Space Team Online Web Chat

Date: April 16, 1997

Featuring: Steve Sokol
Lead Forecaster
NASA Johnson Space Center, Houston, TX

Oran/NASA Chat Host: . . . . Wed, Apr 16, 10:05AM PDT (-0700 GMT). . . Steve Sokol is a lead weather forecaster in the Space Meteorology Group at NASA Johnson Space Center. He is responsible for analyzing and monitoring weather patterns that may affect flight plans of space shuttles.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 10:06AM PDT (-0700 GMT). . . And now, here is Steve Sokol to answer your questions.

Mr_Dunk/Pueblo West, Colorado: . . . . Wed, Apr 16, 9:57AM PDT (-0700 GMT). . . Good morning from Colorado!

Oran/NASA Chat Host: . . . . Wed, Apr 16, 9:57AM PDT (-0700 GMT). . . Welcome Mr. Dunk!!

5TH GRADE/ATASCADERO: . . . . Wed, Apr 16, 10:01AM PDT (-0700 GMT). . . Hello, Mr. Sokol.

Mr_Dunk/Pueblo: . . . . Wed, Apr 16, 10:05AM PDT (-0700 GMT). . . You might want to check out an article that I got published here in the Pueblo paper last week that talks about STO. Click this button to take a look.

steve sokol-jsc: . . . . Wed, Apr 16, 10:15AM PDT (-0700 GMT). . . I just printed out your article Mr. Dunk...the questions are coming fast so will read it later. first glance looks interesting.

5TH GRADE/ATASCADERO: . . . . Wed, Apr 16, 10:06AM PDT (-0700 GMT). . . How fast were the winds in Hurricane Hugo?

steve sokol-jsc: . . . . Wed, Apr 16, 10:13AM PDT (-0700 GMT). . . Hi 5th graders thanks for asking. There was a large band of 140 to 165 knot winds(160 to 190 mph) wind on the east through northeast side of the storm In addition to great damage in Charleston S.C. it downed many thousands of acres of forest.

Mr_Dunk/Pueblo: . . . . Wed, Apr 16, 9:59AM PDT (-0700 GMT). . . I worked with Frank Brody at JSC for a while when I was in Houston. I opened a new magnet high school there called the High School for Meteorology and Space Science. The Space-flight Meteorology group at NASA is really great!

steve sokol-jsc: . . . . Wed, Apr 16, 10:07AM PDT (-0700 GMT). . . Hi Mr. dunk from Colorado...nice to have you on...I think we were working with the magnet school just the other day.

Mr_Dunk/Pueblo: . . . . Wed, Apr 16, 10:08AM PDT (-0700 GMT). . . Steve, I really think that the Madison High School program is great!

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:16AM PDT (-0700 GMT). . . Waverly, where are you from?

Waverly: . . . . Wed, Apr 16, 10:16AM PDT (-0700 GMT). . . Hi, we're from Albany, Oregon

Paul/ PA Homeschooler: . . . . Wed, Apr 16, 10:13AM PDT (-0700 GMT). . . Mr. Sokol, my name is Paul Moore. I am a 5th grade homeschool student. My family and I were at the launch of STS-80 in November, 1996. It was delayed several days because of high winds. What is the highest wind speed a shuttle can be launched in?

steve sokol-jsc: . . . . Wed, Apr 16, 10:26AM PDT (-0700 GMT). . . Hi to Sts-80 launch attendees. These are good questions. The crosswind limits for RTLS(return to Launch site) are 15 kts. RTLS would occur 25 min after launch if there was an emergency. TAL (transoceanic Abort sites) would occur 35 min after launch in Spain or Africa. These have never occurred but we always forecast for them as well as for EOM...the normal end-of-mission landing sites. KSC (USAF forecasts for the exact launch time and they have a 20 kt wind limit from certain directions. They(45th wx sq-USAF) follow launch commit criteria rules(LCC) and we follow flight rules They are closely related. But all forecasts after launch are handled by SMG(spaceflight Meteorology Group) because we are located with the flight control team in Mission Control. And for Mr. Dunk. If both KSC and Edwards (EDW) were unavailable we could land at Northrup Strip at White Sand N.M. That happened on STS-3. We can also come down early or stay up longer...but there are usually only 2 or 3 precise landing opportunities available each day.

Adam/stanthony: . . . . Wed, Apr 16, 10:35AM PDT (-0700 GMT). . . Do you know if there is any kind of severe weather on other planets?

Sarah: . . . . Wed, Apr 16, 10:37AM PDT (-0700 GMT). . . Have you been to The Nine Planets? There is information about the weather there.

steve sokol-jsc: . . . . Wed, Apr 16, 11:21AM PDT (-0700 GMT). . . Hi Sarah...looks like a good site.

Waverly: . . . . Wed, Apr 16, 10:11AM PDT (-0700 GMT). . . What kind of conditions do you need to take off for the shuttle?

WES: . . . . Wed, Apr 16, 10:36AM PDT (-0700 GMT). . . Have you ever had to stop a launch at the last second due to bad weather?

steve sokol-jsc: . . . . Wed, Apr 16, 10:37AM PDT (-0700 GMT). . . Thanks Paul and Thanks Waverly...The shuttle is a big glider that must land about an hour after de-orbit burn. The forecast must be right since it cannot go to another airport. We give forecasts for RTLS,TAL and EOM. We follow a precise timeline...and give fight director and astronaut briefings from 3 or more days before launch...throughout the mission...and in the crucial days...hours and minutes before landing. We give forecast before payload bay door closing, before deorbit burn, etc. Generally the shuttle must have ceilings and visibilities of 8000ft/5mi for most landing and 5000/4 for RTLS. No showers or thunderstorms are allowed within 20-30 miles of the landing site and crosswinds must be less than 15 kts. there are many variations on these rules for night landings...longer missions, etc.

WES: . . . . Wed, Apr 16, 10:29AM PDT (-0700 GMT). . . What would happen if the power went out and there was a shuttle landing?

steve sokol-jsc: . . . . Wed, Apr 16, 10:40AM PDT (-0700 GMT). . . Wes...If the power went out we would go to backup power in Mission Control...In fact, we also advise Mission Control and many other JSC facilities about lightning and other severe weather...hurricanes, etc.

WES: . . . . Wed, Apr 16, 10:30AM PDT (-0700 GMT). . . What was it like in Hurricane Hugo?

steve sokol-jsc: . . . . Wed, Apr 16, 10:43AM PDT (-0700 GMT). . .WES, Hurricane Hugo was not that bad at flight level 10,000 feet in a NOAA P-3. There was very little lightning or turbulence. However 2 days before they almost lost one in Hugo. Every storm is different and can be different on each day. I have flown into some very strong storms with USAF in the Western Pacific.

Allen_Family/Homeschool_Ark.: . . . . Wed, Apr 16, 10:35AM PDT (-0700 GMT). . . What kind of things did you learn flying into so many typhoons?

steve sokol-jsc: . . . . Wed, Apr 16, 11:11AM PDT (-0700 GMT). . . Allen...I learned everyone was different and to respect the power of nature. There is severe weather on other planets but not like we have...and I do not consider myself an expert on it.

Paul/PA Homeschooler: . . . Wed, Apr 16, 11:23AM PDT (-0700 GMT). . . What was the longest amount of time you were in a hurricane?

Paul, in the USAF C130 typhoon flights we usually flew up to 13 hour missions. Though often that was mostly en route and return...If the storm was close we could spend as much as 13 hrs in the storm environment...taking fixes in the eye as often as every 3 hrs. On one mission near Wake Island, the other aircraft had mechanical problems and we had to fly another 13 hr mission shortly after the first, and we had continous lightning and turbulence in the eye wall cloud during one 2 hour penetration.

Charlotte/BHHS-England: . . . . Wed, Apr 16, 10:20AM PDT (-0700 GMT). . . What's the worst weather a shuttle has had to land in so far?

steve sokol-jsc: . . . . Wed, Apr 16, 10:52AM PDT (-0700 GMT). . . Charlotte...How are you? Usually we manage to keep the shuttle from landing in bad weather by using high resolution satellite pictures...radar...astronaut -flown weather recon flights wind towers...experience...and many other things. We may have gone a knot or 2 over on crosswinds...or had a shower near the edge of our 20 or 30 mile circles... or had some clouds slightly lower or higher...or move in after landing...but usually if the weather is too bad at one site like KSC we will switch to Edwards in California or vice versa. We often carry it right down to the last few minutes though...and it saves a million dollars every time we land in Florida.

WES: . . . . Wed, Apr 16, 10:21AM PDT (-0700 GMT). . . Do you know anything about the solar flare?

steve sokol-jsc: . . . . Wed, Apr 16, 10:54AM PDT (-0700 GMT). . . Yes Wes I got questions about the solar flare from as far away as our NASA people in Russia. There is a good web site in Boulder for that info. You might refer to the Space Environment Center home page in Boulder as a start.

alyssa/stanthony: . . . . Wed, Apr 16, 10:27AM PDT (-0700 GMT). . . What would happen to the shuttle if there was bad weather in the area?

steve sokol-jsc: . . . . Wed, Apr 16, 10:57AM PDT (-0700 GMT). . . Alyssa/stanthony...The shuttle might be blown off the runway...the thermal tiles for reentry could be damaged...which would be especially bad if they got wet/corroded during the launch phase.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:31AM PDT (-0700 GMT). . . Steve, can you describe the various locations of your group's weather-gathering equipment around the world?

steve sokol-jsc: . . . . Wed, Apr 16, 11:00AM PDT (-0700 GMT). . . Mr. Dunk, Most of the equipment we use is in Florida...California...White Sands...Spain...Morocco...and Africa. The USAF and NASA send personnel to these sites. There are also a couple of dozen sites around the world that can be used as emergency landing sites.

Waverly: . . . . Wed, Apr 16, 10:32AM PDT (-0700 GMT). . . Hi Steve, is it hard to travel back and forth between houses?

steve sokol-jsc: . . . . Wed, Apr 16, 11:00AM PDT (-0700 GMT). . . Waverly...I only live 7 miles from JSC

Adam/stanthony: . . . . Wed, Apr 16, 10:32AM PDT (-0700 GMT). . . Do you use Doppler radar at the space center?

steve sokol-jsc: . . . . Wed, Apr 16, 11:02AM PDT (-0700 GMT). . . Adam...Yes...we have a Doppler radar that monitors both Melbourne(Florida) and League City (near JSC). This is the only dual-dedicated Doppler radar.

WES: . . . . Wed, Apr 16, 10:32AM PDT (-0700 GMT). . . Could you tell us about some interesting weather on other planets?

steve sokol-jsc: . . . . Wed, Apr 16, 11:03AM PDT (-0700 GMT). . . Wes...we don't forecast for the other planets

Adam/stanthony: . . . . Wed, Apr 16, 10:34AM PDT (-0700 GMT). . . Do you work for any TV stations? Where? Channel?

steve sokol-jsc: . . . . Wed, Apr 16, 11:04AM PDT (-0700 GMT). . . Adam...no...though I have helped a couple of people get jobs with T.V.I might do it some time...but this has to be one of the most interesting weather jobs in the world.

Paul/PA Homeschooler: . . . . Wed, Apr 16, 10:34AM PDT (-0700 GMT). . . What does it feel like going to the center of a hurricane?

steve sokol-jsc: . . . . Wed, Apr 16, 11:09AM PDT (-0700 GMT). . . Paul...First you fly across hundreds of miles of low level cumulus clouds suppressed by the sinking air far from the storm...then you begin fly through increasingly strong feeder bands of strong thunderstorms...finally you fly into a donut-like circle of thunderstorms in the wall cloud where turbulence...icing. . .thunder...lightning and strong updrafts/downdrafts can beat you up pretty bad. Then you break out into the eye...which cab be completely clear or have quite a few clouds in it. There is usually a strong downdraft as you go into the eye. The strongest winds at the surface are under the northeast corner of the wall cloud usually. Once I saw an almost green wall cloud.

WES: . . . . Wed, Apr 16, 10:42AM PDT (-0700 GMT). . . Have you ever had to stop a launch at the last second due to bad weather?

steve sokol-jsc: . . . . Wed, Apr 16, 11:19AM PDT (-0700 GMT). . . Wes one flight I worked we cleared the weather...but a computer shut the launch down at 1.9 sec due to a hardware problem. On STS-64...We launched at the last minute through a break in afternoon thunderstorms...I advised the flight director "go right now". We tried for 2 days to land in Florida but were forced by thunderstorms to go to Edwards. I was lead forecaster on the return to flight mission(STS_26). Thunderstorms kept us and USAF forecaster in Florida busy and one shower kept me from giving an RTLS go until the last 18 sec. We also had rain at the desert TAL site Ben Guerir, Morocco!...and when we switched to Moron Spain... the visibility suddenly went to less than 5 miles due to the farmers burning their sunflower fields. We probably would not have returned to flight for another week...but we got off just in time.

Adam/stanthony: . . . . Wed, Apr 16, 10:37AM PDT (-0700 GMT). . . Have you ever been on a space shuttle? Which one?

steve sokol-jsc: . . . . Wed, Apr 16, 11:23AM PDT (-0700 GMT). . . Adam...I have not been on a shuttle...I did apply for astronaut for a couple of years...but stuck to weatherman after that.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:37AM PDT (-0700 GMT). . . Will the X-33 (next generation space shuttle) be more or less affected by weather compared to the current shuttle?

steve sokol-jsc: . . . . Wed, Apr 16, 11:24AM PDT (-0700 GMT). . . Mr. Dunk...Hopefully less...but I don't know much about it yet

WES: . . . . Wed, Apr 16, 10:44AM PDT (-0700 GMT). . . Has a hurricane ever destroyed the launch pad?

steve sokol-jsc: . . . . Wed, Apr 16, 11:34AM PDT (-0700 GMT). . . Wes...No hurricane has ever destroyed the launch pad! They roll back the shuttle to avoid approaching storms.

John: . . . . Wed, Apr 16, 11:01AM PDT (-0700 GMT). . . A comet would have some influence on the ocean waves so as to influence in the atmospheric humidity?

steve sokol-jsc: . . . . Wed, Apr 16, 11:36AM PDT (-0700 GMT). . . John...I do not know...But to the shuttle crew a storm that had a tornado in it would probably have an overshooting top (a top much higher than surrounding thunderstorms that would indicate a very strong updraft. When this storm collapses is usually when the tornado is coming down to the ground.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:46AM PDT (-0700 GMT). . . Click this button if you would like to visit the homepage of the Spaceflight Meteorology Group (Steve's cyber-home).

steve sokol-jsc: . . . . Wed, Apr 16, 11:30AM PDT (-0700 GMT). . . Thanks Mr. Dunk for putting our web site on...Saved me some time. Read about my last mission Sts-82 if it is still on there. We had an awesome overflight of JSC as the shuttle headed for Florida at 2:14 in the morning. We had waved off the first opportunity due to low clouds. Then we gave a go for the second...and last opportunity and it came almost straight overhead with a huge plume lit up by the moon. The sonic boom came about 6 seconds later after the shuttle' plume filled up the whole sky. I was wathcing it with John Young...the first shuttle commander on STS-1../Even he was impressed!

Paul/PA Homeschooler: . . . . Wed, Apr 16, 10:47AM PDT (-0700 GMT). . . Would you like to go into space yourself?

steve sokol-jsc: . . . . Wed, Apr 16, 11:37AM PDT (-0700 GMT). . . Paul...Yes...especially as a weather mission specialist.

John: . . . . Wed, Apr 16, 10:53AM PDT (-0700 GMT). . . Steve will that comet ever be back in our lifetime?

steve sokol-jsc: . . . . Wed, Apr 16, 11:42AM PDT (-0700 GMT). . . John...I am not an astronomer...though some NASA people are. That is the thing about working here...people think you know everything about space..NASA...and that you are a rocket scientist. Some of my friends are rocket scientists...and there are some cute T-shirts that say "why yes, I am a rocket scientist!" But I am not, and I know mostly about the weather and how it applies to shuttle landings.

Allen_Family/Homeschool_Ark.: . . . . Wed, Apr 16, 10:57AM PDT (-0700 GMT). . . Mr. Sokol, What is a gravity wave & how did you forecast it?

steve sokol-jsc: . . . . Wed, Apr 16, 11:49AM PDT (-0700 GMT). . . Thanks Allen Family...that is one of my most famous weather calls. There was a line of storms west of Florida...and it looked like little chance that the cloud bands ahead of the storms were going to allow a Florida landing(STS_60). However, I spotted a break in the clouds moving like a front at 30 knots towards KSC. It appeared to be a gravity-wave like feature set up by strong westerly winds flowing over the top of the thunderstorm line...like mountain wave clouds. I had Hoot Gibson...the weather recon astronaut fly 70 miles west of KSC to confirm the break in the clouds...we had already passed up the first chance to land at KSC due low clouds. Anyway, I told the flight director it would get worse for awhile after de-orbit burn and then get better. The clouds cleared 15 min before the shuttle landed...and they did not have to fly through a single cloud.

Paul/PA Homeschooler: . . . . Wed, Apr 16, 11:01AM PDT (-0700 GMT). . . If the weather is clear on the east coast could I see a night shuttle launch from PA? I live near Gettysburg, PA.

steve sokol-jsc: . . . . Wed, Apr 16, 11:51AM PDT (-0700 GMT). . . Paul...possibly for a high inclination launch(Sts-85...7Aug97 perhaps)

Waverly: . . . . Wed, Apr 16, 11:04AM PDT (-0700 GMT). . . How hot and cold is it in space?

steve sokol-jsc: . . . . Wed, Apr 16, 11:52AM PDT (-0700 GMT). . . Waverly...I do not know right off hand...In the part of the atmosphere I worry about it gets down to -65 degrees centigrade or so up around 40-50,000 feet.

John: . . . . Wed, Apr 16, 11:05AM PDT (-0700 GMT). . . Suppose there was a powerful hurricane, would a comet as close as this one make it more powerful due the gravitational pull or weaker?

steve sokol-jsc: . . . . Wed, Apr 16, 11:53AM PDT (-0700 GMT). . . John, I do not know...not even sure if the hurricane center does.

Paul/PA Homeschooler: . . . Wed, Apr 16, 11:17AM PDT (-0700 GMT). . . What is the ave. temp. on the moon?

steve sokol-jsc: . . . . Wed, Apr 16, 11:55AM PDT (-0700 GMT). . . Sorry Paul other people know those moon facts better than me. They even analyze the moon rocks here at JSC.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 11:08AM PDT (-0700 GMT). . . Do any of you have a favorite weather link on the Internet? I like Intellicast because they have great coverage with radar summaries and NEXRAD radar.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 11:24AM PDT (-0700 GMT). . . Another *kewl* weather link is the Weather Undergound.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:49AM PDT (-0700 GMT). . . Have you all had a chance to see the comet Hale-Bopp?

Waverly: . . . . Wed, Apr 16, 10:50AM PDT (-0700 GMT). . . Our whole class has seen it in the NW sky. On clear nights it's beautiful.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 10:51AM PDT (-0700 GMT). . . Mr. Dunk, I have seen Comet Hale-Bopp both in the early morning and evening. It's an awe inspiring sight.

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 10:53AM PDT (-0700 GMT). . . I live in a rural part of Colorado, and the view of the comet and the stars is simply incredible. The comet is truly amazing to look at.

Paul/PA Homeschooler: . . . . Wed, Apr 16, 10:55AM PDT (-0700 GMT). . . Hale-Bopp looks great from the great PA and I wish I could discover a comet myself someday.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 10:57AM PDT (-0700 GMT). . . If anyone is interested, please visit our Comet Hale-Bopp site for great information and pictures of the comet!

Waverly: . . . . Wed, Apr 16, 11:02AM PDT (-0700 GMT). . . Great your button worked, and it looks like a good place to visit and explore.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 11:03AM PDT (-0700 GMT). . . Waverly, great!

Oran/NASA Chat Host: . . . . Wed, Apr 16, 11:25AM PDT (-0700 GMT). . . For those of you interested in learning more about our Shuttle Team experts, please visit our Shuttle Team Online site.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 11:26AM PDT (-0700 GMT). . . For those of you interested in learning more about today's NASA Chat Host, and other online projects, please visit our Quest Home Page.

Oran/NASA Chat Host: . . . . Wed, Apr 16, 11:31AM PDT (-0700 GMT). . . THANKS TO STEVE SOKOL AND EVERYONE FOR JOINING US TODAY. WE HOPE YOU ENJOYED TODAY'S CHAT!!!

Mr_Dunk/Pueblo_West_Colorado: . . Wed, Apr 16, 11:26AM PDT (-0700 GMT). . . Oran, I've really enjoyed today's session (I love meteorology). Keep up the great work!

Paul/PA Homeschooler: . . Wed, Apr 16, 11:30AM PDT (-0700 GMT). . . Thank you for answering my questions. I really enjoyed it. I hope I can talk to you again sometime.

5TH GRADE/ATASCADERO: . . . . Wed, Apr 16, 11:32AM PDT (-0700 GMT). . . Thanks Mr. Sokol for taking the time to answer our questions. 5th graders in Atascadero, CA.

Mr_Dunk/Pueblo_West_Colorado: . . Wed, Apr 16, 11:32AM PDT (-0700 GMT). . . One of the things that I'd like to do before I die is see a shuttle launch and landing. My father-in-law used to work on the landings (C. C. "Buck" Gay), so I have a close personal touch with the program. Thanks again for a good chat!

Mr_Dunk/Pueblo_West_Colorado: . . . . Wed, Apr 16, 11:28AM PDT (-0700 GMT). . . Steve, thanks for your time. Tell Frank Brody hello from Mark Dunk. Great job !!!!!!!!!

steve sokol-jsc: . . . . Wed, Apr 16, 11:58AM PDT (-0700 GMT). . . Thanks MR DUNK

steve sokol-jsc: . . . . Wed, Apr 16, 11:58AM PDT (-0700 GMT). . . Thank you Paul

steve sokol-jsc: . . . . Wed, Apr 16, 11:59AM PDT (-0700 GMT). . . Thanks 5th grade/ATASCADERO

Allen_Family/Homeschool_Ark: . . . . Wed, Apr 16, 12:04PM PDT (-0700 GMT). . . Thanks for your time