Weather-guessing 2-3 weeks in advance?

[201er]

You're not going to find any useful weather forecasts for 3 weeks out.

https://aviationweather.gov/progchart/sfc?fore=thumb

However, starting a week out, you can start following the prog charts to get an idea of how things are trending and planning. If you see a 3 day window of good wx in the region you are planning (in other words trip day +/- 1 a day) you're in pretty good shape. If it's iffy, you'll have to wait for more info closer to.

 

https://aviationweather.gov/windtemp/plot

Starting about 3 days out, particularly in winter, you'll want to start watching the temps aloft as well. Select Plot > Temperature, Vert Level > Cruising Altitude, Time > Departure/Arrival. This plots the forecast temperatures aloft around the entire country. Can help with thinking if icing is a concern or not.

 

Lastly, it's not the weather that you're going to be planning 3 weeks, 3 months, or 3 years out. It comes down to knowing how to plan trips in a private airplane to account for the unexpected. And weather is not the only concern. Maintenance problems, pilot health issues, etc.

I've done a lot of trips around the country and nearby countries and have found that short of major maintenance issues, I can make just about any trip in +/- a day. Heck, usually it's +/- morning vs evening of the same day with IFR capability. As the more accurate 3 and 1 day out forecasts start to come in, I start planning a contingency. If the day of my trip is looking impossible, I might leave a day early to make sure I make it on time. Worst case, I usually plan a low key day the day after arrival just in case I arrive late. So in other words, never plan an important business meeting on the day of arrival or the day after arrival. Have that buffer of coming a day early or day late. That covers the vast majority of incidentals. Even things like needing a starter or a tire, not just weather.

I think of this strategy not only as a weather strategy but also largely as a risk mitigation strategy. Many accidents are the result of getthereitis. By planning a 3 day window for getting places, it greatly reduces the pressure to perform a flight or continue a flight when you should not. Even with the best of advance weather planning, what you actually get can be quite different. There's always the possibility of having to cut it short or divert. So, having reserve time planned is important.

With that said, the majority of flights go smooth and as planned. Usually there's a way to divert around weather (if it's not at the departure or destination) or alter the time a little earlier or later to make it work. The spare days relieve the pressure and help deal with more severe weather. And finally, when that plan isn't good enough, it's time to start thinking about other modes of transportation. Particularly the train or greyhound because even the airlines can be affected by weather. The kind of weather that will ground us for multiple days in a row (hurricane, snowstorm) is probably going to ground them too!

[Greg Ellis]

On 1/11/2020 at 4:29 PM, PJClark said:

@aviatoreb... yeah, I knew all that.  The post was dumb.  The right question  might better have been put as "how do you convince your passengers (ie, copilot, ie wife) that not knowing for sure that you're  going or not, until maybe the night before (or morning of!), Is OK?"

So much for gin-influenced MS posting!

Having a wife that has grown up in aviation helped me a lot.  However, we had the discussion that sometimes we may not know if we are going until the day before and sometimes we may not know what time we are going until the day of.  She understood and realized I would just keep her in the loop of when she needed to be ready to go and it would never be a hurried situation.

[Yetti]

There are also some good trends but they are more of historical.  Houston rain on July 4th Traditionally yes.   Freezing cold mist/fog crap the week of the trail ride.  Yes.   For winter weather in Texas you can watch the trough that sits over new mexico.   If it starts to move our way then IFR weather will ensue.  If it retreats then clearish weather will ensue.    If high thin clouds move in from the west, then rain is on the way within 24 -72 hours.  Learned that on my checkride from the DPE.

Conditions and trends for your area may vary greatly, please consult the user manual.

[MinneMooney]

I tell my wife that, looking at the long range forecast there’s likely going to be rain next weekend when we have a trip planned and she will ask “what time”.

[aviatoreb]

25 minutes ago, MinneMooney said:

I tell my wife that, looking at the long range forecast there’s likely going to be rain next weekend when we have a trip planned and she will ask “what time”.

And your answer is?

[Mooney in Oz]

On 1/11/2020 at 1:49 PM, PJClark said:

One of the (many) things I've not figured out is how to plan a trip, and be sure I'm really going to "go", more than the few days in advance that I can be sure of the weather.

I'll be the first to admit that my weather reading prowess when it comes to looking at the maps is...let us agree "crap".  :-)  Pilot Training was 35 years ago and even if I didn't sleep through most of the weather classes the brain cells must've got killed off in a bar somewhere long ago.

So any tips on how this is done successfully and consistently, I'd sure appreciate. Or I guess on the other hand if nobody can really plan much further in advance than the Forecast Discussion, that'd be good to know too: at least I won't feel quite as dumb!

thx

PJ

 

On 1/13/2020 at 2:28 AM, Yetti said:

windy.com has three different models you can compare.  The european model will give you about 10 days and has been pretty accurate for the gulf coast as to 3-5 days I decide to fly commercial vs. being fogged in.

I find windy.com to be very useful as it predicts thunderstorms, cloud cover and wind not only at surface level but also at altitude plus many other useful features in overlay pictorials. 

Have a play around with it.

[MinneMooney]

9 hours ago, aviatoreb said:

And your answer is?

Silence. After attempting to explain the realities of weather forecasting the first half dozen times, I’ve “thrown in the towel”. She also believes that “future radar” setting in the Storm app.

[PMcClure]

I have found that I can usually get to my destination within 24 hours of my hopeful ETA. I let my passengers know a few days in advance how things are looking and remind them that the search and rescue is typically done in clear weather the next day. I also book a Southwest refundable tix for business trips and have canceled them with my engine running.

I may plan a trip 2-3 weeks ahead but without any real expectation of completing it on an exact day. 1 week out I can improve my guess. But 2-3 days out is when I can make a call if we will make our plan or not. Then allowing 24 hours of flexibility, I bet I have a 98% success rate. 

[aviatoreb]

13 minutes ago, MinneMooney said:

Silence. After attempting to explain the realities of weather forecasting the first half dozen times, I’ve “thrown in the towel”. She also believes that “future radar” setting in the Storm app.

Please recommend the shadowing theorem to your wife.

http://mathworld.wolfram.com/ShadowingTheorem.html

[aviatoreb]

5 minutes ago, PMcClure said:

I have found that I can usually get to my destination within 24 hours of my hopeful ETA. I let my passengers know a few days in advance how things are looking and remind them that the search and rescue is typically done in clear weather the next day. I also book a Southwest refundable tix for business trips and have canceled them with my engine running.

I may plan a trip 2-3 weeks ahead but without any real expectation of completing it on an exact day. 1 week out I can improve my guess. But 2-3 days out is when I can make a call if we will make our plan or not. Then allowing 24 hours of flexibility, I bet I have a 98% success rate. 

Exactly - in a big picture - sometimes its sunny.  Sometimes its stormy.  Plan to flex accordingly.

BTW a much under valued under discussed strategy for getting there in better conditions is instead of getting there late - get there early!  Sometimes the best strategy is to leave a bit earlier than planned to beat that front or whatever.

I trave GA to all those destinations I can build in some flex. For those I cannot I travel commercial.  Even commercial sometimes has delays (yuk!  we all have spent a night at the hotel at ORD), but when that happens you can blame those damned airlines and everyone gets it, rather than people blaming you - can you believe that flake didn't show up on time?!

[MinneMooney]

10 minutes ago, aviatoreb said:

Please recommend the shadowing theorem to your wife.

http://mathworld.wolfram.com/ShadowingTheorem.html

Well you obviously haven’t met my wife!

[jlunseth]

On 1/11/2020 at 4:29 PM, PJClark said:

@aviatoreb... yeah, I knew all that.  The post was dumb.  The right question  might better have been put as "how do you convince your passengers (ie, copilot, ie wife) that not knowing for sure that you're  going or not, until maybe the night before (or morning of!), Is OK?"

So much for gin-influenced MS posting!

You know, I just tell them that straight up.  If they come back at me later with “Will we be able to go?” I tell them exactly the same thing. If they persist, I tell them my job as a pilot is to keep them safe.

But as far as forecasting the weather on a given day, I have that nailed.  I have this DeLorean I have all rigged up to help me. Finding a good flux capacitor was a real bear once the factory closed down, had to sift through a lot of junk yards to find one in good working condition. Personal use only.

[PMcClure]

35 minutes ago, aviatoreb said:

 Even commercial sometimes has delays (yuk!  we all have spent a night at the hotel at ORD), but when that happens you can blame those damned airlines and everyone gets it, rather than people blaming you - can you believe that flake didn't show up on time?!

I have gotten to where if the weather is bad enough that I can't go, then I don't want to go on commercial either. Their planes are much more capable but the complexity of the environment is so much higher. Delays and cancelations are no fun - private or commercial. The exceptions are probably winter weather conditions where  I dare not tread and commercial guys have the equipment. 

[ArtVandelay]

1 hour ago, jlunseth said:

 

But as far as forecasting the weather on a given day, I have that nailed.  I have this DeLorean I have all rigged up to help me. Finding a good flux capacitor was a real bear once the factory closed down, had to sift through a lot of junk yards to find one in good working condition. Personal use only.

Don’t we have a chicken and egg problem here, I thought you needed to predict a lightning strike to make the DeLorean work?

[jlunseth]

Oh, that was easy. Endless loop. So yes, the first time I had to wait until there was an actual thunderstorm, but after the first one then I knew when the rest would be coming.  Took a little planning is all. Makes this weather stuff easy, no great trick to it.

Edited January 18, 2020 by jlunseth