Estimating OVC for VFR planning?

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
The question:

Is there a way, based on weather data, to get at least a rough estimate what the ceiling is going to be a couple days in advance?

The reason:

I've got a business trip on Monday to OKC. We're supposed to have good weather all through Texas and Oklahoma on Monday. So I could fly the trip up on Monday morning, do my meeting, and fly back Monday night.

However, I would like to stay over Monday night.

Tuesday is calling for overcast, but I can't tell how low the ceilings are going to be. I do not want to scud run back to AUS from OKC on Tuesday, so I'm trying to figure out if I need to come back on Monday, or if it will be high enough to come back on Tuesday.

This is for scheduling purposes for the plane.
 

tgrayson

New Member
Tuesday is calling for overcast
Weather, several days ahead, is very, very unreliable. (See "Chaos Theory" or "The Butterfly Effect.")

If I were you, I would schedule the plane through Tuesday, but I would wait to make the call Monday evening. There ought to be some terminal forecasts available giving better ceiling predictions. If it looks iffy, fly back Monday night. But if you absolutely have to be back on Tuesday, don't fly at all, unless you're willing to rent a car to drive home. Pressure leads to bad decisions.
 

surreal1221

Well-Known Member
You could search out for some forecast data that shows cloud tops and bases, but this data is indeed very unreliable even inside of 12 hours.

I'd just wait until the evening prior to make a slightly informed go / no-go decision. Then adjust the decision as needed the morning prior to departure and constantly evaluate that decision until your scheduled time of departure nears.
 

Holocene

Well-Known Member
Yeah, I wouldn't treat a Tuesday forecast very seriously at all. Even 24-hour forecasts sometimes only yield extremely rough approximations of the actual weather.

Realistically, you won't know much for certain until you get a briefing a couple hours in advance. From there; decide accordingly.
 

Goldmember

Well-Known Member
If Monday is clear and Tuesday is calling for overcast, then an airmass is probably moving into the area and you can follow its general track on satellite or if rain is coming, radar. On Monday, check the metars for airports that are coming under the system and see what their ceilings are and then you can get a picture of what to expect where you are going to be. Give it a fudge factor or 200-300 AGL if you are next to a fairly large body of water.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
I'd just wait until the evening prior to make a slightly informed go / no-go decision. Then adjust the decision as needed the morning prior to departure and constantly evaluate that decision until your scheduled time of departure nears.
If I were you, I would schedule the plane through Tuesday, but I would wait to make the call Monday evening. There ought to be some terminal forecasts available giving better ceiling predictions. If it looks iffy, fly back Monday night. But if you absolutely have to be back on Tuesday, don't fly at all, unless you're willing to rent a car to drive home. Pressure leads to bad decisions.
If Monday is clear and Tuesday is calling for overcast, then an airmass is probably moving into the area and you can follow its general track on satellite or if rain is coming, radar. On Monday, check the metars for airports that are coming under the system and see what their ceilings are and then you can get a picture of what to expect where you are going to be. Give it a fudge factor or 200-300 AGL if you are next to a fairly large body of water.
All good advice. Thank you. It's about what I expected and was thinking but I wanted to find out from the more experienced.

Goldmember - I'm still going to do that - track it and see what the ceilings are at the airports the day before and then check when Tuesday rolls around. It will be interesting to see what's in common there.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Time to get that instrument rating, bro. Then, problem solved. ;)
Yeah, I know. It's a cashflow problem more than anything else - the down economy has had an effect on my comp plan at work, which means less money coming in, which means less money to fly. IR has to wait a bit.

I'm basically flying enough to maintain currency and some degree of proficiency right now. The only reason I'm thinking about flying this trip on Monday is that I've already got the money in the flight account for the plane I've been using. I need the XC PIC time so I might as well use it.
 

Douglas

Old School KSUX
Time to get that instrument rating, bro. Then, problem solved. ;)
:yeahthat:


also, you can double dip. If you are going to rent the airplane anyway, book a II while you are at and double dip.

You need 50 hours of x-c time.
Find a II that is light on students and can spend two days devoted to you.
- You get to start Instrument training, it will be an actual IFR flight possibly in actual.
Real world x-c, with the real possibility of weather, sounds like a great training experience, and you were going to pay for the airplane anyway.

If the CFII has nothing else going on he might do it for the price of dual and a room at a hotel. That is if he has nothing else going on his schedule.

Just a suggestion, take it or leave it.
 

mooneyguy

been around forever
I've had pretty good luck with these guys:

http://www.usairnet.com/cgi-bin/launch/code.cgi?Submit=Go&sta=KPWA&state=OK

Nice graphical display of all the usual numbers plotted out three or four days.
I'll second the link above...here is the Austin link http://www.usairnet.com/cgi-bin/launch/code.cgi?Submit=Go&sta=KAUS&state=TX

It's a pretty good site, and they are usually close enough to get a good picture of what the weather might be. Obviously like others have said a 48 hour forecast is not worth a lot, but this is better then nothing!
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
I'll second the link above...here is the Austin link http://www.usairnet.com/cgi-bin/launch/code.cgi?Submit=Go&sta=KAUS&state=TX

It's a pretty good site, and they are usually close enough to get a good picture of what the weather might be. Obviously like others have said a 48 hour forecast is not worth a lot, but this is better then nothing!
Thanks. I'd never seen that site before, but it's pretty cool. Have it bookmarked now. Thanks again!


also, you can double dip. If you are going to rent the airplane anyway, book a II while you are at and double dip.


If the CFII has nothing else going on he might do it for the price of dual and a room at a hotel. That is if he has nothing else going on his schedule.

Just a suggestion, take it or leave it.
It's a real good idea, it's just not one I can implement on this trip.

Right or wrong, I'm really, really picky about my instructors. There is a CFII I would like to use, however, I'm not sure he's going to be available for me depending on his career plans. As I'm a little bit short on money at the moment, this isn't a big problem - we'll know more about where/when he will be in a few weeks. If it looks like he's not going to be available, he's got a couple names for me to interview as possible instructors. Either way, waiting a couple weeks isn't going to hurt.

Looks like they've revised the forecast (I know, two days in advance isn't terribly valid) for OKC and DFW areas for Tuesday showing mostly clear. Hmmm...
 

surreal1221

Well-Known Member
What time you looking to leave and what time you looking to come back?

I'll take a quick look at the forecast models I have access to. Cruise altitude you are planning on as well.

Or - take a look at this data.

http://www.rap.ucar.edu/weather/mod...clouds&hours=hr36hr42hr48hr60hr24hr72hr30hr84

It simply shows forecast cloud cover between 6 and 12k.

Here is one for cloud cover below 6k.

http://www.rap.ucar.edu/weather/mod...clouds&hours=hr36hr42hr48hr60hr24hr72hr30hr84

Both these run from 12z on Monday to 00z on Thursday.

850mb (~5,000ft) fcst for 1200z through 1800z on Monday shows a fair bit of moisture across NRN to SERN OK. But by 1800z it's on it's way to the east and a fair bit of warm air is already on it's way northward as the surface high continues to move EWD, and not much moisture advection coming out of the gulf until about 0000z on Weds, and continues to increase across the Texas gulf coast and into the Houston area by the 0000z on Thursday.

700mb (~10,000ft) fcst for 12z on Tuesday shows moisture across ERN OK, but it's only at 70% (FEW-SCT territory). By 00z Weds it's moved well EWD into Illinois.

I'm willing to go out on a limb and say you'll probably be alright and should have a decent trip.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
What time you looking to leave and what time you looking to come back?

I'll take a quick look at the forecast models I have access to. Cruise altitude you are planning on as well.
I'm pretty flexible on when I can leave AUS. Was thinking around 8-9am or so. Cruise around 7,500 or so.

Was going to come back either 6-7pm on Monday evening or around 8-9am Tuesday morning - and again, somewhere between 6,500 and 8,500 depending on winds and headings.

Wasn't going to start the flight planning until this evening.

Thanks Surreal. I appreciate it.

EDIT - Just saw your post revised with those links. Thanks! Those are really cool.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Well, an update in case anyone is still following this thread.

I gotta cancel the flight. The winds aloft are gonna be hellacious...in both directions. Between that and the routing I'd have to run, it's going to make the trip roughly 4 hours each way, and I don't have the dosh for that. 2.5-3 each way I can swing.

Oh well...there will be other opportunities.
 

HeyEng

NAHB Doesn't Give a Crap
Well, an update in case anyone is still following this thread.

I gotta cancel the flight. The winds aloft are gonna be hellacious...in both directions. Between that and the routing I'd have to run, it's going to make the trip roughly 4 hours each way, and I don't have the dosh for that. 2.5-3 each way I can swing.

Oh well...there will be other opportunities.
Bummer dude. That really sucks, and yeah, those winds are pretty stiff. I was going to fly up to OKC over the weekend, but an alternator had other plans for me. In hindsight, I am glad we didn't fly since the ceilings were absolute crap yesterday all over the Hill Country. Of course on Thursday and Friday they were forcasting "beautiful" weather...:) I'll be glad to get the IR!!!
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Bummer dude. That really sucks, and yeah, those winds are pretty stiff. I was going to fly up to OKC over the weekend, but an alternator had other plans for me. In hindsight, I am glad we didn't fly since the ceilings were absolute crap yesterday all over the Hill Country. Of course on Thursday and Friday they were forcasting "beautiful" weather...:) I'll be glad to get the IR!!!
All the IR in the world wouldn't have helped in this case. Winds aloft at 3K were 330@26 and only got worse going higher.

I'd already had a ticket booked on SWA just in case. Probably just as well. It was bumpy as hell going out this morning. In retrospect, the flight wouldn't have been all that much fun. Since I'm paying out of pocket to fly right now, I'm still trying to have fun with it. Keeps it from getting old.
 

surreal1221

Well-Known Member
Wise decision. . .wind it's clear, it's windy as hell. Just your luck man.

No worries, it wasn't all that fun out there today anyway. You're not missing anything.
 
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