Tropical update

By: Dr. Jeff Masters , 4:16 PM GMT on July 21, 2007

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A tropical wave a few hundred miles north of Puerto Rico is moving into a region where an upper-level low pressure system is spinning. The two weather systems are producing plenty of clouds and thunderstorms over a wide region of ocean. Wind shear is about 20 knots over the area, so not much development today is expected. However, wind shear is expected to drop to about 15 knots Sunday in the area, which could allow some slow development. Water vapor satellite loops show that the tropical wave has brought copious moisture into the previously dry upper level low, and this low could gradually develop a surface low pressure area as thunderstorm activity continues to moisten the region. This system is currently stationary, but is expected to drift northwards over the next two days. A Hurricane Hunter aircraft is scheduled to investigate the area Sunday afternoon.


Figure 1. Water vapor image from this morning showing the upper level low that is sucking in moist air from a tropical wave.

Carolina low pressure system
Thunderstorm activity is starting to pick up off the Carolina coast waters, thanks to a cold front that has pushed off the coast. A regular extratropical low pressure system is expected to develop here today, an move northwards, bringing rain to New England on Monday. Due to high wind shear of about 30 knots and cool SSTs, this low is not expected to be tropical.

In case you missed it, here is my blog on the science of QuikSCAT that was presented at Thursday's Congressional hearing on NHC's turmoil.

OK, now you can go back to reading Harry Potter :-)

Jeff Masters

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694. CycloneOz
5:56 PM GMT on July 22, 2007
GREAT NEWS!

You can now download the MASTER COPY of the 2005 Hurricane Season. The time lapse animation was created from the GOES East IR imagery from 2005.

It is a .avi video file. This video is worth the disk space and download time to add to your collection.

Of course, you can still view the video without downloading by going to Google Video, but the quality of the MASTER COPY is much better!
Member Since: August 26, 2006 Posts: 10 Comments: 3756
693. ustropics
5:43 PM GMT on July 22, 2007
That SW Caribbean wave is going slightly north of Guatemala and Nicaragua...appears headed for the Yucatan.

Yup and still heading west per say the 205pm TWD.
692. CaicosRetiredSailor
5:29 PM GMT on July 22, 2007
IKE
You are very welcome.
signed
"no one"
lol
Member Since: July 12, 2007 Posts: 0 Comments: 6049
691. IKE
5:02 PM GMT on July 22, 2007
There's a new blog...nice of no one to inform us.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
690. borlando
5:02 PM GMT on July 22, 2007
FLAGLER COUNTY, TORNADO WARNING

A Tornado Warning remains in effect until 130 PM EDT for eastern
Flagler County...

At 1254 PM EDT... a tornado was reported in Flagler Beach. Other
waterspouts offshore may move over the coastal area over the next 30
minutes. This tornado was located near Flagler Beach. This tornado
was moving slowly west.
689. IKE
4:59 PM GMT on July 22, 2007
On the 1500 UTC shear map from CIMSS...the shear is weakening in the area that wave is headed...the 20 knot shear has moved north and east from where it was at 1200UTC....

Link
Member Since: June 9, 2005 Posts: 23 Comments: 37858
688. IKE
4:56 PM GMT on July 22, 2007
ustropics...

That SW Caribbean wave is going slightly north of Guatemala and Nicaragua...appears headed for the Yucatan.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
687. ustropics
4:54 PM GMT on July 22, 2007
ustropics
I'm using Firefox, I was speaking of the Blog entry text.
Thanks CRS


I have increased the font for the blog entries :)
686. guygee
4:41 PM GMT on July 22, 2007
Seems like a NE surge/backdoor front is sweeping down the FL East Coast today. Winds at buoy Station 41009 20 NM East of Cape Canaveral, FL have shifted from W to N over the past few hours, and winds at buoy Station 41012 40NM ENE of St Augustine, FL are due East at 23 kts gusting to 27 kts as of 1550 GMT. Pressures in the area are around 30.00". At 1600 GMT MAYPORT NAS is reporting lgt rain winds E17G24 and pressure 30.02F.

Member Since: September 16, 2005 Posts: 0 Comments: 3171
685. ustropics
4:38 PM GMT on July 22, 2007
The SFC low is something we have not seen from most of the waves of late, correct?

It was noted in the 5am TWO I believe and the 8am TWD.
684. CJ5
4:27 PM GMT on July 22, 2007
Posted By: Drakoen at 4:07 PM GMT on July 22, 2007.

Possible. It already has a SFC low. Conditions are only marginal for development though...


The SFC low is something we have not seen from most of the waves of late, correct?
Member Since: July 4, 2007 Posts: 0 Comments: 1755
683. CJ5
4:19 PM GMT on July 22, 2007
Posted By: Drakoen at 4:07 PM GMT on July 22, 2007.

Possible. It already has a SFC low. Conditions are only marginal for development though..


Drak, what maps do you use to see/confirm SFC lows?
Member Since: July 4, 2007 Posts: 0 Comments: 1755
682. moonlightcowboy
4:09 PM GMT on July 22, 2007
CV wave also showing some 30 kt winds on the lastest sfc map.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
681. CaicosRetiredSailor
4:07 PM GMT on July 22, 2007
ustropics
I'm using Firefox, I was speaking of the Blog entry text.
Thanks CRS
Member Since: July 12, 2007 Posts: 0 Comments: 6049
680. Drakoen
4:07 PM GMT on July 22, 2007
Posted By: CJ5 at 3:53 PM GMT on July 22, 2007.

This GFS model is showing some development from the current wave off of Africa. Thoughts?
Link


Possible. It already has a SFC low. Conditions are only marginal for development though...
Member Since: October 28, 2006 Posts: 57 Comments: 30565
679. StormJunkie
4:06 PM GMT on July 22, 2007
thel, good to see ya. How's life in the MYB?

Talk to ya soon. I really am out now. Everyone have a great day!
Member Since: August 17, 2005 Posts: 26 Comments: 16874
678. thelmores
4:04 PM GMT on July 22, 2007
who is Harry Potter? LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
677. ustropics
4:03 PM GMT on July 22, 2007
I visited your site, thanks for the work there, however it is very had to read for someone with "old eyes" like mine, I had to increase size of text and select it to get some contrast.... this is meant as a constructive comment.

Thank you CRC. I haven't cross browser checked it nor have I tried different resolutions (I use 1400 X 900) so everything appears fine to me but I will increase the font size. Are you talking about the blog entries or the text in general on the site? Blog entry text can be more easily fixed but I can increase the size of all text.
676. CaicosRetiredSailor
3:59 PM GMT on July 22, 2007
ustropics
I visited your site, thanks for the work there, however it is very had to read for someone with "old eyes" like mine, I had to increase size of text and select it to get some contrast.... this is meant as a constructive comment.
CRS
Member Since: July 12, 2007 Posts: 0 Comments: 6049
675. Patrap
3:54 PM GMT on July 22, 2007
GOES WV loop Atlantic Tropical Basin..Link
Member Since: July 3, 2005 Posts: 426 Comments: 128767
674. ustropics
3:54 PM GMT on July 22, 2007
well obviously as it continues into Central America some of the convection to the north will also travel into the NW Caribbean. Regardless if it is tracking West or WNW (definitely not NW yet) land is going to become and inhibitor.
673. CaribbeanDude
3:54 PM GMT on July 22, 2007
A tropical wave, albeit not huge, is passing through our West Indies right now....

"Tropical wave entering the area, with fast-moving precipitation evident on radar loop. NWS, in another excellent discussion at 6am this morning, warns mariners of the possibility of 35kt gusty winds with this system."


Member Since: August 8, 2006 Posts: 0 Comments: 46
672. CJ5
3:53 PM GMT on July 22, 2007
This GFS model is showing some development from the current wave off of Africa. Thoughts?
Link
Member Since: July 4, 2007 Posts: 0 Comments: 1755
671. StormJunkie
3:52 PM GMT on July 22, 2007
Morning SW, jp, wb, and CRS ☺

Love the NRL site.

One of the many pages that can be found from the Quick Links page. Easily navigate some of the best imagery, model, marine, and wind data pages on the web. As well as much more all from one page.

I'm out. See y'all later, and as promised I will post some more lightning pics this afternoon.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
670. Chicklit
3:49 PM GMT on July 22, 2007
Thanks CaribbeanDude, it looks that way from satellite photos, too.
Member Since: July 11, 2006 Posts: 14 Comments: 11356
668. BahamaPapa
3:49 PM GMT on July 22, 2007
Murko I am in Nassau.
667. moonlightcowboy
3:48 PM GMT on July 22, 2007
Same to you, StormW!

...and thanks, Jp. We've all watched that wave a long time now! It held its own through the night and seems to be holding good so far today. I know there's some shear ahead though.

...and Dr. Lyons sort of just "dismissed" it, too. lol
Member Since: July 9, 2006 Posts: 184 Comments: 29610
665. ustropics
3:45 PM GMT on July 22, 2007
You sure? Looks WNW to me.

The convection has shifted more to the northeast giving that impression but the wave as a whole is tracking west.

TROPICAL WAVE IS IN THE CARIBBEAN ALONG 80W S OF 21N MOVING W
NEAR 15 KT
. A BROAD LOW LEVEL INVERTED-V SIGNATURE IS NOTED.
CONVECTION HAS ALSO INCREASE OVER THE SW CARIBBEAN WITH CLUSTERS
OF SCATTERED MODERATE CONVECTION FROM 12N-15N BETWEEN 78W-81W.
THIS FEATURE WILL MOVE ACROSS CENTRAL AMERICA AND THE NW
CARIBBEAN TODAY...
664. Murko
3:43 PM GMT on July 22, 2007
I notice that the WU forecast track for Cosme has it doing a sharp 180 turn. Is this just a screw up?

PS Where are you BahamaPapa? I'm on North Eleuthera.
Member Since: July 13, 2007 Posts: 0 Comments: 155
662. weatherblog
3:42 PM GMT on July 22, 2007
Well, I suppose we have three area of interests today:

To me understandings of a 13 yr. old:

1. Carolina Disturbance

2. Bermuda disturbance with ULL

3. Tropical Wave off of Africa

If the carolina disturbance were to develop into a cyclone, it probably would be subtropical--maybe extratropical. And we may have soon, Subtropical Storm Chantal.

The Bermuda Disturbance interacting with a ULL is an area to watch, as conditions are slowly becoming favorable. This disturbance would head, of course, head out to sea, as most cyclones do in the mid-atlantic...nothing unusual. Well, anyways, it has became a bit organized in the last 24 hours, but, if any development, it would be slow.

Last, we have a tropical wave off of the Africa coast, moving slowly...It looks like it has a surface low, as an evident spin. But, it is very low of convection. Convection is usually most important with any sysytem that wants to get stronger. Also, the conditons aren't the best now for this system, but as it very slowly moves west, some slow development is possible, becasue it may get some convection and organize. Nothing to worry about; just wait and see...we all have plenty of time to watch this.
Member Since: July 10, 2006 Posts: 27 Comments: 1623
661. ustropics
3:41 PM GMT on July 22, 2007
What do you all think of the area just west of 80 in the Carri bean? Any chance of development there?

I have been watching it through the morning hours but there are quite a bit of inhibitors. Pressure is around 1010 but shear remains high in this area (20 knots) and convection is rather limited. Chances are slim as it continues west into Central America.

USTropics
659. hurricane23
3:39 PM GMT on July 22, 2007
Even if this area becomes better organized the odds of it affecting the united states are slim.

Member Since: May 14, 2006 Posts: 8 Comments: 13804
658. IKE
3:39 PM GMT on July 22, 2007
Posted By: ustropics at 6:59 AM CDT on July 22, 2007.

The wave along 80W south of 21N (the one I believe you are referring to) is actually moving west at 15 kt and should continue so into Central America later today.


You sure? Looks WNW to me.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
656. CaicosRetiredSailor
3:38 PM GMT on July 22, 2007
Thanks Patrap for
NRL global sat page.. I like the:

NRL Monterey Images with NOGAPS Overlays
Link
CRS
Member Since: July 12, 2007 Posts: 0 Comments: 6049
655. amazinwxman
3:37 PM GMT on July 22, 2007
is there evidence of a low trying to form because there's convection off the coast? Tell me if this is right or not please. When a low forms is there proof of it forming because convection is around and then the convection causes pressure to fall which causes more convection which then spins and a low has to form on the surface is that right on how a low forms or am I even close?
654. Patrap
3:36 PM GMT on July 22, 2007
N Atlantic Imagery

Link
Member Since: July 3, 2005 Posts: 426 Comments: 128767
653. Patrap
3:34 PM GMT on July 22, 2007
Forget it folks.Best to keep the focus on the topics.Not me.Or the SK guy.
Member Since: July 3, 2005 Posts: 426 Comments: 128767
652. Patrap
3:34 PM GMT on July 22, 2007
I hold no anger. Only directing words to an attack on my character FRIEND. To be sure I have zero words for a poster like that.
Member Since: July 3, 2005 Posts: 426 Comments: 128767
651. BahamaPapa
3:33 PM GMT on July 22, 2007
What do you all think of the area just west of 80 in the Carri bean? Any chance of development there?
649. ustropics
3:31 PM GMT on July 22, 2007
To be sure er,StormKAt..you havent a clue about tropical weather or anything related to what we do here as a group.Your insignificant .Aparently you dont have a learning curve capable of grasping the tropical scenery.But you try to demean me.Most find you a lil loopy. Have a good day SK.But your post from yesterday are..all gone.As they will be today.

I believe StormKat was banned...Your anger is noted but this blog is designated for discussing weather.
648. amazinwxman
3:30 PM GMT on July 22, 2007
so there is evidence now that an area of low pressure is or will be forming off of the Carolina coast now is that right?
647. Patrap
3:26 PM GMT on July 22, 2007
NRL global sat page..Link
Member Since: July 3, 2005 Posts: 426 Comments: 128767
644. moonlightcowboy
3:20 PM GMT on July 22, 2007
Current SAL loops, water vapor and SAL info here.
Member Since: July 9, 2006 Posts: 184 Comments: 29610

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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.