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MariceH
14th Aug 2010, 08:15
Hello,

I was wondering what kind of weather briefing you guys obtain before embarking on a cross-country VFR flight?? What stuff do you look at? Can't really find a structured approach in the books..

Cheers!
Marie

Blink182
14th Aug 2010, 08:32
Register with Met Office.......... use the F215 and Airmet,
Met Office: GA briefing services (http://www.metoffice.gov.uk/aviation/services/uknationalairnavigation.html)

Metars here........ www.TheHangar.co.uk - METARs in Plain English (http://www.thehangar.co.uk/metars/index.php)

Overall situation here........ Wind Map - Britain Observations (http://www.xcweather.co.uk/) and SkyLinkWeather Aviation - Latest Weather for London Stansted (http://skylinkweather.com/metar/metarmapindex.php?Z=1)

Good site with lots of links.........weather+soaring (http://s214580749.websitehome.co.uk/)

Fill yer Boots !

IO540
14th Aug 2010, 08:46
Everything is on the internet now.

A reasonable safe approach for a VFR flight is

1) get the MSLP charts (available up to 5 days ahead) and if there are other people involved then knock the plan on the head if there is a major frontal system forecast. Otherwise, never cancel a flight on the basis of a forecast :) Forecasters throw in everything including the kitchen sink otherwise 10,000 old ladies phone them up and moan.

2) On the day, before the flight, get the TAFs/METARs for the two ends, the alternate(s), and airfields along the route, and scrap the flight if anywhere along the route the cloudbase is forecast (or actually) below 1500ft, or visibility below 8km (or 3km if radio navigating e.g. GPS) 2hrs before to 2hrs after your ETA there. Remember taf/metar cloudbases are above the airfield elevation. Otherwise you GO.

3k vis will be either haze, or heavy rain which itself brings hazards e.g. flying underneath a CB. But the latter will be evident on the MSLP, and in the TAFs as e.g. PROB30 TEMPO +TSRA etc.

Avoiding fronts is the simplest way to have an easy life.

The above is for flying below clouds. VFR on top requires different data, and is more complex because one is often up against airspace. But this is a great method for foreign touring.

Fuji Abound
14th Aug 2010, 08:51
Dont forget wind - be comfortable with the wind at your destination and / or alternates relative to availble running headings and any forecast en route turbulence.

Miroku
14th Aug 2010, 08:57
I find XC Weather very useful.

I'm probably going to regret asking this but what are MSLP charts?

Fuji Abound
14th Aug 2010, 09:12
Miroku

Let me google that for you (http://tinyurl.com/3x5ee4z)

:)

:ok:

IO540
14th Aug 2010, 09:13
Yes wind of course, sorry... but it doesn't matter so much enroute, except for range purposes. And then we get onto how to accurately establish fuel flow, etc.....

MSLP charts are mean sea level pressure charts e.g. these (http://www.mwis.org.uk/synoptic.php)

That is not the best site; like most free sites it presents charts pulled off various other sites and often they are not the latest available. I use Avbrief (http://www.avbrief.com/briefingservices.html) for a good collection of stuff, all in one place and reasonably well organised.

MSLPs exist in various forms. The above ones come from UK Met Office data, and are among the very few things which the UKMO releases for free. If you want a far greater range of free weather you have to go to the U.S.-run GFS system, and most weather websites which produce fancier presentations derive it from GFS e.g. this (http://wxmaps.org/pix/euro.fcst.html) (the 2nd row down is the most useful for VFR).

Miroku
14th Aug 2010, 09:31
Many thanks. It's always obvious when someone points it out...............

Gertrude the Wombat
14th Aug 2010, 09:53
Some of the time the area forecast could mean anything, the TAF says you can't fly, the METAR says it was fine half an hour ago. So, you can deduce nothing from the online weather sources (TAFs are often significantly worse than what actually happens ... but only often, not always).

Listening to the radio at home sometimes helps - if you can hear lots of students flying solo it can't be that bad; if the radio is completely silent apart from passing multi-engine IFR traffic talking about ice it's maybe not such a good day.

On some days it comes down to driving to the airport and looking out the window (where I live it's the nearest place I can go to see in a straight line at ground level for several miles in order to judge the visibility). On the most marginal days you then chat to people who've just landed (this is particularly the case on days when the TAF claims G35 and you find that actually there's a lightish breeze).

As IO540 says, if you always cancel a flight just because the forecast doesn't guarantee it's going to be flyable then you will hardly ever fly.

I always warn my passengers that there's a 50% chance of cancellation in summer, 75% in winter, and to expect me to cancel after we've all arrived at the airport. In the most extreme case, I had to fly one circuit with an instructor for club currency before going up with my passengers, and it was during this circuit that we decided that the weather really was crap after all, so on landing I told the passengers to go home.

IO540
14th Aug 2010, 10:01
The thing is that no matter how you wrap it up, truly 100% legal VFR flight below the cloudbase, for long distances (say 200nm plus), is never going to be easy (in terms of being able to get airborne with confidence) unless you pick good weather over a large area i.e. a high pressure zone.

douglas.lindsay
15th Aug 2010, 13:57
Avoiding fronts is the simplest way to have an easy life

difficult advice for a Scot to follow... :sad:

Steve N
15th Aug 2010, 16:20
Orbifly is a good one.

See menus at the top and home in on your area and chart type.

Does Europe.

Here's a view homed in on the UK.

Hover over the point on the map.

Orbifly Met'map
(http://tinyurl.com/373gmmh)

IO540
15th Aug 2010, 16:51
Great site but

Maintenance in progress
to improve Met'Map !
The service can be
temporarily disrupted.

..... which is why one needs more than one bookmark in one's phone :)

sammypilot
15th Aug 2010, 16:51
Several airfields have webcams e.g. Wellesbourne Mountford. If they have one or there is one nearby I always have a look to see what the weather is really like. The same applies for en route waypoints.

MariceH
16th Aug 2010, 15:46
Thanks guys! You've been really helpful! Where do you come up with this? Did your instructors teach you this, or something that you learn with experience??

Miroku
16th Aug 2010, 15:53
In my case, mainly this forum!

IO540
16th Aug 2010, 15:58
Yeah, you learn just about everything useful off the internet.

In the PPL, you learn how to deal with carb icing :)