can www.usairnet.com be relied on for wx forecasts?

[SivaGanesha 2]

I've been a little disappointed lately with the weather forecasts online at www.usairnet.com. Poor information from this site has, unfortunately, caused me to make several bad decisions regarding planning my weekends re skydiving and other activities in recent weeks.

I know that no one can predict the weather with absolute certainty, but I seem to recall (when I used to fly Cessnas) that aviation forecasts were pretty accurate within 12 hr or so. The quality of these forecasts these days, unfortunately, seems to be far worse that I remember, even over the very short term of a few hours. For example, the current time is about 4pm Thursday. The forecast for the ceilings at Livermore, CA at the current time is >12k. The actual ceiling is, according to the AWOS, just 200 feet.

That's about as far off as it is possible to be--to the point where the information from www.usairnet.com is inaccurate to the point of being useless.

Am I using this information incorrectly or is there somewhere else that is better to go for such forecasts?

How do pilots use information that is so inaccurate to safely plan flights?

"It's hard to have fun at 4-way unless your whole team gets down to the ground safely to do it again!"--Northern California Skydiving League re USPA Safety Day, March 8, 2014

[slotperfect 7]

I use a combination of usairnet, AWOS from two local airports, and weather.com to make all o fmy weather decisions from the house. They are not always right, but the are right MUCH more often than in the past when all I had (knew about) was the weather channel.

Arrive Safely

John

[chutem 0]

http://adds.aviationweather.noaa.gov/metars/

Try this.

James

[NWFlyer 2]

To be honest, I think a lot of it has to do with the time of year in Northern California. I think it's just damned tough to predict weather patterns right now. As I'm sure you've noticed, we've had a lot of clouds and fog lately, and it's really tough to tell which fog's going to burn off by noon and which fog is going to sock in and become a cloud bank that keeps jump planes on the ground all day. I don't know that usairnet is any better or worse than any other site, but the fact that they're trying to be more precise re: cloud cover and ceilings than the "general purpose" weather sites means that when they're wrong, they can seem more wrong than the sites that were more vague with their predictions.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[skydived19006 4]

My understanding is that USAirnet is using NOAA or some other souce for the data (just like all the rest). USairnet simply has more stuff like cloud ceiling forecast which the ground based masses don't really give a care about.

Garbage in, garbage out.

Experience is what you get when you thought you were going to get something else.

AC DZ

[SivaGanesha 2]

Quote

To be honest, I think a lot of it has to do with the time of year in Northern California. I think it's just damned tough to predict weather patterns right now. As I'm sure you've noticed, we've had a lot of clouds and fog lately, and it's really tough to tell which fog's going to burn off by noon and which fog is going to sock in and become a cloud bank that keeps jump planes on the ground all day. I don't know that usairnet is any better or worse than any other site, but the fact that they're trying to be more precise re: cloud cover and ceilings than the "general purpose" weather sites means that when they're wrong, they can seem more wrong than the sites that were more vague with their predictions.

Good points--I guess I hadn't realized until now how foggy it gets this time of year just east of the mountains. I've lived in the SF Bay Area for quite a number of years but this is the first year I'm trying to skydive regularly. The last jump I made the fog had burned off right at Byron but from altitude you could see a low layer of fog still covered a great deal of the surrounding area. I can imagine that sort of thing is indeed very hard to predict.

"It's hard to have fun at 4-way unless your whole team gets down to the ground safely to do it again!"--Northern California Skydiving League re USPA Safety Day, March 8, 2014

[rlogan2 0]

ADDS as recommended previously by Chutem is certainly the more accurate weather predictor for flying and skydiving. I often include usairnet in planning two days out ,when will the sun shine again? The biggest fault I have with them is wind speed does not include (gust) Sunny and 10 mph tomorrow sounds great but if gusting to 22mph not so good. I have written them complementing them on their overall site but they not receptive to including wind gust. Excluding the wind gust deficiency I have found them fairly accurate in the
Carolinas.

[Dust-It 0]

Try this for more wind info,I'm useing it more for
paragliding than skydiveing.Use it with the other sites .

BD Chuck

http://www.windmapper.com/?Loc=FL

[Fast 0]

The pretty graphical chart that USAirnet provides is just a graphical front to a text based forecast from the National Weather Service. I mean, i guess they can get it wrong like anyone else, but at least in my area the NWS/NOAA guys seem to get things pretty close.

~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

[wolfriverjoe 1,351]

Quote

The pretty graphical chart that USAirnet provides is just a graphical front to a text based forecast from the National Weather Service. I mean, i guess they can get it wrong like anyone else, but at least in my area the NWS/NOAA guys seem to get things pretty close.

True, but in your (our) area, you just have to look west and wait. Out there, with the coast and the mountains, there's a lot more variables to deal with.

When I first started flying, my instructor would show me forecasts, and then compare the later reports of actual conditions. We have more accurate short term forcasts because we have the more favorable conditions/topography

"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

[LyraM45 0]

Quote

I've been a little disappointed lately with the weather forecasts online at www.usairnet.com. Poor information from this site has, unfortunately, caused me to make several bad decisions regarding planning my weekends re skydiving and other activities in recent weeks.

I know that no one can predict the weather with absolute certainty, but I seem to recall (when I used to fly Cessnas) that aviation forecasts were pretty accurate within 12 hr or so. The quality of these forecasts these days, unfortunately, seems to be far worse that I remember, even over the very short term of a few hours. For example, the current time is about 4pm Thursday. The forecast for the ceilings at Livermore, CA at the current time is >12k. The actual ceiling is, according to the AWOS, just 200 feet.

That's about as far off as it is possible to be--to the point where the information from www.usairnet.com is inaccurate to the point of being useless.

Am I using this information incorrectly or is there somewhere else that is better to go for such forecasts?

How do pilots use information that is so inaccurate to safely plan flights?

First of all, take it from me , weather is definitely an imperfect science. I write aviation TAF's every day and I try my hardest to hit hourly predictions throughout the forecast, but sometimes it just isn't going to happen. Some weather events more than others will really nail a forecaster; fog is the biggest offender. (and I am about to start my new job with the NWS in the San Fran area.... I better buck up on the fog forecasting, eh? )

I have never been to usairnet.com but I will tell you what I have said in many wx threads already on this website: The National Weather Service is your best source for information. They are the end all be all scientists behind the forecasts from scratch. Right now I work for private sector doing general aviation and business jet forecasting. I can always reference government TAF's when I am issuing my personal TAF for an area. These guys do the actual science and do not have other TAF's to look off of or reference to make sure they are on the right track. They really are the best of the best when it comes to forecasters and their information is usually the most accurate out of any weather sources you may get your information from.

Another good place for hourly forecasts is a MOS product:

http://www.nws.noaa.gov/mdl/synop/products/bullform.met.php#bottom

Find the airport you're looking for in the list and it spits out a nice grid of wx data that is pretty good use towards aviation. It will give you the vis, cigs, precip, and anything else you need to see if it's jumpable at that location.

As for filing flight plans-- I'm sure that is up to the pilot flying, if he's 91 or 135, if he's filing his own flight plan, and if he's VFR or not. At my work the forecasters work directly across from the flight planners and for a part 91 we can file the guy anywhere no matter what the forecast (but our SOP is even if the alternate is bad on a 91 we will still find suitable wx before we file.), and for 135 the flight planners really have to work with the weather people and find alternates and ETP's that are usable based on good weather. It's illegal to file a flight plan with a forecasted alternate that is going to be socked in. If the forecaster can not come up with anything above minimums in the area that he can get to on legal reserve minimums then we call the captain and advise him he might have to delay the trip due to bad wx. I am not sure what goes on at other companies, but the flight planning and wx are done to ensure a safe and uneventful flight. (including departure, enroute, and destination turbulence and weather.)

Anywho... if you ever have any weather related questions you can always pop me a PM!

Apologies for the spelling (and grammar).... I got a B.S, not a B.A. :)