Parkway Posted June 14, 2016 Posted June 14, 2016 well a few questions... What weather site does everyone prefer/use? Is there a way to get a rough idea of what the cloud bases will be a few days ahead? I know you can estimate cloud bases if you have the dew point... Just not sure how to get an idea of what that will be in a few days time?
horsefeathers Posted June 14, 2016 Posted June 14, 2016 Gympie Detailed Forecast - Bureau of Meteorology Has just about everything you need (including dewpoint), barring turbulence report. Just change to your required location Also Windyty, wind forecast, for a visual view of winds, temps, clouds. Allows you to choose the height as well 2 3 1
Parkway Posted June 14, 2016 Author Posted June 14, 2016 Thanks, feel like I shoulda found that myself haha
Romeo Juliet Whiskey Posted June 14, 2016 Posted June 14, 2016 Parkway, you might want to check out MetEye as well: MetEye Rich
Old Koreelah Posted June 14, 2016 Posted June 14, 2016 Try this Norwegian site; I know people who claim it beats any Au forecast: Weather forecast for Wellard 1
graham brown Posted June 16, 2016 Posted June 16, 2016 Glider pilots use BLIP Maps. They have cloud base, wind, thermals, wave, etc etc AusRASP
Kununurra Posted June 16, 2016 Posted June 16, 2016 When you go to the bom site click on Australia then weather and waves maps, You can change to show wind also and either focus on Australia or a specific state. Just remember when you change states to hit refresh or the time zone will be out for you It gives you a week of forecast and it is pretty accurate.
Cosmick Posted June 16, 2016 Posted June 16, 2016 Windyty has winds, temperature and cloud at different altitudes up to 2 weeks forecast. Great for looking for that tail wind www.windyty.com PS> Just noticed previously mentioned by Horsefeathers. Still worth a second mention as is a fantastic tool. 2
Birdseye Posted June 17, 2016 Posted June 17, 2016 A general comment I'd make on forecasts is that they are just that; a forecaster's (actually more likely a Bureau computer's) interpretation of what the weather should do. A pre-flight should include checking that forecast conditions match the actual e.g. is the temp and dew point in the forecast range, is the wind direction as forecast, is the barometric pressure in line with the forecast, etc etc? On more than one occasion, as a pilot and an ATC, the answers came up with no. On a couple it involved telling the forecaster/observer that fog was forming when there was no prediction on any forecast. Another day I cancelled a planned cross channel flight due to changed conditions that led to unforecast IMC conditions across the south east of England .
facthunter Posted June 17, 2016 Posted June 17, 2016 Forecasts are predictions based on assumptions and some facts. Formation of visible moisture depends on a few things, including moisture content and temperature of the parcel of air. There is another factor called condensation nuclei, without which the temp may go below the dew point with NO formation of small water drops. Air temp drops as a result of radiation, mixing of two or more air masses or adiabatically as it expands when rising over a hill etc due to less pressure acting on it. Air mass analysis can forecast outcomes quite well and the MSL pressure isobars give wind strength and direction also. air from over the oceans in the tropics is called tropical maritime air and has the highest moisture content potential. nev
Old Koreelah Posted June 17, 2016 Posted June 17, 2016 ...Formation of visible moisture depends on a few things, including moisture content and temperature of the parcel of air. There is another factor called condensation nuclei, without which the temp may go below the dew point with NO formation of small water drops... ...which is why Tasmania's Hydro people have been seeding suitable air masses for decades. Last week it worked better than expected and now they're being sued.
facthunter Posted June 17, 2016 Posted June 17, 2016 The big system that moved in had nothing to do with cloud seeding. All that effort seeding would blow away in those circumstances.(Strong winds). Seeding doesn't create the low that fed moist air to the area. Nev
Old Koreelah Posted June 17, 2016 Posted June 17, 2016 The big system that moved in had nothing to do with cloud seeding. All that effort seeding would blow away in those circumstances.(Strong winds). Seeding doesn't create the low that fed moist air to the area. Nev No doubt, but the possibility that it contributed to the extraordinary rainfall will keep lawyers focussed.
bandit Posted June 23, 2016 Posted June 23, 2016 There is also Metcheck I have only found it recently - but so far its been pretty accurate. Allows you to select "aviation" as a hobby , then gives wind speed and direction at gnd and at 2500ft + cloud base and 0 deg altitude Metcheck.com - Aviation Weather Forecasts - 8 Day Aviation Weather Forecast for Yorkrakine.
Nightmare Posted June 23, 2016 Posted June 23, 2016 well a few questions...What weather site does everyone prefer/use? Is there a way to get a rough idea of what the cloud bases will be a few days ahead? I know you can estimate cloud bases if you have the dew point... Just not sure how to get an idea of what that will be in a few days time? BOM has a aviation section. When or if you start your XC training, there is a huge section about weather, how to read the weather maps and how to interpret the aviation weather forecasts and reports. I have the Dyson/Holland Cross Country Training Manual for RAA.Finding cloud bases a few days in advance? That's crystal ball stuff. You can only make guesses. If the weather forecaster experts can't get it exactly right, who can? 1
facthunter Posted June 23, 2016 Posted June 23, 2016 They can never be precise about FOG either even over a short period, let alone days. Things (conditions) change and the outcomes change accordingly. You will always have to do a lot for yourself as you fly along. Nev
pmccarthy Posted June 23, 2016 Posted June 23, 2016 FOG (written in capitals like that) is the biggest killer in underground mining - it stands for Falls Of Ground!
DWF Posted June 24, 2016 Posted June 24, 2016 I have not found that sort of FOG to be a widespread problem in aviation. It is usually the other way around - 'aviation' falling on the ground.
Parkway Posted June 24, 2016 Author Posted June 24, 2016 BOM has a aviation section. When or if you start your XC training, there is a huge section about weather, how to read the weather maps and how to interpret the aviation weather forecasts and reports. I have the Dyson/Holland Cross Country Training Manual for RAA.Finding cloud bases a few days in advance? That's crystal ball stuff. You can only make guesses. If the weather forecaster experts can't get it exactly right, who can? Yeah rough guesses is what I'm looking for. I'm constantly trying to organise my next lesson around work, weather and the planes schedule, just want to be able to get a rough idea. I've been getting it pretty close lately thanks to a few of your recommendations, cheers!
Nightmare Posted June 24, 2016 Posted June 24, 2016 My very basic understanding of reading the weather maps so far is: -High Pressure systems = ok weather, -Low pressure systems = bad weather(including high probability of low and cloud above SCT.) -Low pressure troughs and the worse Cold weather front= bad weather about 100nm in front and improving poor weather 50nm behind -The wind basically follows the isobars with a tendency to go from high pressure to low. The wind blows anti-clockwise around Highs, and clockwise around lows(at the top of a high, the wind will be blowing roughly 90⁰ and on top of a low at 270⁰). The direction varies up to 10⁰ clockwise (towards the low) over water and up to 40⁰ clockwise over land. At ground level up to the inversion layer (about 2000ft) the wind may vary more tending to be directed by the terrain, and the strength will be about a third of the speed at upper levels (eg. wind at 5000ft is 30kt, at the SFC it should be about 10kt) -You can gauge how strong the wind may be from how close the isobars are to each other, the closer they are, the stronger the wind. This effect is somewhat different as the latitude changes. Also if the ARFOR specifies Fog or cloud in your area 1000ft or lower, BKN or above, or turbulence above MOD, forget flying for that period. Unless you're IFR rated of course. Hope this helps. If I have anything wrong, please correct me. This is from my study of the met section of my XC training manual. You can find these weather maps on the BOM home page Australia's official weather forecasts & weather radar - Bureau of Meteorology
facthunter Posted June 25, 2016 Posted June 25, 2016 A high pressure system can hold down smog, smoke and be conducive to fog and frost. Wind always flows from high pressure to lower pressure. Cyclone = low pressure clockwise rotation around in SOUTHERN Hemisphere. Anticyclone = HIGH pressure and anticlockwise rotation in southern hemisphere. the wind is at an angle to the isobars (lines of equal pressure) and crosses them at an angle of around 30 degrees Air mass analysis is a good reference to get likelihood of weather . The surface the airmass travels over modifies it and the latitude/temperature has a big effect too. Land and sea is defined as continental and maritime. latitude = temperature can be labelled Tropical/ temperate and polar. Hot air can carry a lot of moisture. Cold air cannot. Some of the driest air on the earth is over the poles. The most moisture laden air is tropical maritime. Moisture gives weather systems their energy, from latent heat of vapourisation, and it can be enormous equalling many atom bombs over a short period of time. Tropical cyclones remain strong over the sea but diminish over land or travelling further from the equator. That's a few of the basics for research and study. ( for the moment). Nev 1
Nightmare Posted June 25, 2016 Posted June 25, 2016 A high pressure system can hold down smog, smoke and be conducive to fog and frost. Wind always flows from high pressure to lower pressure. Cyclone = low pressure clockwise rotation around in SOUTHERN Hemisphere. Anticyclone = HIGH pressure and anticlockwise rotation in southern hemisphere. the wind is at an angle to the isobars (lines of equal pressure) and crosses them at an angle of around 30 degreesAir mass analysis is a good reference to get likelihood of weather . The surface the airmass travels over modifies it and the latitude/temperature has a big effect too. Land and sea is defined as continental and maritime. latitude = temperature can be labelled Tropical/ temperate and polar. Hot air can carry a lot of moisture. Cold air cannot. Some of the driest air on the earth is over the poles. The most moisture laden air is tropical maritime. Moisture gives weather systems their energy, from latent heat of vapourisation, and it can be enormous equalling many atom bombs over a short period of time. Tropical cyclones remain strong over the sea but diminish over land or travelling further from the equator. That's a few of the basics for research and study. ( for the moment). Nev Thanks Nev, I forgot to mention that the rotation direction of the highs and lows only applies to the Southern Hemisphere, thanks for clarifying that. Your moist air explanation I think will help Parkway out a lot with predicting low cloud/fog conditions.
facthunter Posted June 25, 2016 Posted June 25, 2016 There's plenty more with Lapse rates, (Vertical through the atmosphere) actual and adiabatic and the effect of condensation resulting. (Cloud base) wet and dry bulb temps (dew point) relative and absolute humidity. It's a pity I can't recommend a good book on this , but it was ever thus even when I did it. You have to source many and aggregate the "bits" that are relevant from them all. For operators in the system (airlines) it often gets reduced to operational requirements and little else. This approach doesn't work with U/L operations, where 1/2 hours fuel, at the rate many fly,(cover the ground) won't get you out of a weather system, you shouldn't be near in the first place. Nev 1
Nightmare Posted June 25, 2016 Posted June 25, 2016 There's plenty more with Lapse rates, (Vertical through the atmosphere) actual and adiabatic and the effect of condensation resulting. (Cloud base) wet and dry bulb temps (dew point) relative and absolute humidity. It's a pity I can't recommend a good book on this , but it was ever thus even when I did it. You have to source many and aggregate the "bits" that are relevant from them all.For operators in the system (airlines) it often gets reduced to operational requirements and little else. This approach doesn't work with U/L operations, where 1/2 hours fuel, at the rate many fly,(cover the ground) won't get you out of a weather system, you shouldn't be near in the first place. Nev The weather experts summarize all this info for us in the form of the ARFOR's TAF, TTF's etc anyway. Helps to understand it a little bit though.
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