93L near tropical depression strength

By: Dr. Jeff Masters , 2:31 PM GMT on June 25, 2010

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The first tropical depression of the 2010 Atlantic hurricane season appears imminent in the Western Caribbean, as the areal coverage and intensity of heavy thunderstorm activity associated with the tropical wave (Invest 93L) continue to increase. The storm has developed a surface circulation near 16.5N, 82.5W at 8am EDT, about 100 miles northeast of the Nicaragua/Honduras border. This is far enough from land that development will be slowed only slightly. Satellite loops show a poorly organized system, with only a modest amount of heavy thunderstorm activity near the center. However, the developing storm is affecting the weather across the entire Western Caribbean, and bands of heavy thunderstorms are quickly building over a large region. Pressures at ground stations and buoys all across the Western Caribbean have been falling significantly over the past day (Figure 2.) Water vapor satellite loops show that moist air surrounds 93L, and there is not much dry air to slow down development. There is an upper-level high pressure system a few hundred miles west of 93L, and the clockwise flow air around this high is bringing upper-level winds out of the northwest of about 10 - 15 knots over 93L, contributing to the 10 - 15 knots of wind shear observed in this morning's wind shear analysis from the University of Wisconsin's CIMSS group. Sea Surface Temperatures are very warm, 29 - 30°C. The Madden-Julian oscillation (MJO) currently favors upward motion over the Caribbean, which will act to increase the chances of tropical storm formation this week. The main negative for 93L is a combination of lack of spin and wind shear. Last night's pass of the ASCAT satellite showed a broad, elongated circulation, which will need to tighten up in order for 93L to become a tropical depression. The Hurricane Hunters are scheduled to fly into 93L at 2pm EDT this afternoon to see if a tropical depression has formed.


Figure 1. Morning visible satellite image of the central Caribbean disturbance 93L.


Figure 2. Combined plot of wind speed, wind gusts, and pressure at buoy 42057 in the Western Caribbean. Pressure (green line) has fallen significantly over the past two days, and winds are beginning to increase.

Forecast for 93L
The greatest risk from 93L to the Western Caribbean will be heavy rainfall, and the nation most at risk is Honduras. The counter-clockwise flow of air around 93L will bring bands of rain capable of bringing 4 - 8 inches of rain to northern Honduras over the next two days. Heavy rains of 3 - 6 inches can also be expected in northeast Nicaragua, Cuba, Belize, the Cayman Islands, and Mexico's Yucatan Peninsula. The storm is moving west-northwest at about 10 mph, and this motion is expected to gradually slow over the next five days to about 6 mph. I expect that by tomorrow, 93L should be closer to being directly underneath the upper level high pressure system to its west, which would act to lower wind shear and provide more favorable upper-level outflow. NHC is giving 93L a 70% chance of developing into a tropical depression by Sunday morning, which is a reasonable forecast. The storm will probably be a tropical depression or tropical storm with 40 mph winds when it moves over Mexico's Yucatan Peninsula on Sunday. The storm will probably spend a day or so over the Yucatan, resulting in significant weakening. Once 93L emerges over the Gulf of Mexico, it will take the storm 24+ hours to recover its strength.

A trough of low pressure is expected to swing down over the Eastern U.S. on Monday. If this trough is strong enough and 93L develops significantly, the storm could get pulled northwards and make landfall along the northern Gulf of Mexico coast. This is the solution of the GFDL and HWRF models. If 93L stays weak and/or the trough is not so strong, the storm would get pushed west-northwestwards across Mexico's Bay of Campeche and make landfall along Mexican coast south of Texas, or in Texas. This is the solution of the NOGAPS, ECMWF, and Canadian models. A likely landfall location is difficult to speculate on at this point, and the storm could hit virtually anywhere along the Gulf of Mexico coast given the current uncertainty in its development. The amount of wind shear in the Gulf of Mexico next week is also highly uncertain. There is currently a band of high shear near 30 knots over the Gulf. The GFS model predicts that this band of high shear will lift northwards, keeping low wind shear over the Gulf next week. However, the ECMWF model keeps high shear entrenched over the Gulf of Mexico, which would make it unlikely 93L could intensify into a hurricane. In summary, I give 93L a 60% chance of eventually becoming Tropical Storm Alex, and 10% chance of eventually becoming a hurricane.

Elsewhere in the tropics
A tropical wave a few hundred miles northeast of the northernmost Lesser Antilles Islands is producing a modest amount of heavy thunderstorm activity. This system was designated Invest 94 by NHC this morning, and is passing beneath a trough of low pressure that is generating 30 - 40 knots of wind shear. However, by Sunday, the storm will be in a region of much lower wind shear, and NHC is giving the storm a 10% chance of developing into a tropical depression by Sunday morning. We do have one model, the GFS, which develops the system early next week. The GFS model takes the storm to the northwest and then north, predicting it will be very close to Bermuda on Tuesday.


Figure 3. Hurricane Celia as a Category 4 storm at 20:55 UTC Thursday, June 24, 2010, as captured by NASA's MODIS instrument.

Impressive Hurricane Celia hits Category 5
The first Category 5 hurricane in the Northern Hemisphere this year is Hurricane Celia in the Eastern Pacific. Celia's 160 mph winds make it tied with Australia's Tropical Cyclone Ului as the strongest tropical cyclone in the world so far in 2010. Celia has likely peaked in intensity, and is not expected to threaten any land areas.

Wind and ocean current forecast for the BP oil disaster
East to southeast winds of 5 - 15 knots will blow in the northern Gulf of Mexico today through Tuesday, according to the latest marine forecast from NOAA. The resulting weak ocean currents should push the oil to the west and northwest onto portions of the Louisiana and Alabama coasts, according to the latest trajectory forecasts from NOAA and the State of Louisiana. I would expect Mississippi to have its most serious threat of oil yet early next week as these winds continue. The longer range outlook is uncertain, and will depend upon what 93L does.

Resources for the BP oil disaster
Map of oil spill location from the NOAA Satellite Services Division
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's interactive mapping tool to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Jeff Masters

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Quoting MiamiHurricanes09:
True, but when in a hurricane you are experiencing much stronger turbulence than in a tropical depression, per se. Yes it is calm when you are in the eye, but what if it is needed to analyze the eye wall?


The reason I said this is because I had a hurricane Hunter talk to my school about flying into hurricanes, and he said it was definately a lot scarier to fly into a depression/disturbance/storm than into a hurricane. He told us horror stories about flying into a depression one time. He also mentioned that flying into a hurricane was really easy. When I heard this, i was surprised as well. Really interesting!
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Quoting taco2me61:
well uh I was hoping I was wrong too but I'm not.... They are starting to move all boats out and stop the collection of crude.... From what I'm uderstanding they will be removing the cap from the top of the leak....

Taco :o(

thanks for the info, hopefully this thing will do whatever it is going to do quickly so they can get back at it.
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Quoting extreme236:


Ike has the most advanced JFV detector this blog's ever seen.


I think JFV and IKE could be related? I notice they both have 3 letter names in all caps. Hmmmm.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting extreme236:


Ike has the most advanced JFV detector this blog's ever seen.


yea so advanced, a shower curtain rod hits him in the back of the head when JFV is present lol
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Quoting scott39:
I think KaBoom!


That's right. Intensification is very likely from this, considering how warm those SSTs are (mid-high 80s)

-Snowy
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Quoting HaboobsRsweet:

I do not htink that is 100% true. A hurricane actually does not have a lot of turblance because it is uniform and the speed is similar around the same path. To have turblence you need rapid change in speed or direction and that doesnt really happen much in a hurricane.
True but a gust of 150 miles an hour causes more turbulence than a gust of 50 miles per hour.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
3672. IKE
I'm surprised there aren't warnings for the northern coast of Honduras. The center is near the coast.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
amazing shots on those floaters!
looks like a couple of Tsar bombs going off
Quoting Patrap:
TD-1
Floater - Visible Loop


NASA MSFC Viewer TD-1
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Quoting CaneWarning:


LOL how'd you guess already?


Ike has the most advanced JFV detector this blog's ever seen.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
3668. Michfan
Looks like the early models are getting a handle on it. Will be interesting to see what the later 00Z models spit out.
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Quoting F4PHANTOM:
Trending left?


It sure looks like it to me. This is probably a Texmex event.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting GlobalWarming:
anything coming down the pipeline after alex, y'all?
JFV, listen, we already know it's you. But yes we are monitoring an area of disturbed weather labeled 94L. It has a 20% chance of tropical formation in the next 48 hours, as per NHC.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting ecflweatherfan:
What I wonder is how big the wind field will be once it grows up. Hopefully not the size of Special K of 2005.

This why the hype and wish casting on here bugs me..
Someone is worried that TD might become a ( I won't say it cause he didn't)
I'd put the chances of that at at about
.0000000001
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Quoting MiamiHurricanes09:
True, but when in a hurricane you are experiencing much stronger turbulence than in a tropical depression, per se. Yes it is calm when you are in the eye, but what if it is needed to analyze the eye wall?

I do not htink that is 100% true. A hurricane actually does not have a lot of turbulence because it is uniform and the speed is similar around the same path. To have turblence you need rapid change in speed or direction and that doesnt really happen much in a hurricane.
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Quoting IKE:


Howdy JFV.....


LOL how'd you guess already?
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting gordydunnot:
I hate to criticize here, but why doesn't everyone calm down a little bit and wait to you can string a couple of sentences together that make some sense about the ongoing tropical weather and then post. As when someone posted earlier. if everyone on this blog post three and four word sentences it is going to be hard to follow blog. MAYBE THIS IS THE CONSTRAINT THE DOC NEEDS WHEN THE TROPICS FIRE UP.


I AM SO GLAD YOU TYPED THAT IN ALL CAPS. IT REALLY GOT YOUR POINT ACROSS MUCH BETTER. THANK YOU.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
3659. Patrap
TD-1
Floater - Visible Loop


NASA MSFC Viewer TD-1
Member Since: July 3, 2005 Posts: 426 Comments: 128632
Quoting jurakantaino:
How can he be in a flight ,isn't he 13 years old. Have to congratulate you kid a future John Hope in the making.
Thanks.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting KEEPEROFTHEGATE:
are you drinking taz
Forgot to take his meds.
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3656. Gorty
@twooks

I am thinking 50 mph at 11PM
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3655. IKE
Quoting GlobalWarming:
Hi, Ike.


Howdy JFV.....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting MrstormX:


Of course, I agree that you are extremely bright for a 13 yr old... if you keep it up you will be working at the NHC by 21.
Unless I can get a doctorate degree by the age of 21, it ain't happenin'. Lol.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting GlobalWarming:
anything coming down the pipeline after alex, y'all?


94L might have a shot
Member Since: July 8, 2005 Posts: 259 Comments: 24163
Quoting MiamiHurricanes09:
No, why?
How can he be in a flight ,isn't he 13 years old. Have to congratulate you kid a future John Hope in the making.
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I hate to criticize here, but why doesn't everyone calm down a little bit and wait to you can string a couple of sentences together that make some sense about the ongoing tropical weather and then post. As when someone posted earlier. if everyone on this blog post three and four word sentences it is going to be hard to follow blog. MAYBE THIS IS THE CONSTRAINT THE DOC NEEDS WHEN THE TROPICS FIRE UP.
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Quoting weatherman566:
Good, glad I'm not posting stuff for nothing.

Miami-

Did you read my post? It is actually more difficult to fly into an unorganized system, such as a depression or storm, versus flying into a hurricane. They have to get into the center of the storm to get data, and when you are flying in something like 93L, you can run into a lot of turbulence because you do not know where you are flying at exactly. In a hurricane, once you are in the eye, it is smooth sailing. (or flying huh?)
True, but when in a hurricane you are experiencing much stronger turbulence than in a tropical depression, per se. Yes it is calm when you are in the eye, but what if it is needed to analyze the eye wall?
Member Since: September 2, 2009 Posts: 130 Comments: 21194
3647. twooks
On the next advisory, I expect TS Alex 40 mph...
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Quoting MiamiHurricanes09:
With current satellite presentation and estimates mostly ranging in the tropical storm threshold, I think we already have one, unofficially of course.


Of course, I agree that you are extremely bright for a 13 yr old... if you keep it up you will be working at the NHC by 21.
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3643. Patrap
00z Early Cycle NHC model tracks
Invest93
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

Member Since: July 3, 2005 Posts: 426 Comments: 128632
3642. uplater
Quoting scott39:
I meant the way you Quote.


LOL, one would hope he is older than his quotes
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Quoting uplater:


prolly because the maturity with which you analyze trends in the ocean and on the internet seriously belies your real age! =)
Quoting scott39:
You seem older than your Quotes.
Thanks.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
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Quoting PcolaJess:


ugh, was really, really hoping you were wrong lol
well uh I was hoping I was wrong too but I'm not.... They are starting to move all boats out and stop the collection of crude.... From what I'm uderstanding they will be removing the cap from the top of the leak....

Taco :o(
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Quoting Tazmanian:
OMG I SEE A EYE

Did you forget to take your meds today? seriously, just concerned about your posts, there way, way out there!
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3637. scott39
Quoting scott39:
You seem older than your Quotes.
I meant the way you Quote.
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Quoting AstroHurricane001:


Size comparison:

Ike 2008:


Bill 2009:


Compare Alex 2010:

This is apples and orange
IKE Bill were solidly coalesced cat 5 hurricanes with almost 400nm diameters
Alex maybe is 60 miles condensed 500 miles of mush and the convection near jamaica is from the next wave soon to be best friends with Alex maybe(ok probably)
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Canadian model:

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Quoting MrstormX:
TS is pretty immanent.
With current satellite presentation and estimates mostly ranging in the tropical storm threshold, I think we already have one, unofficially of course.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
3633. HadesGodWyvern (Mod)


Alternative ADT cyclone image that shows current dvorak intensity for AL01-2010
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Good, glad I'm not posting stuff for nothing.

Miami-

Did you read my post? It is actually more difficult to fly into an unorganized system, such as a depression or storm, versus flying into a hurricane. They have to get into the center of the storm to get data, and when you are flying in something like 93L, you can run into a lot of turbulence because you do not know where you are flying at exactly. In a hurricane, once you are in the eye, it is smooth sailing. (or flying huh?)
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3631. Seastep
Question.

Why would the 18Z models initialize with Celia accurately as an intense cyclone and Darby as a weak TS or TD?

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The news story I saw said BP would have to if the storm became a threat...not that they were shutting down. They did say the cap would come off and takes 5 days to move everything out.
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3629. scott39
Quoting MiamiHurricanes09:
Yes, why?
You seem older than your Quotes.
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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.