Category 4 Earl headed for a close brush with North Carolina

By: Dr. Jeff Masters , 3:16 PM GMT on August 31, 2010

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Powerful Category 4 Hurricane Earl is pulling away from Puerto Rico and the northern Lesser Antilles Islands, and is eyeing its next potential landfall--North Carolina's Outer Banks. Earl brought heavy rain and high winds to Puerto Rico and much of the northern Lesser Antilles yesterday, though it appears that the islands were spared major damage. One exception may be Anegada in the British Virgin Islands, population 200. The eye of Earl passed just north of Anegada at noon yesterday, and Earl's south eyewall probably brought sustained winds of 100 mph to the island. Second hardest hit was probably Anguilla. Amateur weather observer Steve Donahue at anguilla-weather.com estimated gusts of 100 mph on Anguilla; his anemometer broke at 88 mph. Winds in St. Thomas in the U.S. Virgin Islands remained above tropical storm force (39 mph) for five hours yesterday afternoon, peaking at 52 mph, gusting to 62 mph, at 4:49 pm. Heavy rains hit Puerto Rico, where radar-estimated rainfall amounts of up to 5 - 7" occurred. Earl brought waves of sixteen feet to San Juan, and waves at buoy 41043 offshore of Puerto Rico reached 31 feet early this morning.


Figure 1. Morning satellite image of Earl, taken at 10:30am EDT 8/31/10. Image credit: NASA/GSFC.


Figure 2. Radar estimated rainfall for Earl from the San Juan, Puerto Rico radar. Isolated regions of 5 - 7 " of rain occurred in three locations on Puerto Rico. The rays fanning out to east from the radar location marked with a "+" are due to mountains blocking the view of the radar.

Intensity forecast for Earl
Wind shear as diagnosed by the latest SHIPS model forecast shows a moderate 10 - 20 knots of wind shear over Earl, due to upper level winds out of the southwest from a trough of low pressure to Earl's west. This moderate shear is predicted to continue through Friday, but should not appreciably affect Earl, since the hurricane is so large and strong. Ocean temperatures are 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. Earl is undergoing an eyewall replacement cycle, which may diminish its winds by 10 -20 mph for a day or so. However, the storm will probably regain strength after completing this cycle, and it is likely Earl will be a major Category 3 or 4 hurricane at its closest approach to North Carolina Thursday night and Friday morning. 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 2 hurricane on Friday night, when it could potentially make landfall in Massachusetts. Earl is more likely to be a Category 1 hurricane on Saturday morning, when it could potentially make landfall in Maine or Nova Scotia, Canada.


Figure 3. Swath of surface winds from Earl predicted by the 2am EDT Tuesday, August 31, 2010 runs of NOAA's GFDL model (left) and HWRF model (right). Hurricane force winds (yellow colors, above 64 knots) are predicted to stay off the coast. Tropical storm force winds (light green colors, above 34 knots) are predicted to affect coastal North Carolina, Massachusetts, and Eastern Maine. Winds between 58 mph - 73 mph (dark green colors) are predicted to small portions of the coast. Image credit: Morris Bender, NOAA/GFDL.

Track forecast for Earl
The latest set of computer models runs from 2am EDT (6Z) this morning push Earl's projected track a little closer to the U.S. East Coast, and we now have two of our six reliable models predicting a U.S. landfall. The latest NOGAPS run shows Earl hitting the Outer Banks of North Carolina late Thursday night, then striking Southeast Massachusetts late Friday night, and Eastern Maine on Saturday morning. The HWRF model predicts a strike on Eastern Maine Saturday morning, but keeps Earl offshore from North Carolina and Massachusetts. None of the other computer models show Earl hitting the U.S., but several models bring Earl within 100 - 200 miles of North Carolina's Outer Banks and Southeast Massachusetts. It is likely that Earl will being a 12-hour period of heavy rain and tropical storm force winds of 39+ mph to North Carolina's Outer Banks, beginning on Thursday evening. NHC is giving Cape Hatteras a 12% chance of receiving hurricane force winds. By Friday evening, western Long Island, Rhode Island, and Southeast Massachusetts can expect a 6 - 8 hour period of heavy rain and tropical storm force winds of 39+ mph. NHC is giving Nantucket a 11% chance of receiving hurricane force winds. These odds are 4% for Boston, 6% for Providence, 5% for Eastport, Maine, and 11% for Yarmouth, Nova Scotia. 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. 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 Cape Hatteras three days from now. The average error in a 4-day forecast is 255 miles, which is about the distance Earl is expected to be from the coast of New England four days from now.

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. Waves from Hurricane Danielle killed two swimmers in the U.S. over the weekend and forced hundreds of water rescues along the U.S. East Coast. Earl's waves will be worse, and will likely cause millions of dollars in beach erosion damage.

Fiona
Tropical Storm Fiona is speeding west-northwest towards Hurricane Earl, but is unlikely to bring tropical storm force winds to the Lesser Antilles. Satellite loops show that heavy thunderstorm activity has increased in some of the outer bands this morning, but remains limited near the center. Wind shear is currently moderate, 10 - 15 knots, and the main impediment to development continues to be dry air associated with the Saharan Air Layer (SAL) surrounding the storm.

Forecast for Fiona
Fiona is moving quickly to the west-northwest, at about 24 mph. This means it is catching up to Earl, which is moving at 15 mph. By tonight, Fiona will be beneath Earl's upper-level outflow channel. Strong upper-level winds from Earl's upper-level outflow and a ridge of high pressure to the northwest of Fiona will bring high levels of wind shear, 20 - 30 knots, to Fiona tonight through Friday, and probably arrest the storm's development. The scenario now called for by all the models is for Fiona to be drawn into the low pressure wake of Earl and turn to the northwest. Fiona will pass to the northeast of the Lesser Antilles, and will probably not bring tropical storm force winds to the islands. Fiona should then continue to the northwest and then turn north, passing very close to Bermuda on Saturday morning. It is possible Earl could destroy Fiona through high wind shear before Saturday.


Figure 4. Morning satellite image of Fiona. High level cirrus clouds flowing out from the center of Earl as part of its upper level outflow can be seen starting to impinge upon the western side of Fiona's circulation.

Danielle is dead
Tropical Storm Danielle has succumbed to the cold North Atlantic waters, and is no longer a tropical storm.

98L
A new tropical wave (Invest 98L) moved off the coast of Africa yesterday, and is centered a few hundred miles south of the Cape Verdes Islands. Strong easterly winds from the African Monsoon are creating a moderate 10 - 20 knots of shear, and the disturbance is currently disorganized. A large area of dry air lies to the north and west of 98L, and this will interfere with development. The latest SHIPS model forecast predicts shear will remain moderate, 10 - 20 knots, for the next five days, and some slow development of 98L is possible as it moves westward at 15 mph. NHC is giving a 10% chance of this system developing into a tropical depression by Thursday, and none of the computer models develop it.


Figure 5. Morning satellite image of 98L.

A rare triple threat in the Western Pacific
Over in the Western Pacific, we have an unusual triple feature--three named storms all within 700 miles of each other. A 3-way interaction between these storms is occurring, making for a very tough forecast situation. The storm of most concern is Typhoon Kompasu, which hit Okinawa today as a Category 2 typhoon. Kompasu is expected to recurve northeastward and hit North Korea on Thursday as a Category 2 typhoon. It is unusual for a powerful typhoon to thread the tight Yellow Sea and hit North Korea, and I don't know how prepared they are for strong typhoons. Kompasu is expected to hit the most populous region of North Korea, but the country is pretty mountainous, and a significant storm surge disaster is probably unlikely. In the South China Sea, Tropical Storm Lionrock and Tropical Storm Namtheun are moving through the straights between Taiwan and China towards each other. Neither are predicted to develop into typhoons, but heavy rains are occurring in Guangdong and Fujian Provinces, further exacerbating the flood conditions China has suffered this summer.


Figure 6. An unusual triple feature over the Western Pacific--three simultaneous named storms all within 700 miles of each other. Image credit: NOAA/SSD.

"Hurricane Haven" airing again this afternoon
Tune into another airing of my live Internet radio show, "Hurricane Haven", at 4pm EDT today. Listeners will be able to call in and ask questions. The call in number is 415-983-2634, or you can post a question to broadcast@wunderground.com. Be sure to include "Hurricane Haven question" in the subject line.

Today's show will be about 45 minutes, and you can tune in at http://www.wunderground.com/wxradio/wubroadcast.h tml. The show will be recorded and stored as a podcast.

I may have a short update this afternoon, once the latest models runs are available.
Jeff Masters

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Quoting yoboi:
where is earl going?
I think that is the big question right now.
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Quoting PalmBeachWeather:
Is this about the time I heard
"You're doing a good job Brownie"?


Probably best to just not go there....
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Would someone be nice enough to pin point Fiona's center of circulation on a map? It hard to discern for the untrained eye (like mine). Thanks!
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1477. angiest
Quoting DestinJeff:
Whoa. I am good.

How's that for a freakin' Blogcast, huh?


Yeah I was going to say something and just didn't get to it.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting StormW:
NWS LOCAL STATEMENTS FOR EARL


Active September on the way! wouldn't be surprise to see some serious CV hurricane long trackers.
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Quoting DestinJeff:
Whoa. I am good.


That probably scared you, lol.
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1474. GetReal







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Quoting Welling2000:
Washingtonian,

Flood's not being rude. He's being shocked about the Gulf Loop Current mention. Whatever could make you think he's being rude?
Okay like maybe I was reading it incorrectly then?.And looky here looks like Earl is going to be in my backyard.Better start taking steps now even though I live in D.C
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The Outerbanks will be closest to the center and most likely see the worse winds and tidal surge. Don't let the bend you see on the new track off the NC coast fool you. Earl will circle around that to the W and the eye will not be that far offshore of the banks. That area is your bullseye for a good swipe for the time being.
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1471. angiest
Quoting sammywammybamy:




My Explanation on the Waves Coming off Africa


Comments or Questions?
- SWB


Is wave 1 actually a wave or an MCC? They all look too close together given the period of AEWs.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1470. yoboi
where is earl going?
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Quoting jscs:


Completely agree. But to tell people in Charleston, at this moment, that off the beach you won't even know there is a storm is irresponsible at this moment. As it stands, the turn to the NW sharp is a prediction... until that sharp turn, Charleston simply isn't in the clear.

In the clear, y'all are pretty much safe, stop making a mountain out of a molehill.
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1464. markot
98 i think will be a problem....
Member Since: September 2, 2009 Posts: 0 Comments: 226
Quoting angiest:


No I believe that is the radius.

It is the radius - so the wind field is 400 miles across.
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I take it most of you hat the weather channel,by the way my favorite username on the blog has to be that guy called sammywammybamy.
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1460. Zeec94
Hurricane Watches in Effect from VA Beach, Virginia to the South Edge of North Carolina.
Member Since: June 26, 2010 Posts: 0 Comments: 126
1459. Zeec94
Hurricane Watches in Effect from VA Beach, Virginia to the South Edge of North Carolina.
Member Since: June 26, 2010 Posts: 0 Comments: 126
Quoting angiest:


No I believe that is the radius.

It is the radius - so the wind field is 400 miles across.
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floodman - sorry here is the link...

Link
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Quoting MoltenIce:
Looks like Fiona is getting dangerously close to Earl.


Yea, and it's getting close to dinner time! ...wonder if Earl will be hungry?
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Poor Fiona she gotten a little to close to a cannibal. Earl Lecter, brother of Hannibal.
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Looks like Fiona is getting dangerously close to Earl. I would not be surprised the Fiona somehow managed to integrate her circulation with Earl.
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floodman - here's an update to that one. you don't believe we are doomed yet???
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Washingtonian,

Flood's not being rude. He's being shocked about the Gulf Loop Current mention. Whatever could make you think he's being rude?
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1450. Engine2
18z GFS soon
Member Since: February 27, 2006 Posts: 0 Comments: 482
1449. CJ5
Quoting Floodman:


The loop current has stopped? Really? When did this happen? Being part of the thermohaline circulation that would indicate that the whole system is stopping (as they are all inter-dependent and inter-connected); why hasn't this made the headlines, given that it would indicate a collapse of the current climate regimen?



LOL..propaganda...not even current..
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I think TWC just called everyone on the E Coast idiots...
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Quoting tropicfreak:


Safe???? You call a cat 3 bearing down on NC safe??


They are looking for any glimmer of hope to cling to. "Oh, new model says it will stay off the coast, all clear!!!" All it has to do is jog a little West anywhere along that path and it is bad news.

It will be over, when it is over.
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Hurricane Watch
HURRICANE EARL LOCAL STATEMENT
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
503 PM EDT TUE AUG 31 2010

...HURRICANE WATCH ISSUED AS HURRICANE EARL APPROACHES THE COAST
OF NORTH CAROLINA...

.AREAS AFFECTED...
THIS LOCAL STATEMENT PROVIDES IMPORTANT INFORMATION AND
RECOMMENDED ACTIONS FOR PEOPLE AND MARINE INTERESTS IN SELECT
LOCATIONS AND COASTAL WATER LEGS OF EASTERN NORTH CAROLINA AND
ADJACENT COASTAL WATERS.

.WATCHES/WARNINGS...
A HURRICANE WATCH IS IN EFFECT FOR THE FOLLOWING LOCATIONS...
WASHINGTON...TYRRELL...MAINLAND DARE...BEAUFORT...MAINLAND HYDE...
CRAVEN...PAMLICO...CARTERET...ONSLOW...OUTER BANKS DARE AND OUTER
BANKS HYDE.

FOR MARINE INTERESTS...A HURRICANE WATCH IS IN EFFECT FOR ALL OF
ATLANTIC COASTAL WATERS INCLUDING ALBEMARLE AND PAMLICO SOUNDS.

PLEASE CHECK THE LATEST PUBLIC AND MARINE FORECASTS FOR DETAILED
INFORMATION ABOUT ADDITIONAL HAZARDS.

.STORM INFORMATION...
AT 4 PM EDT...THE CENTER OF HURRICANE EARL WAS LOCATED NEAR
LATITUDE 22.0N...LONGITUDE 68.8W. THIS WAS ABOUT 1070 MILES
SOUTH-SOUTHEAST OF DUCK NC...OR ABOUT 1000 MILES SOUTH-SOUTHEAST
OF BUXTON NC.
STORM MOTION WAS NW OR 305 DEGREES AT 14 MPH. STORM INTENSITY WAS
135 MPH.

.SITUATION OVERVIEW...
MAJOR HURRICANE EARL IS CURRENTLY NORTH OF THE DOMINICAN REPUBLIC
AND IS MOVING TOWARD THE NORTHWEST. THE HURRICANE IS EXPECTED TO
PASS JUST EAST OF THE OUTER BANKS THURSDAY NIGHT. A HURRICANE
WATCH HAS BEEN ISSUED FOR PORTIONS OF EASTERN NORTH CAROLINA.

.PRECAUTIONARY/PREPAREDNESS ACTIONS...
PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR INLAND LOCATIONS...TROPICAL CYCLONE CONDITIONS ARE ASSOCIATED
WITH HIGH WIND...BUT FOR COASTAL LOCATIONS AND PLACES PRONE TO
COASTAL FLOODING...THEY ARE ASSOCIATED WITH BOTH HIGH WIND AND
STORM SURGE. FOR THE MARINE WATERS...TROPICAL CYCLONE CONDITIONS
ARE ASSOCIATED WITH HIGH WIND AND DANGEROUS SEAS. TROPICAL
CYCLONES ARE COMPRISED OF HURRICANES...TROPICAL STORMS... AND
TROPICAL DEPRESSIONS. HURRICANES HAVE WINDS OF 74 MPH OR
HIGHER...WHICH EQUATES TO 64 KNOTS OR HIGHER. TROPICAL STORMS HAVE
WINDS OF 39 TO 73 MPH...WHICH EQUATES TO 34 TO 63 KNOTS. TROPICAL
DEPRESSIONS HAVE WINDS OF LESS THAN 39 MPH OR 33 KNOTS.

HEAVY RAIN...TORNADOES...AND WATERSPOUTS ACCOMPANY TROPICAL
CYCLONES. A HURRICANE WATCH MEANS THAT THE STATED CONDITIONS ARE
POSSIBLE WITHIN THE NEXT 48 HOURS FOR THE SPECIFIED AREAS. IN
ORDER TO MAKE THE BEST DECISIONS...BE SURE THAT YOU UNDERSTAND THE
TERMINOLOGY AND DEFINITIONS ASSOCIATED WITH TROPICAL CYCLONE
EVENTS.


&&

.NEXT UPDATE...
THE NEXT LOCAL STATEMENT WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE IN NEWPORT/MOREHEAD CITY SHORTLY. IT WILL PROVIDE
IMPORTANT DETAILS REGARDING THE EVOLVING TROPICAL CYCLONE THREATS
AND THEIR POTENTIAL IMPACTS UPON THE AREA.

NCZ045>047-080-081-093>095-098-103-104-012115-
/O.NEW.KMHX.HU.A.1007.100831T2103Z-000000T0000Z/
WASHINGTON-TYRRELL-MAINLAND DARE-BEAUFORT-MAINLAND HYDE-CRAVEN-
PAMLICO-CARTERET-ONSLOW-OUTER BANKS DARE-OUTER BANKS HYDE-
503 PM EDT TUE AUG 31 2010

...HURRICANE WATCH IN EFFECT...

...NEW INFORMATION...
A HURRICANE WATCH HAS NOW BEEN ISSUED. A MORE DETAILED STATEMENT
WILL FOLLOW SHORTLY.

$$
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Quoting JRnOldsmar:


floodman - he is a link - this may or may not be the one posted earlier on the blog
Link


That's the eddy...it's a spin off of the loop current...LOL
Member Since: August 2, 2006 Posts: 10 Comments: 9922
Quoting StormJunkie:
So everyone that was talking about TWC saying major shift W...Did they get you to watch? If so, they did a good job of marketing...Which reminds me I need to do some marketing homework...Arghh.


TWC is garbage, nothing but a hype machine
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The SSD satellite images do not seem to be working.
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1440. xcool
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Quoting futuremet:
Fiona has been sneakily going west of the forecast points today. Hopefully it start moving more to the west-northwest over the next six hours.


I don't see Fiona making it past 70W. Likely to recurve with Earl.
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1437. angiest
Quoting BobinTampa:



you talking about yourself or the models??


The models. The ones that had the NHC forecasting Earl to stay away from the Leewards and away from the east coast.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1436. KEEPEROFTHEGATE (Mod)
07L/MH/E/C3
MARK
22.03N/68.96w
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Quoting Floodman:


The loop current has stopped? Really? When did this happen? Being part of the thermohaline circulation that would indicate that the whole system is stopping (as they are all inter-dependent and inter-connected); why hasn't this made the headlines, given that it would indicate a collapse of the current climate regimen?
You sound a little rude no?
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1434. xcool
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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.