97L gets disrupted by Hispaniola

By: Dr. Jeff Masters , 12:53 PM GMT on July 21, 2010

Share this Blog
5
+

A tropical wave (Invest 97L) near the north coast of Hispaniola has been disrupted by interaction with the island, plus the effects of moderate wind shear of 10 - 20 knots. The storm is no longer a threat to develop into a tropical depression today, and the Hurricane Hunter flight that was scheduled for today has been postponed until Thursday. The disturbance has brought heavy rains of 8+ inches to Culebra, Vieques, the Virgin Islands, and some of the northern Lesser Antilles Islands. Wunderblogger Weather456 reported that the power was knocked out on the island of St. Kitts for about 24 hours, due to the intense lightning associated with 97L. All of Puerto Rico and the Virgin Islands are under flash flood watches today.

Satellite images of 97L show a relatively meager number of heavy thunderstorms that are not well-organized. The curved bands to the north and east of the center have disappeared, and there is no evidence of low-level spiral banding or of a surface circulation. Surface observations over the northern Dominican Republic show only light winds, with no westerly winds indicating that a surface circulation is forming. Long-range radar loops from San Juan show a much reduced amount of thunderstorm activity.


Figure 1. Total radar-estimate rainfall for 97L.

Track Forecast for 97L
The storm is in a fairly straightforward steering current environment, and 97L should progress steadily to the west-northwest through Saturday. The rains from 97L's thunderstorms will bring the threat of isolated flooding to the Dominican Republic today, and to Haiti on today and Thursday. Heavy rains from 97L will affect eastern Cuba, the Turks and Caicos Islands, and the eastern Bahamas Thursday, and South and Central Florida can expect heavy rains to arrive Thursday night or Friday morning. The latest suite of model runs from 2am EDT this morning (6Z) foresee 97L making landfall on the Florida coast somewhere between Miami and Cape Canaveral on Friday, then continuing into the Gulf of Mexico on Saturday. Only the Canadian model foresees a threat to Texas, and the other models predict a second landfall between eastern Louisiana and the Florida Panhandle.

Intensity Forecast for 97L
The primary detriment to development of 97L today will be its close proximity to the landmass of Hispaniola. Once the storm pulls away from the island tonight, 97L has a better chance of development. Also hindering development over the next two days will be the presence of dry, stable air in its path over the Bahamas, thanks to the upper-level low to the north of the Dominican Republic. The SHIPS model predicts shear will stay in the moderate range, 10 - 20 knots, over the next three days, which should allow for some steady development of 97L on Thursday and Friday before it reaches Florida. NHC is giving 97L a 60% chance of developing into a tropical depression by Friday, which is a reasonable forecast. I think there is a 70% chance 97L will eventually become Tropical Storm Bonnie, sometime in the next five days. Sudden rapid development before 97L reaches Florida is unlikely, due to the storm's current state of disorganization and the dry air over the Bahamas. It's very unlikely that 97L has time to organize into a hurricane before hitting Florida. I put the odds of 97L making it to hurricane strength before reaching Florida at 5%, and I give a 20% chance it will be a hurricane in the Gulf of Mexico. The probability of 97L being a hurricane in the Gulf of Mexico will depend heavily upon how long the storm spends over water in the Gulf, which is very uncertain. The environment in the Gulf of Mexico should be favorable for intensification, if passage over Florida does not disrupt the storm too much.

I'll have a new post Thursday morning, or earlier if there's a major change to 97L.

Famed climate scientist Steven Schneider dies
Steven Schneider, one of the most influential and talented climate scientists of our time, died on Monday. Ricky Rood has a tribute to Dr. Schneider in today's blog. Ricky comments, "He is known for feistiness. His last book was Science as a Contact Sport: Inside the Battle to Save Earth's Climate. He was a man who was, bluntly, harassed and threatened by those who did not like his message. He never shrank from the battle."

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: 1712 - 1662

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 | 94Blog Index

Quoting nrtiwlnvragn:


All models except the ECMWF have the capability of center relocation, but it is a manual process. If the model center does not do it, you get the spun-up center from the model as in the recent GFS ensemble members starting from different locations:

AL 97 2010072112 03 AP01 0 199N 711W
AL 97 2010072112 03 AP03 0 201N 718W
AL 97 2010072112 03 AP04 0 205N 708W
AL 97 2010072112 03 AP06 0 203N 714W
AL 97 2010072112 03 AP07 0 196N 711W
AL 97 2010072112 03 AP08 0 205N 719W
AL 97 2010072112 03 AP09 0 204N 720W
AL 97 2010072112 03 AP10 0 199N 719W
AL 97 2010072112 03 AP11 0 198N 719W
AL 97 2010072112 03 AP12 0 202N 708W
AL 97 2010072112 03 AP13 0 195N 700W
AL 97 2010072112 03 AP14 0 203N 717W
AL 97 2010072112 03 AP15 0 197N 720W
AL 97 2010072112 03 AP16 0 200N 721W
AL 97 2010072112 03 AP18 0 209N 719W
AL 97 2010072112 03 AP19 0 201N 711W


resulting in?
Member Since: Posts: Comments:
1710. Bonz
Quoting ElConando:


It is Karen's remnants I tell ya!


My brother and I were just talking about Karen last night. Tenacious storm.
Member Since: Posts: Comments:
Quoting Patrap:


The G-4 dosent look for a CoC.

They Way Aloft sniffing and sonde dropping the Uppers.


Why do I make myself look stupid LOL. I meant to say ground obs, something in the back of my mind was saying GIV.
Member Since: Posts: Comments:
Quoting WxLogic:


This "popcorn convection" has been initiated by the more persistent convective complex to its E/NE. Won't be surprised of a LLC relocation closer to the deeper convection.

We'll have to see too how it continues to behave through DMIN. So far it has been fighting shear quite well compared to other past disturbances so far this season.


It is Karen's remnants I tell ya!
Member Since: Posts: Comments:
Quoting StormW:


Popcorn caster! LOL!


That would be me sir.. (raises hand nervously)
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Quoting StormW:
DVORAK LOOP


Storm-how's that wave off Africa looking to you?
Member Since: Posts: Comments:
1705. Patrap


G-4 NOAA49 in Progress
Member Since: July 3, 2005 Posts: 419 Comments: 127355
1704. IKE
NAM takes it to Cuba...in 42 hours....


Member Since: Posts: Comments:
1703. Patrap
Quoting CybrTeddy:
HIGHLY doubt red unless the GIV finds a closed LLC. In that case development would be imminent.


The G-4 dosent look for a CoC.

They Way Aloft sniffing and sonde dropping the Uppers.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
HIGHLY doubt red unless the GIV finds a closed LLC. In that case development would be imminent.

EDIT: I meant Ground obs. They've been showing 1008 mb pressures in the Grand Turks region.
Member Since: Posts: Comments:
Quoting unf97:


Status quo. NHC will probably keep it at 50%, or bump it back to 60%.


Agreed! Come on now, they classified 96L as TD2 when it had little to no convection. Why can't they do the same with this one? Bugs me when they do that.. 50-60% is a very good bet because despite how it looks convective wise, 97L has organized quite well this afternoon, developed a LLC (exposed). It's well on it's way to TD status for tomorrow.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Quoting StormW:


Popcorn caster! LOL!


I think they call that Reddenbachercaster lol
Member Since: Posts: Comments:
Quoting Seflhurricane:
too low i think it may stay the same or go back to 60% looks better than this morning
(my thought)

I agree with you Seflhurricane.
Member Since: Posts: Comments:
1696. WxLogic
Quoting StormW:


Popcorn caster! LOL!


LOL... I'm hungry you know. :P
Member Since: Posts: Comments:
Quoting StormW:


Popcorn caster! LOL!


LOL!
Member Since: Posts: Comments:
Quoting Floodman:


So you're saying that the models ALWAYS initialize in the right spot? Is that troll bomb getting to you?


All models except the ECMWF have the capability of center relocation, but it is a manual process. If the model center does not do it, you get the spun-up center from the model as in the recent GFS ensemble members starting from different locations:

AL 97 2010072112 03 AP01 0 199N 711W
AL 97 2010072112 03 AP03 0 201N 718W
AL 97 2010072112 03 AP04 0 205N 708W
AL 97 2010072112 03 AP06 0 203N 714W
AL 97 2010072112 03 AP07 0 196N 711W
AL 97 2010072112 03 AP08 0 205N 719W
AL 97 2010072112 03 AP09 0 204N 720W
AL 97 2010072112 03 AP10 0 199N 719W
AL 97 2010072112 03 AP11 0 198N 719W
AL 97 2010072112 03 AP12 0 202N 708W
AL 97 2010072112 03 AP13 0 195N 700W
AL 97 2010072112 03 AP14 0 203N 717W
AL 97 2010072112 03 AP15 0 197N 720W
AL 97 2010072112 03 AP16 0 200N 721W
AL 97 2010072112 03 AP18 0 209N 719W
AL 97 2010072112 03 AP19 0 201N 711W
Member Since: Posts: Comments:
Quoting stillwaiting:
i'll go w/70%



i got with %80
Member Since: Posts: Comments:
i'll go w/70%
Member Since: Posts: Comments:
I highly doubt they would drop it to 30% and the center is right there by the Turks and Caicos Islands, not even close to Cuba yet
Member Since: Posts: Comments:
1689. unf97
Quoting Seflhurricane:
curious on what the NHC will have on the next TWO


Status quo. NHC will probably keep it at 50%, or bump it back to 60%.
Member Since: Posts: Comments:
Quoting CyclonicVoyage:


Interesting way to look at it, makes sense.



Hey guys, take another closer look at the 850 mb (mid-level) vorticity map in post 1659. The max mid-level vorticity (redish yellowish colors) is to the east of the Turks and Caicos, right? The alleged surface "center" over the Turks and Caicos islands. So as you go from the surface to the mid-levels, the system is titled eastward with height, right? Hence, wind shear is a problem for 97L.
Member Since: Posts: Comments:
50%, the circulation has become better defined with stations reporting pressures in the 1008 - 1010 mb area. Its the NHC, so you never know.
Member Since: Posts: Comments:
Quoting StormW:


INVEST 97L SYNOPSIS ISSUED 10:35 A.M. JULY 21, 2010
thanks and sorry for asking
Member Since: Posts: Comments:
1685. Patrap
The Overall Broad circ is Strong..

..it has a lot of Flavor..as the Momentum Piles westward,,look for the ULL as it nears the CONUS proper to weaken and as the System slides west as well..a favorable environment will occur Downstream..

The Intensity Graph timeline shows the schedule well for now.

Member Since: July 3, 2005 Posts: 419 Comments: 127355
Quoting IKE:


I'd go with 30%. I doubt they drop it that much, but the center is exposed and moving toward Cuba.
too low i think it may stay the same or go back to 60% looks better than this morning
(my thought)
Member Since: Posts: Comments:
1683. WxLogic
Quoting reedzone:


So I'm not the only one seeing a small spin just south of that popcorn convective cell..


This "popcorn convection" has been initiated by the more persistent convective complex to its E/NE. Won't be surprised of a LLC relocation closer to the deeper convection.

We'll have to see too how it continues to behave through DMIN. So far it has been fighting shear quite well compared to other past disturbances so far this season.
Member Since: Posts: Comments:
1680. Bonz
Would that steering put it across the Florida Straits?
Member Since: Posts: Comments:
One concern about 97L is that if it takes the westerly path toward Tx/La border, it will be a fast moving storm moving in WNW direction at landfall. If (TS or Hurricane Bonnie) is moving at 16 mph, the North eyewall winds will be the strength of a category higher storm.

If a Cat-1 moving WNW at 16 mph w/ wind speed 80 mph... North eyewall winds will be 96 mph or Cat-2 strength. If a weak Cat-2 had winds of 96 mph, due to forward speed the North eyewall winds would be 112 mph or weak Cat-3 level.

Storm surge would also be stronger into the bays and rivers due to fast forward speed and water being pushed toward shore by the NW winds.
Member Since: Posts: Comments:
Quoting IKE:


I'd go with 30%. I doubt they drop it that much, but the center is exposed and moving toward Cuba.


I really doubt 30%.
Member Since: Posts: Comments:
Quoting StormW:
18Z 700-850mb Layer Mean Steering


Dang, looks pretty unidirectional to me!
Member Since: August 2, 2006 Posts: 46 Comments: 11659
Pressure dropping, convection popping, doesn't seem to be weakening to me.
Member Since: Posts: Comments:
The SHIPS shear forecast could certainly change, but right now it keeps shear at 15-20kts, which if that happens would keep a tropical cyclone from becoming too strong.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1674. IKE
Quoting Seflhurricane:
curious on what the NHC will have on the next TWO


I'd go with 30%. I doubt they drop it that much, but the center is exposed and moving toward Cuba.
Member Since: Posts: Comments:
Quoting Drakoen:


NOAA G-IV plan will be dropping dropsondes south of the system and that will let us know whether or not it is closed.
How about this
Puerto Plata DR is calm and due south..
So with 97L moving WNW 10knots that gives us a relative wind of west at 10 knots at PP
http://weather.noaa.gov/weather/current/MDPP.html
Member Since: Posts: Comments:
Quoting weathermanwannabe:
97L is chasing the ULL to some degree (we have seen this pattern before over the years) so follow the ULL and 97L will probably be close behind it;..The interesting thing to watch for in the longer term is where the low will cross over Florida.....If it pulls 97L accross the Peninsula further to the north as some models have suggested, there might be very little left over for any type of regeneration in the Gulf......I think it boils down to what the Florida east coast is going to get out of this and I am not going to place any bets at the present time because there are too many undertainties (sheer-dry air) at the moment in the short-term.


Read to post 1542.
Member Since: Posts: Comments:
curious on what the NHC will have on the next TWO
Member Since: Posts: Comments:
1669. alcomat
Quoting CybrTeddy:


97L is a persistent little bugger.. these little buggers usually develop into a serious headache for someone. I've seen far worse looking invests at this stage that have become powerful systems. Whether or not conditions are going to favorable for that to happen we'll wait and see. I do see a 40 mph TS by Saturday though.
I think your prediction is right on, my same thoughts too nothing more than 40-50mph ts..
Member Since: Posts: Comments:
97L is chasing the ULL to some degree (we have seen this pattern before over the years) so follow the ULL and 97L will probably be close behind it;..The interesting thing to watch for in the longer term is where the low will cross over Florida.....If it pulls 97L accross the Peninsula further to the north as some models have suggested, there might be very little left over for any type of regeneration in the Gulf......I think it boils down to what the Florida east coast is going to get out of this and I am not going to place any bets at the present time because there are too many undertainties (sheer-dry air) at the moment in the short-term.
Member Since: Posts: Comments:
Quoting CybrTeddy:


CIMSS is likely overdoing the shear, as SHIPS analyzed it at 20-25 knots or so IIRC.




thank you sir
Member Since: Posts: Comments:
Quoting StormW:
DVORAK LOOP
storm what are your thoughts on 97L
Member Since: Posts: Comments:
Quoting Jeff9641:


??? it is under a pocket of 30 to 40 knt shear according to that link. ULL got stronger today than we thought earlier. This ULL needs to move so Bonnie can come to life.



wind shear is not 30 too 40kt turst me on this 97L would not be haveing falling mbs if wind shear was that strong
Member Since: Posts: Comments:
Quoting Jeff9641:


??? it is under a pocket of 30 to 40 knt shear according to that link. ULL got stronger today than we thought earlier. This ULL needs to move so Bonnie can come to life.


CIMSS is likely overdoing the shear, as SHIPS analyzed it at 20-25 knots or so IIRC.
Member Since: Posts: Comments:
1662. scott39
Quoting NCHurricane2009:


This is why I am still thinking this is not going to develop. This is a vigorous surface trough at the moment with wind shear preventing further development.
Im not sold on ULL keeping tandum with 97L in regards to the GOM yet.
Member Since: Posts: Comments:

Viewing: 1712 - 1662

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 | 94Blog 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

Overcast
62 °F
Overcast