Not a trace of Don; What's next?

By: Dr. Jeff Masters , 7:41 PM GMT on July 30, 2011

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Don is dead

Tropical Storm Don, the fourth named storm of the 2011 season, made landfall near Baffin Bay, Texas yesterday evening around 10pm CDT in less-than-grand fashion. The storm was looking very weak for the 24 hours before landfall, but fizzled rapidly after landfall, and by early Saturday morning, there was barely a trace of the storm to show that it even existed in the first place.

NHC Hurricane Specialist Eric Blake probably said it best in this mornings 5am EDT discussion on the storm:

THE DON IS DEAD. THE CYCLONE LITERALLY EVAPORATED OVER TEXAS ABOUT
AS FAST AS I HAVE EVER SEEN WITHOUT MOUNTAINS INVOLVED. DON HAS NO
CONVECTION...MEAGER RAINFALL...AND ONLY A SLIGHT SIGNATURE IN
SURFACE OBSERVATIONS AND RADAR DATA. THEREFORE...THIS IS THE LAST
ADVISORY ON THIS SYSTEM.


Figure 1. Total precipitation accumulation for the storm, estimated by radar.

The heaviest rainfall was falling south of the storm's center yesterday, so it wasn't surprising that Brownsville saw the most rain, 0.63 inches. KBRO also recorded 18 mph wind gusts. But to the north of the center, where many of the media were located, not a drop of rain fell. Corpus Christi saw zero inches of rain, but did record gale-force wind gusts (39 mph). Harlingen, near Baffin Bay, and close to where the center made landfall, saw 0.20 inches of rain and 18 mph wind gusts. This storm did very, very little to relieve any drought conditions in Southern Texas. And so it continues.

What's next: Invest 91L continues to impress

Invest 91L, which is located near 12°N 48°W in the central Atlantic, continues to impress today, and has shown signs of more organization over the past 24 hours. 91L will probably develop into a tropical cyclone before it reaches the Lesser Antilles, so residents of these islands should remain watchful and prepared. Satellite loops show not only organized thunderstorm activity, but also the makings of a surface circulation. Something this wave has working against it right now is dry air—there's a large mass of Saharan air on the north and east sides of the system, which could at least prevent significant intensification. Also, University of Wisconsin CIMSS analysis shows some strong wind shear (30-40 knots) to the north of the wave. However, I don't expect this to prevent development of the wave. Wind shear out ahead of the system is relatively low (5-15 knots). Moisture is plenty high within the system, and sea surface temperatures are warm and toasty (28°C+) and will only get warmer as 91L moves west into the Caribbean.


Figure 2. Infrared satellite of invest 91L taken at 1:15pm EDT today.

Forecast for 91L
Most of the reliable forecast models (GFS, CMC, FIM, and the ECMWF) have come to agree that 91L will develop, however, they differ on how long-lived that will be. Some of the models are suggesting it will be a short-lived tropical cyclone, not making it out of the Caribbean alive, and some suggest that it will hold together and intensify as it moves north of the Caribbean islands. The forecast track for the system will most likely be to the northwest through the Caribbean, at which point it will take a northeast turn near the Bahamas, never reaching the U.S. coast. HWRF agrees with this track (and also brings the system to category 2 strength by August 3rd). However, there is still some uncertainty that the system could track west, south of the Caribbean islands, and potentially into the Gulf of Mexico. However, none of the models that suggest this solution actually show that the wave will be a tropical cyclone at that point.

The National Hurricane Center is giving this wave an 80% chance of developing into at least Tropical Depression Five over the next 48 hours. Chances are we will see Emily out of this system. A Hurricane Hunter mission is scheduled for tomorrow at 2pm EDT, but I wouldn't be totally surprised to see them call this system this evening, given the threat to the Lesser Antilles.

Watching a northwest Caribbean disturbance

A broad area of disturbed weather is producing some heavy thunderstorms in the northwest Caribbean, southeast of the Yucatan Peninsula. Little to no low-level circulation exists with this feature, and none of the models are picking up on it. The Hurricane Center has "blobbed" this item (as I like to say) with a "near 0%" chance of developing over the next 48 hours. This disturbance could cause major flooding in the region given the amount of thunderstorm activity, and predictability for systems like this (potential Bay of Cempeche tropical cyclones) is very low. Models have a short lead time on development, and they spin up very fast once they enter the Bay of Campeche given the favorable topography of the land surrounding it. The difference between this system, though, and one like Arlene, is that there is very, very little low level circulation already present. Pre-Arlene was a bit more organized before it crossed the Yucatan, and so it's hard to imagine that this disturbance will be able to hold together, should it get that far.

If 91L develops, I'll be back tomorrow with a post.

Angela

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Quoting NICycloneChaser:
Does anybody have any idea why recon isn't updating?



there out there waiting too get closeer
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Recon sames stuck in one stop on Google earth?Product: Air Force Tropical RECCO Message (URNT11 KNHC)
Transmitted: 31st day of the month at 16:28Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Mission Purpose: Investigate fourth suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 03

Mandatory Data...

Observation Time: Sunday, 16:24Z
Radar Capability: Yes
Aircraft Altitude: Below 10,000 meters
Coordinates: 15.9N 60.2W
Location: 90 miles (144 km) to the ENE (62°) from Roseau, Dominica.
Turbulence: Light
Conditions Along Flight Route: In the clear
Pressure Altitude: 7,620 meters
Flight Level Wind: 5 knots (~ 5.8 mph) (Bearing was unavailable.)
- The above is a spot wind.
- Winds were obtained using doppler radar or inertial systems.
Flight Level Temperature: -19°C
Flight Level Dew Point: -24°C
Weather (within 30 nautical miles): Shower(s) (continuous or intermittent precipitation - from cumuliform clouds)
400 mb Surface Altitude: 7,600 geopotential meters

This is last observation!
Member Since: April 29, 2007 Posts: 0 Comments: 7669
Just curious? will we see a td at 2pm or 5pm?
Im not voting just asking you guys
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Quoting BadHurricane:
Maybe HH crashed?
Don't say that!
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Quoting Bradenton:


*eye roll*
Wow first comment and you have has an accoun for almost 3 years!
Member Since: July 22, 2010 Posts: 1 Comments: 3841
Quoting palmpt:


I have been here for many years and cannot agree more. My family and I were newly killed by Katrinas storm surge. And we live nearly 25 feet above sea level. Share anything you think is relevant. It is appreciated.


which is all well and good if you site the source in the first place; which he failed to do

he just posted it out of nowhere, maybe give us a little background on how he got that information; then if it verifies we know his info can be trusted.

To just throw it out there the way he did is what caused the issue.
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Quoting IceCoast:


Yup, a little farther out...



which means a little further west, which means a little closer to me...
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Quoting farhaonhebrew:
Emergency Manager Puerto Rico press conference at 4pm...
Well that says a lot!
Member Since: July 22, 2010 Posts: 1 Comments: 3841
Quoting naplesdreamer28:
Is there actual support that 91L could continue a Westward trend toward the US or is is just a temporary thing?
It's kinda up in the air right now dreamer.How's Naples these days? I was there fron 1985-1991 loved it, was a great little town!
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Does anybody have any idea why recon isn't updating?
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting AWeatherLover:
I guess I won't post that information anymore since it upsets people. I probably shouldn't since the calls are technically for NHC and NWS personnel only. Back to lurking.


*eye roll*
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good afternoon Baha
I am hoping this will be
Emily Post...

Well mannered and not disturbing us.
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2988. palmpt
Quoting DirtDan:




I wouldn't worry too much about it. Certain people on this blog seems to get their panties in a bunch over nothing. If you have useful info then please continue to post it...


I have been here for many years and cannot agree more. My family and I were newly killed by Katrinas storm surge. And we live nearly 25 feet above sea level. Share anything you think is relevant. It is appreciated.
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13.2N/52.8W trucking west
Member Since: April 29, 2007 Posts: 0 Comments: 7669
Emergency Manager Puerto Rico press conference at 4pm...
Member Since: July 14, 2008 Posts: 0 Comments: 246
Quoting IceCoast:
CMC looks very similar to GFS



Too close to Florida, and too much trouble for the Bahamas. One little jog to the west, and S. Florida might be in some trouble. By the way, my 3 year old granddaughter is Emily, and do to her being "strong willed", we have enjoyed using the nickname "Hurricane Emily". I laughed when I saw the lists of names, and then went uh-oh...could be an omen! LOL Hope not! Oh, it definitely looks to be a depression or TS to my unofficial eyes. Really, a healthy looking system right now. Much better than poor Don.
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Quoting Hurricanes101:


they are not going to classify this, recon is not updating either

He is basically saying the NHC now feels it is more disorganized than they originally thought, they will not upgrade it


Just maybe not as originally thought, satellites can give storms better appearances if it has a good mid-level vortex.
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yeah... storms that come near the bahamas always recurve off the east coast... especially Katrina.
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Quoting bappit:

Then posting info from that call is a bit like speaking out of turn. We have no way of knowing if the info is being reported correctly. It is just hearsay.


NWS would not like it
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Quoting VAbeachhurricanes:


except i dont see another trough on the left side of the image...


Yup, a little farther out...

Edit: Wow, blog stretches that image weird, here's a link.
Link

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2980. Gearsts
Quoting DoubleAction:
Looks like two separate systems now. They will have to circle the wave approaching the islands it has it's own vorticity. 91L will impede development unless it can gain more distance. Very interesting setup. What might become 92L needs to locate it's center closer to the convection nearing the islands if it wants to survive.
They will merge or we will not see Emely soon.
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Link91LandSpawnLoopFloater
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So what would happen if Emily's baby hit the gulf coast simultaneously while Emily hit North Carolina? As improbably as that is, I think that the weather channel would explode.
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2977. hydrus
Quoting naplesdreamer28:
Is there actual support that 91L could continue a Westward trend toward the US or is is just a temporary thing?
The NOGAPS is forecasting a more westward movement..
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2976. JRRP
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2975. DirtDan
Quoting AWeatherLover:
I guess I won't post that information anymore since it upsets people. I probably shouldn't since the calls are technically for NHC and NWS personnel only. Back to lurking.




I wouldn't worry too much about it. Certain people on this blog seems to get their panties in a bunch over nothing. If you have useful info then please continue to post it...
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91L catching up to the wave in front of it, yum I'm going eat you it says
Member Since: April 29, 2007 Posts: 0 Comments: 7669
Looks like two separate systems now. They will have to circle the wave approaching the islands it has it's own vorticity. 91L will impede development unless it can gain more distance. Very interesting setup. What might become 92L needs to locate it's center closer to the convection nearing the islands if it wants to survive.
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2972. bappit
Quoting nrtiwlnvragn:
The NHC hosts a daily conference call at 1:00 PM EDT. If someone has access to the call in number......

Then posting info from that call is a bit like speaking out of turn. We have no way of knowing if the info is being reported correctly. It is just hearsay.
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Maybe HH crashed?
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Is there actual support that 91L could continue a Westward trend toward the US or is is just a temporary thing?
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Quoting VAbeachhurricanes:


not at all, hows he saying that??


they are not going to classify this, recon is not updating either

He is basically saying the NHC now feels it is more disorganized than they originally thought, they will not upgrade it

when people on here hear something like that, they leave or RIP it; sad fact but true
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Estimated recons postion

Last transmit was 16:19
Took off at 16:20
Traveled ~265 nm between those times
An hour after last transmit.. the recon might be between the other wave and the main wave
Member Since: August 30, 2008 Posts: 1 Comments: 224
Looks like we have to wait right up to 2 p.m. for this update....
Member Since: October 25, 2005 Posts: 19 Comments: 21485
Quoting wxgeek723:


You watch that trash? Lol
I know this is a big no no but i like FOX news political views. I watch CNN for news and watch fox for politics and for weather i pay attention to this blog.
Member Since: July 22, 2010 Posts: 1 Comments: 3841
CFN13 Has this thing on the loop every ten minutes. Very annoying
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Quoting TampaFLUSA:
Unless you have proof, its hearsay.


I'd like to hope that his statements are well founded, making up things and saying they're coming from the NHC is a big no-no.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting IceCoast:
CMC looks very similar to GFS



except i dont see another trough on the left side of the image...
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2961. wxhatt
Quoting Hurricanes101:


Well thank the Lord you said this, I was about to waste 5 days tracking this storm

*rolls eyes*


It's not Gospel my friend, it's just a good chance.
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The NHC hosts a daily conference call at 1:00 PM EDT. If someone has access to the call in number......
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2959. bappit
Quoting VAbeachhurricanes:


Thats east of every single model.

There is an important disclaimer on that web site.

"As these data are experimental, there may be times where the updates are not timely or not available. Experimental products should be not be solely relied upon to make important decisions regarding weather forecasts."

I am guessing the map posted is based on earlier model runs which were further east.
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on visible imagery it's looking more and more like both have somewhat of a circulation.
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Quoting Hurricanes101:


If this is true, you are basically saying we need to go away and not watch this, seriously you are


not at all, hows he saying that??
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2956. Patrap
..."cuz your the Storm that I believed in"..
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2955. 7544
91L is getting that structure look to it and wants to eat the wave in the front thats not moving as 91l is moving west then become on big ts imo
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I guess I won't post that information anymore since it upsets people. I probably shouldn't since the calls are technically for NHC and NWS personnel only. Back to lurking.
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CMC looks very similar to GFS

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Quoting jdjnola:


The wave by the islands is Emily's baby, which she is going to eat for lunch, like a fish (but not a "fish storm"). Gross.


I disagree. I think "Emily's Baby" will move away westward.
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Quoting hurricanehunter27:
OMG FOX news weather fail, they just called 91L Emily.


You watch that trash? Lol
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Unless you have proof, its hearsay.
Quoting AWeatherLover:


I got it from the NHC 1:00 update call. Also would like to note that although they said they won't be starting advisories on it yet, they aren't ruling out the possibility that the HH might find a very small closed low during their investigation. They said that they do expect the two systems to finally merge in the next 24-48 hours, as invest 91L continues to move west, and the disturbance remains fairly stationary.
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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.