Dangerous Tropical Storm Irene headed for the Dominican Republic

By: Dr. Jeff Masters , 2:38 PM GMT on August 21, 2011

Share this Blog
48
+

Tropical Storm Irene roared into life last night, transitioning from a tropical wave to a 50 mph tropical storm in just a few short hours. Irene is getting organized quickly, and has the potential to become a hurricane by Monday morning. All interests in the Dominican Republic, Haiti, Cuba, the Bahamas, and South Florida should prepare for the arrival of this dangerous storm. An Air Force hurricane hunter aircraft in the storm found the strongest winds near 18°N latitude to the north of Irene's center at 8am this morning. After passing through the center, the plane returned to the area of strongest winds two hours later, and found that flight level winds at 5,000 feet had increased by about 5 - 8 mph. However, the pressure in the latest center fix taken at 10am EDT remained the same as two hours previously, 1007 mb, and the plane noted that Irene's center was not circular, signs that the storm still has some work to do before serious intensification can begin. Visible satellite loops and radar out of Martinique show the storm has rapidly organized this morning, with well-developed spiral bands forming and a large area of intense thunderstorms to the north of the center. Irene has shrugged off the dry air that was bothering it yesterday, and wind shear has fallen to the low range, 5 - 10 knots, as analyzed by the University of Wisconsin CIMSS group. Torrential rains and strong gusty winds are affecting the northern Lesser Antilles this morning. A wind gust of 41 mph was recorded at St. Eustatius at 8am local time.


Figure 1. Morning satellite image of Irene.

Track forecast for Irene
The computer models are in agreement that Irene will pass just south of Puerto Rico tonight, then hit the south coast of Hispaniola in the Dominican Republic or Haiti on Monday afternoon. Irene should then emerge into the channel between Haiti and Cuba on Tuesday afternoon, when the storm will have 12 or so hours over water before having to contend with Cuba. A trough of low pressure is expected to move across the Eastern U.S. on Wednesday and Thursday, turning Irene to the northwest and north by Thursday. The timing and strength of this trough varies considerably from model to model, and will be critical in determining where and when Irene will turn to the north. Irene's strength will also matter--a stronger Irene is more likely to turn northward earlier. The most likely path for Irene is a track just east of the Florida Peninsula and into Georgia, South Carolina, or North Carolina by next weekend, but a landfall near Miami then directly up the Florida Peninsula is also a reasonable solution--like Tropical Storm Fay of 2008 did. Fay formed just off the coast of Puerto Rico, and was never quite able to get organized enough to become a hurricane, due to passage over Hispaniola and Cuba. Fay topped out as a strong tropical storm with 70 mph winds, and did over $500 million in damage in the U.S., mostly due to flooding rains in Florida that accumulated to over 25 inches in a few areas. Fay also dumped heavy rains on Hispaniola, triggering flooding that claimed eight lives.


Figure 2. Track of Tropical Storm Fay of 2008.

Intensity forecast for Irene
Irene is embedded in a large envelope of moisture now, and wind shear will remain low, 5 - 10 knots, for the next five days. With water temperatures very warm, 28 - 30°C, these conditions should allow for intensification except when land is interfering. Irene's current appearance on satellite loops gives me the impression of a storm that is not fooling around, and I expect Irene will be a hurricane before hitting Hispaniola on Monday. Passage over Hispaniola will not destroy Irene, since it is a fairly large storm. Once the storm finishes with Hispaniola, it will have to deal with Cuba, which will keep Irene from intensifying significantly. Once Irene pops off the coast of Cuba Wednesday or Thursday into the Florida Straits, Irene will likely be a tropical storm. If the storm then has at least a day over water before hitting land, it will likely become a hurricane again, and could become a major hurricane if it ends up missing South Florida and moving over the warm waters on either side of the Florida Peninsula.

Harvey hits Belize
Tropical Storm Harvey made landfall at 2pm EDT on Saturday near Dangriga Town, Belize, as a tropical storm with 60 mph winds. Harvey continues to dump very heavy rains on southern Mexico, but dissipation is expected tonight as the storm pushes inland. Harvey was a small storm, and the strongest winds were confined to a short stretch of coast near where the center came ashore. Winds at Belize City, Belize on Saturday topped out at 15 mph.


Figure 3. Radar image of Harvey taken at 11:30am EDT on Saturday, August 20, 2011, a few hours before landfall in Belize. A small closed eye is visible just south of the offshore islands of Belize. Image credit: Belize National Meteorological Service.

Invest 98L northwest of the Cape Verde Islands
A tropical wave few hundred miles northwest of the Cape Verde Islands off the coast of Africa, Invest 98L, has become disorganized and lost most of its heavy thunderstorms. The disturbance is moving over colder waters and encountering drier air, and NHC is giving 98L only a 10% chance of developing into a tropical depression by Tuesday. The latest set of model runs keep 98L well out to sea away from any land areas over the next five days.

Links
Long-range radar out of Puerto Rico

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: 2873 - 2823

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160Blog Index

Quoting charliesurvivor04:
I live on the west coast of Fla. and I know most of the models take it over the East coast but why is the GFDL still taking it West? Could all the other models be wrong?


Really depends on how much interaction Irene has with Hispanola. The more interaction with the land the weaker the storm will be and the further west it will go before turning north.
Member Since: Posts: Comments:
Levi can you give me a link to the St croix buoy/station
Member Since: Posts: Comments:
2869. mbjjm
Microwave imagery Irene











Member Since: Posts: Comments:
2868. breald
Quoting StormJunkie:


Nice. Maybe in a year when I have my avionics degree and FCC certification; I can find a way in to the maintenance market for the Hunters...


That is a great field to get into. My ex got his avionics certification. It was a tough test to pass, but I am sure you will do fine.
Member Since: Posts: Comments:
St. Croix pressure is 1003 mb
Member Since: Posts: Comments:
Quoting Levi32:


Welcome to the blog. I believe some are focusing too much on the "eye" feature on radar, which is not really an eye, and draws the human eye to it as the center of the storm, when reality the center is on the southeast side of that clear area. Thus, the clear area will naturally rotate southwest and give the illusion of a wobble in that direction.


Levi, would that then mean that once she becomes vertically stacked the center would relocate under that clear area or would the clear area relocate under the current center?
Member Since: Posts: Comments:
Quoting Clearwater1:


Maybe because it calculates a weakening when hits a land mass? Just a guess.


Because the GFDL shows it weakening quite a bit due to crossing directly over the spine, and tall mountains of Hispanola and E Cuba. Weaker storm= track slightly further West.

All the other models have it clipping the N Coast of Hispanola, therefore less weakening, a much more significant storm.
Member Since: Posts: Comments:
2862. KEEPEROFTHEGATE (Mod)
she'll hesitate interaction with pr don't fret we will be a go again after midnight
Member Since: July 15, 2006 Posts: 174 Comments: 54639
Look like only small part of Irene will hit the northern side of Hispaniola and it's pretty much flat there...

Member Since: August 1, 2011 Posts: 28 Comments: 8032
ok so I went out and stocked up on some batteries so that should mean that the storm won't hit south florida right? haha
Member Since: Posts: Comments:
Member Since: Posts: Comments:
2858. Grothar
Looks like it is moving due West. Thought is was supposed to go to the North of Puerto Rico. This might change the models again. Just saying.
Member Since: July 17, 2009 Posts: 71 Comments: 26558
2857. Levi32
Quoting TropicalAnalystwx13:


Then, what IS that clear area??

-----

Outflow on the SW side of the system...Not beautiful.



A patch of dry air, possibly accentuated a bit by the core the way an eye would be. We could easily see the beginnings of an eyewall start to form around the east side of it eventually.
Member Since: Posts: Comments:
When will Recon be getting back into Irene?
Member Since: Posts: Comments:
2854. Drakoen
Irene does not have an eye. Microwave imagery imagery suggests a partial eyewall on the southern side, but certainly not closed.

Member Since: Posts: Comments:
Quoting Levi32:


Welcome to the blog. I believe some are focusing too much on the "eye" feature on radar, which is not really an eye, and draws the human eye to it as the center of the storm, when reality the center is on the southeast side of that clear area. Thus, the clear area will naturally rotate southwest and give the illusion of a wobble in that direction.


Radar reveals the center is just east of St. Croix. It's not the large hole, but it's the smaller hook looking feature in this loop.



Member Since: Posts: Comments:
Quoting Levi32:
We're still waiting for healthier convection to envelope Irene's core, like the kind that was firing last night.

levi what do you think Irene may go do you agree with the current NHC track
Member Since: Posts: Comments:
Member Since: April 29, 2007 Posts: 0 Comments: 7935
Aloha from St. Thomas. I'm sitting on a boat in Charlotte Amalie harbor. Have been having pretty good winds in the 40kt range with some gusts up in the mid 50's on my apparent wind instrument. We have been in that strong NW portion for a couple of hours now. I'll be glad to see Irene go bye bye. For my friends in PR, I hope she doesn't get much stronger by the time she gets there. Will keep you posted tonight as things move along.
Member Since: Posts: Comments:
2849. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 174 Comments: 54639
Quoting scott39:
Not to mention the dramatization of how strong it may get.


+1000
Member Since: Posts: Comments:
Getting gusty...
Member Since: July 7, 2010 Posts: 0 Comments: 5695
2846. Grothar
img src="">
Member Since: July 17, 2009 Posts: 71 Comments: 26558
2845. THL3
Can they launch a dropsonde up?
Member Since: Posts: Comments:
2844. KEEPEROFTHEGATE (Mod)
Quoting TropicalAnalystwx13:
Wow...Look at the outflow on the NW quadrant..*breaks down in tears* Beautiful !

and deadly
Member Since: July 15, 2006 Posts: 174 Comments: 54639
2843. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128875
Quoting charliesurvivor04:
I live on the west coast of Fla. and I know most of the models take it over the East coast but why is the GFDL still taking it West? Could all the other models be wrong?


Maybe because it calculates a weakening when hits a land mass? Just a guess.
Member Since: August 26, 2006 Posts: 0 Comments: 1548
Caribbean Radio Guide...if it ain't here...you don't need it
Link
Member Since: Posts: Comments:
2839. WxLogic
Quoting Drakoen:
Not sure if this was already posted, but the ECWMF and the ECMWFEPS are not too far off. With the ECMWFEPS on the left, and the ECWMF operational on the right Florida needs to continue to monitor this system.


Nope it wasn't posted Drakoen... was meaning to check it out but got side track. Thanks for pointing that out.
Member Since: Posts: Comments:
Quoting Levi32:


Welcome to the blog. I believe some are focusing too much on the "eye" feature on radar, which is not really an eye, and draws the human eye to it as the center of the storm, when reality the center is on the southeast side of that clear area. Thus, the clear area will naturally rotate southwest and give the illusion of a wobble in that direction.


Then, what IS that clear area??

-----

Outflow on the SW side of the system...Not beautiful.

Member Since: Posts: Comments:
Quoting weatherxtreme:
When will recon be getting in there again?



7pm
Member Since: May 21, 2006 Posts: 5091 Comments: 115255
2836. Levi32
Quoting TropicalAnalystwx13:


Levi, if the only land it has to contend with is Puerto Rico, exactly how strong could the system get?

Just a guesstimate.


Well it probably won't avoid northern Hispaniola. If it were to avoid it by a wobble or something, then we would be talking about a steadily-strengthening hurricane, likely into a major before it reached the US. Much of its final intensity will depend on which U.S. state it hits. Florida means less time over water, while the Carolinas mean more.
Member Since: Posts: Comments:
...it's raining again...
Member Since: July 7, 2010 Posts: 0 Comments: 5695
Quoting Levi32:
We're still waiting for healthier convection to envelope Irene's core, like the kind that was firing last night.

I agree.
Sounds like you were staying at the same Holiday Inn Express I was last night...and you heard the yelling going on in the room nextdoor. I think they were watching as the GFS run came in, but I'm not sure.
Member Since: Posts: Comments:
2833. 7544
somebody check irenes pressure l please
oh i mean blood pressure shes getting alittle upset lol
Member Since: Posts: Comments:
Here is something worth pointing out:

2:00 PM Thursday - wind speed is 85 MPH (offshore)
2:00 PM Friday - wind speed is 60 MPH (Orlando, FL)

Depending on land interaction, these may be much higher. Sustained winds of 60 MPH near Orlando, FL is nothing to laugh at as Gainesville, FL had sustained winds of 40 mph with gusts to 60 with both Frances & Jean back in 2004. This caused a lot of downed trees and power outages.
Member Since: Posts: Comments:
She sure is wobbling.... wobble of to central florida so i can fish my flowing culverts
Member Since: Posts: Comments:
Quoting Levi32:
1001mb at St. Croix and falling like a rock.



Just updated- 1000mb and still dropping.
Member Since: Posts: Comments:
Almost looks like "the eye" is sort of splitting in half... So is the north part or south part the real center? Anyone else seeing this?
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
Wow...Look at the outflow on the NW quadrant..Beautiful *sniffle*


lol
Member Since: July 7, 2010 Posts: 0 Comments: 5695
I live on the west coast of Fla. and I know most of the models take it over the East coast but why is the GFDL still taking it West? Could all the other models be wrong?
Member Since: Posts: Comments:
Quoting charlottefl:


An eyewall is definitely forming. This is 0.5 degree tilt out of San Juan. 9,500 ft above the radar site.


It's still open to the NE
Photobucket
I've seen hurricanes that look worse, this is a great looking tropical storm
Member Since: Posts: Comments:
2824. Skyepony (Mod)
There's WUndercams on St Croix..

Member Since: Posts: Comments:
Quoting Drakoen:
As I had mentioned earlier, it seems as though PR could get a direct hit from Irene.


Hey Drak, interested to hear your thoughts on track?
Member Since: July 17, 2008 Posts: 0 Comments: 1242

Viewing: 2873 - 2823

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160Blog 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.