Dr. Jeff Masters' WunderBlog

Dangerous Tropical Storm Irene headed for the Dominican Republic
Posted by: Dr. Jeff Masters, 2:38 PM GMT on August 21, 2011 +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
Categories: Hurricane
  Permalink | A A A
Reader Comments
Display: 0, 50, 100, 200 Sort: Newest First - Order Posted
Viewing: 3301 - 3351

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

3301. WeatherNerdPR 10:30 PM GMT on August 21, 2011    
There was (briefly) a TVS in Cayey:

Member Since: July 7, 2010 Posts: 0 Comments: 5490
3302. OracleDeAtlantis 10:31 PM GMT on August 21, 2011    
Quoting Stormchaser2007:
SC it is...

Stop it!
Member Since: August 27, 2009 Posts: 0 Comments: 323
3303. stormwatcherCI 10:31 PM GMT on August 21, 2011    
Quoting HurricaneIrene:


West-casting it towards the Cayman islands, I see, if only, SIGH.
Actually I am hoping it heads straight to FIU where your dorm is. Back off.
Member Since: October 9, 2008 Posts: 0 Comments: 8063
3304. KEEPEROFTHEGATE (Mod) 10:31 PM GMT on August 21, 2011    
Member Since: July 15, 2006 Posts: 147 Comments: 41332
3305. MidwestGuy 10:31 PM GMT on August 21, 2011    
Quoting ncstorm:


I second that about the blog being kaput if Levi left!







I 3 rd. that
Member Since: September 5, 2010 Posts: 0 Comments: 32
3307. Patrap 10:32 PM GMT on August 21, 2011    
Member Since: July 3, 2005 Posts: 377 Comments: 112987
3308. xcool 10:32 PM GMT on August 21, 2011    
P451:
lol
Member Since: September 26, 2009 Posts: 2 Comments: 15526
3309. Levi32 10:32 PM GMT on August 21, 2011    
Quoting NCHurricane2009:


Is this still on the track you projected for Irene this morning Levi?


Yes, because it puts it on a line to Puerto Rico for its first real landfall.
Member Since: November 24, 2005 Posts: 593 Comments: 25612
3310. HCW 10:32 PM GMT on August 21, 2011    
.....
Member Since: August 10, 2002 Posts: 0 Comments: 1291
3312. TropicalAnalystwx13 10:32 PM GMT on August 21, 2011    
Quoting WeatherNerdPR:
There was (briefly) a TWISTER in CAYEY!!

Obviously gone now.


Obviously.
Member Since: July 6, 2010 Posts: 92 Comments: 25982
3315. WeatherNerdPR 10:32 PM GMT on August 21, 2011    
Quoting Vincent4989:

Winds of?

Just by looking, and hearing it, 30 - 40mph gust. The two closest stations are ~5 miles north or south of me.
Member Since: July 7, 2010 Posts: 0 Comments: 5490
3317. HurricaneDean07 10:33 PM GMT on August 21, 2011    
So with Irene north of St Croix that would bring Irene probably even further into PR, and that in part would also bring Irene further north, and cuase her skim the coast more than come into the coast...
Member Since: October 3, 2010 Posts: 40 Comments: 4129
3318. biloxibob 10:33 PM GMT on August 21, 2011    
Quoting Levi32:


Yes, because it puts it on a line to Puerto Rico for its first real landfall.
Maybe a little bit south of PR?
Member Since: August 21, 2011 Posts: 0 Comments: 138
3319. xcool 10:33 PM GMT on August 21, 2011    


eye
Member Since: September 26, 2009 Posts: 2 Comments: 15526
3322. islander101010 10:34 PM GMT on August 21, 2011    
teleconnecting for the carolinas
Member Since: September 11, 2010 Posts: 0 Comments: 3076
3323. NCHurricane2009 10:34 PM GMT on August 21, 2011    
Quoting Levi32:


Yes, because it puts it on a line to Puerto Rico for its first real landfall.


Would you say it has been moving WNW or west over last hours...I keep getting mixed messages about current motion when studying radar and sat loops...I really can't tell right now....
Member Since: September 15, 2009 Posts: 302 Comments: 3389
3326. Levi32 10:34 PM GMT on August 21, 2011    
Recon taking off in the center of the storm lol. 995.4mb pressure.
Member Since: November 24, 2005 Posts: 593 Comments: 25612
3327. c150flyer 10:35 PM GMT on August 21, 2011    
Quoting Stormchaser2007:
Down to 996



What program is that that you are using??
Member Since: September 12, 2008 Posts: 0 Comments: 70
3328. TropicalAnalystwx13 10:35 PM GMT on August 21, 2011    
I must say, Irene has the satellite appearance of at least a 70 mph storm. Look at the banding features, the outflow, the bulk of convection to the N/NE of the center, just wow...

Member Since: July 6, 2010 Posts: 92 Comments: 25982
3331. HuracanTaino 10:35 PM GMT on August 21, 2011    
69mph winds in squalls,reported in Charlotte Amalie, Saint Thomas...
Member Since: May 31, 2011 Posts: 0 Comments: 536
3332. OracleDeAtlantis 10:35 PM GMT on August 21, 2011    
Quoting stormwatcherCI:


If these are the current steering layers for the strength that Irene is can someone please tell me how she can go WNW when it looks clearly West or even a little WSW. Also, is the line with the arrows on it a ridge or if not what is it ?
She looks to me, to be going a little southwest now.
Member Since: August 27, 2009 Posts: 0 Comments: 323
3334. Clearwater1 10:36 PM GMT on August 21, 2011    
Quoting Stormchaser2007:


Hopefully this clears it up for the folks who thinks its heading WSW...

It's clear the coc is over st Crx., So, if the coc is over PR in a few hours or so, the def. wnw. If it's south of PR, well then heading west. But def came up to St. Cr from St. Kits. That's def wnw
Member Since: August 26, 2006 Posts: 0 Comments: 1503
3335. Bluestorm5 10:36 PM GMT on August 21, 2011    
Lowest pressure so far is 995.4
Member Since: August 1, 2011 Posts: 12 Comments: 4304
3336. stormpetrol 10:36 PM GMT on August 21, 2011    
Quoting stormwatcherCI:
Actually I am hoping it heads straight to FIU where your dorm is. Back off.


I guess if some here had experienced what we did with Ivan in 2004 , they wouldn't be so quick to call us wishcasters, we just call it like we see, whether right or wrong, we're entitled to our opinions, don't let such persons get to you , I've learned to basically just pass them by, anyway when they experience a major hurricane that pounds them for 36 hours non stop and its consequences maybe they'll grow up a bit, just saying...
Member Since: April 29, 2007 Posts: 0 Comments: 6494
3337. TropicalAnalystwx13 10:36 PM GMT on August 21, 2011    
When using pressure, a Category 1 hurricane has pressures lower than 994 mb...Recon just found 995 mb. This leads me to believe that the system is around 70 mph at this time, and I believe that recon will find some interesting readings...

The pressure thing does apply to Irene since she is NOT of monsoonal nature like Alex of last season was.
Member Since: July 6, 2010 Posts: 92 Comments: 25982
3339. benirica 10:36 PM GMT on August 21, 2011    
If it is going to intensify I sure hope it makes landfall as a hurricane.
It would be sad to have a repeat of TS Jeanne back in 2004... came in as a 70mph storm and devastated crops. Unfortunately, since it was a tropical storm insurance for the farmer's losses did not cover.
Member Since: August 3, 2006 Posts: 0 Comments: 1142
3340. KeyWestwx 10:36 PM GMT on August 21, 2011    
Quoting Clearwater1:
Many here will disagree with you, but I've been thinking at least due west. We shall see.
It appears it's shifting a little wsw but I think it's an illusion of shawdows created by high cloud tops and a few other factors. See the visible loop for that. To me it looks like the center is going to pass right over the south portion of PR. t
This might hinder developement some.
Member Since: September 20, 2008 Posts: 0 Comments: 261
3341. chrisdscane 10:36 PM GMT on August 21, 2011    
Quoting NCHurricane2009:


Would you say it has been moving WNW or west over last hours...I keep getting mixed messages about current motion when studying radar and sat loops...I really can't tell right now....




look at the satelite and radar its moving west ok, mayne even a sw job if u look closely and analyze it u'll see
-
Member Since: July 21, 2010 Posts: 0 Comments: 739
3343. Patrap 10:37 PM GMT on August 21, 2011    
Member Since: July 3, 2005 Posts: 377 Comments: 112987
3344. mrpuertorico 10:37 PM GMT on August 21, 2011    
i have 997 on my personal weather station
Member Since: July 10, 2006 Posts: 0 Comments: 833
3345. FISHHEAD4UFl 10:37 PM GMT on August 21, 2011    
its definetly looking like shes going
west not wnw
Member Since: August 17, 2011 Posts: 0 Comments: 22
3346. stormwatcherCI 10:37 PM GMT on August 21, 2011    
Quoting OracleDeAtlantis:
She looks to me, to be going a little southwest now.
I see that too but others are saying wnw so IDK.
Member Since: October 9, 2008 Posts: 0 Comments: 8063
3347. Stormchaser2007 10:38 PM GMT on August 21, 2011    
Quoting c150flyer:


What program is that that you are using??


GRLevel2 Analyst with a bunch of placefiles
Member Since: June 9, 2007 Posts: 4 Comments: 15296
3348. NCHurricane2009 10:38 PM GMT on August 21, 2011    
Quoting TropicalAnalystwx13:
I must say, Irene has the satellite appearance of at least a 70 mph storm. Look at the banding features, the outflow, the bulk of convection to the N/NE of the center, just wow...



She HAS to be stronger in the next advisory...just has to be....
Member Since: September 15, 2009 Posts: 302 Comments: 3389
3349. Abacosurf 10:38 PM GMT on August 21, 2011    
Quoting Levi32:
Recon taking off in the center of the storm lol. 995.4mb pressure.
Wonder how many times that has been done....LOL
Member Since: August 28, 2008 Posts: 0 Comments: 916
3350. Grothar 10:38 PM GMT on August 21, 2011    
Quoting TropicalAnalystwx13:
I must say, Irene has the satellite appearance of at least a 70 mph storm. Look at the banding features, the outflow, the bulk of convection to the N/NE of the center, just wow...

Quoting TropicalAnalystwx13:
I must say, Irene has the satellite appearance of at least a 70 mph storm. Look at the banding features, the outflow, the bulk of convection to the N/NE of the center, just wow...



Yep, beginning to take on that comma shape like I mentioned about an hour ago. Interesting to see what it does tonight. I hope all our friends in PR and the other islands stay safe.
Member Since: July 17, 2009 Posts: 58 Comments: 19680
3351. Bluestorm5 10:38 PM GMT on August 21, 2011    
Plane going to NE toward the strongest part of Irene. I think they'll find ~63knots flight level, ~55 knots surface. What ya'll think?
Member Since: August 1, 2011 Posts: 12 Comments: 4304

Viewing: 3301 - 3351

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

New Comment
Community Standards Policy Comments will take a few seconds to appear.
Post Your Comments
Please sign in to post comments.
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.
About JeffMasters
Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Community Activity