A Gulf of Mexico and an Eastern Atlantic Disturbance Worth Watching

By: Dr. Jeff Masters , 1:53 PM GMT on July 06, 2013

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A tropical disturbance (designated 94L by NHC on Friday) is over the Western Gulf of Mexico, and is headed north towards the Texas/Louisiana coast at 5 - 10 mph. Satellite loops show a modest area of disorganized heavy thunderstorm activity that has been steadily growing this morning. Wind shear has fallen to the moderate range, 10 - 20 knots, since Friday, and the lower wind shear is likely responsible for the increase in thunderstorm activity. A trough of low pressure over the Western Gulf of Mexico is pumping dry air into the west side of 94L, interfering with development. The disturbance should move inland by Sunday morning, bringing heavy rains of 1 - 3" along the Upper Texas and Western Louisiana coasts through Monday morning. None of the reliable forecast models predict that the disturbance will develop, and the disturbance has only a day over water with marginal conditions for development. In their 8 am EDT July 6 Tropical Weather Outlook, NHC gave the disturbance a 20% chance of developing into a tropical depression or tropical storm by Monday.


Figure 1. The Saturday morning NHC Tropical Weather Outlook shows two "Invests" worth watching: 94L over the Gulf of Mexico (area 1), and 95L over the Eastern Atlantic (area 2.) Both were given 20% chances of developing by Monday. Image credit: NHC.

Cape Verdes tropical wave 95L
As we approach mid-July, it's time to begin turning our attention to tropical waves coming off the coast of Africa. We have our first such system worthy of attention today, a tropical wave designated 95L over the Eastern Atlantic near 8°N 33°W, about 800 miles southwest of the Cape Verde Islands. Satellite loops show a modest area of heavy thunderstorms that is showing a moderate amount of spin. Wind shear is moderate, 10 - 20 knots, and ocean temperatures are warm, 28°C. The 8 am EDT Saturday forecast from the SHIPS model predicted that 95L would encounter cooler waters of 27.5°C over the weekend as it headed west to west-northwest at 15 - 20 mph. Wind shear is expected to remain moderate though Monday, which may allow for some additional organization. However, 95L is embedded in a very large area of dry air associated with the Saharan Air Layer (SAL), and July African waves typically have considerable trouble getting organized in the very dry air of the SAL. The disturbance could arrive in the Lesser Antilles Islands as early as Tuesday. A band a strong upper-level winds associated with the subtropical jet stream is expected to be over the northern islands at that time, and if 95L has penetrated as far north as 15°N latitude by that time, it will have to face very high wind shear of 30+ knots. But if 95L stays farther to the south, wind shear should be lower, giving the storm a better chance of development. None of the reliable forecast models predict that 95L will develop. In their 8 am EDT July 6 Tropical Weather Outlook, NHC gave the disturbance a 20% chance of developing into a tropical depression or tropical storm by Monday.


Figure 2. MODIS image of 95L taken at approximately 11 am EDT Saturday, July 6, 2013. Image credit: NASA.

Elsewhere in the tropics
A large upper-level cold-cored low pressure system a few hundred miles north of Puerto Rico will move west over the next dew days, arriving in the Bahamas by Sunday and South Florida by Tuesday. The models do not show that this low will will acquire a surface circulation, and there is only minimal heavy thunderstorm activity associated with it.

In the Eastern Pacific, Tropical Storm Erick is brushing the southwestern coast of Mexico, and is expected to intensify into a Category 1 hurricane on Saturday afternoon. Erick will bring heavy rains of 3 - 5 inches to Southwest Mexico, but the core of the storm is currently expected to remain just offshore. Erick will likely weaken to a tropical storm on Monday, when it will pass just south of Baja.

Cool San Francisco time-lapse fog video
Videographer Simon Christen has created a spectacular 4-minute time-lapse video of fog rushing in past the Golden Gate Bridge into San Francisco. He writes: ""Adrift" is a love letter to the fog of the San Francisco Bay Area. I chased it for over two years to capture the magical interaction between the soft mist, the ridges of the California coast and the iconic Golden Gate Bridge. This is where “Adrift” was born. The weather conditions have to be just right for the fog to glide over the hills and under the bridge. I developed a system for trying to guess when to make the drive out to shoot, which involved checking the weather forecast, satellite images and webcams multiple times a day. For about 2 years, if the weather looked promising, I would set my alarm to 5am, recheck the webcams, and then set off on the 45-minute drive to the Marin Headlands. I spent many mornings hiking in the dark to only find that the fog was too high, too low, or already gone by the time I got there. Luckily, once in a while the conditions would be perfect and I was able to capture something really special. Adrift is a collection of my favorite shots from these excursions into the ridges of the Marin Headlands."


Video 1. Adrift from Simon Christen on Vimeo.

Jeff Masters

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Quoting 952. wunderkidcayman:


Hmm can anyone tell me who the hell is this guy this tropicaltrouble2013 guy



jfv
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Solar Plane Completes Cross-Country Trek

The solar-powered airplane will finally complete its coast-to-coast journey early Sunday morning with a victory lap around Lady Liberty

Read more: http://newsfeed.time.com/2013/07/06/solar-plane-c ompletes-cross-country-trek/#ixzz2YJ97ATZf
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Quoting 942. TropicalTrouble2013:


But of course you do..so that they could reach your longitude & latitude over there in the Cayman Islands, eh?

You'll never change..but luckily, everybody in here already knows that proclivity of yours.


Hmm can anyone tell me who the hell is this guy this tropicaltrouble2013 guy
Member Since: June 13, 2009 Posts: 2 Comments: 14983
Quoting 940. Grothar:
Here is the 18Z





When you see that small a spread, dat far out, pay attention I say.

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Quoting 936. TropicalTrouble2013:
You're employed? I had no clue.

Is it a summertime gig?

Hi, Drew!




HI jfv you been reported
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Quoting 928. superpete:


Wunderkid- I hear you, except Ivan was the first week of September 2004, we are at the first week of July.Despite how vigorous 95L looks now,this isn't September.As usual,this will be a slow watch & wait scenario for development down the road during the next few days as many factors come into play

I hear you it's not sept but this year I believe anything can happen
Member Since: June 13, 2009 Posts: 2 Comments: 14983
Quoting 936. TropicalTrouble2013:
You're employed? I had no clue.

Is it a summertime gig?

Hi, Drew!

Living near the coastline, I have a job cleaning beach houses (you know, the ones tourists love to come and wreck). Takes a lot of time and effort, lol.
Member Since: July 6, 2010 Posts: 113 Comments: 34481
Quoting 941. wunderkidcayman:
Polls time

What will 95L be for the next TWO
A. 40%
B. 50%
C. 60%
D. 70%
E. 80%
F. 90%
G. 100%
H. 30% the same no change yet
A-D
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Quoting 929. MechEngMet:


Hey hey, watch that 'Age' stuff m-kay?! I'm only as old as I feel. But yes, Some nights I can't sleep either. Soooo... I occasionally stay up late talking with my friends Jack and Evan. Sometimes an old salt friend of mine named Morgan (claims he's some kind of captain or something) brings over his pet wild turkey, and then things really get out of hand.



I've met dat Captain, and he can also Hurt you if you talk too late with him.

Arrrrgh'
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Polls time

What will 95L be for the next TWO
A. 40%
B. 50%
C. 60%
D. 70%
E. 80%
F. 90%
G. 100%
H. 30% the same no change yet
Member Since: June 13, 2009 Posts: 2 Comments: 14983
Here is the 18Z

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Quoting 929. MechEngMet:


Hey hey, watch that 'Age' stuff m-kay?! I'm only as old as I feel. But yes, Some nights I can't sleep either. Soooo... I occasionally stay up late talking with my friends Jack and Evan. Sometimes an old salt friend of mine named Morgan (claims he's some kind of captain or something) brings over his pet wild turkey, and then things really get out of hand.



I hear ya. Gave me a gut chuckle. ;)
Member Since: July 9, 2006 Posts: 184 Comments: 29613
Quoting 926. wunderkidcayman:
I'm expecting models to shift further S again

I agree. I'm sticking with my prediction.
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However, 95L is embedded in a very large area of dry air associated with the Saharan Air Layer (SAL), and July African waves typically have considerable trouble getting organized in the very dry air of the SAL. The disturbance could arrive in the Lesser Antilles Islands as early as Tuesday. A band a strong upper-level winds associated with the subtropical jet stream is expected to be over the northern islands at that time, and if 95L has penetrated as far north as 15N latitude by that time, it will have to face very high wind shear of 30 knots. But if 95L stays farther to the south, wind shear should be lower, giving the storm a better chance of development. None of the reliable forecast models predict that 95L will develop. In their 8 am EDT July 6 Tropical Weather Outlook, NHC gave the disturbance a 20% chance of developing into a tropical depression or tropical storm by Monday.

Jeff Masters
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Quoting 926. wunderkidcayman:
I'm expecting models to shift further S again



If the models continue to trend south then there is a chance it could miss a lot of shear if it moves through the southern Caribbean....won't be totally out of the woods but it would weaken it some but once it gets out of the shear it could have a chance to gain back some of what it lost
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Quoting 916. txjac:


As long as it brings rains to Texas I'm good with that
Amen, to that!
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Quoting 916. txjac:


As long as it brings rains to Texas I'm good with that
Hey, I really hope that my rain dance from the other day does the trick for you.
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Quoting 807. Hurricanes101:
Um why do we keep sharing all of these 10 day forecasts from people comparing it to other stores?

This is 95L, like no other system before it, comparing it to other storms is pointless when it is just an invest. Saying it looks to be a storm for "enter certain area here" is crazy this far out.

There is nothing wrong with looking at the possibilities, just be careful in how you do it. Kick back and watch, there is a lot to come with this system and plenty of time for things to change numerous times.
This is analoging, some of it more primitive than others. While no two tracks are the same, looking at previous storms [in aggregate forming climatology] can give insights into the kinds of conditions that will likely lead to a type of track. Comparison between past and current conditions can give some idea of possible tracks for a current or future TC. So people are not crazy. In fact, they're doing what TC forecasters did as a matter of course over the last 100 years.

Moreover, no one has said "this storm is for a certain area". Instead, people have been very logically looking at current conditions and using their understanding of typical TC behaviour to suggest possible tracks. Given this is the first MDR system with any serious developmental potential, everybody's got an opinion. Some people find it easier to use the analog storms to show what they are thinking. But don't mistake this conversation for doom and gloom wishcasting. I think we've matured enough as a community and as individuals to avoid that. Mostly.
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Quoting 923. TropicalTrouble2013:


Cody, where have you been, child? I haven't seen you on all day long.

Busy Saturday, I'd presume?

Yeah, just got home from work.
Member Since: July 6, 2010 Posts: 113 Comments: 34481
Quoting 887. moonlightcowboy:


Respect, fellas, but that's not banding though it does have that appearance. There is no rotating surface low. What you're seeing are low-level easterlies underneath the trough. I mentioned this last night, but I think you two old cluckers (like me) had turned in already! :) I'd tried to sleep earlier, couldn't, got back up and saw your posts, but missed y'all I guess. I still think you're going to get a heap of rain, likely some good gusts too.


Hey hey, watch that 'Age' stuff m-kay?! I'm only as old as I feel. But yes, Some nights I can't sleep either. Soooo... I occasionally stay up late talking with my friends Jack and Evan. Sometimes an old salt friend of mine named Morgan (claims he's some kind of captain or something) brings over his pet wild turkey, and then things really get out of hand.

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Quoting 828. wunderkidcayman:
Hey guys after examining 95L and another storm I see some very very close similarities

That storm is Hurricane Ivan of 2004 it follows the same way forms from a strong tropical wave with a low it had similar problems such as dry air and SAL to its N

It moved quickly Wward as 95L is

Something tells me 95L is going to do some big things


Wunderkid- I hear you, except Ivan was the first week of September 2004, we are at the first week of July.Despite how vigorous 95L looks now,this isn't September.As usual,this will be a slow watch & wait scenario for development down the road during the next few days as many factors come into play
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By looks of that Bermuda high there could be a lot of storms reaching the US this year
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I'm expecting models to shift further S again
Member Since: June 13, 2009 Posts: 2 Comments: 14983
Quoting 919. weatherlover94:
Guys is there a chance that 95 L could go north of the Caribbean and miss the shear ?


That's where the models want to take it. The agreement has the track bringing it up north of the Antilles and then paralleling the Antilles as it heads off for Florida.

Quoting 920. TropicalAnalystwx13:
I see we have a code orange Invest 95L in the eastern Atlantic.

The biggest struggle for this wave, by far, will be the trade wind flow created by the unusually intense Bermuda High across the northern Atantic. When trade winds at the lower levels are moving quickly towards the west, it prevents disturbances from gaining cyclonic turning and westerly winds on the south side of the low. This has been an issue for many storms over the past few years. There's also a lot of dry air in the central Atlantic.

I wouldn't say development was particularly likely, but it's possible.


Ah, look who's tardy to the party. (That has to be my favorite phrase, lol).
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Quoting 919. weatherlover94:
Guys is there a chance that 95 L could go north of the Caribbean and miss the shear ?


Not with that high over Bermuda
Member Since: June 13, 2009 Posts: 2 Comments: 14983
One thing I'd like to know about the NHC is why they never really cite trade winds as unfavorable for development. Take Ernesto from last year for example. They never did state why it wasn't strengthening in the Caribbean and seemed perplexed. Having said that, they obviously know that trade winds that are too strong are unfavorable for closing off low pressure centers. Why then do they state conditions for development will be "improving" or "are favorable" for further development/intensification when models show otherwise and that trade winds out ahead should be quite stout?

Just makes me wonder if they see things differently. Here is the current TWO...notice the wording:

A VIGOROUS TROPICAL WAVE IS LOCATED OVER THE EASTERN ATLANTIC ABOUT
850 MILES SOUTHWEST OF THE CAPE VERDE ISLANDS. ASSOCIATED SHOWER
AND THUNDERSTORM ACTIVITY IS SHOWING SIGNS OF IMPROVED ORGANIZATION
AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO GRADUALLY BECOME MORE
CONDUCIVE FOR DEVELOPMENT OVER THE NEXT FEW DAYS.
THIS SYSTEM HAS A
MEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS IT MOVES WESTWARD AT 20 TO 25 MPH.

Member Since: July 15, 2006 Posts: 17 Comments: 10300
Quoting 919. weatherlover94:
Guys is there a chance that 95 L could go north of the Caribbean and miss the shear ?


depends on the strength and how good it is vertically stacked
Member Since: September 19, 2005 Posts: 2 Comments: 4266
I see we have a code orange Invest 95L in the eastern Atlantic.

The biggest struggle for this wave, by far, will be the trade wind flow created by the unusually intense Bermuda High across the northern Atantic. When trade winds at the lower levels are moving quickly towards the west, it prevents disturbances from gaining cyclonic turning and westerly winds on the south side of the low. This has been an issue for many storms over the past few years. There's also a lot of dry air in the central Atlantic.

I wouldn't say development was particularly likely, but it's possible.
Member Since: July 6, 2010 Posts: 113 Comments: 34481
Guys is there a chance that 95 L could go north of the Caribbean and miss the shear ?
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Gfs suggests the cold core low will ventilate 95l in the gom,if so this is a very bad signature.Hope it's wrong.
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916. txjac
Quoting 911. interpreter:
Don't think anything is going to develop with 94L. the upper air support is not there and it is just going to run out of room and time.

95L has a chance once it is able to gain some latitude in assisting with it gaining spin and power. May be strong enough to ward off the dry as it moves just north of due west.


As long as it brings rains to Texas I'm good with that
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Hi everybody
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A little more agreement on intensity.

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913. beell

METEOSAT 9 07/06 18Z

Last good shot of the day from the CIMSS site.
Link

The dust shown here serving as a good tracer of the dry SAL layer.
Member Since: September 11, 2007 Posts: 154 Comments: 18212
92W



The GFS is now agreeing with the CMC that it will become a typhoon.





The CMC seems to be doing a good job this year for the WPAC.
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Don't think anything is going to develop with 94L. the upper air support is not there and it is just going to run out of room and time.

95L has a chance once it is able to gain some latitude in assisting with it gaining spin and power. May be strong enough to ward off the dry as it moves just north of due west.
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Quoting 881. TropicalTrouble2013:
Grathar, it's been ages!!!!!!!!!!!!!!!!!!!!!!!!

How's WU's number one fan doing after his health scare back in May?



Hey, stranger!. The doctors figured out that if I keep breathing, I should be fine.
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Quoting 898. MississippiWx:


Looks like just as much convection as ever. In fact, this is probably the strongest the convection has been yet.

It's a tightly compact system, so any changes in the environment can disrupt it or strengthen it. In other words it is susceptible to changes.
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I've been off for awhile. Has anyone mentioned the Hebert Box or the John Hope rule yet??? Just wondering.


It definitely looks like the islands and Florida will have to monitor this one closely.


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Quoting 868. Tazmanian:



other low riding wave too watch


With 95L cuttin the brush for them. Those of us attempting to analog are coming up with '04 and '05 as examples of early, numerous southerly CV jump-offs. '05 didn't have the Bermuda high to careen off, '04 does. But '05 had an abormally early active season, '04 did not.

So I guess we should expect a hybrid of the two seasons.
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need to wait until 95l fully breaks away from ITCZ and see if it survives on its own
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Quoting 903. MississippiWx:


We will see. Trade winds are going to be a problem for it unless it is already a closed low. If it can establish itself and become strong enough before the trade winds increase, it might be able to survive them.



Yeah, and it needs to find the brake handle, but sure looks pretty good.
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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