Erika dumping heavy rain on the Lesser Antilles

By: Dr. Jeff Masters , 2:12 PM GMT on September 03, 2009

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Tropical Storm Erika is hanging together despite strong wind shear, and is bringing high winds and much-needed heavy rain to the Lesser Antilles Islands. Winds on the south shore of Dominica Island were sustained at 37 mph this morning, and 8.03" of rain have been measured at the airport over the past two days. Winds and rain at nearby islands have been less, according to our wundermap for the region. The Hurricane Hunters are in the storm now, and have generally encountered top winds of 40 - 45 mph at the surface. They did find one spot of 50 - 65 mph winds, but that was likely due to outflow from a strong thunderstorm, and is not representative of Erika's wind field.


Figure 1. Radar image of Tropical Storm Erika at 9:15am EDT 9/3/09. Image credit: Meteo France.

Erika has improved in organization a bit since last night, but remains weak and disorganized, thanks to about 20 knots of shear at the 200 mb level, as seen on last night's Guadeloupe upper air sounding. Radar animations out of Martinique show plenty of heavy rain moving through the Lesser Antilles, but little organization of the echoes. Satellite imagery shows no low-level spiral bands and little upper-level outflow. Long range radar out of Puerto Rico is beginning to show rain echoes from Erika approaching the island.

The forecast for Erika
The computer models have come into better agreement about the track of Erika, taking the storm west-northwest over Puerto Rico and the Dominican Republic. This track will take Erika into a band of significantly higher wind shear of 25 - 35 knots, Friday through Saturday. Considering that Erika is barely maintaining itself as a tropical storm with 20 knots of shear, the combined effects of the higher shear and the encounter with the high mountains of Hispaniola and Puerto Rico should be enough to cause Erika to dissipate by Sunday. Erika's remains will still be capable of dumping very heavy rains of 3 - 5 inches over the Dominican Republic and 1 - 3 inches over Haiti and the Southeast Bahamas, due to the slow motion of the storm. By Monday, when the remains of Erika should be over the Bahamas, the storm will have penetrated through the band of high wind shear over the Greater Antilles, and shear may fall low enough for redevelopment of the storm. This is a scenario offered by the NOGAPS model, which then takes Erika northward towards North Carolina. The other models predict quite a bit more shear in the region than the NOGAPS, and any redevelopment of Erika early next week remains an iffy proposition. The GFDL and HWRF models continue to insist that Erika will brush off the high shear this weekend, avoid Hispaniola, and intensify into a Category 2 hurricane five days from now. These models have not been giving enough emphasis to how the current shear is affecting Erika, and are being discounted at this time.

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Elsewhere in the Atlantic
A large, strong tropical wave with plenty of spin emerged from the coast of Africa this morning. The wave is not yet generating much in the way of heavy thunderstorms, but has the potential to gradually develop into a tropical depression by early next week. NHC is giving this wave a low (less than 30% chance) of developing into a tropical depression by Saturday. The GFS model has been consistently developing this wave in its runs over the past few days.

I'll have an update this afternoon.

Jeff Masters

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529. StormChaser81
5:52 PM GMT on September 03, 2009
WTNT31 KNHC 031751
TCPAT1
BULLETIN
TROPICAL STORM ERIKA INTERMEDIATE ADVISORY NUMBER 8A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009
200 PM AST THU SEP 03 2009

...AIRCRAFT RECONNAISSANCE FINDS CENTER OF POORLY-ORGANIZED ERIKA
FARTHER SOUTHWEST...

AT 2 PM AST...1800 UTC...THE TROPICAL STORM WARNING FOR DOMINICA
AND GUADELOUPE HAVE BEEN DISCONTINUED.

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR PUERTO RICO...THE
U.S. AND BRITISH VIRGIN ISLANDS...ST. MARTIN...ST. BARTHELEMY...
ANTIGUA...BARBUDA...MONTSERRAT...ST.KITTS...NEVIS...ANGUILLA...
ST. MAARTEN...SABA...AND ST. EUSTATIUS. A TROPICAL STORM WARNING
MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN
THE WARNING AREA WITHIN 24 HOURS.

INTERESTS IN THE DOMINICAN REPUBLIC AND HAITI SHOULD MONITOR THE
PROGRESS OF ERIKA.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA
OUTSIDE OF THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 200 PM AST...1800 UTC...THE CENTER OF POORLY-ORGANIZED TROPICAL
STORM ERIKA WAS LOCATED BY AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT NEAR LATITUDE 16.6 NORTH...LONGITUDE 64.7 WEST OR ABOUT
80 MILES...130 KM...SOUTH OF ST. CROIX AND ABOUT 155 MILES...
245 KM...SOUTHEAST OF SAN JUAN PUERTO RICO.

ERIKA IS MOVING TOWARD THE WEST NEAR 9 MPH...15 KM/HR...AND THIS
MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS WITH A
GRADUAL INCREASE IN FORWARD SPEED. ON THE FORECAST TRACK...THE
WEATHER ASSOCIATED WITH ERIKA WILL CONTINUE TO MOVE THROUGH THE
LEEWARD ISLANDS TODAY AND APPROACH THE U.S. AND BRITISH VIRGIN
ISLANDS AND PUERTO RICO LATER TODAY AND TONIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/HR...WITH HIGHER
GUSTS. GRADUAL WEAKENING IS LIKELY DURING THE NEXT COUPLE OF
DAYS...AND ERIKA COULD BECOME A TROPICAL DEPRESSION LATER TODAY OR
TONIGHT. IT IS ALSO POSSIBLE THAT ERIKA COULD DEGENERATE INTO A
REMNANT LOW OR TROPICAL WAVE.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280
KM...PRIMARILY TO THE EAST OF THE CENTER.

THE LATEST MINIMUM CENTRAL PRESSURE MEASURED BY THE AIR FORCE
RECONNAISSANCE HURRICANE HUNTER AIRCRAFT WAS 1008 MB...29.77
INCHES.

ERIKA IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 3 TO 5
INCHES OVER THE CENTRAL AND NORTHERN LESSER ANTILLES...PUERTO
RICO...AND THE U.S. AND BRITISH VIRGIN ISLANDS...WITH ISOLATED
MAXIMUM AMOUNTS OF 8 INCHES POSSIBLE.

Member Since: August 11, 2008 Posts: 0 Comments: 2315
528. TampaSpin
5:52 PM GMT on September 03, 2009
492. DellOperator 1:44 PM EDT on September 03, 2009
Quoting TampaSpin:
We might actually have a true established LLC finally near St. Johns island...
Quoting TampaSpin:
We might actually have a true established LLC finally near St. Johns island...






That bright swirl you are mentioning is the mid level swirl. Surface circulation out ran its upper structure it was trying to rebuild. A repeat performance Erika put on yesterday.



I don't think so i think the swirl that came out was just one of the two and the stronger has taken over....look at the lower level clouds.....they are being pulled in toward the Certain i mentioned....Could be wrong...JMO
Member Since: September 2, 2007 Posts: 179 Comments: 20448
527. toasterbell
5:52 PM GMT on September 03, 2009
TexNowNM, thank you very much for the advice. I'll check it out. I have two little kids, a full-time job, and a husband on the heart transplant list, so my extra time is limited, but I imagine I can do some good.
Member Since: August 21, 2008 Posts: 0 Comments: 8
526. StonedCrab
5:52 PM GMT on September 03, 2009
Quoting midgulfmom:
Afternoon, Just popped in and was going to ask the same. I think you must have covered it all.. Sorry I missed the latin lesson. :( Thanks! :)


illegitimi non carborundum
Member Since: October 30, 2007 Posts: 0 Comments: 270
524. thegoldenstrand
5:52 PM GMT on September 03, 2009
How is it that the low that has been reported is so far to the west of the blob called Erika. This girl is not in very good shape.
Member Since: August 16, 2008 Posts: 0 Comments: 111
523. KEEPEROFTHEGATE (Mod)
5:51 PM GMT on September 03, 2009


looks like she's getting some reduction work done shrinking with every new frame
Member Since: July 15, 2006 Posts: 178 Comments: 56141
522. justalurker
5:50 PM GMT on September 03, 2009
good afternoon 456

checking your update now, staying dry?
Member Since: August 18, 2009 Posts: 0 Comments: 157
521. Squid28
5:50 PM GMT on September 03, 2009
Quoting Floodman:


Another thing: you can stand next to a 60' coastal pine and never realize how tall it really is until you see it laying across the neighbor's house...


They are even bigger when laying across your own home. Always been amazed at how far a 13' trampoline could fly....
Member Since: May 23, 2006 Posts: 0 Comments: 343
520. midgulfmom
5:50 PM GMT on September 03, 2009
Quoting Floodman:


You missed further arguments on whether Erika will strengthen/weaken, move WSW, W, WNW or NW, arguments on the efficacy of the models currently used for forecasting, a brief lesson in Latin (where I showed how badly I misspent my youth) and Orcasystems unintentional blinding of himself...did I miss anything, guys?
Afternoon, Just popped in and was going to ask the same. I think you must have covered it all.. Sorry I missed the latin lesson. :( Thanks! :)
Member Since: July 9, 2005 Posts: 2 Comments: 1164
518. watchingnva
5:50 PM GMT on September 03, 2009
Quoting IKE:


Problem is...recon isn't flying down there....yet.

Finding winds under 30 w/the naked swirl.


already noted that...we will see what the find when they go east...
Member Since: September 7, 2005 Posts: 7 Comments: 1526
517. Dakster
5:49 PM GMT on September 03, 2009
Uh Ohhh... Here comes NRAamy's purple pictures...
Member Since: March 10, 2006 Posts: 0 Comments: 10819
516. Cavin Rawlins
5:49 PM GMT on September 03, 2009
Good Afternoon

Erika dumping heavy rains across the Islands
Member Since: July 24, 2005 Posts: 407 Comments: 19076
515. Chiggy007
5:49 PM GMT on September 03, 2009
12z GFDL moved even further North...

514. NRAamy
5:50 PM GMT on September 03, 2009
Do do ? Or they are dodo?

doodie...
Member Since: January 24, 2007 Posts: 317 Comments: 31946
513. watchingnva
5:48 PM GMT on September 03, 2009
...and they found the pressure down to 1008mb with the swirl now...lol

17:36:30Z 16.583N 64.600W 976.9 mb
(~ 28.85 inHg) 275 meters
(~ 902 feet) 1008.0 mb
(~ 29.77 inHg

Link
Member Since: September 7, 2005 Posts: 7 Comments: 1526
511. TheDawnAwakening
5:48 PM GMT on September 03, 2009
I agree TampaSpin. I agree with that. Also I agree with watchingnva.
Member Since: October 21, 2008 Posts: 248 Comments: 3970
509. TexNowNM
5:48 PM GMT on September 03, 2009
Quoting toasterbell:
I've got a question for those of you in emergency management/disaster response. Can you tell me where to find information on career opportunities in the field? I'm kind of looking for a career change, and I think it's an area that I'd enjoy.

I am involved with disaster response as a volunteer and will probably do this full time when my kids are grown. I now have two separate avenues of future employment because of my volunteer work. That is how people get to know you and it might be something for you to consider. If you have a religious affiliation you might check into what your church or synagogue offers. Some have paid positions. Get in touch with your local Red Cross, also. They can possibly give you some ideas.

In the mean time, you can take some great emergency response classes through the Salvation Army. You don't have to be a member and no one pressures you to join. Most of us that work with them from my town aren't members and I can still deploy. Just the volunteer part might help you with an unsatisfactory job while you work towards a career change.

Best Wishes.
Member Since: October 14, 2008 Posts: 0 Comments: 179
508. IKE
5:47 PM GMT on September 03, 2009
Quoting watchingnva:
Image Hosted by ImageShack.us


shes definitely taken on a much better cyclonic look over the last few hours with the banding...


Problem is...recon isn't flying down there....yet.

Finding winds under 30 w/the naked swirl.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
507. Orcasystems
5:47 PM GMT on September 03, 2009
COC #1

Time: 17:36:30Z
Coordinates: 16.5833N 64.6W
Acft. Static Air Press: 976.9 mb (~ 28.85 inHg)
Acft. Geopotential Hgt: 275 meters (~ 902 feet)
Extrap. Sfc. Press: 1008.0 mb (~ 29.77 inHg)
D-value: -



Member Since: October 1, 2007 Posts: 81 Comments: 26516
505. Dakster
5:47 PM GMT on September 03, 2009
Sophocoles?

How was he in person, I've only read about him.
Member Since: March 10, 2006 Posts: 0 Comments: 10819
502. IKE
5:46 PM GMT on September 03, 2009
Quoting iceman55:
all models dodo very poor job.


Do do ? Or they are dodo?
Member Since: June 9, 2005 Posts: 23 Comments: 37860
501. watchingnva
5:46 PM GMT on September 03, 2009
Image Hosted by ImageShack.us


shes definitely taken on a much better cyclonic look over the last few hours with the banding...
Member Since: September 7, 2005 Posts: 7 Comments: 1526
I don't think shear or dry air are making the thunderstorm tops warm, but the fact that she is reorganizing a new stronger and large low level circulation near 16N and 62W. Convection is now flaring with the new developing low level circulation. If the hurricane hunters just bypassed the old low level circulation without doing any crisscrosses then the NHC and the HH might think that she is forming the newer and large circulation over the Leeward Islands. I believe that this is the first time that the whole convective mass is showing rotation within one low pressure center, this is the reorganizing state we have all been waiting for, but it could be too late for her to strengthen much more than a 50mph tropical storm.
Member Since: October 21, 2008 Posts: 248 Comments: 3970
Quoting iceman55:
all models dodo very poor job.


dodo???
Member Since: August 18, 2009 Posts: 0 Comments: 157
Quoting LPStormspotter:


Wow. Gotta stink when something is coming your way... I live in SE Tx. My sister lived in Fort Worth for many years. said everybody there would say.. I wish houston would get hit so we can get some rain.. Its sad but true. To wish something like that for rain. Not thinking of the people who loose everything they have worked for. Or the kids who have to change schools and loose everything they have and their friends. i know after going thru Alicia,Allison,and Ike i would never wish that on anyone. I live 5 miles from Sylvan Beach. At the same time this is my home and im not leaving


heck we are up to 48% post Ike occupancy here at the corner of Shoreacres & La Porte now (adjusted for those homes torn down already). Who knows maybe I will quit seeing demo trucks in another year or so.

LPSS Did you go to LPHS? If so what year for grad?
Member Since: May 23, 2006 Posts: 0 Comments: 343
Quoting tbrett:

You could have saved your self a lot of typing by putting "same ol same ol" LOL (except Orcasystems blinding himself, that one was new)


That could come under same same also.. I am normally good for at least one stupid thing a day. If you have doubts.. ask SWMBO'ed.

Member Since: October 1, 2007 Posts: 81 Comments: 26516
494. BDAwx
Quoting LPStormspotter:


Wow. Gotta stink when something is coming your way... I live in SE Tx. My sister lived in Fort Worth for many years. said everybody there would say.. I wish houston would get hit so we can get some rain.. Its sad but true. To wish something like that for rain. Not thinking of the people who loose everything they have worked for. Or the kids who have to change schools and loose everything they have and their friends. i know after going thru Alicia,Allison,and Ike i would never wish that on anyone. I live 5 miles from Sylvan Beach. At the same time this is my home and im not leaving


i would never wish a hurricane on anyone for rain because there are other ways that you can get rain eg. a cold front. but they do produce rain despite their devastation.

Bermuda could use some rain... last month we only got 3.32in. usually we get 5.64in. despite Bills outer bands, and since august of 2008 we are in a deficit of 8+inches. and high pressures seems to have set in...

But everything on this island is built to withstand winds up to 110mph. or is built better, so i have never experienced losing everything i have or having schools completely destroyed, not many here have. It is common, though, to be cut off from the rest of the world as the singular airport is closed or ships aren't allowed in, and to have no power for up to a month after a storm. On top of that everything is very expensive.
Member Since: Posts: Comments:
Quoting Dakster:


LOL. hey flood you write latin very well... Did you live in rome during the crusades?


No, but as a Saracen I did get to interview a great many priests

**SIGH**

The old days
Member Since: August 2, 2006 Posts: 10 Comments: 9922
Quoting TampaSpin:
We might actually have a true established LLC finally near St. Johns island...
Quoting TampaSpin:
We might actually have a true established LLC finally near St. Johns island...





That bright swirl you are mentioning is the mid level swirl. Surface circulation out ran its upper structure it was trying to rebuild. A repeat performance Erika put on yesterday.
Member Since: May 31, 2007 Posts: 0 Comments: 210
Quoting Dakster:


I had too much contact with the oustide world... The cold showers were not as annoying as the incessant HEAT as A/C doesn't work too well without power. I don't know how you had computers working without power. Driving is hectic/dangerous as no traffic lights work...

Yes fun times for all. Looking forward to never doing it again. All other perils were as you described...


Ice becoming a commodity people fight strangers over, and nights so eerily quiet you can hear a pin drop in areas where otherwise noise polution would have been deafening.

...I still remember clearly what Georges did to Jayuya and Ponce...as exhiliarating as it was for me as a youngster aspiring to be a meteorologist...I wouldn't wish it upon any island.
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Magister Mundi sum!
Member Since: October 30, 2007 Posts: 0 Comments: 270
Quoting Floodman:


Another thing: you can stand next to a 60' coastal pine and never realize how tall it really is until you see it laying across the neighbor's house...


LOL. hey flood you write latin very well... Did you live in rome during the crusades?
Member Since: March 10, 2006 Posts: 0 Comments: 10819
Quoting Floodman:


You missed further arguments on whether Erika will strengthen/weaken, move WSW, W, WNW or NW, arguments on the efficacy of the models currently used for forecasting, a brief lesson in Latin (where I showed how badly I misspent my youth) and Orcasystems unintentional blinding of himself...did I miss anything, guys?

You could have saved your self a lot of typing by putting "same ol same ol" LOL (except Orcasystems blinding himself, that one was new)
Member Since: Posts: Comments:
483. Bonz
"Another thing: you can stand next to a 60' coastal pine and never realize how tall it really is until you see it laying across the neighbor's house..."

True. The neighbor across the street had one come down and break through his patio hurricane shutters. (He lives on a canal and there were a row of those pines. What Frances and Jeanne didn't finish off, Wilma did.) No more big pines.
Member Since: Posts: Comments:
i double that..i live out west..where it would take 20 minutes it took 2 hours with alot of right turns
Member Since: Posts: Comments:
Quoting Dakster:


I still got tape backup and 8" floppies. Need any extras? I keep them next to my manual calculator.

Hey Flood, do you still have the compass galileo gave you?


Indeed I do...use it daily...GPS indeed...
Member Since: August 2, 2006 Posts: 10 Comments: 9922
The new wave off Africa has Bill's size and vorticity..

Any take on here...? :)

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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