97L continues to grow more organized; headed for Bahamas and Florida

By: Dr. Jeff Masters , 7:07 PM GMT on July 20, 2010

Share this Blog
1
+

A tropical wave (Invest 97L) between Puerto Rico and the Dominican Republic has continued to become more organized today, and is a threat to develop into a tropical depression as early as Wednesday morning. The disturbance has brought heavy rains of 8+ inches to Culebra and Vieques islands over the past day, and all of Puerto Rico and the Virgin Islands are under flash flood watches today. The storm could bring an additional 3 - 6 inches of rain to the islands over the next two days. The upper level low centered a few hundred miles north of the Dominican Republic is no longer bringing high levels of wind shear to 97L; wind shear has fallen to the moderate range, 10 - 15 knots, which should allow 97L to continue to develop today. Satellite images of 97L show a moderate area of steadily organizing thunderstorms, with curved bands developing to the north and east of the center. There are no signs of a surface circulation on satellite imagery or on the 10:38am EDT ASCAT pass. Surface observations show only light winds over Puerto Rico and the Dominican Republic, but the surface winds at Punta Cana on the eastern tip of the Dominican Republic have shifted to the west this afternoon, indicating that a surface circulation may be forming just north of that location. Long-range radar loops from San Juan do not show any evidence of a surface circulation. The Hurricane Hunter mission scheduled for today was canceled, but is scheduled to fly Wednesday afternoon.


Figure 1. Total precipitation from 97L as predicted by the 12Z (8 am EDT) July 20, 2010 run of the HWRF model. Image credit: Morris Bender, NOAA/GFDL.

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 Wednesday, and to Haiti on Wednesday and Thursday. Heavy rains from 97L will begin moving into eastern Cuba, the Turks and Caicos Islands, and the eastern Bahamas on Wednesday, and South Florida can expect heavy rains to arrive as early as Thursday night. The latest suite of model runs from 8am EDT this morning (12Z) foresee a more northerly track for 97L into Central Florida. Several models develop 97L into a tropical storm, with both the GFDL and HWRF models predicting 97L will hit South or Central Florida as a tropical storm on Friday. Most of the models have 97L entering the Gulf of Mexico on Saturday, but the amount of time 97L has over the Gulf may be limited to a day or less if the storm ends up exiting into the Gulf near Tampa Bay. The NOGAPS model predicts a more southerly path across South Florida and into Louisiana.

Intensity Forecast for 97L
One factor potentially aiding development of 97L will be the Madden-Julian oscillation, which currently favors upward motion over the Gulf of Mexico and Caribbean. The Madden-Julian oscillation is a pattern of enhanced rainfall that travels along the Equator from west to east. The pattern has a wet phase with large-scale rising air and enhanced thunderstorm activity, followed by a dry phase with large-scale sinking air and suppressed thunderstorm activity. Each cycle lasts approximately 30 - 60 days. When the Madden-Julian oscillation is in its wet phase over a hurricane-prone region, the chances for tropical storm activity are greatly increased. Also in favor of development are the warm ocean temperatures of 29°C. The SHIPS model predicts shear will stay in the moderate range, 10 - 20 knots, over the next five days. The primary detriment to development of 97L over the next three days will probably 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. If the center forms close to the coast of the Dominican Republic, the high mountains of Hispaniola may also be a problem for the storm. NHC is giving 97L a 60% chance of developing into a tropical depression by Thursday, 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 today or on Wednesday is unlikely, due to the dry air over the Bahamas. I put the odds of 97L making it to hurricane strength before reaching Florida at 30%, 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 land or interacting with land over the next four days, which is very uncertain.

"Hurricane Haven" airing again this afternoon
Tune into another airing of my live Internet radio show, "Hurricane Haven", at 4pm EDT today. Listeners will be able to call in and ask questions. The call in number is 415-983-2634, or you can post a question in the comments area on my blog during the show. You can also email the questions to me today before the show: jmasters@wunderground.com. Be sure to include "Hurricane Haven question" in the subject line. Some topics I'll cover today on the show:

1) Invest 97
2) A look ahead at the coming two weeks

Today's show will be about 45 minutes, and you can tune in at http://www.wunderground.com/wxradio/wubroadcast.h tml. The show will be recorded and stored as a podcast.

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: 3078 - 3028

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 | 62Blog Index

3078. cg2916
NEW BLOG!!!
Member Since: Posts: Comments:
97L was split off all the convection to the east by the Cold dry air that comes off PR and DR at night as well as a mid level ridge of it's own making from all the convection yesterday that had poor outflow.

I is now nice and compact and over the Silver,Navidad banks.
This will allow it to to spin up very quickly and if it moves north away from the DR, Cuba and into the Bahamas it can become a TD/TS at anytime. So don't get complacent yet.

Member Since: Posts: Comments:
Goodmorning all,

I have a feeling that once 97L gets away from the coast it will get its act together and will become stronger. Right now, I feel that everyone from the keys north to central florida should pay close attention to this system.
Member Since: Posts: Comments:
Quoting StormW:
COC Developing near 19.8N;69.7W based on visible satellite loop.

Woo hoo! I got one right! *happy dance*
Member Since: Posts: Comments:
3074. KEEPEROFTHEGATE (Mod)
Quoting DestinJeff:
2010 hurricane season is poised to go down in history as the most over-hyped event since Geraldo opened Al Capone's secret vault
we got a 132 days to go a lot can happen in 30 days that leaves 102 days for even more to happen
Member Since: July 15, 2006 Posts: 169 Comments: 53296
What is the difference between the orange and yellow lines on the sheer maps?
Member Since: Posts: Comments:
Possible LLC forming near 20/70
Member Since: Posts: Comments:
this morning on twc stephanie said la nina is forming and it means less hurricanes and that was a contributer to them changing their storm forecast for the season? Thats not fair for them to change the number in July. thats cheating.
Member Since: Posts: Comments:
3069. srada
I hope Weather456 comes on this morning..very interested to hear his take on 97L
Member Since: Posts: Comments:
3068. Skyepony (Mod)
DR MASTERS HAS A NEW BLOG UP!

I'll get mine update in the next hr or so:)
Member Since: Posts: Comments:
well i was thinking it was time for a Storm update but didnt want to be rude and ask :)
Member Since: Posts: Comments:
3063. KEEPEROFTHEGATE (Mod)
Linkcorrected
Member Since: July 15, 2006 Posts: 169 Comments: 53296
3062. gator23
Quoting weatherwart:

Isn't he more of a WestCentralCaster? ;-)

my favorite, MASTERCASTER
Member Since: Posts: Comments:
Quoting StormW:


I'm checking stuff out now.

Gang, I would much appreciate if questions could be held until my update is posted so I may finish performing analysis.

TIA!


Ok everybody step back! Give the man some air!!
Member Since: Posts: Comments:
Quoting gator23:



This deserves a bump, anyone? anyone?

Isn't he more of a WestCentralCaster? ;-)
Member Since: Posts: Comments:
3059. gator23
Quoting HurricaneNewbie:
Another caster for the books. For those that say see I told you I knew where it was going to hit.
"History Caster"


How about just plane old "forecaster"
Member Since: Posts: Comments:
Ok storm are you going for the Redundant Caster title
Member Since: Posts: Comments:
3056. gator23
Quoting gator23:
Is Weather Underground South Casting? The model plots for the HWRF and GFDL are much further south here. Is Dr Masters a SouthCaster, someone please explain

Link

then here

Link



This deserves a bump, anyone? anyone?
Member Since: Posts: Comments:
3055. KEEPEROFTHEGATE (Mod)
Linkcorrected
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Another caster for the books. For those that say see I told you I knew where it was going to hit.
"History Caster"
Member Since: Posts: Comments:
Something tells me by looking at the trend of models 97 might even go up the east coast like SC or NC.. is that all possible? Doesn't look like it will make it in the gulf..
Member Since: Posts: Comments:
Storm W... when do you expect for that ULL to move away?
Member Since: Posts: Comments:
3048. srada
Quoting srada:


ummm..I said if the northen trends keeps up..its kinda of hard for a storm to hit northern florida and geographically hit GOM for a second landfall unless it does a loop de loop..


and I'm looking at the 12Z dynamic models
Member Since: Posts: Comments:
Quoting weatherwart:


Frances or Erin, same difference... both passed right over my house in west central Florida. Not fun.



rgr that.
Member Since: Posts: Comments:
3045. gator23
Quoting Jeff9641:
Hi Guys here are the updated models from 8AM. Seems to be a split between C and a S FL landfall. I would go right down the center is my best guess and most do strengthing this to a strong TS or min Hurricane.


http://www.coaps.fsu.edu/~maue/tropical/models/AL97_2010072112.png

Good morning Jeff, Yes I would say that the models have shifted north, however, our most accurate models th HWRF and especially the GFDL have not budged. They have been consistant in making this a Central/North Florida Storm. They have not changed much since this started and I have no reason to disagree. CUE THE MIAMI CASTERS
Member Since: Posts: Comments:
WOW the Atlantic has close to 5 ULL's out there. I think it might be be a while before we see another hurricane.
Member Since: Posts: Comments:
Quoting PensacolaDoug:
Copycat caster...


How bout "copycatster"?


That could work too.. I like it.
Member Since: Posts: Comments:
3042. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 169 Comments: 53296
3041. srada
Quoting louisianaweatherguy:


what models are you looking at? everyone of the models I saw this morning shifted a little over toward MS/AL/Pensacola landfall in the gulf...


ummm..I said if the northen trends keeps up..its kinda of hard for a storm to hit northern florida and geographically hit GOM for a second landfall unless it does a loop de loop..
Member Since: Posts: Comments:
Copycat caster...


How bout "copycatster"?
Member Since: Posts: Comments:
what is difference between statistical and dynamic?
Member Since: Posts: Comments:
Quoting PensacolaDoug:
Quoting earthlydragonfly:


Yesterday the CMC model was showing a storm spin up and travel to South Fl. and another right after it from about the same location about 48 hours hitting central fl. and traveling up the center of the state. Maybe this is what the model was alluding to?



When it comes to "cyclone-genesis" the CMC is a hardly a bastion of meteorlogical exelence!


Oh I know.. Actually none of the model do a good job pre-cyclone genesis. But they can serve to hint at where to look for favorable environments in the future. They do very well with Current large weather pattern and what they may do in the future. So they can basically put a arrow on the map for us to check out.
Member Since: Posts: Comments:
3036. gator23
Is Weather Underground South Casting? The model plots for the HWRF and GFDL are much further south here. Is Dr Masters a SouthCaster, someone please explain

Link

then here

Link
Member Since: Posts: Comments:
Quoting earthlydragonfly:


Yesterday the CMC model was showing a storm spin up and travel to South Fl. and another right after it from about the same location about 48 hours hitting central fl. and traveling up the center of the state. Maybe this is what the model was alluding to?



When it comes to "cyclone-genesis" the CMC is a hardly a bastion of meteorlogical exelence!
Member Since: Posts: Comments:
3032. KEEPEROFTHEGATE (Mod)
morn WU bloggers
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Morning Senior Chief Caster.... I got a new one today in reference to someone that acts like someone else here on the blog.

Copycat caster...
Member Since: Posts: Comments:
Good morning, StormW. :)
Member Since: Posts: Comments:
Quoting earthlydragonfly:


Yesterday the CMC model was showing a storm spin up and travel to South Fl. and another right after it from about the same location about 48 hours hitting central fl. and traveling up the center of the state. Maybe this is what the model was alluding to?


It still is hinting at that senerio. Not as prominent as yesterday. It is now also showing a Storm in the Catl developing.
Member Since: Posts: Comments:
Mornin Storm!
Member Since: Posts: Comments:

Viewing: 3078 - 3028

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 | 62Blog 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.