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: 3223 - 3173

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 Littleninjagrl:
I posted earlier but the blog moves so fast I think it got missed. Can someone please tell me what if anything Irene might throw at Tampa? The reason I ask is we have had a lot of rain lately and our street has been flooding a little every time it rains. The ground really hasn't had a chance to dry up so we were thinking of tying back a few trees in our front yard just in case. Any help would be appreciated.


Depends on the track, but it is a big storm, and even if it rides up the coast you could get a bunch of rain.

If it goes up the center of the state, a lot more rain!
Member Since: Posts: Comments:
3222. bwi
Conditions at CHSV3 as of
(5:54 pm AST)
2154 GMT on 08/21/2011:
Wind Direction (WDIR): W ( 270 deg true )
Wind Speed (WSPD): 5.1 m/s
Wind Gust (GST): 6.2 m/s
Atmospheric Pressure (PRES): 996.5 mb
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Recon has taken off!

Fire up Google Earth.


Thought they weren't supposed to take off for another hour...
Member Since: Posts: Comments:
easternmost buoy just reported 5:42 pressure of 29.43,or 996.61mb. But wind had shifted to the wnw so it won't go much lower. This is at least a 995mb storm!
Member Since: Posts: Comments:
Intense run of the GFS.

Member Since: Posts: Comments:
Strong supercell crossing Southern NJ...



Member Since: Posts: Comments:
PR radar is the best place to see real time movement/direction. For now, looks due west to me. St Crx in the coc
Member Since: Posts: Comments:
Sabana Grande, PR: extremely calm, no winds whatsoever, very light drizzle, some dark clouds from the SE.
Member Since: Posts: Comments:
Levi...quick question...Do you expect the market to open up or down tomorrow morning? Thanks!!
Member Since: August 13, 2007 Posts: 0 Comments: 10492
3213. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128888
3212. Levi32
996.5mb and light west winds.

Member Since: Posts: Comments:
Quoting Skyepony:
Taz~ LBAR is still liking Greg to come your way..just thought you'd wanna see.





thanks
Member Since: Posts: Comments:
3210. amd
Quoting stormpetrol:
I think there is no doubt now that Irene is actually moving a tad south of due west, if this trend continues, I think the track will probably shift left at 11pm.jmo


Buiy CHSV3

Read the wind direction from 12 pm to now. It has gone from ENE to WNW. That means it has gained latitude, and is currently just to the NNE of St Croix.
Member Since: Posts: Comments:
Recon has taken off!

Fire up Google Earth.
Member Since: Posts: Comments:
Quoting MississippiWx:


LOOKS WSW
Member Since: Posts: Comments:
Quoting wpb:
how close is this run to the prior 12zrun


Similar, but a little east.
Member Since: Posts: Comments:
Quoting Patrap:




westward motion
Member Since: Posts: Comments:
Methurricanes,
thinking 65 mph, 996 MB
Member Since: Posts: Comments:
Quoting interstatelover7165:
Taz where do you get that info? NHC i'm assuming?





here you go


Link
Member Since: Posts: Comments:
Quoting stormpetrol:
I think there is no doubt now that Irene is actually moving a tad south of due west, if this trend continues, I think the track will probably shift left at 11pm.jmo
Many here will disagree with you, but I've been thinking at least due west. We shall see.
Member Since: Posts: Comments:
Quoting Tazmanian:
AM HAPPY TOO REPORT THAT THE RECON HAS TAKE IN OFF

Super-Happy Taz Time!
Member Since: July 7, 2010 Posts: 0 Comments: 5695
3200. wpb
Quoting WxLogic:
102HR:

TROF not as strong... could get caught underneath a building high temporarily

how close is this run to the prior 12zrun
Member Since: Posts: Comments:
3199. WxLogic
114HR:

Doing its best on breaking free before making landfall.

Member Since: Posts: Comments:
Quoting Tazmanian:
AM HAPPY TOO REPORT THAT THE RECON HAS TAKE IN OFF
Taz where do you get that info? NHC i'm assuming?
Member Since: Posts: Comments:
Quoting Levi32:


I think that's a great idea Littleninja. Irene could still easily come into east Florida, and given that she's a large system, Tampa could potentially see tropical storm conditions on the outer edge of a system making landfall on the peninsula. I would definitely think about taking some precautions in case the track is into Florida.


Thanks Levi!!!!!
Member Since: Posts: Comments:
3193. Skyepony (Mod)
Taz~ LBAR is still liking Greg to come your way..just thought you'd wanna see.

Member Since: Posts: Comments:
Quoting BaltimoreBrian:
I'll guess a 25% chance of a landfall in FL, 10% in GA, 50% in SC, and 10% in NC, with 5% either dying or out to sea.

What do you think Levi? Or you Drakoen?


I don't know how you can base a forecast on a few sets of model runs shifting....Florida is still the highest likely to get this storm. IMO
Member Since: Posts: Comments:
well, this isnt a 50 mph Tropical storm anymore.
Im guessing closer to 70-75 mph.
Member Since: Posts: Comments:
AM HAPPY TOO REPORT THAT THE RECON HAS TAKE IN OFF
Member Since: Posts: Comments:
storms a movin towards the coast here in swfl,some may get strongimg src="2011 08 21 18 12 00 55">
Member Since: Posts: Comments:
3187. Gorty
She has a nice eye. Developing hurricane.
Member Since: Posts: Comments:
Quoting HurricaneIrene:



An unreliable run, CLEARLY.


This is what a troll looks like. If you should see a troll, please help the blog out by clicking '-' and 'Ignore User'. Thank you.
Member Since: Posts: Comments:
Dangerous system

Heading for SC still

Member Since: Posts: Comments:
pretty interesting listeningLink
Member Since: August 13, 2007 Posts: 0 Comments: 10492
3183. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128888
Funny and not surprising how it's an I storm that may end up breaking the tropical storm streak.

Only once has it been used for a storm that didn't become a hurricane since 1995 (in 2007; it wasn't used in 1997).

Just the way the alphabet falls with the increased quantity of storms that are observed these days due to various factors.

I guess with this going on, nobody's paying much attention to Libya. Looks like it might finally be coming to the end.
Member Since: Posts: Comments:
Quoting duajones78413:
Just curious, what are the chances that this misses the US altogether?


Very slim. However, even if for some reason Irene doesn't make landfall in the US she's pretty big so we'd get rain impact and potential tornadoes spawn up from her bands.
Member Since: Posts: Comments:
Quoting Littleninjagrl:
I posted earlier but the blog moves so fast I think it got missed. Can someone please tell me what if anything Irene might throw at Tampa? The reason I ask is we have had a lot of rain lately and our street has been flooding a little every time it rains. The ground really hasn't had a chance to dry up so we were thinking of tying back a few trees in our front yard just in case. Any help would be appreciated.


I would just monitor my local weather for the next few days. They should have a better idea of where Irene is going by then.
Member Since: Posts: Comments:
Quoting FLdewey:


Depends on the track... just gotta wait and see.


thanks! I figured...LOL Just trying to stay ahead of the game :)
Member Since: Posts: Comments:
3176. Skyepony (Mod)
CURRENT ESTIMATE
Date (yyyymmddhh): 2011082117
SATCON (2mem): MSLP = 995 hPa MSW = 51 kt
ADT: 999 hPa 47 kt Scene: CRVBD
CIMSS AMSU: 995 hPa 52 kt Bias Corr: 0 (TPC)
CIRA AMSU: NA hPa NA kt Tmax: NA


Notice SATCON is being a little more aggressive than ADT... & that Scene type is Curved Band not eye..

Member Since: Posts: Comments:
The models are limited when analyzing a storms interaction with large land islands...put me down for a poof. I don't think this one is going to do too much.
Member Since: Posts: Comments:
3174. MahFL
Those new central bands just made the eye about half as wide......
Member Since: Posts: Comments:
Quoting NICycloneChaser:


This run of the GFS will parallel the Florida Coast a couple of hundred miles offshore and make a bee line for the Carolinas, or slightly west of there. The run might be wrong, but that's what it will show.


Good evaluation...
Member Since: October 26, 2003 Posts: 0 Comments: 363

Viewing: 3223 - 3173

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.

Local Weather

Mostly Cloudy
70 °F
Mostly Cloudy