Category 4 Earl headed for a close brush with North Carolina

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

Share this Blog
5
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1383 - 1333

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

Quoting StormW:
Here's a good site for folks:

Experimental TROPICAL CYCLONE IMPACTS - DECISION SUPPORT
Good post Storm, hope people use it to their advantage.
Member Since: Posts: Comments:
Quoting sammywammybamy:
Wow Some FruitCake is Calling in From New Orleans..LOL.. God This is Better than the Jerry Springer Show..

Making Popcorn.


What's wrong with someone calling in from New Orleans.....and why a fruitcake?? Do you have any better questions?? All I hear is you bashing the people....STEP UP!!
Member Since: Posts: Comments:
THERE IS SOME SOUTHWESTERLY SHEAR DISRUPTING THE
UPPER-LEVEL OUTFLOW OVER THE WESTERN SEMICIRCLE OF EARL. THIS SHEAR
IS CAUSED BY A WEAK UPPER-LOW OR TROUGH OVER THE EASTERN BAHAMAS AS
OBSERVED ON WATER VAPOR IMAGES. HOWEVER...MODELS WEAKEN THE UPPER
LOW AS EARL MOVES AROUND IT...RESULTING IN A MORE FAVORABLE
ENVIRONMENT.
Member Since: Posts: Comments:
Quoting TerraNova:


And the danger is a whole lotta "small nudges" adding up to a big western shift. But I guess the models continuing to keep the center offshore (most of them, anyway) is a good sign.
Remeber what lesson Charley taught us.....
Member Since: Posts: Comments:
I guess 98L has a chance to develop if it can escape the shear and dry SAL to the north. Witht that being said, even if 98L does not turn into Gaston, September is shaping to be a mighty crazy month in the tropics. I mean, not only will we have CVS to deal with but also closer to home in the caribbean and GOM, things begin to get interesting as well.
Member Since: Posts: Comments:
He is now moving NW according to the NHC
Member Since: Posts: Comments:
Quoting Chucktown:


Just got off a conference call with NWS here in Charleston. We are not expecting anything here except for rough surf and maybe some erosion. In fact if you are not at the beach on Thursday, you will not even know there is a Cat 3/4 hurricane offshore. Sunny with highs in the 90's for the rest of the week here.


Wouldn't have expected anything different way down there in Charleston
Member Since: Posts: Comments:
1376. hydrus
There is a broad low showing on the NAM in 84 hours.Link
Member Since: Posts: Comments:
1375. BrandiQ
5:00 PM AST Tue Aug 31
Location: 22.0°N 68.8°W
Max sustained: 135 mph
Moving: NW at 14 mph
Min pressure: 940 mb
Member Since: Posts: Comments:
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.
Member Since: Posts: Comments:
Whats going on will Earl an Eye wall Replacment? or is it just weaker please inform me. Have not looked at Earl sence 7am.
Member Since: Posts: Comments:
Quoting TropicalNonsense:


it does look to be moving further north in the last few
frames rwdobson. It may be feeling the weakness now.
We need a few more hours of observation to be sure
though because it's hard to tell from the wobbles.


Agreed, won't really know for sure until we get some more frames.
Member Since: June 12, 2002 Posts: 0 Comments: 1589
Furthest west with new advisory is 75.5.
Member Since: Posts: Comments:
Quoting angiest:


OK, so you are saying it is already there? To me it still looks to be SE (roughly) of the next point.


No, it's not there yet. Turn on the TFP and stop it on the last frame. And pretty clear it is just NE of the forecast track.
Member Since: August 17, 2005 Posts: 26 Comments: 16554
000
WTNT22 KNHC 312042
TCMAT2
HURRICANE EARL FORECAST/ADVISORY NUMBER 26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
2100 UTC TUE AUG 31 2010

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A HURRICANE WATCH HAS BEEN ISSUED FOR THE EAST COAST OF THE UNITED
STATES FROM NORTH OF SURF CITY TO DUCK NORTH CAROLINA...INCLUDING
THE PAMLICO AND ALBEMARLE SOUNDS.

A TROPICAL STORM WATCH HAS BEEN ISSUED FROM CAPE FEAR NORTH CAROLINA
NORTHEASTWARD TO SURF CITY.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH OF SURF CITY TO DUCK NORTH CAROLINA...INCLUDING THE PAMLICO
AND ALBEMARLE SOUNDS
Member Since: Posts: Comments:
Will Dr. Masters be on ABC (nat'l) tonight? He mentioned an interview.. curious to watch. :)
Member Since: Posts: Comments:
Quoting DestinJeff:
5pm track coming with harder angle turn, cone clips obx.


The loops from the last two hours at NOAA definately show a more Norhtly component to movement.
Member Since: Posts: Comments:
Quoting StormJunkie:


You can call it E of track if you want...lol


At least you know what I was trying to say...
Member Since: Posts: Comments:
HURRICANE EARL FORECAST/ADVISORY NUMBER 26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
2100 UTC TUE AUG 31 2010

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A HURRICANE WATCH HAS BEEN ISSUED FOR THE EAST COAST OF THE UNITED
STATES FROM NORTH OF SURF CITY TO DUCK NORTH CAROLINA...INCLUDING
THE PAMLICO AND ALBEMARLE SOUNDS.

A TROPICAL STORM WATCH HAS BEEN ISSUED FROM CAPE FEAR NORTH CAROLINA
NORTHEASTWARD TO SURF CITY.

HURRICANE CENTER LOCATED NEAR 22.0N 68.8W AT 31/2100Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 12 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 940 MB
EYE DIAMETER 30 NM
MAX SUSTAINED WINDS 115 KT WITH GUSTS TO 140 KT.
Member Since: Posts: Comments:
Omg. All day with the "its moving w nw wnw" "its south of FTP north of FTP" give it a rest people.
Member Since: Posts: Comments:
Quoting GoWVU:
How does it look for Charleston SC?


Just got off a conference call with NWS here in Charleston. We are not expecting anything here except for rough surf and maybe some erosion. In fact if you are not at the beach on Thursday, you will not even know there is a Cat 3/4 hurricane offshore. Sunny with highs in the 90's for the rest of the week here.
Member Since: Posts: Comments:
Quoting angiest:


There is no 2PM track. It was last updated at 11PM. 2PM is just an update to position, intensity, and heading.


I know, it's the same as the 11 o'clock track with a new position estimate.
Member Since: Posts: Comments:
1360. angiest
Quoting StormJunkie:


Not supposed to be there until 8pm est.


OK, so you are saying it is already there? To me it still looks to be SE (roughly) of the next point.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting GoWVU:
How does it look for Charleston SC?


Beautiful...Serious high pressure in place right now. First time in weeks there has not been a cloud in the sky.
Member Since: August 17, 2005 Posts: 26 Comments: 16554
Quoting angiest:


Except it doesn't seem to have reached the next TFP yet.


Not supposed to be there until 8pm est.
Member Since: August 17, 2005 Posts: 26 Comments: 16554
1355. GoWVU
How does it look for Charleston SC?
Member Since: Posts: Comments:
Quoting VAbeachhurricanes:


not really, only one road all the way up to the north and its one lane... takes forever


Ocracoke is accessible by ferry only. Also the road between Oregon Inlet and Hatteras washes out very easily. In comparison the northern obx is easier to evacuate.
Member Since: Posts: Comments:
Quoting washingtonian115:
Not to me it wouldn't,you probally can't see my post because you have me on ignore. The more left the more trouble Earl will potentially cause....


And the danger is a whole lotta "small nudges" adding up to a big western shift. But I guess the models continuing to keep the center offshore (most of them, anyway) is a good sign.
Member Since: Posts: Comments:
Quoting rwdobson:


yeah, radar would be nice...and it looks like the sat loop lost the last frame.


it does look to be moving further north in the last few
frames rwdobson. It may be feeling the weakness now.
We need a few more hours of observation to be sure
though because it's hard to tell from the wobbles.
Member Since: Posts: Comments:
Quoting sammywammybamy:
LOL... Wow.. Some Guy/Kid.. Just Made me Choke... He Just Called in...

Ahahahaha

"Will the 3 storms all become one giant mega storm!"
actually a rather reasonable question 3 storms look like they might run into each other in the PACIFIC
Member Since: Posts: Comments:
1348. angiest
Quoting StormJunkie:


You can call it E of track if you want...lol


Except it doesn't seem to have reached the next TFP yet.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting moonlightcowboy:


Hey, TN! Good to see you. Yup, I'm with you - seems to be several variables, too much can happen, or not happen, still I think.


Yeah, I tried to giving the WV loop the good old fashion stare but I only ended up dizzier than I started out.

Member Since: Posts: Comments:
Quoting sammywammybamy:


I Wonder if Someone has Ever Prank Called. Ahahah That Would be Funny.
Not to me it wouldn't,you probally can't see my post because you have me on ignore.
Quoting TerraNova:


Stay tuned for 5 PM! I don't expect a significant shift in either direction from the 2 PM track. If anything, a slight nudge to the left.
The more left the more trouble Earl will potentially cause....
Member Since: Posts: Comments:
Quoting Vero1:


What?? Not East or West of Track? lol


You can call it E of track if you want...lol
Member Since: August 17, 2005 Posts: 26 Comments: 16554
How do I add an Avatar?
Member Since: Posts: Comments:
1343. angiest
Quoting TerraNova:


Stay tuned for 5 PM! I don't expect a significant shift in either direction from the 2 PM track. If anything, a slight nudge to the left.


There is no 2PM track. It was last updated at 11PM. 2PM is just an update to position, intensity, and heading.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting CJ5:


Look back at the images I was referencing. They show no wobble in the last few seconds. Now, it could be that particular graphic is not good with direction but you would have to be blind not to see it.
Glad I waited for the blog to respond. Don't care to be called blind.
Member Since: Posts: Comments:
1341. Vero1
Quoting StormJunkie:
Earl is N of the forecast points.


What?? Not East or West of Track? lol
Member Since: Posts: Comments:
Sal can have em, I'm going to PR Friday and on a cruise to Aruba, Dominicia, and a few other islands.
Member Since: Posts: Comments:


How dry I am....
Member Since: Posts: Comments:
Quoting Chapelhill:
It is likely a watch will go up soon. Evacuations from the northern outer banks can happen quickly compared to the southern end of the banks.


not really, only one road all the way up to the north and its one lane... takes forever
Member Since: Posts: Comments:
Quoting washingtonian115:
Their's a shift in the cone to the west?.I hope not,because remember folks even if E
arl does hit along the east coast as a cat 2 storm,the storm surge could still be high,due in part that some places are vonurable.


Stay tuned for 5 PM! I don't expect a significant shift in either direction from the 2 PM track. If anything, a slight nudge to the left.
Member Since: Posts: Comments:
Quoting TerraNova:


Not good....way too many variables out there!


Hey, TN! Good to see you. Yup, I'm with you - seems to be several variables, too much can happen, or not happen, still I think.
Member Since: Posts: Comments:
1334. angiest
Hmm is some of the dry air to Earl's west beginning to get moistened up? Looks like some of those outflow boundaries triggered some convection near Cuba.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
It is likely a watch will go up soon. Evacuations from the northern outer banks can happen quickly compared to the southern end of the banks.
Member Since: Posts: Comments:

Viewing: 1383 - 1333

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

Top of Page

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.

Local Weather

Partly Cloudy
74 °F
Partly Cloudy