Category 3 Hurricane Earl pounding northern Lesser Antilles and Puerto Rico

By: Dr. Jeff Masters , 2:40 PM GMT on August 30, 2010

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An intensifying Hurricane Earl is pounding Puerto Rico and northern Lesser Antilles Islands with heavy rain and high winds this morning. The eye of Earl passed just north of Anguilla at 9am EDT, and Juliana airport on neighboring St. Martin Island recorded sustained winds of 47 mph, gusting to 68 mph at 8am EDT before going silent. An Air Force Hurricane Hunter aircraft currently in Earl just found a central pressure of 960 mb at 9:42 am EDT. This is a significant drop of 25 mb in 25 hours. Top flight level winds at 10,000 feet seen by the Air Force aircraft were 128 mph. Using the usual rule of thumb that the surface winds are 90% of the 10,000 foot flight level winds gives one surface winds of 115 mph, which is right at the border of Cat 2/ Cat 3 strength. Top winds seen at the surface by the Air Force's SFMR instrument were lower, 104 mph. Recent satellite imagery shows that Earl is not perfectly symmetrical--there is still fewer heavy thunderstorms on the hurricane's north side, suggesting that upper-level northerly winds are bringing 5 - 10 knots of wind shear to the storm.


Figure 1. Radar image of Earl taken at 7am EDT 8/30/10 from the St. Maarten radar. Image credit: Meteorological Service of the Netherlands Antilles and Aruba.

Outlook for the Caribbean islands today
Latest radar animations out of Puerto Rico and St. Marten show that the eye of Earl is on track to pass just to the northeast of the islands of Anguilla, St. Maarten, and The Settlement in the British Virgin Islands today. The periphery of Earl's southern eyewall will probably bring Category 1 hurricane conditions to some of these islands today. NHC is giving its highest odds for hurricane-force winds to Saint Maarten--a 99% chance. These odds are 4% for St. Thomas in the Virgin Islands, and 2% for San Juan, Puerto Rico. The main threat to Puerto Rico will be heavy rains--up to eight inches in isolated areas. Earl's rains, in addition to causing flooding and dangerous landslides, will also help alleviate drought conditions that have affected many of the islands this year.

Intensity forecast for Earl
Wind shear as diagnosed by the latest SHIPS model forecast is nearly non-existent over Earl--just 3 knots--put is probably higher than that, based on the fact that the northern portion of Earl cloud pattern is ragged. Further evidence of this is the fact that Earl's eyewall had a gap in its west side, according to the latest report from the Hurricane Hunters. Ocean temperatures are a near-record 30°C, and very warm waters extend to great depth, resulting in a total ocean heat content highly favorable for rapid intensification. These nearly ideal conditions for intensification should bring Earl to Category 4 strength by Tuesday morning, and Category 5 is not out of the question. Earl should be able to maintain major hurricane status through Thursday, when it will make its closest approach to North Carolina. Sea surface temperatures are very warm, 29°C, along the U.S. East Coast, and wind shear is expected to remain low through Thursday. By Friday, when Earl will be making its closest approach to New England, wind shear will rise to a high 20 - 30 knots and ocean temperatures will plunge to 20°C, resulting in considerable weakening. Earl will still probably be a Category 2 hurricane on Friday, when it could potentially make landfall in Massachusetts or Nova Scotia, Canada.


Figure 2. Swath of surface winds from Earl predicted by the 2am EDT Monday August 30, 2010 run of NOAA's GFDL model. Hurricane force winds (yellow colors, 64 kt and above) are predicted to stay off the coast and tropical storm force winds (light green colors, 34 knots and above) are predicted to stay off the U.S. coast, but affect the coast of Canada. Image credit: Morris Bender, NOAA/GFDL.

Track forecast for Earl
Once Earl passes the Lesser Antilles, steering currents favor a northwesterly course towards North Carolina. History suggests that a storm in Earl's current location has a 25% chance of making landfall on the U.S. East Coast, and Earl's chances of making a U.S. landfall are probably close to that. None of the computer models show Earl hitting the U.S., but the storm will likely come uncomfortably close to North Carolina's Outer Banks and to Massachusetts. The latest set of model runs (2am EDT, or 6Z) project Earl will miss North Carolina by 200 - 300 miles on Thursday, and Massachusetts by a similar distance on Friday. Keep in mind that the average error in a 4 - 5 day NHC forecast is 200 - 300 miles, so the East Coast cannot breathe easily yet. The Outer Banks of North Carolina and Cape Cod, Massachusetts are both at the edge of the cone of uncertainty. NHC is giving Cape Hatteras a 9% chance of receiving hurricane force winds. These odds are 14% for Nantucket, 4% for Boston, and 2% for New York City. The main determinant of whether Earl hits the U.S. or not is a strong trough of low pressure predicted to move off the U.S. East Coast Friday. This trough, if it develops as predicted, should be strong enough to recurve Earl out to sea late in the week, with the storm just missing landfall in the U.S., but possibly making landfall in Nova Scotia, Canada.

Regardless of Earl's exact track, the U.S. East Coast can expect a long period of high waves beginning on Thursday. Significant beach erosion and dangerous rip current will be the rule, due to waves that will reach 10 - 15 feet in offshore waters (Figure 3.)


Figure 3. Wave forecast for 8am Friday, September 3, 2010, as produced by the 8pm EDT August 29 run of NOAA's Wavewatch III model. The model is predicting waves of 4 - 5 meters (13 - 16 feet) in the offshore waters from North Carolina to New Jersey.

Hurricane History for the northern Lesser Antilles
The last Cape Verdes-type hurricane to affect the Barbuda and the surrounding northern Lesser Antilles Islands was Hurricane Debby of 2000, which passed over the islands on August 28 as a Category 1 hurricane. Damage was less than $1 million, and no fatalities were reported. The last hurricane of any kind to pass through the northern Lesser Antilles Islands was Category 4 Hurricane Omar, on October 16, 2008. Omar took an unusual track, moving towards the northeast, and the storm's eyewall missed all of the islands. Omar did $80 million in damage to the Caribbean, mainly on the islands of Antigua, Barbuda, Dominica, the SSS Islands (Saba, St. Eustatius, and St. Maarten), and the U.S. Virgin Islands. No direct deaths were attributed to Omar, and the name Omar was not retired from the 6-year rotating list of hurricane names.

Links to track Earl
Wundermap of the northern Lesser Antilles Islands
Long range radar out of San Juan, Puerto Rico
Visible rapid scan satellite loop

97L
The tropical wave (Invest 97L) now 1000 miles east of the Lesser Antilles Islands has a well-defined surface circulation and enough heavy thunderstorms to be classified as a tropical depression, if it can maintain that state for another six or so hours. Satellite loops show the surface circulation clearly, but also that heavy thunderstorm activity has been slow to build. The storm is experiencing low wind shear of less than 5 knots, and is over warm 29°C waters. The main impediment to development continues to be dry air associated with the Saharan Air Layer (SAL) surrounding the storm. The latest SHIPS model forecast calls for shear to stay in the low range, 5 - 10 knots, through Tuesday, and this should allow 97L to organize into a tropical depression today or Tuesday. NHC is giving 97L a 90% chance of developing into a tropical depression by Wednesday.

97L is moving quickly to the west, at about 20 mph. This means it is catching up to Earl, which has slowed down to 14 mph. By Tuesday night, Earl is expected to be a large and powerful major hurricane with a well-developed upper-level outflow channel heading clockwise out from Earl's center at high altitudes. These strong upper-level winds will bring high levels of wind shear, 20 - 30 knots, to 97L, and probably arrest the storm's development. The most likely scenario depicted in the computer models is for 97L to be drawn into the low pressure wake of Earl and pass to the northeast of the Lesser Antilles. Earl would then eventually destroy 97L through high wind shear, and by robbing the storm of its moisture. An alternative scenario is that 97L will stay far enough away from Earl that it will be able to pass through the northern Lesser Antilles islands as a tropical storm on Wednesday and Thursday, then bend northwestwards to potentially threaten the Bahamas and U.S. East Coast. There is a very high degree of uncertainty on what may happen to 97L. History suggests that a storm in 97L's current location has a 25% chance of making landfall on the U.S. East Coast.


Figure 4. Morning satellite image of 97L.

Danielle
Hurricane Danielle is on its way to oblivion over the cold North Atlantic waters, and is only of concern to shipping interests.

Elsewhere in the Tropics
Over in the Western Pacific, tropical cyclone activity is ramping up, with two named storms expected to affect land this week. As is typical in a La Niña year, these storms have developed close to mainland Asia, and don't have a lot of time over water to intensify into strong typhoons. The storm of most concern is Typhoon Kompasu, which is expected to hit Okinawa today and recurve northward into Korea on Thursday. It now appears the Kompasu will not have major impacts on China's largest city, Shanghai. In the South China Sea, the fearsome sounding Tropical Storm Lionrock is forecast to hit the Chinese coast near Hong Kong on Tuesday, but is not predicted to develop into a typhoon.

The GFS model is predicting formation of a tropical depression off the coast of Africa about seven days from now.

Jeff Masters

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Post 357, it has never been going NNW, get your directions straight. Its closer to WNW, not a degree or two from NNW!
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Will the florida coastline feel any wave effect from Hurricane Earl or is he too far out?
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Hi All!! Can someone update me on the current conditions in St. Thomas. My mom is there and I have been unable to reach her......by the way I live on the OBX of North Carolina......
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Quoting rwdobson:


Actually it's the opposite. A stronger hurricane is pulled northward more easily.


Almost true. When a hurricane reaches upper end CAT4 and CAT5 wind speed and structure they tend to turn less and slower due to their own gyroscopic pressures. They do turn, but not as easily.
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Quoting FunkStorm:


But your also not talking craziness.


yeah that's quite true
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Quoting Abacosurf:


The scary part to me is the 30 mile error they have made in just 3 hours.

The last advisory took it over the 65 at the 20.

Now it is passing the 65 at 19.5.

It's likely going to pass 10 miles south of that point too.
I had mentioned last night that Earl really needed to gain a lot of lattitude before 65 W. Now Earl is still not beyond 20 N and givin the more favorable conditions for strengthening, the trac will change again. Major hurricanes really get tricky bc they dont always go poleward and this storm now could go due w more so than nw and may not turn as n esepecially if the trof stalls out.
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Quoting katrinakat5:
ok i will try this again dangerous hurricane earl is heading on a west to wnw course with wobbles to the south at times...it sstill hasnt climed to 19 north yet...the high to the north of ear and steering him is grwing stronger and the weakness has almost filled back in..this is keeping earl on that westerly component ...the trof that is supposed to turn earl is a very shallow one ..it will do very little to earl in regards to steering him..the bottom line the most important factoe is ear has not yet made the turn and and watches are already out for the southern bahamas..the NHC has not had a good handle on earl since the beginning..it was going north of the islands and then pass 100 miles n of puerto rico ...not to mention the RIT of earl...so people im just saying you in sou fla could be dealing with a cat 5 breathing down your neck if earl does not turn by 66west...you see what puerto rico is going through now according to the NHC that would never happen...so people in sou fla wise up be alert and be ready for a cat 5 named earl..


StormTop,
It has been 5 years since you did a correct forcast...I'm not saying you are right or wrong here because we have yet to see that NE turn...but you were correct with Katrina when everyone else was wrong.

I am in Ft Lauderdale and we are mostly prepared for the season, just always those last minute items...but I'm just not worried about Earl yet for South Florida.
But stranger things have happened.
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From a newbie/lurker.....my take on KatrinaKat is the same as the bedtime story i read my daughter.....Chicken Little. My preference falls to the ones who make statements and provide verifying data to back it up. Back behind the bushes i goooooooo.........
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000
WTNT52 KNHC 301556
TCEAT2
HURRICANE EARL TROPICAL CYCLONE POSITION ESTIMATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
1200 PM AST MON AUG 30 2010

AT 12 PM AST THE CENTER OF HURRICANE EARL WAS ESTIMATED FROM SAN
JUAN DOPPLER RADAR NEAR LATITUDE 18.8 NORTH...LONGITUDE 63.7 WEST
OR ABOUT 90 MILES...145 KM EAST-NORTHEAST OF ST. THOMAS AND 160
MILES...255 KM EAST OF SAN JUAN PUERTO RICO.

$$
FORECASTER BROWN/BERG
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.
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I just know that our Labor weekend plans are ruined here in Ft Lauderdale. Was planning a weekend at the beach but the rip currents are CRAZY here now w/ Danielle and Earl coming by....blah!!!
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would you guys please quit quoting that bozo. He gets off on you guys quoting him and arguing with him. He is nothing short of pathetic.
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366. Vero1
Quoting latrendsetter:
Its Official, All tv stations in south florida are now reporting if that earl does not take that nw track and not just a jog to the nw within 24 hours that south florida will be under the gun. There saying for everyone to pay attention for the next 24 hours to see what develops.

*****VOICE YOUR OPINIONS************





I agree
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Looks like Earl might have finally made the NW turn looking at last few loops.
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Quoting IamTheCanesSurfer:


It is turning as we chat here. gee


Well let's make sure that is a real turn and not a wobble, shall we?
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting shawn26:
Levi says Florida is not a threat at all and I trust what he says.


I agree PLUS add the NHC to the list as well saying it's not hitting SFL and that is where I live.
Everyone just needs to sit back and if you are in the forecast cone, just monitor the track.
Don't freak and get ready for a storm. Nothin' else you can do....
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Quoting FunkStorm:


Where's your forecast room?

Answer: Moms Basement
Tools: Ruler and a kite
Brains: None
Forecast skill: Lower than 0%
Accuracy: See forecast skill



just saying.... I live in my basement at my house haha
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Levi is not an expert, but he is extremely intelligent on this stuff. These storms obviously can so anything they want to.
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Its Official, All tv stations in south florida are now reporting if that earl does not take that nw track and not just a jog to the nw within 24 hours that south florida will be under the gun. There saying for everyone to pay attention for the next 24 hours to see what develops.

*****VOICE YOUR OPINIONS************



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Quoting kwgirl:
Anytime there is a storm in the Caribbean or Atlantic, especially where Earl is right now, it can be a threat to So. Fl. I call that area the "slot". I just hope that if it heads for Florida, that it interacts with some mountains before hand (not that I am wishing anything on the islands, but my expierience has been only moutainous regions can knock down a large hurricane). We all need to watch where this is going. I think I will go to the Grotto tonight to light a candle. Everyone keep safe!
That was exactly what I posted a few posts back. they are all looking at that 285 degree heading
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HurricaneEarl's heading had turned northward to 1.8degrees north of WestNorthWest
from its previous heading of 10.6degrees west of WestNorthWest
H.Earl's average speed moving between its last 2 reported positions was ~16.7mph(~26.8km/h)

29Aug . 03pmGMT - - 17.2n58.4w - - 75mph - - - 985mb - -NHC.Adv. #17
29Aug . 06pmGMT - - 17.4n58.9w - - 75mph - - - 978mb - - #17A
29Aug . 09pmGMT - - 17.6n59.5w - - 85mph - - - 978mb - - #18
30Aug . 12amGMT - - 17.7n60.3w - - 85mph - - - 972mb - - #18A
30Aug . 03amGMT - - 17.9n61.1w - 100mph - - - 971mb - - #19
30Aug . 06amGMT - - 18.1n61.8w - 100mph - - - 969mb - - #19A
30Aug . 09amGMT - - 18.3n62.4w - 105mph - - - 969mb - - #20
30Aug . 12pmGMT - - 18.4n62.9w - 110mph - - - 965mb - - #20A
H.Earl becomes Cat.3
30Aug . 03pmGMT - - 18.7n63.6w - 120mph - - - 960mb - - #21

Copy&paste 17.2n58.4w, 17.4n58.9w, 17.6n59.5w, 17.7n60.3w, 17.9n61.1w-18.1n61.8w, 18.1n61.8w-18.3n62.4w, 18.3n62.4w-18.4n62.9w, 18.4n62.9w-18.7n63.6w, ngd, gdt, myg, pbi, 18.7n63.6w-22.4n73.0w into the GreatCircleMapper for a look at the last 12hours.

H.Earl's center had made a close passage north of or had hit northernAnguilla.
Using straightline projection upon the speed&heading averaged
over the 3hours spanning the last two reported positions:
~38hours from now to Mayaguana, Bahamas after passing*north of Anegada,BritishVirginIslands and closely passing north of the Turks&Caicos

* though close enough that storm surge and storm waves will probably inundate all of the buildings there. There are no safe heights on Anegada.
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Quoting bassis:


Good-bye!


+1
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Quoting kshipre1:
97L looks questionable right now. Maybe a TD or TS at best but not sure if anything more than that


Right now, Earl's outflow is inhibiting development, just as Danielle inhibited organization of Earl.

Once clear of Earl, it could develop rapidly...
Member Since: June 20, 2005 Posts: 22 Comments: 1050
12 z gfs west of the nhc forcast track and west of the 6z run at 54 hours anyway
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:(

yes, that was supposed to be 8 Sep...
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Quoting katrinakat5:
ok i will try this again dangerous hurricane earl is heading on a west to wnw course with wobbles to the south at times...it sstill hasnt climed to 19 north yet...the high to the north of ear and steering him is grwing stronger and the weakness has almost filled back in..this is keeping earl on that westerly component ...the trof that is supposed to turn earl is a very shallow one ..it will do very little to earl in regards to steering him..the bottom line the most important factoe is ear has not yet made the turn and and watches are already out for the southern bahamas..the NHC has not had a good handle on earl since the beginning..it was going north of the islands and then pass 100 miles n of puerto rico ...not to mention the RIT of earl...so people im just saying you in sou fla could be dealing with a cat 5 breathing down your neck if earl does not turn by 66west...you see what puerto rico is going through now according to the NHC that would never happen...so people in sou fla wise up be alert and be ready for a cat 5 named earl..


It is turning as we chat here. gee
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Quoting latrendsetter:
WOW, channel 7 in fort lauderdale weather man said if earl does not start going more north in the next 24 hours or making that turn, then south florida could be under the gun. There saying for people to be prepared. So i guess the next 24 hours is crucall for south florida.


******VOIcE YOUR OPINIONS ON THIS****************
Anytime there is a storm in the Caribbean or Atlantic, especially where Earl is right now, it can be a threat to So. Fl. I call that area the "slot". I just hope that if it heads for Florida, that it interacts with some mountains before hand (not that I am wishing anything on the islands, but my expierience has been only moutainous regions can knock down a large hurricane). We all need to watch where this is going. I think I will go to the Grotto tonight to light a candle. Everyone keep safe!
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54
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97L looks questionable right now. Maybe a TD or TS at best but not sure if anything more than that
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Definately agree with you. 8 Oct is way too far out, but I'm still learning and like to compare the model runs.

I feel pretty safe when they run a storm in my area that far out because 99% of the time that's where it WON'T be! :)
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At 11:56Z, the central pressure was 964MB. So in less than six hours, it's fallen about 9MB - and 5MB in just the last hour and a half.

It ain't the textbook definition of rapid intensification just yet - the storm has dropped 30MB in 24 hours, well short of the required 42MB. But I'm concerned that now that it has finally filled in its eyewall and improved its organization, it may have commenced rapidly deepening its pressure. The water it's passing over must be nice for swimming, but it's uncomfortably hot for hurricanes.

The models are fairly good at spotting storms that become majors. But their record is much spottier at predicting just how large major storms are likely to become. If those 118kt winds pan out, and weren't just an errant reading, then this storm will already have exceeded the peak intensity forecast by three of the five models on their 12Z run. But it would be right in line with the truly frightening SHIPS forecast, which peaks the storm at a scary 135kts, and keeps it a major much longer than the others.
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The new GFS is still showing heights over the eastern US in the 1018-1020 range 48+ hours out. It'll take a very fast-moving trough to break down those heights in time to recurve Earl before threatening NC.
Member Since: September 22, 2005 Posts: 18 Comments: 2317
Quoting FunkStorm:


Which means nothing, its a hurricane, they change course all the time.

Levi is no expert.


Well if he's no expert...he's the closest thing on this blog to being one...and that is a fact..

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St. Maarten Radar

Link
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339. NJ2S
Quoting Relix:
Toa Baja PR: Heavy heavy 35+mph gusts winds at a constant 25mph or so. Heavy squalls. We still have power here in Levittown.


im from campanilla/candelaria :) live in NJ now tho
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Quoting clwstmchasr:
Looking at the center fixes on Google Earth, Earl has move in a direction of about 303 degrees. Wobble or the NW predicted motion?
looks like he is beginning the turn as expected to me also.
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Hello everyone:

I raise a question about invest 97 L.

Are we getting better I think they look pretty today?.

If you observe from the animations, you can see that was quite reduced dry air, while the convention is improving little by little with the passage of time.

If this trend continues remains very good, very probable invest will be declared the 97 L, as tropical depression 08 - L.

Greetings from Spain.
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Quoting Flyairbird:
Does it really matter if a house landed on half of your house or all of it?


Matter if the eyewall cross your house - trust me :)
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Here's a link to a webcam at Levrick Bay on Virgin Gorda, BVI. The southern eyewall of Earl will be passing over or just north of Virgin Gorda in a few hours. The camera isn't aimed terribly well, but you can still see the effects of the storm...so long as the power lasts.

The image updates every fiften minutes.

Leverick Bay HOA webcam
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Quoting BDAwx:
What kind of storm surge would you get from a category 2 hurricane going up the Bay of Fundy?

It would definitely be something to see! Due to time constraints (I was traveling with family) I didn't get to watch the tide come in when I was there. Hard to imagine looking at the low tide perspective.
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Quoting FunkStorm:


Which means nothing, its a hurricane, they change course all the time.

Levi is no expert.


Good-bye!
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About

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