Hurricane warnings for North Carolina for Category 3 Earl

By: Dr. Jeff Masters , 3:21 PM GMT on September 01, 2010

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Hurricane warnings are flying for the coast of North Carolina, as Hurricane Earl chugs to the northwest at 17 mph. Earl has weakened some over the past day, thanks to an eyewall replacement cycle and some dry air that got wrapped into the core of the storm. Earl's eye made a direct hit on NOAA buoy 41046 at 4am EDT this morning. The buoy recorded a surface pressure of 943 mb, exactly what the Hurricane Hunters were estimating. The buoy measured winds in the eyewall of 76 mph, gusting to 96 mph. The peak winds of Earl were stronger than this, though, since the buoy only reported measurements once per hour, which is not a fine enough resolution to see the peak winds. The buoy is also located at a height of 5 meters, which is less than the standard ten meter height used to do wind measurements, so an additional upward adjustment needs to be made. Peak waves at the buoy were a remarkable 49 feet.

A recent microwave "radar in space" image (Figure 2) shows that dry air has spiraled into the core of Earl, knocking a gap into the southern eyewall. The latest 9am EDT report from the Hurricane Hunters confirmed that the southwest portion of the eyewall was missing. Top winds seen by the Hurricane Hunters were only Category 2 strength, and Earl may be weaker than the stated 125 mph winds in the 11am NHC advisory.


Figure 1. Image of Hurricane Earl taken by astronaut Douglas Wheelock aboard the International Space Station on Tuesday, Aug. 31, 2010.

>
Figure 2. Microwave "radar in space" image of Hurricane Earl taken at 6:45am EDT Wednesday, September 1, 2010. The southern portion of Earl's eyewall was missing, thanks to a slug of dry air (blue colors) that had spiraled into Earl's core.

Intensity forecast for Earl
Recent satellite loops show that upper level outflow is good to the north and east of Earl, but is poor on the southwest side. The latest SHIPS model forecast shows that this is because upper level winds out of the southwest are creating 15 - 20 knots of wind shear on Earl's southwest side. The winds are from a trough of low pressure to Earl's west. This trough is forecast to weaken and move to the west away from Earl, which should reduce the shear to 10 - 15 knots by Thursday morning. If true, the relaxation in shear may give Earl enough time to mix out the dry air it ingested and regain its previous 135 mph Category 4 intensity. Water vapor satellite loops, though, show there is still plenty of dry air on Earl's west side that could potentially wrap into the storm if there is enough wind shear to drive it into Earl's circulation. Ocean temperatures are still very high, a near-record 29.5 - 30°C, and very warm waters extend to great depth, resulting in a total ocean heat content favorable for intensification. It is likely Earl will be a Category 2 or 3 hurricane at its closest approach to North Carolina Thursday night and Friday morning, with a small chance it will be at Category 4 strength. By Friday night, 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 1 or 2 hurricane on Friday night, when it could potentially make landfall in Massachusetts. Earl is more likely to be a strong tropical storm or weak Category 1 hurricane on Saturday morning, when it could potentially make landfall in Maine or Nova Scotia, Canada.

Impact of Earl on North Carolina
The latest set of computer models runs from 2am EDT (6Z) this morning are very similar to the previous set of runs. The NOGAPS model brings Earl closest to the coast, predicting the west eyewall of the the hurricane will hit the Outer Banks of North Carolina near 2am Friday. If this track verifies, a period of 40+ mph winds will affect coastal North Carolina for a period of 12 - 18 hours beginning at about 6pm EDT Thursday night. Earl's expected radius of hurricane-force winds of 60 miles to the west will bring hurricane conditions as far west as Morehead City and Elizabeth City in North Carolina. Earl's radius of tropical storm-force winds to the west, over land, will probably be about 150 miles, so locations from Wilmington to Norfolk could see sustained winds of 40 mph in this worst-case model scenario. Storm surge would not be significant along the North Carolina coast facing the open ocean, since winds would be offshore. However, a significant storm surge of 3 - 6 feet could occur in Pamlico Sound, due to strong west to north winds. Coastal Highway 12 out of the Outer Banks would likely be blocked by sand and debris or washed out, resulting in a multi-day period where everyone on the Outer Banks would be stranded. Is is possible that the NOGAPS scenario is not the worst case, and that Earl will strike farther west, resulting in the Outer Banks getting the fearsome maximum winds of the storm's right front quadrant. However, it is more likely that Earl will pass just offshore, resulting in North Carolina receiving the weaker west side winds. Since Earl's forward speed will be about 20 mph at that time, the winds on the hurricane's west side will be about 40 mph less than the right front quadrant on the east side. The NHC wind probability forecast is calling for a 23% chance of hurricane-force winds on Cape Hatteras, 7% for Morehead City, and 3% for Norfolk, Virginia.

Impact of Earl on New England
The NOGAPS model brings Earl closest to the coast of New England, predicting the west eyewall of the the hurricane will pass over Nantucket at about 2am Saturday morning, and the tip of Cape Cod a few hours later. If this track verifies, 40+ mph winds would affect southeastern Massachusetts for a period of 6 - 12 hours beginning at about 8pm EDT Friday night. Earl should be a weaker Category 1 or 2 hurricane then, with hurricane-force winds extending 30 miles to the left of its track. Hurricane conditions would then affect the eastern tip of Long Island, coastal Rhode Island, and Southeast Massachusetts. Earl's radius of tropical storm-force winds to the north, over land, will probably be about 150 miles, so locations from Central Long Island to southern Boston would experience sustained winds of 40 mph in this worst-case model scenario. A storm surge of 3 - 5 feet might occur in Long Island Sound, and 2 - 3 feet along the south coast of Long Island. A deviation to the left, with a direct hit on eastern Long Island and Providence, Rhode Island, would probably be a $10 billion disaster, as the hurricane would hit a heavily populated area and drive a drive a 5 - 10 foot storm surge up Buzzards Bay and Narragansett Bay. The odds of this occurring are around 5%, according to the latest NHC wind probability forecast. The forecast is calling for a 25% chance of hurricane-force winds on Nantucket, 8% in Providence, 6% in Boston, and 18% in Hyannis. Keep in mind that the average error in position for a 3-day NHC forecast is 185 miles, which is about how far offshore Earl is predicted to be from New England early Saturday morning.

Impact of Earl on Canada/Maine
Late morning Saturday, Earl is expected to make landfall somewhere between the Maine/New Brunswick border and central Nova Scotia. At that time, Earl should be a strong tropical storm or weak Category 1 hurricane. This won't be another Hurricane Juan, the 2003 Category 2 hurricane which made a direct hit on Halifax, Nova Scotia, causing over $200 million in damage. Earl's impact is likely to be closer to 2008's Hurricane Kyle, which hit near Yarmouth, Nova Scotia, as a Category 1 hurricane with 75 mph winds. Kyle produced a storm surge of 2.6 feet, and did $9 million in damage to Canada. The NHC wind probability forecast is calling for a 29% chance of hurricane-force winds in Yarmouth, 24% in Halifax, and 17% in Eastport, Maine.

Beach erosion
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 currents will be the rule, due to waves that will reach 10 - 15 feet in offshore waters. Beach erosion damage in the mid-Atlantic states will likely run into the millions, but will probably not be as bad as that suffered during Nor'easter Ida in November of 2009. That storm (the remains of Hurricane Ida that developed into a Nor'easter) remained off the coast for several days, resulting in a long-duration pounding of the shore that caused $300 million in damage--$180 million in New Jersey alone.

Record ocean temperatures off the U.S. Mid-Atlantic Coast
The period May - July was the hottest such 3-month period in history for the Northeast and Southeast U.S., according to NOAA's National Climatic Data Center. Most of the hurricane-prone states along the coast, including New Hampshire, Massachusetts, Rhode Island, New Jersey, Delaware, Maryland, Virginia, North Carolina, and South Carolina had their hottest May - July in the 116-year record. These record air temperatures led to record ocean temperatures, according to an analysis I did of monthly average 5x5 degree SST data available from the UK Met Office Hadley Centre.. The region of ocean bounded by 35N - 40N, 75W - 70W, which goes from Cape Hatteras, North Carolina to Central New Jersey, had the warmest July ocean temperatures since records began in 1875--a remarkable 2.12°C (3.8°F) above average. The year 2008 was a distant second place, with temperatures 1.5°C (2.7°F) above average. The ocean region off the Southeast U.S. coast, bounded by 30N - 35N, 80W - 75W, from the Georgia-Florida border to Cape Hatteras, North Carolina, had its 4th warmest July ocean temperatures on record. Temperatures were 0.8°C (1.4°F) above average, which fell short of the record 1.1°C anomaly of 1944. The August numbers are not available yet, but will probably show a similar story.

All this warm water off the East Coast means it is much easier for a major hurricane to make landfall in the mid-Atlantic or Northeast U.S. Usually, ocean temperatures fall below the 26.5°C threshold needed to support a hurricane as soon as a storm pushes north of Cape Hatteras, North Carolina. This year, those temperatures extend all the way to the New Jersey coast (Figure 3.) Such warm ocean temperatures increase the odds of a major hurricane making it to the mid-Atlantic or New England coasts. Since record keeping began in 1851, there have been only 15 major hurricane in U.S. coastal waters north of the North Carolina/Virgina border--about one per decade. The last such storm was Hurricane Alex of August 6, 2004.


Figure 3. Water surface temperatures from AVHRR satellite data for the 6-day period ending August 31, 2010. Ocean temperatures of 26.5°C, capable of supporting a hurricane, stretched almost to Long Island, New York. Image credit: Ocean Remote Sensing Group, Johns Hopkins University Applied Physics Laboratory.

Fiona
Tropical Storm Fiona last night showed us why hurricane forecasting is such a difficult job. The storm made an unexpected slow-down in forward speed. This slow-down resulted in less wind shear affecting Fiona than expected, since the storm is farther from the upper-level outflow of Hurricane Earl. The wind shear analysis from the University of Wisconsin CIMSS group shows just a moderate 10 - 20 knots of shear affecting Fiona, which is low enough that the storm has been able to organize into a respectable 60 mph tropical storm. Martinique radar shows that the outer bands from Fiona are bringing heavy rain squalls to the same islands of the northern Lesser Antilles that were affected by Earl. Our wundermap shows that winds in the islands are all below 20 mph, but winds will increase to 30 - 40 mph later today as Fiona draws closer. Satellite loops show that heavy thunderstorm activity has decreased some in recent hours. This may be due to the fact that Fiona is currently crossing the cold water wake of Earl.

Forecast for Fiona
In the short term, moderate wind shear and dry air should keep Fiona from attaining hurricane status, though we do have several models that predict it could become a Category 1 hurricane. Fiona is likely to come close enough to Bermuda on Saturday or Sunday to pose a threat to that island, though it is possible high wind shear from Earl could kill the storm by then. The long term fate of Fiona remains unclear, with some models calling for dissipation this weekend, and other models calling for Fiona to be left behind by Earl to wander over the ocean near Bermuda early next week.


Figure 4. Morning radar image of Fiona from the Martinique radar. Image credit: Meteo France.

TD 9
Invest 98L gained enough heavy thunderstorm activity to be classified as Tropical Depression Nine this morning. This wil probably be Tropical Storm Gaston by tomorrow morning. The latest SHIPS model forecast predicts shear will remain moderate, 10 - 15 knots, for the next five days, and TD 9 could be a Category 1 hurricane five days from now, as predicted by the GFDL model. The storm will likely pose a threat to the northern Lesser Antilles Islands by Tuesday.

Next post
I'll have an update this afternoon.

Jeff Masters

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Quoting StormW:
Evening!


Evening Storm.......This is going to be a real nail biter in terms of every wobble on approach to the the NE and we are still 10 days away from the peak of the season with several more probably in the pike.....Time for coffee and sedatives.
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1621. unf97
Quoting StormW:
Evening!


Good evening Storm. Hope all is well.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
1620. KEEPEROFTHEGATE (Mod)
07L/MH/E/C4
MARK
26.44N/73.00W
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1619. xcool


this not 2009
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Hi, StormW!
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1617. xcool
btwntx08 this not going out sea
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Quoting IKE:
...FIONA MOVING OVER THE OPEN ATLANTIC... ...ALL WATCHES AND WARNINGS BEING DISCONTINUED...
5:00 PM AST Wed Sep 1
Location: 20.2°N 62.9°W
Max sustained: 60 mph
Moving: NW at 20 mph
Min pressure: 997 mb


Pressure back down.
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Quoting ncstorm:


Um no I was wrong..actually the center or eye of Earl is almost making landfall in the outerbanks..


? I dont see that at all.. link?
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1614. leo305
Earl is going to have DMAX to strengthen tonight, the dry air is the only thing stopping it.. the gulf stream is going to be in his path as well
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Earl is a situation all From the Mid Atlantic to the Eastern Provinces of Canada should keep aware of. It could be a dangerous situation for some.
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1612. xcool
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Quoting sailfish01:
http://www.ssd.noaa.gov/goes/flt/t4/flash-rgb.html

Fiona COC exposed, She is falling apart.


Fiona never really had ideal conditions thanks to big brother Earl, looks like we'll be tracking Gaston for a while however.
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Quoting StSimonsIslandGAGuy:
Between 2 and 5 pm, Earl moved 0.6 W and 0.6 N, for a distance of 56 miles, averaging 19 mph.
The distance to me decreased from 650 miles to 595 miles, or 55 miles, indicating that Earl is continuing to head almost directly towards me. But the XTRAP 'model' will soon be proven wrong once again!


XTRAP isn't a model.. it just shows if a storm were to go in the same direction it is now going where it would end up, with no other factors taken in account like troughs or anything else..
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Any models hinting at what Gaston will become and may go?
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1605. leo305
The cone shifted west and now includes all of long island
Member Since: April 17, 2010 Posts: 0 Comments: 1753
If Earl's trend continues, I think we'll see the Hurricane Warning's extended to Paramore Island, VA at the 11 PM update (this will include the Virginia Tidewater).
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1603. angiest
OBX is now very close to the hurricane force wind circle.
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Quoting StSimonsIslandGAGuy:
I believe that tonight Earl will become the strongest hurricane in the open Atlantic since Isabel.


He's certainly looking the best he's looked since Monday evening I think. He just might, but not too much stronger than now.
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1601. ncstorm
Quoting TreasureCoastFl:


NC looks to be fairing better now.. thank goodness. Hopefully Earl will push even further northeast later?


Um no I was wrong..actually the center or eye of Earl is almost making landfall in the outerbanks..one more wobble to the west and we got a landfall in NC
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1600. IKE
...FIONA MOVING OVER THE OPEN ATLANTIC... ...ALL WATCHES AND WARNINGS BEING DISCONTINUED...
5:00 PM AST Wed Sep 1
Location: 20.2°N 62.9°W
Max sustained: 60 mph
Moving: NW at 20 mph
Min pressure: 997 mb
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting Dixiegirl:


I was thinking the same thing. In Louisiana it will be gas-TAWn with the n not really pronounced but suggested.


gas-TAWn can stay far away from Louisiana. Gustav was bad enough for us.
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1598. scCane
Fiona is trying to put her clothes back on

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Quoting tatoprweather:


Cyber, Ive been new to the post this year but i have observed you bring good information and analysis. I've being reading (Storm, Levi et al)about how the "patterns" could bring Gaston or maybe future Hermine on a more westerly path possibly affecting the Caribbean. I have even read about this year being so similar to 1998 (Georges) in terms of patterns. Could you explained a little bit more how the actual steering patterns could bring those systems to our area (Caribbean, PR)


I can't explain it properly, I'm not a expert, but its because the way the ridge is situated over the United States this year that storms will tend to enter the Caribbean or hit the Leeward Islands and head NW under a influence of troughs sneaking by the ridge.

Forgive me, my weakness is on patterns.
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1595. ncstorm
Quoting tropicfreak:


Yes it has


You right..the center of Earl now sits right off the coast of NC ..the right side of the cone is the eastern side of NC..my bad..
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1594. sfranz
Actually, there are some of us up here in New England watching the discussion. The yard clean up is done. I have a pile of plywood in the garage, but can't get a clear signal if I should pack up and head north or just watch for a bit longer.

It is frustrating, because we have more than 6 million people here and about five major roads out. And with the uncertainty, we're not even sure which way to run, if we need to.

Good times!
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Ho ho ho we ave Gaston
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1592. leo305
Quoting AllStar17:
I have been VERY impressed with Brian Norcross' Tropical Updates on TWC. He seems to be doing a great job explaining things and going in depth into the forecasts.

Thoughts?


He is the best met that there was in miami, during Wilma/Katrina

Amazing, simply amazing, he would tell it like it is, TWC just limits his time.
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Quoting CybrTeddy:
Virgina should expect similar conditions to that of Hurricane Isabel.

New York, Connecticut, Rhode Island, and Massachusetts need to get ready now.

img src="
http://www.nhc.noaa.gov/storm_graphics/AT07/refresh/AL0710W5_NL_sm2+gif/152331W5_NL_sm.gif" alt="" />


Va?? uh oh that means me, but don't know what exactly what we here in Richmond will see.
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Quoting ncstorm:


Im talking about NC..it seems its farther east now..


NC looks to be fairing better now.. thank goodness. Hopefully Earl will push even further northeast later?
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Quoting ConchHondros:
Im not looking at another model...Im consulting a rather large glass of Jeremiah Weed, watching Drak, Storm, Levi, and Flood. I have "All Along The Watchtower" on 10 and will shortly set up my 'cane chart at the bottom of a chicken brooder and see what my daughters pet silkie Isabella thinks about Earls track...fear the chicken...


Now that is a plan!!!
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Quoting RuBRNded:


Good job on the avatar Pat, Clint Eastwood is ex Army, lol


Yeah were is your Chesty Puller Avitar?
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Man I was going to Carova Beach but now I may not.... well i'll go anyway just to ride in the car and take video of Earl if it hits NC.
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1586. unf97
Quoting AllStar17:
I have been VERY impressed with Brian Norcross' Tropical Updates on TWC. He seems to be doing a great job explaining things and going in depth into the forecasts.

Thoughts?


I have great respect for Bryan Norcross. He was great during coverage of Hurricane Andrew when it hit South FL in 1992. He is one of the best hurricane experts in the business and hiring him was the best thing The Weather Channel has done in years.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
http://www.ssd.noaa.gov/goes/flt/t4/flash-rgb.html

Fiona COC exposed, She is falling apart.
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Quoting kshipre1:
can someone real quick send me a link showing the tropical African satellite that shows the waves coming off Africa? thanks


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Quoting CybrTeddy:
Gaston now predicted to become a Hurricane and go towards the Caribbean.


Cyber, Ive been new to the post this year but i have observed you bring good information and analysis. I've being reading (Storm, Levi et al)about how the "patterns" could bring Gaston or maybe future Hermine on a more westerly path possibly affecting the Caribbean. I have even read about this year being so similar to 1998 (Georges) in terms of patterns. Could you explained a little bit more how the actual steering patterns could bring those systems to our area (Caribbean, PR)
Member Since: Posts: Comments:
Quoting CybrTeddy:
Virgina should expect similar conditions to that of Hurricane Isabel.

New York, Connecticut, Rhode Island, and Massachusetts need to get ready now.

img src="
http://www.nhc.noaa.gov/storm_graphics/AT07/refresh/AL0710W5_NL_sm2+gif/152331W5_NL_sm.gif" alt="" />


Come on now?!
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1581. angiest
Quoting Patrap:
Gustav Hit La.this Date 2 years ago.



I forgot how big he was.
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Quoting ncstorm:
Well. the cone is still the same..even the models have trended west but the NHC cones dont? what gives?


Yes it has
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Shhh...No one tell Snookie NJ is next...
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1578. JamesSA
The potential path of Gaston looks troubling. He is just enough South of the other three that it looks probably that somebody will get hit, but who? It will be interesting to see where the models want to take him once they get a good initial fix.

It is going to be a lively time on the blog for sure!
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1577. ncstorm
Quoting SouthNJcoastKen:


the cone did shift... south jersey was further outside the cone at 2pm than we are now


Im talking about NC..it seems its farther east now..
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Virgina might see similar conditions to that of Hurricane Isabel.

New York, Connecticut, Rhode Island, and Massachusetts need to get ready now.


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Quoting AllStar17:
I have been VERY impressed with Brian Norcross' Tropical Updates on TWC. He seems to be doing a great job explaining things and going in depth into the forecasts.

Thoughts?

I couldn't agree more. Brian Norcross should be their "hurricane expert". He went through Andrew, and he has great experience.
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1574. KEEPEROFTHEGATE (Mod)
2010 Storms
All Active Year


Atlantic
09L.GASTON
08L.FIONA
07L.EARL

East Pacific
94E.INVEST

Central Pacific

West Pacific
93W.INVEST
08W.KOMPASU
07W.LIONROCK

Indian Ocean

Southern Hemisphere
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Quoting ncstorm:
Well. the cone is still the same..even the models have trended west but the NHC cones dont? what gives?


the cone did shift... south jersey was further outside the cone at 2pm than we are now
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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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