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Spectacular cloud holes yesterday

By: Dr. Jeff Masters, 5:01 PM GMT on January 30, 2007

An unusually large series of cloud holes developed over Mississippi, Louisiana, Texas, Arkansas, and Alabama yesterday, which were captured by several alert wunderphotographers (see the thumbnail images at the bottom). These cloud holes (also called "dissipation trails" or "distrails") are formed when an aircraft passes through a deck of clouds containing water drops that have cooled below the freezing point of water. The exhaust particles of the aircraft's engines serve as nuclei for the supercooled water drops to freeze on, and the resulting ice crystals fall towards the ground as "fall streaks". Also, engine heat and turbulence along the wing tips mixes moist and dry air, helping create clear holes. It typically takes about 20 minutes for a cloud hole to form after an airplane has passed, so it is not obvious that a aircraft create the holes.

Visible image of the clouds holes of January 29, 2007, as seen by NASA's Terra satellite.

For more detailed information on this event, including animations and upper-air plots, see the University of Wisconsin CIMSS Satellite blog.

I'll have a preview on Wednesday of the upcoming blockbuster climate report scheduled to be released Friday by the U.N. Intergovernmental Panel on Climate Change (IPCC).

Jeff Masters
Alabama Sky
Alabama Sky
Very cold here in Alabama. Temp this am was 20 degrees. Brrrr
Negative Contrail 1
Negative Contrail 1
Even though I was sick as a dog (and home from work), I went out in the freezing cold this morning and took pictures, when I saw this cloud out the window. I just couldn't miss this one. ;) The second photo is looking west, this one was looking east. I sent it to the Chief Meteorologist at KXAS-TV - NBC5 in Dallas-Fort Worth. Here's what he said.... "It's a kind of 'negative' contrail. Apparently the jet exhaust caused the cirrus cloud layer to condense and fall out as snow, leaving a gap in the clouds. I don't think I've ever seen one like it.

Atmospheric Phenomena

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

vary cool
On the local weather here in New Orleans..The local Met Bob Breck on Fox here caught the contrail X and Hole as it past New Orleans on the Tower cam view they have.He synced it with the view from the Visible loop and we saw the hole and Contrail x ..pass right over the city.Was neato!...
dr m you have mail
dr m you get my wu e mail?????
How do we know those are not comet chunks from McNaught?

CB..some days you really do scare me.....postulate with me..the heat upon entry into the earths atmosphere..the time it would take the comet chunk from entry into the atmosphere to finally dropping to earth...the size that chunk would have had to be..and yet...no radar signature.....hmmmmm....do you really think it was comet poop?
Nice Dr. M. Have seen that a few times, and didn't know or even think, what it meant. Now I know, and will watch for more. Thanks! Eglin AFB is my backyard at home, and will watch for more oddities from the flights when home.
CB became a pumpkin? In any event, the news report that I saw said there was a plane overhead. Fortunately, it wasn't blue ice (or worse).
thanks,Dr. Masters
dos any one no when the next hurricane forcast update comeing out it sould be soon right ????
In April Taz.
Fortunately, it wasn't blue ice (or worse).

Couldn't be. Planes aren't allowed to dump while airborne anymore. Seems a few years back, someone got a 200 pound blue ice chunk in their garden.
: HurricaneMyles thanks why the long wait i was hoping it would be comeing out in march or some in but that long?
Taz...There isnt much accurracy, if any at all, in these early season predictions. There's no point in putting out 3-4 since theres a 75% chance they'll be wrong. There also probably isnt much connection between pressure patterns now and ones expected during the hurricane season.
HurricaneMyles i see now ok
But it's still fun to make and read other's forecasts.It's like how everyone starts talking about NFL playoff seedings in October;the predictions are usually wrong,but we just can't help ourselves.
Hi again everyone
hey TS2!How'd it go last night?You stay warm?
Mo Rain ..... 5
hey Pat
Hello Kris hows yer day?
same here,rain..doing taxes on one Tab,And here on another.
Just kris just. I had about 3 covers over me and still nearly froze
They owe me again..The Feds.Thats always a good thing.Usually spend it on Jazz Fest In April.
hi pat
Hello T2 was cold for ya I c.Itll get better next few days looks Like.
Checking out the topic I ran across something interesting...This is the same picture. 1st we have NOAA saying it's Dec 2003 & the leading theory of the air ready to freeze & the planes & all.

Then we have this piece copyrighted from Scott Stevens and WeatherWars.info. Same pic, but taken in late summer 2003, if he recalls correctly... If you've read anything about weather wars you know his claim is this hole was made by HAARP or something similiar. This statement was interesting..The accepted explanation was that there was a condensation nuclei present that initiated the event. Still no answer as to why the circular shape and source of the nuclei to trigger its formation. Since that's all pretty well explained on the NOAA event of the day site.
Hopefully it will and hopefully my heating doesn't break down again.
Dora is getting more orginised and as i said in Dr. M last blog it also looks like Arthur in away
Dora has a Good overall look to it with good Inflow at the surface and Outflow aloft.Classic setup for some strengthening..
Maybe faltering a bit?Seems open to the SW Link
I remember someone posted a microwave pass a few hours ago and it was closed with stronger returns on the image.
Holes in clouds have been observed and photographed for at least 70 years. Some of the more interesting explanations include: evaporation of clouds by meteors; two winds colliding; flying saucers, atomic explosions and the one I liked was the door to the fourth dimension.

There are two serious explanations. Sometimes invisible falling streaks of ice crystals from higher clouds are intercepted by thin, lower cloud. The ice crystals induce freezing of some of the water droplets, which then fall from the cloud...leaving an almost perfectly circular hole.

[Evidence, also, strongly supports the suggestion that passing aircraft punch holes in thin clouds. Airplane exhaust produces ice particles; in time, these ice crystals become large enough to fall out and eventually evaporate. Also, engine heat and turbulence along the wing tips mixes moist and dry air causing clear holes.]

here's what I tried to link to Link
She's in a area for favourable development aswell. Look out anything that's in her road.
Here's another one,but from a while ago about 4:18 eastern time Link
UFOs using CO2 laser beams to punch holes in clouds to spy on airports?..lol.Link
What kind of person would follow UFO's and making up funny stories
Here's another good pic from yesterday.

What are the blue & white small vertical lines?
TS2, I was thinking the same thing. Being this caused by planes & them spending so much time with theorys of this happening over an airport...
Yes theorys that never work or are stupid i guess they also cut themselves from the real world and never follow scientific things like what actully causes the hole in the cloud. Heres some advice for these people,WAKE UP AND SMELL THE COFFEE!!
read in the news paper yesterday that the climate report is going to be overly optomistik and basically painting a rosie picture of global warming. The article went on to say that the report only discusses and annalyses iceburg melt and not ice shelf melt. Has anyone read something similar!?
Why does it have to be UFO'S?

Well i think it's because hardly anyone knows conclusive evidence that UFO's exsists and also hardly anyone knows what kind of damage they can do. Do you know anything conclusive about UFO's CB?
Here's one over my place yesterday, I've also got some pic's of the long straight ones too.

I waited on the little green men, but they didn't show. LOL

Hi SL, Well maybe they were eating ther lunch or midday snack LOL.
Statement as of 7:55 PM EST on January 29, 2007

... Record lowest high temperature set at Melbourne...

a record lowest high temperature of 54 degrees was set at Melbourne
today. This breaks the old record of 57 set in 1978.

UFOs ..tunnels....All I want to know is what the weather today and tommrow is going to be...lol
Hmmm... Were all my cats here this morning???

SL "Here kitty, kitty!"

They were some neat looking clouds though.
Come on CB give me a little snippet please
I think there is life on other planets.Wether or not it comes to earth is debatable.
well cb you can get the ufo people to come down and build your tunnels and pay them with some of sls cats...we saw the hole over her house where they were checking them out yesterday
Auburn! Doghouse!
Other people will probably disagree but im not one of those people
do you belive in dinosaurs CB?
Lower than normal shear in the MDR this H-season?CFS Shear forecast
Even after the ice storm of last week, this month has already been declared the warmest January on record for Belgium, and probably many other European countries. This was the 8th record-setting month in line...
its all them cow farts and exhaust fumes off them UFOs causing it to be so warm
I still say there's a T.Rex in the
Auburn, check your blog..lol
Ill be back later,i'm away for a little drive around Orlando
Holes in the sky. What next ? Something mighty fall through. Is this where fallen angels come from ?
Auburn you are great...LMAO at your post about farts...Dang must be a big hole in the cloud cover over Toronto....Hey Rang...see any yet???
well sure they do BC...look how abundant it is ...more methane than ant other fuel
I meant that as a joke CB...I can only wonder if what you said was one.LOL
Good Afternoon everyone.
That's unusual. Did you hear about the ice that fell in Florida? I heard it was about 18 inches.
And for that matter,who knows what small populations of creatures are wandering throught the California mountains or Florida swamps?
See cb...figure out how to stop methane from destroying the ozone and you wont need tunnels..there is plenty of methane gas on this planet
Falling ice in Florida ?
I'll be back later.Bye guys.It was just a joke CB.
Just so we're on the same page,CB.LOL
87. MDI
About these holes in the clouds - very neat. Are these pictures archived somewhere? I sure would like to see the one from the day a UFO was supposedly seen at O'Hare. Witnesses reported a hole in the clouds as the UFO sped up and away. This is a serious request. Anyone with info can PM me if that is more comfrtable than here. Thanks.

Science is about answering questions
90. MDI
ahh no. That will not suffice.
what's that got to do CB?

Unless it said:

"And on the 5th day our Lord created all men little and green",then I'm not convinced.
Hello Cyclone, what are you on about ?

try this link MDI
BBL...have fun you guys
Oh my goodness.....Little green men, skunk apes, and Bigfoot all on the same "50 comments" page? I am trying to just get my facts straight on Global Warming........

How can I take anything serious if we are debating ufo's and weather wars?

I know most of you are joking...those who are not are just silly. IMHO
I'm just joking.But I've had enough Global warming discussion over the past few months to last for years,so if that's what the topic is switching to...Be back later.
I did not want to discuss it......I was just showing that even with lots of scientific evidence it is hard to decipher and get answers...

but little green men..
weatherboykris i see the map you post so when could we see this Lower than normal shear ????
hurricane season.
hello : catastropheadjuster
oh my run for your lives

LOL!!! La Nina does not automatically mean a bad hurricane season (or vice-versa).
FEMA assistance denied for residents affected by Christmas Day tornadoes

Disgusting once again from the Feds. Nothing learned from Katrina at all.
It typically does,STL.
so you'll think where gonna have low wind shear? Boy if we start off with a early hurricane season it's gonna be a long one. Do you'll think La Nino will come into effect early or is she gonna take effect at all?
Oh, I think we will definately see a La Nina in the next few months (considering how short the life of the last La Nina was, there is a question of whether it will last through hurricane season):

The upper ocean heat content is already negatine - meaning that the water overall is now cooler than normal in the ENSO region; SSTs are still above normal but not for long as cool water upwells:

I'm thinking La Nina
will have an effect all hurricane season,with an especially above average October,which could be bad news for FLorida since the storms coming from the October MDR typically go towards South Florida.
Here are maps showing the MDRs and typical tracks of stomrs for each month.Link
Well the freeze forecast for last night was a bust, temp of 28 was forecast, but we only dropped down to 32.5 before midnight. Low after midnight was 33.1 Looks like advection cold beat out radiation cold, which is usual here on the island.
Perhaps if we had had more aircraft creating holes in the cirrus and altostratus overhead, we could have radiated down more. LOL
Atmosweather, with this Link going on, I am not surprised they don't have enough funding to help the victims of the Christmas tornadoes.
How come FEMA helps some people but not others; is it some kind of discrimination?
There are probably criteria.Something like salary,total damage,stregnth of the event.I don't know any details,but that's what it sounds like.
They use what they call an "Event Criteria"..if its met ,they spend .If it dont..they dont spend.Its a discombobulated outdated system thats needs Congressional Oversight.
SOme FEMA info and insight to problems in SNOW events...Link
...."Over a number of years, there has been confusion regarding FEMA's policies for providing assistance for snow removal. In particular, during the `blizzard of 1996' there was confusion and controversy surrounding FEMA's snow removal policies and eligibilities for Federal assistance. Representatives and other officials in New York, Pennsylvania, the District of Columbia, and other jurisdictions complained about FEMA's approach to snow removal assistance. Criticisms ranged from a lack of clarity, consistency, and uniformity to both overly restrictive and overly generous criteria for Federal assistance"...
Posted By: weatherboykris at 9:18 PM GMT on January 30, 2007.

I'm thinking La Nina
will have an effect all hurricane season,with an especially above average October,which could be bad news for FLorida since the storms coming from the October MDR typically go towards South Florida.

That would be August, September and October according to your link Weatherboy! NO THANKS! Looking forward to another quiet season. Taxes and insurance rates are on the rebound here. It would be nice to keep that trend going but, of course, there is always red tape in the event of another Hurricane!
Well what I meant was that storms that form in the October MDR(the western Carribean)almost exclusively go to South Florida.They aren't like Cape Verde stomrs that could go to the Carolinas,storms in the Carribean in October almost without failure go to South Florida.
133. ryang
I am fine.How's your weather.
La Nina conditions have begun!We may just skip neutral and go right to cold!Today's anomaly map:
hey Ryang.
compare with 4 days ago:
I'm feeling blue!
Or.... buy a Mac , Taz...LOL
: weatherboykris maps tooo big make then smaller
too big?They look fine on my computer.
weatherboykris how stong is La Nina you think
not on my lap top they dont
It hasn't formed yet.I meant to say that La Nina is coming,not that it is here.Sorry
are they better now?I set width at 700.
They measure 1174x640 pixels for me. BIG (even with a 1024x768 monitor); you have to add width=xxx (best to use a number no larger than 800, preferably 640 as that is the default width of the blog and some users may still have 800x600 monitors; in your own blog this is not a real problem; I often stretch my own blog a little if I have an image that I want to post in my entry that is larger than 640 pixels wide but not really large).
So what do you guys think?Looks like that cold water must already be reaching the surface.
weatherboykris yes thats more like it
Man that cut off low today did a class A job of sending rain in everyplace but here. We where that 20% of the area that didnt pick up a lot of anything. Just a drizzle.
Shear dropping infront of Dora.
154. Inyo
haha lightning10, its raining in Ventura again, probably not what you wanted to hear.
158. 882MB
Hey everybody, I have been reading comments on the upcoming 2007 ATLANTIC HURRICANE SEASON! May i ask a question, During a LA NINA HURRICANE SEASON where do HURRICANE TEND to FORM IN THE CARRIBEAN, ATLANTIC OR, GULF OF MEXICO TO HIT FLORIDA OR THE SOUTHEAST?
CIMSS MIMIC of Dora..interesting 50 frame loop...Link
An eyewall collapse and a reformation cycle ..nice view of it as it drifts south.
Hmmm... let's look at some La Nina years since 1995 (the current active period):

1995 (maturing La Nina)

1998 (maturing La Nina)

1999 (decaying La Nina)

I would say the Atlantic; however, notice that the exact steering patterns still vary (either they hit the U.S. from the open Atlantic, like 2004 or they don't, like last year; storms that form in the Gulf and Caribbean almost always gurantee a landfall). This can be easily explained: highly favorable conditions result in tropical waves rapidly developing into storms once they leave Africa (example from 1995); storms that develop further west do so because conditions in the eastern Atlantic are not as favorable (possibly one reason why so many storms formed near land and made landfall in 2005).

seems global warming is affecting the animals as well as humans as seen in this example..so plug up the cows and shoot down any UFOs you see(they use methane for fuel..just ask CB)
Good point STL,storms that develop too soon are more likely to recurve in to the Atlantic.Part of the reason why we saw so many storms recurve last year.I'm pretty sure Florence was an example and so was Debby.For a classic Cape Verde storm to make landfall in the U.S.,you'd want it to develop only a few hundred miles from the Lesser Antilles,such as Frances and Floyd.You might be able to call Jeanne a Cape Verde storm also.
STL you for got 2005
Kung Fu Kitty's Dang! Who would've thunk it! lol
The steering currents are just as important (strength and location of the Bermuda High); also, Cape Verde storms must develop close to the Capr Verde islands; otherwise, they are not Cape Verde storms, like if they develop near the Lesser Antilles. For example, Ivan:

Or Hugo:

I normally don't use the NGM model,I consider it's forecasts to be awful;but this may be of some interest to those who do.


The decision of when exactly to turn off the NGM and its MOS is being considered at NWS HQ at this time. It will not likely happen until the off-time AVN MOS has been accepted. The Meteorological Development Lab (MDL which replaced/absorbed the old TDL) has seen the AVN MOS provide a big improvement (relative to the NGM MOS) with the PoP's, and are working on improvements with the max/min so that the AVN MOS will be consistently better (right now, its 24 and 36 hour projections are of equivalent quality). The on-time AVN MOS comes out later than the NGM MOS, so that is why I feel any decision will wait for the off-time AVN MOS to be available. Some forecasters still feel the NGM forecasts are worth looking at, and NWS HQ will have to take that into account when they make their decision.

You get what I mean STL,for a storm from Africa to make it to the U.S.,it typically needs to not develop until it is near the Lesser Antilles,or if it does become a Cape Verde storm it needs to be far south like Ivan was.There are exceptions,as your Hugo map showed.
Good evening guys!
where dos the Bermuda High set up shop in La Nina years like in 2005
Good point indeed!

Systems that typically develope quick of the african coast usually curve away from the united states.Hopefully troffiness will be present and turn everything away.In 2006 there was never a chance for any system of africa making all the way across.Ernesto was the only real significant threat for the U.S.

Those cuban mountains saved me from a major cane.
Anywhere. In fact, last year I was comparing the setup to what occurred in 1995 - if it formed in the Atlantic, forget about it unless you lived in Bermuda, the Azores or the Lesser Antilles (only Caribbean or Gulf storms were significant threats to the U.S. last year).
hey CB
how are you doing?
Futher intensification to major hurricane status seems likely with Dora...

could you just for once post something related to the topic?
This pass was from about 2 hours ago,but it only got some outer bands.Link
not you H23;CB.
You mean the cloud holes?
How are u tonight kris?Cloud cover seems to be holding temps up around here.
EL NINO CONTINUES TO FUTHER WEAKEN...Neutral conditions around the corner.

There has been a sustained cooling of the equatorial Pacific since early December, with current SST anomalies now close to their El Nio thresholds. This is the clearest sign that the El Nio event is weakening and it bodes well for a switch towards average or wetter than average conditions across eastern Australia sometime in the late summer or autumn. In fact, we've already seen a southward extension of tropical moisture which resulted in heavy rain over the NT, SA and the western parts of Queensland, NSW and Victoria. This can be taken as a sign that rainfall patterns are beginning to change across Australia, the timing of which is consistent with that observed during previous events.

In addition to the surface cooling, there has been substantial cooling below the surface; a situation that is likely to promote further weakening of the surface El Nio pattern. However, the SOI, Trade Winds and central-western Pacific cloudiness have seen their decline towards neutral values arrested somewhat during January, in association with a westerly wind burst mid-month. The westerly burst has now dissipated, so it is expected that these other ENSO indicators will continue their general trend towards neutrality over the coming months, in keeping with the weakening of the El Nio event. Furthermore, computer modelling supports the view that the El Nio will continue to decline.


STOP with the Global Warming thing Please this blog is not about Global Warming today so that dos not go with this blog today dr m is talking about Spectacular cloud holes yesterday not Global Warming
191. Leia
Great topic and photos! Thanks for teaching me something I had never seen en masse, or heard of before.
this is the 1st blog i have seen dr m has done that dos not have to do with Global Warming and i want to keep it that way for a day or sonic to see some in new up with out a talk of Global Warming but web it is back to Global Warming and Climate Change
i dont mine the talk about Global Warming but not evere day of the week this is nic to see some in new then this Global Warming evere day can we keep it that way may be for a day or so
what are particulates
Agree cyclonebuster has long as you keep the Global Warming part out for a day or so ok?
204. Inyo
well the last La Nina brought more rain than the current El Nino, and rains this year only started when El Nino fizzled. So i say, bring on the La Nina (for the west coast anyway.. we don't need any more Gulf hurricanes)
anyone on?
who's up at this hour. Its Friday where I am.
Or maybe its Wednesday. What day is it anyway ?
It's not Friday anywhere on earth
11:38 PM here.
Cant be Friday, cause yesterday was Tuesday. Today is certainly Wednesday. And we are all still here. Except for the ones that are not, of course.
so how are you doing?
Its strange hearing from you , as you are still yesterday..........
knock it off.LOL.What do you think of the El Nino?
Are you a voice from the past ?????
I,m from the future. What do you wish to know about tomorow ?
stop it.
El Nino has gone away. The predictions were out again. The forecasters are basing thier predictions on historical info that no longer applies. We are flying blind now, and noone can acurately predict the weather or climate with more than 50 % accuracy. Thats what I think.......
But there is a 50 % chance I may be wrong !!
I hope I have not upset you ........
not really.But seriously,it looks just about over.
Can you recall what the original forecast was, back in Nov. ? I'm trying to remember, but the head is tired...
I think that it was to sustain until June, and dissipate by August. Is that right ?
from December 9th...
Oh, and its Wed. where you are too, so everything is cool.
Yeah,I've finally caught up.
OK. So what do you think caused the change to normal so early in the year. Any ideas ?
Things just didn't develop the way they were supposed to I geuss...you?
goodnight Pottery.
Exactly ! But why didnt they develop as expected ? My point earlier is pertinent here. We are basing our forecasts on what USED to happen. The climate has changed, and will continue to do so. So we are attempting to predict the weather using outdated info. This will change as we understand what is happening NOW, but the info we are getting is not enough yet. Ice caps melting, ocean temps changing, hot dry air from Africa reaching Florida etc. Its all too new........
Nite Nite........
Any insomniacs out there ?
In the morning then...........................
insomniac? you people from the future tire easy. It's only 10pm Tuesday in Cali. - of course, there's no weather here to type about... so, later!
TCWC DARWIN: Northern Territory Australia

11.3S 135.6E - 25 knots 1001 hPa

Tropical Cyclone Advisory
Tropical Low is situated in the southern Arafura Sea about 80 km north of Elcho Island and 165 km northwest of Nhulunbuy.

The Tropical Low is reported moving east at 8 knots.

Tropical Cyclone Watch
A CYCLONE WATCH is now current from Elcho Island to Numbulwar, including Nhulunbuy and Groote Eylandt.
Pottery....We've never done well with ENSO forecasts. I dont think the state of climate change is really make those predictions any worse because they we're already bad to begin with.
good morning
There was a photo just like this a month or so ago called "dove in a hole"
but now I can't find it. I thought it was some sort of thermal microburst of vertical activity. Didn't think of something as narrow or linear as a contrail. The falling snow in it makes a cool "ice bird" pattern inside the clear nucleated hole.
50 frame CIMSS MIMIC of DORA..Vmax 77knots peak Link
ENSO predictions and climate change dont mix. Early season tropical predictions will be interesting!
nice Patrap
got that for any other storms?
looks like maybe an EWRC in the cards soon?The southern rainband seems to be getting stronger.
Actually it is Friday here on earth near the event horizon of a tiny black hole south of Cleavland - TGIF!