Hurricane Irene Prepares to Leave the Bahamas and Head for the US

By: Dr. Jeff Masters , 7:51 AM GMT on August 25, 2011

Share this Blog
17
+

As of 2AM EDT, Hurricane Irene was located at 24.2N, 76.0W, 105 miles east-southeast of Nassau or 760 miles south of Cape Hatteras. It was moving northwest at 12 mph with maximum sustained winds of 115 mph, making it a Category 3 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 950 mb. Hurricane force winds can be found up to 70 miles from Irene's center, and tropical storm force winds can be found out to 255 miles from the storm's center.

Hurricane warnings are in effect for all of the Bahamas. Hurricane and tropical storm watches will likely be posted for the Carolina coastlines later this morning. At this time, Dare County Emergency Management has issued a mandatory evacuation order for all visitors in their county. Dare County Schools will also be closed Thursday and Friday.

Satellite Views
Figure 1 is the infrared satellite image of Irene at 135EDT. The convection is a bit unbalanced around the storm center, which is going to cause Irene to wobble like an unbalanced clothes washer (Analogy courtesy of Angela Fritz) over the next few hours. At the time this image was taken, the convection around Irene's center appears to be getting more vigorous, as cold cloudtops are starting to increase around the storm center. This is important to note because microwave satellite imagery from Wednesday evening suggested Irene was starting an eyewall replacement cycle. Figure 2 shows passive microwave imagery from a Air Force DMSP polar-orbiting satellite. The two concentric green/yellow bands in the image suggest that two eyewall features are present in Irene, and Hurricane Hunter observations confirm this. This has important consequences for Irene's intensity, because in an eyewall replacement cycle, as the inner eyewall weakens, the storm's intensity drops. However, once the inner eyewall is gone, and the outer eyewall contracts to replace it, the storm intensity will increase again.


Figure 1 IR satellite view of Irene taken at 113AM EDT, August 23, 2011


Figure 2 DMSP F18 microwave overpass of Irene at 824PM EDT, August 24, 2011. Image courtesy of the Naval Research Laboratory

Track Forecast

Irene is forecast to move to the northwest, passing over the northwest Bahamas by Thursday evening, then curving to the northeast. Irene then makes landfall in the US near or at the Outer Banks Saturday afternoon, then traveling along the mid-Atlantic coastline of the US. Sunday, Irene may make secondary landfall anywhere from New Jersey to Long Island and the southern New England coastline. In my opinion, New York City may be significantly impacted by Irene. It is also important to note that the windfield of Irene is expected to be large, affecting areas distant from the immediate track of Irene's center. Tropical storm forces winds are expected to be found out to at least 150 miles away from Irene's center on Friday afternoon.

NHC is forecasting for Irene to become a Category 4 storm (winds faster than 130 mph) by Thursday morning. As Irene moves northward into cooler water, the intensity is expected to drop slowly to a Category 2 storm before making landfall in the Outer Banks.


Figure 3 Official track forecast of Irene at 2AM EDT.

Forecast models and today's planned flights
The different forecast models are still in fairly good agreement about Irene's track through the Bahamas and along the east coast of the US. The 00Z GFS run is in close agreement with the 12Z ECMWF run, but the 00Z ECMWF run (shown in figure 4) is continuing the ECMWF's trend of shifting the track westward with each run. NHC forecasters have been placing emphasis on the ECMWF's forecast track when making their forecasts for IRene, so it is possible that the NHC track will shift westwards at the 5AM update.

Looking at the plan of the day valid for today, it will be a busy day for airborne reconnaissance. Three flights for the Air Force hurricane hunters, two flights for the Gulfstream IV (Gonzo), and two flights for NOAA 42, a WP-3D (Kermit). They may have to give NOAA a littering permit for all of the dropsondes used to monitor Irene and her environment, but the forecast improvements they generate are worth the effort.


Figure 4 Plot of the maximum sustained winds in mph over the next week from the 00Z ECMWF forecast.

Impacts

Hurricane force winds will arrive in the northwestern Bahamas today. Storm surge near the center of Irene will be 7-11 feet above tide level. The Bahamas can expect 6-12 inches of rain over the next day or so, and it looks like the Turks and Caicos islands will receive a total of 6-12 inches from Irene. Large, swells from Irene will start landing on the southeastern US coastline later today. Please don't go in the water, as these swells can cause dangerous rip currents. Dr. Masters has catalogued the worst-case storm surge surge scenarios as a function of storm intensity here.

In my opinion, people living from the Carolinas to Cape Cod should pay close attention to Irene and prepare for a wide range of impacts. I think that there is a 75% chance of Irene's secondary landfall will be somewhere between JFK airport and Cape Cod. That said, Irene's size will cause significant impacts for people living far from it's center.

Dr. Masters will have a new blog entry this morning, and Angela Fritz will be covering the afternoon. I'll be back on third shift tonight.

Thanks for reading,

Dr. Rob Carver

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: 1096 - 1046

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

1096. bythegraceofgod
4:40 PM GMT on August 25, 2011
Quoting AussieStorm:
I've always wondered, How does it feel to have such a beast of a storm just a few 100 miles away. This is mother nature at her meanest and her most beautifulness.


It feels like you are waiting on a monster to come and get you.
Member Since: August 5, 2010 Posts: 0 Comments: 28
1095. bythegraceofgod
4:13 PM GMT on August 25, 2011
Quoting zoomiami:



lol -- no I don't cook on it -- I mean so that it doesn't get damaged during the storm.


LOL. I knew what you meant. I bring mine into the garage to protect it. And then cross my fingers I don't get a tree on my house.
Member Since: August 5, 2010 Posts: 0 Comments: 28
1094. portcharlotte
4:11 PM GMT on August 25, 2011
Did you say Iona Road? My dad had a small house on Iona on the water a few years ago..great spot go out into the water-way...He sold it and then passed away a few months ago..loved to fish from his houseboat..sad to lose my dad


Quoting TideWaterWeather:


Iona Road here....howdy neighbor!
Member Since: September 7, 2008 Posts: 0 Comments: 703
1093. TideWaterWeather
4:03 PM GMT on August 25, 2011
Quoting FTmyersZ:
Visible on Miami radar.....Link


Iona Road here....howdy neighbor!
Member Since: September 12, 2008 Posts: 0 Comments: 178
1092. MNhockeymama
3:41 PM GMT on August 25, 2011
Quoting weathers4me:
Just an FYI: During Hurricane Charlie down here in S FL, a lot of house fires were started once the power came back on sometimes a week or two after the storm passed. One reason was due to stuff being stacked on top of the stove and burner being left on. Power came back on and ignited contents on the stove. Just be careful people and evacuate if you live in and evac zone.


Fires can also start if generators are going when the power turns back on. After storms hit S MN 4th of July weekend, a taxidermist had a generator going to keep his freezers on when the power company "lit up the town". The power surge caused a transformer to blow which set the pole on fire which ultimately ended up burning the taxidermy to the ground.
Member Since: September 4, 2010 Posts: 0 Comments: 124
1091. tpabarb
3:38 PM GMT on August 25, 2011
What's up with Wilmington? Public advisory says hurricane watch starts at surf city but cone map clearly has wilmington in the pink.
Member Since: October 20, 2005 Posts: 0 Comments: 54
1090. mistified
3:35 PM GMT on August 25, 2011
Quoting aspectre:

857. mistified [inre the mapping in page17comment823] "Sorry, but what does this mean? The part about headed over Mt. Pleasant SC 1 day 5hrs.! Is this a past forecast or a current one?"

A straightline projection is NOT a forecast. It is information about where the storm was heading over the most recent six hours (given the constraint of having only two data points to work with), and how long it would take if the travel-speed were to remain constant.
Neither a storm's direction nor itstravel-speed is likely to remain steady.
But to help with visualization, instead of giving only a compass direction, I mention a landmark toward which the storm was moving during those 6hours.


Thank you so much for that answer! I am trying to learn these things!
Member Since: August 24, 2011 Posts: 0 Comments: 14
1089. Thoroside
3:31 PM GMT on August 25, 2011
Patrap, where are you able to pull that Long Range Miami radar from on here? I'd like to have that constant in one of my browsers. Thanks.
Member Since: July 22, 2010 Posts: 0 Comments: 14
1088. SPLbeater
3:31 PM GMT on August 25, 2011
So WIlmington is forecast to have gale force winds in 45 hours...great....I have really been praying this system doesnt messup my September beach vacation
Member Since: August 4, 2011 Posts: 46 Comments: 4485
1087. aspectre
3:31 PM GMT on August 25, 2011

857. mistified [inre the mapping in page17comment823] "Sorry, but what does this mean? The part about headed over Mt. Pleasant SC 1 day 5hrs.! Is this a past forecast or a current one?"

A straightline projection is NOT a forecast. It is information about where the storm was heading over the most recent six hours (given the constraint of having only two data points to work with), and how long it would take if the travel-speed were to remain constant.
Neither a storm's direction nor itstravel-speed is likely to remain steady.
But to help with visualization, instead of giving only a compass direction, I mention a landmark toward which the storm was moving during those 6hours.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
1086. MNhockeymama
3:30 PM GMT on August 25, 2011
Quoting HCW:
Irene Flood pic from P.R



Is this seriously a SHARK swimming down a street?
Member Since: September 4, 2010 Posts: 0 Comments: 124
1085. FTmyersZ
3:27 PM GMT on August 25, 2011
Visible on Miami radar.....Link
Member Since: August 26, 2005 Posts: 0 Comments: 60
1084. islander101010
3:25 PM GMT on August 25, 2011
last good luck everyone
Member Since: September 11, 2010 Posts: 1 Comments: 4594
1083. NortheastGuy
3:24 PM GMT on August 25, 2011
Quoting 900MB:
For Long Island: I went to sleep with the Hurricane of 38' and woke up with Gloria lite?



Well that's a good thing!
Member Since: August 26, 2009 Posts: 0 Comments: 87
1082. JBirdFireMedic
3:24 PM GMT on August 25, 2011
NEW BLOG!
Member Since: August 10, 2009 Posts: 0 Comments: 247
1081. Grothar
3:17 PM GMT on August 25, 2011
Member Since: July 17, 2009 Posts: 71 Comments: 26149
1080. ConnecticutWXGuy
3:15 PM GMT on August 25, 2011
Wow it's moving NNW now and missing FL.... how VERY "surprising" ;) ;)
Member Since: November 17, 2010 Posts: 11 Comments: 527
1079. 69Viking
3:15 PM GMT on August 25, 2011
Quoting zoomiami:


That's a good question. I was wondering that myself. Some people here in south florida use the small propane burners inside their homes, and I wondered if that was a problem.


Ahh, lots of homes have gas stoves in them, both propane and natural gas based I believe. Typically you don't cook inside with a grill because of the smoke but I don't see why you couldn't use the grill as your stove and cook with pots and pans if you have an electric stove.
Member Since: August 25, 2006 Posts: 1 Comments: 3025
1078. Zaphod
3:14 PM GMT on August 25, 2011
New blog.
Member Since: October 5, 2005 Posts: 15 Comments: 3239
1077. zawxdsk
3:14 PM GMT on August 25, 2011
Maximum Envelope of Wind for New England - Cat 2 forward speed of 25kts.



More Here Link
Member Since: August 2, 2011 Posts: 0 Comments: 195
1076. wxdrone
3:12 PM GMT on August 25, 2011
It worries me that some think this system is weakening while it's really just a temporary effect of the EWRC.
Member Since: July 4, 2008 Posts: 0 Comments: 41
1075. kshipre1
3:11 PM GMT on August 25, 2011
yeah, saw the same thing. the computer models were indicating the same thing but it seems as per the 11AM advisory that at day 5 it starts going west

maybe they mean the trough will pick it up after day 5?

who knows...

anything that goes west after a few days will have a good chance of continuing west due to the Bermuda High strengthening soon (at least it is supposed to)
Member Since: July 12, 2010 Posts: 0 Comments: 1130
1074. TruthCommish
3:11 PM GMT on August 25, 2011
Quoting zuglie:
Florida is Safe


Really depends on the neighborhood.
Member Since: September 4, 2009 Posts: 0 Comments: 158
1073. hahaguy
3:10 PM GMT on August 25, 2011
Quoting HCW:
TD#10 is getting no love and I hear talk about it being a fish LOL



Looks like ti wants to bend back after next tuesday.
Member Since: August 12, 2007 Posts: 2 Comments: 2838
1072. myway
3:09 PM GMT on August 25, 2011
Quoting Zaphod:
Propane grills are "mostly" safe, if they are working well. Indoor stoves tend not to have maintenance issues due to overfiring and such that outdoor grills do. Why take chances?

"At high enough levels, carbon monoxide is deadly, report researchers at the U.S. Environmental Protection Agency. The deadly gas is created whenever a gas grill is fired up. Carbon monoxide, or CO, is safe when the grill is operating properly, but when used improperly or in defective grills, it can be dangerous. The CDC reports that hundreds die from accidental CO poisoning every year. Fumes should always be vented outdoors with a gas grill to prevent a buildup of CO. Symptoms of carbon monoxide poisoning include nausea, headaches, confusion, shortness of breath and dizziness."


Use a table top butane burner. That is what restaurants use for table side cooking.
Member Since: May 28, 2008 Posts: 0 Comments: 446
1070. AussieStorm
3:08 PM GMT on August 25, 2011
I've always wondered, How does it feel to have such a beast of a storm just a few 100 miles away. This is mother nature at her meanest and her most beautifulness.
Member Since: September 30, 2007 Posts: 9 Comments: 15935
1069. Neapolitan
3:08 PM GMT on August 25, 2011
NEW BLOG ENTRY (with much eye-opening content)
Member Since: November 8, 2009 Posts: 4 Comments: 13537
1068. Patrap
3:08 PM GMT on August 25, 2011
Storm Relative 1km Geostationary Visible Imagery


Member Since: July 3, 2005 Posts: 424 Comments: 128314
1067. HCW
3:07 PM GMT on August 25, 2011
TD#10 is getting no love and I hear talk about it being a fish LOL

Member Since: August 10, 2002 Posts: 0 Comments: 1408
1066. Abacosurf
3:06 PM GMT on August 25, 2011
I am surprised how well it's held it's pressure seeing how ragged she looks.

Nice structure is apparent and this seems like it bodes well for strengthening as it exits Abaco later today.
Member Since: August 28, 2008 Posts: 0 Comments: 361
1065. Zaphod
3:05 PM GMT on August 25, 2011
Propane grills are "mostly" safe, if they are working well. Indoor stoves tend not to have maintenance issues due to overfiring and such that outdoor grills do. Why take chances?

"At high enough levels, carbon monoxide is deadly, report researchers at the U.S. Environmental Protection Agency. The deadly gas is created whenever a gas grill is fired up. Carbon monoxide, or CO, is safe when the grill is operating properly, but when used improperly or in defective grills, it can be dangerous. The CDC reports that hundreds die from accidental CO poisoning every year. Fumes should always be vented outdoors with a gas grill to prevent a buildup of CO. Symptoms of carbon monoxide poisoning include nausea, headaches, confusion, shortness of breath and dizziness."
Member Since: October 5, 2005 Posts: 15 Comments: 3239
1064. 996tt
3:04 PM GMT on August 25, 2011
Any one have a link to map showing actual course taken plots. I would like to see the plots over the past 6 hours to see where turn intiated.
Member Since: September 5, 2008 Posts: 0 Comments: 308
1063. TheMom
3:04 PM GMT on August 25, 2011
Daytona just had 1.6 mins of sideways rain and gone... Sun shining light breeze...This is gonna be interesting these little "touches" from Irene
Member Since: August 3, 2006 Posts: 5 Comments: 672
1062. 69Viking
3:04 PM GMT on August 25, 2011
Wow, that latest track by the NHC puts a lot of the NC coast at risk.
Member Since: August 25, 2006 Posts: 1 Comments: 3025
1061. weathers4me
3:04 PM GMT on August 25, 2011
Just an FYI: During Hurricane Charlie down here in S FL, a lot of house fires were started once the power came back on sometimes a week or two after the storm passed. One reason was due to stuff being stacked on top of the stove and burner being left on. Power came back on and ignited contents on the stove. Just be careful people and evacuate if you live in and evac zone.
Member Since: May 24, 2007 Posts: 0 Comments: 118
1060. myrtle1
3:04 PM GMT on August 25, 2011
nash i live at 33.9n 78.7 w will i have much wind
Member Since: June 8, 2008 Posts: 0 Comments: 30
1059. ecupirate
3:04 PM GMT on August 25, 2011
Quoting zoomiami:


That's a good question. I was wondering that myself. Some people here in south florida use the small propane burners inside their homes, and I wondered if that was a problem.


The regulator and burners are different on an outdoor grill and produce a much larger amount of CO then an indoor product.

Indoor products are tested, regulated, and produce much lower amounts of CO.
Member Since: July 27, 2011 Posts: 0 Comments: 204
1058. Vero1
3:03 PM GMT on August 25, 2011
.
Member Since: July 21, 2008 Posts: 4 Comments: 2233
1057. MahFL
3:03 PM GMT on August 25, 2011
"IT HAS BEEN DIFFICULT TO DETERMINE WHETHER THE HURRICANE HAS GONE
THROUGH AN EYEWALL REPLACEMENT"

Well the NHC are at least honest, which is a rare quality these days....
Member Since: June 9, 2004 Posts: 0 Comments: 3493
1056. stormygace
3:02 PM GMT on August 25, 2011
Chain saw, lots of bug spray, cold beverages on ice (lots of coolers of ice & dry ice in the freezers), plenty of gas for the chainsaw & vehicles & a mindful eye b/c the snakes are disoriented after a good blow & lots of rain & show up in places not usually seen - trying not to drown I reckon.

Wilmington is under Hurricane Watch according to TWC. Got jugs ready to fill, a 3 pack of Clorox (Bleach is the smell of victory IMAO TY Costco!), propane tank filled Monday, generator tested & ready to kick in if/when power goes out, shutters up on ground floor, roller shutters tested & ready to close at any time on upper floors, yard nearly picked up. Just have to slam in some late pepper plants, tip over big tomato plants in pots, take cuttings of tomato plants I can't tip, harvest basil, tomatoes & peppers & then go out to the country plot to harvest tomatoes, peppers, pears & plant/sling field peas & squash for late harvest. Will be making fig preserves & peach/pepper salsa while Irene rolls over.

Hopefully we will just see TS winds & rain, lottsa rain...
Member Since: September 7, 2005 Posts: 23 Comments: 1107
1055. CarolinaHurricanes87
3:02 PM GMT on August 25, 2011
Quoting HCW:


This shows Wilmington in the hurricane force winds area, with the center (and major hurricane winds) offshore by no more than 40-50 miles, and no hurricane watch? Crazy, maybe they know something we dont
Member Since: August 4, 2011 Posts: 0 Comments: 631
1054. kimSCbeaches
3:02 PM GMT on August 25, 2011
Quoting Chucktown:
We've got a media briefing with the Charleston NWS at 11 - I'll let my Lowcountry peeps know if anything has changed.


Please do!! Very anxious here in Murrells Inlet!!
Member Since: September 4, 2008 Posts: 0 Comments: 32
1053. Zaphod
3:02 PM GMT on August 25, 2011
Cat 4 fell off the projections. Maybe the NE will luck out afterall? Intensity projections are so variable....
Member Since: October 5, 2005 Posts: 15 Comments: 3239
1052. JeffM
3:02 PM GMT on August 25, 2011
Looks like a slight nudge to the left
Member Since: August 19, 2005 Posts: 0 Comments: 143
1051. wayfaringstranger
3:01 PM GMT on August 25, 2011
Quoting JeffM:
Moving NNW now


As long as the next update doesn't show another jog to the west, then we could theoretically narrow an impact to the Cape area and JFK.

One more shift west moves that area over by the amount of the shift.

Just curious, will Lady Liberty pull her toga up when wading through the storm?
Member Since: July 12, 2010 Posts: 0 Comments: 235
1050. zoomiami
3:01 PM GMT on August 25, 2011
Quoting stormwatcherCI:
Good morning. That wouldn't make sense as far as propane is concerned. I don't use my grill inside but if you can cook on a propane stove inside why not the grill ?


That's a good question. I was wondering that myself. Some people here in south florida use the small propane burners inside their homes, and I wondered if that was a problem.
Member Since: August 13, 2007 Posts: 10 Comments: 4158
1049. Patrap
3:00 PM GMT on August 25, 2011
Storm Relative 1km Geostationary Visible Imagery


Member Since: July 3, 2005 Posts: 424 Comments: 128314
1048. libertygirl
3:00 PM GMT on August 25, 2011
Link
Member Since: December 10, 2007 Posts: 0 Comments: 195
1047. Vero1
3:00 PM GMT on August 25, 2011
Quoting Zaphod:
DO NOT GRILL INDOORS though!

It's one thing to have the grill indoors so it doesn't blow away. Carbon monoxide is a given with charcoal, and possible (even likely?) with propane.
Quoting ecupirate:


Dont cook inside with a gas grill! Carbon Monoxide will kill you quicker than anything, and a gas gill produces a ton of it!
I normally cook with gas range (not electric) with the windows shut....You are speaking of charcol grills
Member Since: July 21, 2008 Posts: 4 Comments: 2233
1046. Jax82
3:00 PM GMT on August 25, 2011
Member Since: September 2, 2008 Posts: 1 Comments: 1261

Viewing: 1096 - 1046

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog 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
82 °F
Partly Cloudy