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: 3423 - 3373

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

Peak (10s) Flt. Lvl. Wind: 56 knots (~ 64.4 mph)
SFMR Peak (10s) Sfc. Wind: 49 knots (~ 56.3 mph)
SFMR Rain Rate: 4 mm/hr (~ 0.16 in/hr)
(*) Denotes suspect data
At least a 65 mph storm.
Member Since: Posts: Comments:
Quoting bythegraceofgod:
Boy, it sure looks to me like Irene is going south of PR. How can they keep saying she is going north? I just don't see it.


It's because that gaping hole that you are seeing is not an eye, it's a dry air spot, and it is being mixed out, making it look like it's moving WSW. The circulation is moving W/WNW, and recon should prove that after the next pass.
Member Since: Posts: Comments:
:O

Kinda Fat.
Member Since: July 7, 2010 Posts: 0 Comments: 5725
3420. WxLogic
Quoting ElConando:


Its going to the good air. Luckily that is over land.


That land interaction... specially with DR will keep her in check, but if it stays S of PR instead of going through it then then it could intensify some more.
Member Since: Posts: Comments:
Quoting NICycloneChaser:


That's flight-level.



i no i this wanted too point that out
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
Quoting Grothar:


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.


You gonna let me know when I need to board up and split?
Member Since: Posts: Comments:
Quoting Jax82:
rut row, is she gonna pass north, south, or right over PR? Looks like directly.



IF, the center moved due W from it's current location it would be scraping the S coast of Puerto Rico..
Member Since: Posts: Comments:
50 Mph found by Recon so far, 60 Mph flight level in all the latest dropsondes...
Member Since: Posts: Comments:
Quoting mikatnight:
From BoatUS
Wind Fields for Irene
Last Updated On 8/21/2011 6:29:12 PM



Very nice! Thank you.
Member Since: October 26, 2003 Posts: 0 Comments: 363
looks like Irene is taking a dip to the wsw..........
Member Since: Posts: Comments:
She will be a hurricane for sure by 11pm..... looks to pretty not to be
Member Since: Posts: Comments:
the eye developed right over them
Member Since: Posts: Comments:
Quoting Tazmanian:
57 knots
(~ 65.5 mph)
surface winds is 43 knots though...
Member Since: Posts: Comments:
Quoting Patrap:


Are those the lastest and did they shift left?
Member Since: Posts: Comments:
Quoting Tazmanian:
57 knots
(~ 65.5 mph)


That's flight-level.
Member Since: Posts: Comments:
Boy, it sure looks to me like Irene is going south of PR. How can they keep saying she is going north? I just don't see it.
Member Since: Posts: Comments:
Quoting FLdewey:
Getting breezy... 69 MPH wind gust at St. Thomas at 5:56


thank you
Member Since: Posts: Comments:
I can post recon images for a little while.

Member Since: Posts: Comments:
57 knots
(~ 65.5 mph)
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
From BoatUS
Wind Fields for Irene
Last Updated On 8/21/2011 6:29:12 PM

Member Since: Posts: Comments:
Quoting Levi32:


A little bit north of west, I would say, but not due west.
OK...do you think it is heading 271 degrees or 273 degrees? Or maybe 274. Cmon...Cmon...
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Approaching SC

We can't handle another Hugo.
Member Since: Posts: Comments:
3399. HCW
P.R radar reload for updates

Member Since: Posts: Comments:
Irene looks primed for significant development overnight.
Member Since: Posts: Comments:
Quoting HurricaneIrene:


Hi there, have the Hunters arrived yet?


and THAT has convinced me! Goodnight all.

I have a hunch things will continue to trend east with Irene. We'll see.
Member Since: Posts: Comments:
Quoting violet312s:
LOL, not surprisingly HHers flew around St. Croix first.

Gee I wonder why.
Member Since: July 7, 2010 Posts: 0 Comments: 5725
Quoting P451:


Recon heading in. May make it in time to sample the winds and give the NHC enough data to put out a good advisory at 8PM.
Well is to late,for the people of Saint Thomas, without warning been hit by 69mph winds in Charlotte Amalie...
Member Since: Posts: Comments:
Time: 22:28:00Z
Coordinates: 17.7833N 64.7333W
Acft. Static Air Press: 830.3 mb (~ 24.52 inHg)
Acft. Geopotential Hgt: 1,585 meters (~ 5,200 feet)
Extrap. Sfc. Press: 995.4 mb (~ 29.39 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 186° at 12 knots (From the S at ~ 13.8 mph)
Air Temp: 18.0°C (~ 64.4°F)
Dew Pt: 17.5°C (~ 63.5°F)
Peak (10s) Flt. Lvl. Wind: 14 knots (~ 16.1 mph)
SFMR Peak (10s) Sfc. Wind: -
SFMR Rain Rate: -
(*) Denotes suspect data
Member Since: Posts: Comments:
Quoting Levi32:


A little bit north of west, I would say, but not due west.


thx levi but its very slighty north of due west barely wnw
Member Since: Posts: Comments:
Quoting biloxibob:
Maybe a little bit south of PR?


Well...it has been confirmed that Irene is centered just north of St. Croix...

...that would mean Irene would have to from here forthwith to go straight west without ANY SLIGHT northward/wobble component to avoid a landfall on Puerto Rico....so the window has pretty much closed for the center to avoid Puerto Rico to the south....
Member Since: Posts: Comments:
Quoting Levi32:


They didn't even have to leave the ground to arrive lol.

LOL
Member Since: July 7, 2010 Posts: 0 Comments: 5725
Quoting WxLogic:
We'll see in a couple hours and HH fixes but if it continues in the current track (based on SAT/Radar obs) Irene could pass S of the next forecast point.

Would not be surprised given that height across PR/DR are at 589M.


Its going to the good air. Luckily that is over land.
Member Since: Posts: Comments:
Quoting Stormchaser2007:


Yep.


Darn...I wish they were free (sad face)
Member Since: Posts: Comments:
Quoting HurricaneDean07:
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...
If you look at PR radar, you can clearly see it is directly over ST Crx, not NE
Member Since: Posts: Comments:
3387. wpb
has the 18z hmrf model begun
Member Since: Posts: Comments:
3386. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 129093
3384. Levi32
Quoting HurricaneIrene:


Hi there, have the Hunters arrived yet?


They didn't even have to leave the ground to arrive lol.
Member Since: November 24, 2005 Posts: 635 Comments: 26685
Quoting MahFL:
That radio station is pretty cool.


Fascinating to be 'in amang it' from afar...
Member Since: Posts: Comments:
Quoting BahaHurican:
Will you get over it??? why is it that every evening between 5 and 8 p.m. we get these [ahem] bloggers whose only goal in life seems to be to have hurt feelings for other bloggers???? Even if Levi DID mean to be short with the blogger, it was ONE POST!!!! ONE LOUSY POST!!!! You made your point.... get over it already....

And I'm noting this trend of pple who come onto the blog and attack a popular blogger.... Tonight it's Levi, the other night it was Taz, I think somebody even tried to jump Kman last week. I'm only saying, cut it out. There are a lot of behind the scenes bloggers who are going to minus your behind from Irene's formation point to her dissipation point if you don't stop.


This has been over for awhile now....until you just reposted : (
Member Since: Posts: Comments:
3381. WxLogic
We'll see in a couple hours and HH fixes but if it continues in the current track (based on SAT/Radar obs) Irene could pass S of the next forecast point.

Would not be surprised given that height across PR/DR are at 589M.
Member Since: Posts: Comments:
LOL, not surprisingly HHers flew around St. Croix first.
Member Since: Posts: Comments:
3379. KEEPEROFTHEGATE (Mod)
09L/H/I/C1
MARK
17.79N/64.75W
Member Since: July 15, 2006 Posts: 175 Comments: 54858
Quoting TropicalAnalystwx13:


You had to buy them didn't you?


Yep.
Member Since: Posts: Comments:
3376. Patrap


Member Since: July 3, 2005 Posts: 426 Comments: 129093
Quoting MahFL:
That radio station is pretty cool.
nasty right now
Member Since: Posts: Comments:
Quoting NCHurricane2009:


She HAS to be stronger in the next advisory...just has to be....


Well, I'd certainly be very suprised to have a 50mph storm with a pressure of 995mb.
Member Since: Posts: Comments:

Viewing: 3423 - 3373

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.