georgia landfall, and the NOGAPS model, which stalls Ophelia offshore for the next five days until finally bring her across Cape Hatteras, North Carolina on Friday. The official NHC forecast follows the consensus, bringing Ophelia ashore near Charleston, SC on Tuesday. The official NHC forecast has outperformed all the computer models so far for this storm, but keep in mind that the median track error for the NHC 3-day forecasts is about 230 miles, meaning that half of the time, the forecast is worse than that. All residents of the Georgia, South Carolina, and North Carolina coasts need to be prepared for what will most likely be a Category 1 or 2 hurricane, but could be a Category 3.


Figure 1. Average track error of official National Hurricane Center Forecasts (in nautical miles, multiply by 1.15 get get the result in miles). Image credit: Dr. Chris Landsea, NOAA/AOML Hurricane Research Division.

Intensity forecast
Shearing winds are expected to continue to affect Ophelia the next three days, limiting the amount of intensification that will occur. This shear will come from upper-level winds out of the west to southwest. Satellite images clearly show the effect of this shear on the hurricane--the southwest side of the storm has much reduced cloud coverage. On the plus side for the Ophelia, the counter-clockwise flow around an upper-level low to her southeast is beginning to provide an outflow channel to the south, something Ophelia has lacked her entire life. This improving outflow to the south is likely a big part of the reason for her return to hurricane strength today.

The computer models differ on how all these factors will affect Ophelia's intensity. The SHIPS model keeps her just below hurricane strength for the next three days, while the GFDL intensifies her to a Category 3 hurricane. The official NHC forecast calls for a strong Category 1 hurricane at landfall. I believe that given this storm's proven resiliency to shear, plus the opening of a new outflow channel to the south, Ophelia's intensity three days from now should be at least Category 2 and possibly Category 3. A stronger storm than that would be a major surprise.

Dr. Jeff Masters

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76. OldWorld
10:17 PM GMT on September 10, 2005
Not enough atmospheric junk out here.
Gimme gimme, USA landfall.
Must have your polycarbonate fix.
I'm going to pay.
And so too must you.

Please...It's not personal...I'm only trying to survive.

Yours truly,
Your GlobalWeatherSystem
75. killdevilmax
8:23 PM GMT on September 10, 2005
OBXER-

Check your email on this site.
Member Since: August 28, 2005 Posts: 0 Comments: 322
74. leftyy420
6:36 PM GMT on September 10, 2005
the ridge is building se from the north. she will be on the southern side of the ridge and how quickly the ridge moves se offshore will determine ophelias turn to the north and then ne. she will move west for sometime and turn nw and n than ne. we need to see how fast that ridge moves ofshore. most latest model runs show that ridge breaking down quickly and moving offshore rapidly. this is unlikley to happen as quick as they say. we need to watch the next couple model runs as we need run to run conscitency to determine her track
Member Since: August 24, 2005 Posts: 35 Comments: 1987
73. weatherwannabe
6:34 PM GMT on September 10, 2005
JeffMasters has a new post -
72. killdevilmax
6:32 PM GMT on September 10, 2005
Man I lay down for a few minutes and huh?? where is the west movement? Trying to catch up.
Member Since: August 28, 2005 Posts: 0 Comments: 322
71. TybeeIslandGA
6:31 PM GMT on September 10, 2005
Welcome SaintVitus...I know Wilmington Isl well. Actually, I just got back from there. We are watching this closley. Either way I think we will have some "weather" from the storm...but I don't think we will see the worst. You have picked the right place to follow it. There are SEVERAL people on this blog that KNOW what they are talking about. Stay here...follow advise...and you will be just fine. Welcome!!
70. leftyy420
6:25 PM GMT on September 10, 2005
sj gfs model run

Link
Member Since: August 24, 2005 Posts: 35 Comments: 1987
69. taco2me61
6:23 PM GMT on September 10, 2005
I was just wondering the High Pressure that is building in... Is the High coming from the west of Ophila and if so I know it will send her some to the south(how far not sure) then to the west in 2days to make the big O that all of us have stated a few days ago... what do yall think???
Member Since: July 7, 2005 Posts: 6 Comments: 3261
68. HillsboroughBay
6:16 PM GMT on September 10, 2005
St Vitus.

Best of luck. & be ready to duck.

you bring back memories of Thunderbolt. Looks like you are in the cone..Link
67. FBSCharleston
6:15 PM GMT on September 10, 2005
First, let me say I am new to this blog and as far as weather and tropical systems go I am an amatuer at the lowest rank. My wife says I am a repressed mertologist, but I am a horticulturist and avid weather interest goes with the job.

For some Charleston SC perspective, their is no mad rush for gas, supplies or other items here. I have been out several times today and no one is standing in line anywhere I have seen. All of us are taking prelim type preps, moving limbs and yard debris away from the house etc. The general attitude is that this one may hit Charelston, but it won't be very bad, at the least everyone is taking a wait and see attitude til tomorrow morning because of the uncertainity of the NHC tracks over the last 24 hours.

For what it is worth, my gut tells me it will make landfall somewhere near Charleston and be a strong hurricane. No Hugo like in 1989, but a strong cat 1 or low cat 2. Ophelia has just hung around too long to not be a serious problem, but this is based on intuition and not science.
66. mybahamas
6:14 PM GMT on September 10, 2005
the flip-flopping of some of these models has me as lost as a good idea at a filibuster :)
65. SirVivor
6:14 PM GMT on September 10, 2005
Dash, it had the same effect on me. I was there once after visting the Cape Fear/Wilmywood area. I stopped to get gas and needed to get som aspirin, but there was no way I was going to go inside any place there. It was just too surreal. If ever there was a place that screams for God to come in and wipe the slate clean with a major storm, it is this place. Like I said, it is so surreal it is liek something out of Hitchhiker's...or the Twilight Zone.

I hope the storm steers clear of Cape Fear and Wilmington. Very pictureseque and quaint. Also, Hollywood makes a lot of movies in Wilmington/Cape Fear (hence the nickname Wilmywood). However, as pretty as it is, it doesn't hold a candle to the Pensacola Beach to Panama City Beach stretch. Especially around Grayton, Seaside and Seagrove. County Roda 30-A in Walton County is well known for its ecclectic shops, great restaruants and gorgeous beaches. Plus the artist's enclave at Seaside is a wonderful escape. an dthen there is the carillon.... I'm homesick :-(
64. leftyy420
6:11 PM GMT on September 10, 2005
yeah this is a complicated forcast but all models have shufted after the rec model runs yesterday and again today but they all shifted back last night with the reconmodel runs. it is key that in forcastung u take not 1 model run but a couple of runs of that modle togther and lool for a concensus ion the model runs, run to run. a shift could only be temporary and with the next runs could shift back. the key will also be the model runs that will run at 8pm as they will include the recon data. once again u are looking for a run to run consitency not a single model run.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
63. dashwildwood
6:10 PM GMT on September 10, 2005
hawk didnt the models do this same thing yesterday during the same runs? i remember at one point yesterday the gfs had it going straight up the NC coast and the UKMet with it off the coast
62. StormJunkie
6:08 PM GMT on September 10, 2005
Hawk, can you give some expert opinion on the models? What are you seeing in WV, what do you take from Lefty's statements about the recon data being old, and what do you detect from pressure readings?
Member Since: August 17, 2005 Posts: 26 Comments: 16874
61. Hawkeyewx
6:05 PM GMT on September 10, 2005
Link

The 12z UKMET even keeps Ophelia well offshore permanently. The morning models all seem to have completely lost the westward movement.
Member Since: July 5, 2005 Posts: 2 Comments: 1924
60. dashwildwood
6:05 PM GMT on September 10, 2005
Sir, i have only stopped at south of the border once, to be quite honest the place scares me
59. dashwildwood
6:04 PM GMT on September 10, 2005
HPC says the reasons for the north-eastward shift in the models is because of teleconnections and the current teleconnections favoring higher heights in the eastern us which block ophelia from making alot of westward progress......therefore the data from the aircraft will be very important to see if this comes true in a few days
58. Weatherwatcher007
6:00 PM GMT on September 10, 2005
Hawkeyewx, where did you get that information?
57. lowpressure
6:00 PM GMT on September 10, 2005
thanks lefty,, i trust your words,, i was just looking for some learnen...lol
56. SirVivor
5:58 PM GMT on September 10, 2005
Fireworks arent the only illegal things you can get there. My favorite 'Pedro's shop' is Pedro's Trucker's Showers and Nudie Bar...which is between Pedro's Fireworks and Pedro's Drugstore.....and across from Pedro's Gas Station and Pedro's Grocery Store.
55. Weatherwatcher007
5:58 PM GMT on September 10, 2005
So lefty, I see the public advisory saying the winds are still 80mph. She looks like she may be strenghtining. 90kts at the surface?
54. dashwildwood
5:55 PM GMT on September 10, 2005
South of the Border is a great place to get illegal fireworks
53. leftyy420
5:54 PM GMT on September 10, 2005
low i ma not sure why they jump but as u get less reliable data and less info to enter in a complex situation like this the models will jump back ands forth. i told u to watch lasts nights model runs and to watch tonights model runs as they will have the best data. also if ur in the possible impact area from the nhc make plans based on that not the model runs u see. the key to model runs is run to run consitency and of they keep this track for the next 2 runs even with the recon model data than u will see a major shift in the forcast track
Member Since: August 24, 2005 Posts: 35 Comments: 1987
52. Hawkeyewx
5:53 PM GMT on September 10, 2005
12z GFDL has also shifted east and says Wilmington, NC is now the landfall spot.

Regardless of the track, Ophelia is so full of dry air I think it will struggle to gain much more strength. The continuing shear will not help the intensity either.
Member Since: July 5, 2005 Posts: 2 Comments: 1924
51. leftyy420
5:50 PM GMT on September 10, 2005
new vortex is out. her winds have picked up and look to be around 90kts

pressure is 977mb


URNT12 KNHC 101742
VORTEX DATA MESSAGE
A. 10/17:17:50Z
B. 31 deg 40 min N
076 deg 14 min W
C. 700 mb 2903 m
D. 90 kt
E. 130 deg 029 nm
F. 223 deg 077 kt
G. 130 deg 040 nm
H. 977 mb
I. 9 C/ 3046 m
J. 15 C/ 3042 m
K. 14 C/ NA
L. CLOSED WALL
M. C34
N. 12345/ 7
O. 0.02 / 1 nm
P. AF300 1216A OPHELIA OB 19
MAX FL WIND 77 KT SE QUAD 17:05:50 Z
EXCELLENT LOW LEVEL BANDING VISUALLY AND ON RADAR
SE EYEWALL DROPSONDE MAX WIND 210/85 KTS AT 944 MB


Member Since: August 24, 2005 Posts: 35 Comments: 1987
50. SirVivor
5:50 PM GMT on September 10, 2005
Please God...let this one hit Pedro's South of the Border which is located on the SC side of the border between the Carolinas. That 'town' is just too surreal to exist anywhere except maybe in the Hitchhiker's Guide to the Galaxy (Don't panic, and don't forget your towel!). I can just see that giant sombrero flying through the air like a Mexican UFO.....Bright yellow with red zigzag trim around the brim....and big enough to house Pedro and all his cousins and "nieces".
49. lowpressure
5:50 PM GMT on September 10, 2005
Lefty, i fell ya on the mosel runs last night being the most acc. and that the gfdl has been sticking to its guns with the exception of the north jogs, however not to say by any means it will turn more north, but the jumping around in the gfs and some other modles always seem to jump back to almost the same spot on the outer banks, then they go back south.. but that same spot jump is what i want to study to try to figure out why... could you explain if its just someting like maybe they are reading the high in two diff ways and they cant decide between one of the two or well what do you think... i know they will jump,, i just think its strang about that spott....sorry so long alll...lol im learning here...lol
48. CoastalNC
5:40 PM GMT on September 10, 2005
Well, looks like I'm going to drive down to Topsail Island NC and board the place up and take in all the furniture off the screened in porch and generally batten down the hatches, then drive back inland to Durham NC.

*heavy sigh*

(This will probably insure no direct hit to the southern coast of NC by Ophelia. LOL!)

47. leftyy420
5:36 PM GMT on September 10, 2005
at this point the most reliable model runs were the 2 run last night with the recon data. they all showed a landfall near charleston. now tonoght the next model runs will include more recon data but expect a shift in runs throuout the day as the models have less data to draw from. eight now ur best bet in the nhc forcast and if u live noear the ga/sc coast thiru nc/sc coast u need to prepare for period of time to have hurricane force winds and torrential rains. at this point its splitting hairs over her exact landfall. she will have a big wind radii effect a large area. the eye will probly come on shore around charelston or myrtle beach.

she as already slowed and will begin to turn west in the next few hours. landfall is in 48 or 54 hours and conditions will decline well in advance of the cenetr. so by tomm afternoon most of the area i described will experince ts winds or gusts. make plans now as time is running out
Member Since: August 24, 2005 Posts: 35 Comments: 1987
45. billsfaninsofla
5:32 PM GMT on September 10, 2005
welcome SaintVitus... best of luck to you, Tybee and anyone else in the area..
Member Since: September 5, 2005 Posts: 0 Comments: 5800
44. SaintVitus
5:27 PM GMT on September 10, 2005
I've been lurking here, and now I'm jumping in. My handle is "Saint Vitus," because he's the patron saint of protection from storms. I live on Wilmington Island, GA, near Savannah. (Tybee, if you look out your window and wave, I might see you!)
Thanks for all the helpful insights, folks.
Where can I go online to find out the degree of damage expected for a particular area (Chatham County, GA, and especially the coastal islands) given a certain intensity of the storm (Cat 1, etc.)?
Thanks!
43. lowpressure
5:25 PM GMT on September 10, 2005
does anybody have a a concern for the nogaps ,,gfs,, uk all taking this north towards the outerbanks all almost the same track.lefty,,,007???????
42. TAC9
5:23 PM GMT on September 10, 2005
I know it's early but does anyone think Southern Massachusetts will be impacted?
41. Weatherwatcher007
5:15 PM GMT on September 10, 2005
Don't know what this link will do for ya. . .

Link
40. Weatherwatcher007
5:13 PM GMT on September 10, 2005
I don't know. . . Those models. . . I don't know.
39. Weatherwatcher007
5:09 PM GMT on September 10, 2005
How possible is that hawkeyewx?
38. Weatherwatcher007
5:08 PM GMT on September 10, 2005
37. Hawkeyewx
5:07 PM GMT on September 10, 2005
12z GFS, NOGAPS, and UKMET have all given up on the idea of turning Ophelia to the west. They now say the storm will pretty much just stall for a couple days and then move north to brush the outer banks. You can see on the models that not only do they forecast a strong high to build north of the storm, but they think the high will also wrap around to the west of the storm as well, effectively keeping it from moving west at all. They move the storm north and northeast once the next trough races into the area in a few days and breaks down the ridge.
Member Since: July 5, 2005 Posts: 2 Comments: 1924
36. StormJunkie
5:06 PM GMT on September 10, 2005
She a blower and soaker either way 007!
Member Since: August 17, 2005 Posts: 26 Comments: 16874
35. Weatherwatcher007
5:03 PM GMT on September 10, 2005
I like this link. . .

Link

I think the wind field will expand farther inland than that says and I think there MAY be some 50kt winds in Columbia if it moves farther inland.
34. leftyy420
5:02 PM GMT on September 10, 2005
sj i will be in a lobby in a few
Member Since: August 24, 2005 Posts: 35 Comments: 1987
33. TybeeIslandGA
5:01 PM GMT on September 10, 2005
Alright. Thanks for the info SJ! Will you guys be here most of the day? I want to keep an eye on it for SURE. Though it looks north of here, this Island can't take a CAT 1 without being under water...much less a 2 or 3. Will you all be here from time to time?
32. leftyy420
5:00 PM GMT on September 10, 2005
duuno, straing cat to a minimakl cat3 is my best guess. she has limited time over water. she will start to move west soon. i'll be leaving mt self in a few hours to go to sc when my wife gets home from work
Member Since: August 24, 2005 Posts: 35 Comments: 1987
30. POTMROTS
4:59 PM GMT on September 10, 2005
Any thoughts on the South movement sj mentioned?
29. leftyy420
4:59 PM GMT on September 10, 2005
yes weather i feel the nhc tyrack is a litle north but the best guess. watches have nor been issued. hurricane wacthes
Member Since: August 24, 2005 Posts: 35 Comments: 1987
28. HillsboroughBay
4:59 PM GMT on September 10, 2005
"The official NHC forecast has outperformed all the computer models so far for this storm,"

Interesting....TORNADOES...
ISOLATED TORNADOES ARE POSSIBLE NORTH OF WHERE THE STORM CENTER
MOVES ASHORE. THIS IS MOST LIKELY NEAR AND TO THE NORTH OF
CHARLESTON.

This was in the Charleston NHC Hurricane statement.
& worth repeating.

Do they have good warnings for such events on TV in the SOUTH CAROLINA/\ GEORGIA area.?

I Know they do here in Florida. Not so in NY even though they get Nor-Easters that Rival short lived Hurricanes.

They do get Tornado's. I saw 260 MPH recorded in Matittuck Long Island as a Nado off to the side of a summer squall!

Excellent Post SJ


27. Weatherwatcher007
4:58 PM GMT on September 10, 2005
Hey lefty,

What do you think the intensity will be at landfall?
26. killdevilmax
4:57 PM GMT on September 10, 2005
IR enhanced is showing it getting a big gulp of dry air from the west but convective bands are starting to show and wrap north and south.
Member Since: August 28, 2005 Posts: 0 Comments: 322

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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