Onboard This Weekend?

[JennyMorgan]

http://www.edp24.co.uk/news/weather/freezing-temperatures-in-norfolk-and-waveney-1-5297498

[Guest]

Oh super best crank up the stove a bit I guess , at least my husky/ German shepherd will be happy he's not seen snow yet 

[ExSurveyor]

I am up wednesday evening till Monday for a little birthday break.  Hope I get some thermals. I will have to scrape ice off the Scorpios windscreen to go up the pub.  

[HEM]

14 hours ago, psychicsurveyor said:

Hope I get some thermals.

Thats what I & my flying friends hope for but little chance around here until late March at the earliest...

[L8DAVE]

2 minutes ago, HEM said:

Thats what I & my flying friends hope for but little chance around here until late March at the earliest...

Somehow I don't think "Thermal Underwear " will help in getting your glider off the ground 

[HEM]

At times (eg Springtime) its advisable to wear thermal undies (plus suitable trousers) as it can be damned cold up there (1 degree C per 100m cooler).  Thus if its +10C on the ground & you get to 2000m altitude its around -10 C.  Since there should be some sunshine (at least part of the time) this can partially mitigate the cold...

Flying through a snow shower just causes a hissing sound - in a rain shower its as if being machine-gunned.

I've experienced both.

[Hockham Admiral]

HEM, Hi.

Don't forget that you are quoting the dry adiabatic lapse rate; the wet one is half of that.     

(In units that some would easier understand we always used 3 degrees C per 1000 FEET!)

[ChrisB]

When I used to climb we would use

(3.5 X change in elevation)/1000 = temp loss due to elevation in degrees F.

In countries with high mountains, the mountain forcast is quite often for 2000 or 3000 feet so you need to subtract that from your destination height. Not a problem in Norfolk. 

Wind chill will naturally effect temp as well. Most wind forecasts in the UK are for 10 meters above ground level.

[HEM]

23 hours ago, Hockham Admiral said:

Don't forget that you are quoting the dry adiabatic lapse rate; the wet one is half of that.     

Of course I am aware of that - back in my days it used to be one of the exam questions!.  Where I fly we are not allowed into clouds (in fact we are supposed to keep 1000' / 300m vertical separation from clouds) & hence only the dry adiabatic lapse rate was quoted.

[Hockham Admiral]

I asked because the different types cause an unusual effect here in England.

Just in the lee of the pennines is the RAF Station of Shawbury and on the windward side was RAF Llanbedr. On a wet westerly wind day the temperature at Llanbedr might have been, say 10 degs C.

The "mountains" east of Llanbedr are around 1000m so as the wet air rises it cools down by 5 degs and may fall as rain on the hill tops. It then descends and climbs in temperature at the dry rate and gains 10 degs.

Thus a wet day in Llanbedr at 10 degs C can be transformed into a dry day at Shawbury on the other side of the Pennines at 15 degs C .

Ain't meteorology great?   

[ChrisB]

Rain shadow can do funny things.

[Vaughan]

3 minutes ago, ChrisB said:

Rain shadow can do funny things.

This is the effect that has made the Canary Islands so popular as a winter holiday resort. The climate from one side of the islands to the other is totally different.

[2000pi]

Yep Rain Shadows sure do strange things, this one has moved the Pennines from North of Cannock Chase to mid Wales, wonder what it's done with the Southern bit of Snowdonia?

[SPEEDTRIPLE]

Years ago, an ex and me went to the lakes on holiday. We rented a cottage for a week close to the coast, with "Black Combe" over the back fence. Black Combe is only 600 metres high, and it was a warm sunny day, so we decided to walk to its summit. It was rather cold at the top, even though it was only 600 mtrs, and as we decended, it got progressively warmer.  It`s surprising even at that low altitude how much the temps can change. The views out to the Isle of Mann were great though.

[BroadAmbition]

I lived in Gibraltar for four years combined.  The lavantar was sometimes spectacular when it formed.  One side of the rock bathed in hot sunshine, t'other side grey and cool

Griff

[SwanR]

Have to say that we are quite glad that our caravan has been drained down and everything done to winterise it. I have seen many photos of the snow in Lowestoft yesterday. And we had proper snowflakes falling in Essex as well ... only for five minutes but it was definitely there.

[HEM]

On 30.11.2017 at 10:05, Hockham Admiral said:

Thus a wet day in Llanbedr at 10 degs C can be transformed into a dry day at Shawbury on the other side of the Pennines at 15 degs C .

This is the Föhn effect as sometimes experienced in the Munich area (said to cause headaches etc.)

When I visited the Denver area they talked about the Chinook Wind which is the same thing (the URL I give here has a reasonable piccy of how it works).  Certainly on the East side of their mountains the temperatures can vary wildly within a short period of time.