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: 162 - 112

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 Caribbeanislands101:
Hey every one!! How's our invest doing?



Not as good as many were expecting or some even hoped. But the signature is there, and from the most recent data/images seems to be trying to get its act back together again. StormW is working on his synopsis which I can't wait to read.
Member Since: Posts: Comments:
Quoting cg2916:
Don't think anyone posted this:

21/1145 UTC 19.7N 69.6W T1.0/1.0 97L -- Atlantic


TAFB was 1.0/1.5
Member Since: Posts: Comments:
Quoting jasoniscoolman2010x:
look at invest 97L ITS LOOK DIE RIGHT NOW NO T.STORMS AT ALL.




jason,please just relax for a minute,its going to be a long busy season from here fowrard,97L has been effected by sheer,dry air and land interaction.Today should be a day of slow surface organization as the ULL weakens and moves towards the NW carib as 97L moves WNW towrds the lower bahamas area.Factors have not been forecast to be favorable until tomorrow and thats been the forecast!!!!......
Member Since: Posts: Comments:
Don't think anyone posted this:

21/1145 UTC 19.7N 69.6W T1.0/1.0 97L -- Atlantic
Member Since: Posts: Comments:
Quoting Jeff9641:


Ike look at the visible. A very impressive mid level spin and infact the NHC has nailed the placement.
Its actually getting better organized structually at this hour
Member Since: Posts: Comments:
Hey every one!! How's our invest doing?
Member Since: Posts: Comments:
Quoting TXCaneCrasher:

Say coolman, since you have given up on 97L why don't you concentrate on your wave that just came off of Africa and the rest of us will dicuss what is going on with the potential of 97L. Have a good day
Good post.....And what is up with the capitalization all the time?
Member Since: Posts: Comments:
Quoting gator23:


I respectfully disagree with you here Miami, the models that are forecasting Miami last night were showing south dade and the keys, the models that were forecasting Miami last night are now forecasting Palm Beach the GFDGL and HWRF have not been windshield wipers at all they have consistently shown a central Florida track since 2 days ago.
I'm only making a comparison between the 06 model plots and the 12z model plots, not last night's. And, I don't know where the GFDL and HWRF are as a ridge to the north would not allow 97L to go that far north. Plus, 12z models are hinting at south Dade yet again after the 06z plots were hinting at central Florida.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting cg2916:
This is why I expected a model shift


Is that a current enviro or a forecasted one? If forecasted, and what date and time? The latest models that went north obviously see the ridge not as strong in the future... at least for the latest run. Again, I don't give too much finality to single runs, I look for persistence.
Member Since: Posts: Comments:
Daily update, hope this provides a voice of reason.

Disorganized 97L a threat later this week
Member Since: July 8, 2005 Posts: 259 Comments: 24172
Good Gawd Almighty, people! I'll try to whisper this so he won't hear me. In case ya'll haven't noticed, JasonCooman seems to be a little slow. Lay off of him. Just ignore him if you will, but don't acknowledge him.

You people aren't showing much intelligence if you haven't picked up on it yet. He just wants to be part of the gang.

Back to lurking now.
Member Since: Posts: Comments:
Quoting IKE:
97L is in need of....help....doesn't look promising to me....

You dont think the ULL will take its unfavorable conditions with it as it moves away fron 97L?
Member Since: June 13, 2009 Posts: 0 Comments: 6861
Quoting weatherskink:
That ULL is hanging tough .


It's moving west.
Member Since: Posts: Comments:
Quoting bjdsrq:


Not ALL but the only ones worth a hoot did. This is common knowledge.


Common Knowledge? I'd be careful of such far reaching assumptions, you know what they say about those. And that is indeed, common knowledge.
Member Since: Posts: Comments:
Quoting weatherskink:
That ULL is hanging tough .
Thats true but the ull should lose its grip later today to give 97L an oppurtunity to organize furthur
Member Since: Posts: Comments:
Quoting BradentonBrew:
All the latest model runs shifted north (8am.)

Stop saying this. This is not true. ALL of the models did not shift North.


Not ALL but the only ones worth a hoot did. This is common knowledge.
Member Since: Posts: Comments:
This is why I expected a model shift:

Member Since: Posts: Comments:
That ULL is hanging tough .
Member Since: Posts: Comments:
137. IKE
97L is in need of....help....doesn't look promising to me....

Member Since: Posts: Comments:
things are shaping up to be quite the puzzle anytime a system reaches invest so far. thanks to all of our resident expert bloggers for their inputer as a long time lurker it is much appreciated.
Member Since: Posts: Comments:
Quoting reedzone:
Looks like 97L got sheared apart last night. The ULL is moving west now so things should improve tonight. Why are people saying the TWO will bring it down to orange or yellow? I dunno, look at reality folks, TD3 will probably form either tonight or tomorrow. It's just taking some beating from land interaction and wind shear which is moving away from the system.


Yeah, it's already getting better in organization and its convection is growing.
Member Since: Posts: Comments:
Quoting jasoniscoolman2010x:
look at invest 97L ITS LOOK DIE RIGHT NOW NO T.STORMS AT ALL.

Say coolman, since you have given up on 97L why don't you concentrate on your wave that just came off of Africa and the rest of us will dicuss what is going on with the potential of 97L. Have a good day
Member Since: Posts: Comments:
All the latest model runs shifted north (8am.)

Stop saying this. This is not true. ALL of the models did not shift North.
Member Since: Posts: Comments:
Quoting reedzone:
Looks like 97L got sheared apart last night. The ULL is moving west now so things should improve tonight. Why are people saying the TWO will bring it down to orange or yellow? I dunno, look at reality folks, TD3 will probably form either tonight or tomorrow. It's just taking some beating from land interaction and wind shear which is moving away from the system.
exactly good post reed
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
As noted on water vapor imagery the ULL is moving towards the west, finally. Tonight is when things should heat up as shear begins to calm down.
It looked like it was moving W about 2am this morning, so its definitely making some distance from 97L. Does it take all the dry air with it?
Member Since: June 13, 2009 Posts: 0 Comments: 6861


ULL on the move west
Member Since: Posts: Comments:
Quoting KEEPEROFTHEGATE:





Starting to become vertically stacked... I think.
Member Since: Posts: Comments:
Looks like 97L got sheared apart last night. The ULL is moving west now so things should improve tonight. Why are people saying the TWO will bring it down to orange or yellow? I dunno, look at reality folks, TD3 will probably form either tonight or tomorrow. It's just taking some beating from land interaction and wind shear which is moving away from the system.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
As noted on water vapor imagery the ULL is moving towards the west, finally. Tonight is when things should heat up as shear begins to calm down.


Ok, I don't expect a TD when we wake up, but possibly sometime tomorrow or early Friday.
Member Since: Posts: Comments:
Quoting TXCaneCrasher:
bjdsrg
can you show me the model runs you are talking about?


Just go to the WU 97L computer models. They moved north. You can also check out this link to look at consecutive runs:
Link

I recall that WU used to have a feature where they animated consecutive model runs over time along with the actual track. That made it easy to see the model error trends and whipsaws. They don't have that anymore. You have to use the FSU site and watch each run individually.
Member Since: Posts: Comments:
This evening and tonight should be the night we see some significant organizational gains from 97L.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
All models once again doing the wind shear wiper affect. At 12z an evident shift to the left (south Florida) is noted. Also keep in mind that the GFDL and HWRF is from 06z, thus the northerly track.



I respectfully disagree with you here Miami, the models that are forecasting Miami last night were showing south dade and the keys, the models that were forecasting Miami last night are now forecasting Palm Beach the GFDGL and HWRF have not been windshield wipers at all they have consistently shown a central Florida track since 2 days ago.
Member Since: August 26, 2008 Posts: 0 Comments: 2182
Lower convergence is good:



Upper divergence still needs a bit more organization:

Member Since: Posts: Comments:
Storm - I can certainly see a spin at the coordinates you gave.
Member Since: Posts: Comments:
Quoting cg2916:


Shear's lowering, it should start getting its act together again pretty soon, it already is a little.
Yep its going as forecasted today and thursday is the time this thing should organize into a tropical depression
Member Since: Posts: Comments:
Hi everyone, good news from Dr Masters but need to monitor until it makes landfal. There have been storms that have strengthened dramatically
just ofshore in the bahamian waters, most likely they had ideal conditions that 97L doesnt have but anything is possible hopefully its just a weak system when and if it comes through.
Member Since: Posts: Comments:



Member Since: Posts: Comments:
As noted on water vapor imagery the ULL is moving towards the west, finally. Tonight is when things should heat up as shear begins to calm down.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting scott39:
Man you are soooo gone! poof poof poof I hope everybody else does the same thing to you today!


We have.
Member Since: Posts: Comments:

Viewing: 162 - 112

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.