How to read the weather briefing in the training manual?
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Hello.
Coming back to the training manual to fixate some things I started paying more attention to the weather brefing - also because WDP gives you a weather briefing and I’d like to understand it better.
I have been using METAR for a bit and can understand some things, yet, I’m pretty lost on what some other things mean.
Taking Mission 1: Basic Handling from the training manual as an example, I have the following:
WEATHER brief: RKJK INFO: 0955LT ILS RWY36 TL140 320/02KT 30SM FEW080 28/23 A2991 NOSIG.
Following it, there’s a brief explanation: “FAIR weather, scattered clouds at 8000 feet, winds 320°/02 knots, temperature 28°C, dew point 23°C, altimeter 2991, NO SIGnificant changes.”
Alright, with this I can therefore infer (and also understand that) RKJK is the ICAO for KUNSAN AB, TL140 transition altitude on flight level 140(?), 320/02KT is the wind and the bearing, 28/23 are the temperatures, A2991 the altimeter (QNH) and NOSIG “NO SIGnificant changes.”.
Yet, I have no idea what 0955LT and 30SM means.
As for ILS RWY36 does it mean it’s the current active runway and that it’s “ILS-able”? And FEW080, I suppose 080 has to do with the clouds, but how to read the FEW (does it also means Fair Weather)?
Also, is there a way to receive this weather briefing during the campaign (without Weapons Delivery Planner) or even listen to it on the ground after commiting to pit?
Thanks!
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SM is Statute Miles and indicates visibility.
LT is Local Time
TL oops, I see you’ve got that one…
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0955LT = 09h55m am local time
TL140 = technically, that should probably be TRL140 for Transition Level 140. Transition Altitude (TA) is fixed for a region, AFAIK based on the highest terrain in that region, and the TRL is decided based on atmospheric conditions to maintain 500+1ft or 1000+1ft actual separation (depending on local procedures) between aircraft that are flying on the TA and the TRL. In between the TA and TRL, you have the Transition Layer (TL) in which nobody is allowed to level off for prolonged periods of time, because of different altimeter settings (QNH vs QNE)
30SM = visibility of 30 Statute Miles. Anywhere but the US uses meters for this, though (from 0250 to 9999, IIRC; 250m to 10km or more).Cloud cover is measured in oktas (1/8th’s):
SKC = Sky clear (0 oktas)
FEW = Few (1 to 2 oktas)
SCT = Scattered (3 to 4 oktas)
BKN = Broken (5 to 7 oktas)
OVC = Overcast (8 oktas)
NSC = nil significant cloud
CAVOK = Ceiling And Visibility OK (visibility more than 10km, and no clouds below 5,000ft)If the METAR says FEW080, that means 1 to 2 oktas clouds at 8000ft. If the text below the METAR says Scattered, then one of the two is wrong.
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Thanks, that makes a lot more sense now!
Indeed, the Scattered was probably a [minor] typo in the manual.If you don’t mind, what’s the difference between CAVOK, SKC and NSC then? They all sound a bit alike, although maybe NSC and CAVOK means there ARE clouds, just not significant. Would this mean one could say/read SKC070 followed by CAVOK, since even with scattered clouds there is over 10km of horizontal visibility and the clouds present are not significant?
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No, scattered clouds with +10km visibility would be written as 9999 SCT070 (or 10SM SCT070 for US).
EDIT: I should add I’m not entirely certain of this, but AFAIK:
CAVOK is a very specific set of conditions where both visibility and cloud base need to be above a certain threshold. In case one of those conditions is not met, other designators are used instead.
From what I can find on the topic, I think NSC could be used whenever no Towering Cumulus (TCu) or Cumulonimbus (Cb) are spotted, regardless of altitude. Perhaps in automated METAR, or stations with basic equipment that cannot accurately measure cloud base height? And SKC would be used when NO clouds are seen. -
CAVOK = Ceiling and visibility OK : Visibility is at least 10 kilometres, no clouds below 5000 feet or minimum sector altitude (whichever is higher), and there is no current or forecast significant weather such as precipitation …