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AnthonyGA
18th Apr 2010, 14:03
I seem to recall that there are special notations that can appear on METARs when there is volcanic ash in the air, but when I look at current METARs for airports closed because of volcanic ash, I can't see anything special (in fact, I seem to see CAVOK more than anything else).

Am I just remembering incorrectly? Or does ash have to actually be dusting the airport to get into the METAR? Or what?

seilfly
18th Apr 2010, 16:09
VA is for volcanic ashes and I have been looking for that on METARs as well without finding any so far...

mad_jock
18th Apr 2010, 16:48
Newquay had them for a bit

Chris Scott
18th Apr 2010, 17:10
Yes, take LGW/EGKK METARs, for example.

As I write, the current one (1550z) is giving CAVOK. I'm not surprised, because here on the North Downs I've yet to SEE any deposit on the ground, and have no means of detecting it in the local air. Presumably, the Met observer at Gatwick is similarly handicapped? Visibility, >10k, is presumably too good to justify a Haze report.

Normally, the only Met phenomenon that justifies the closure of an airfield is lying snow. in that case, the METAR has the remark: "SNOCLO". The latter is not an observation of the actual weather. In this case, Gatwick is closed (correct me if I'm wrong) because NATS has closed certain types of airspace, including that - from the surface upwards - at Gatwick. Again, not necessarily because of the current weather observed at the station.

Would it not make practical sense to annotate METARS with "VOLCLO", or equivalent, as a warning to young aviators?

Chris

Ecam Action Man
18th Apr 2010, 19:25
In this scenario entire FIRs have been affected by VA (http://www.youtube.com/watch?v=5g3xASwdDwk)and entire FIRs have been closed, so you can find met indications on FIRs SIGMETLIMM SIGMET 03 VALID 170930/171300 LIMM- LIMM MILANO FIR VA CLD FCST AT 170700Z SFC/FL200 N OF LINE N4650 E02752 - N4607 W01101 FL200/FL350 N OF LINE N4729 E02844 - N4429 E00201 FCST AT 171200Z SFC/FL200 N OF LINE N4408 E02131 - N4414 W00134 FL200/FL350 N OF LINE N4440 E02059 - N4423 E01258 - N4503 E00840 - N4331 E00416=
and closure information on notamsNEW TODAY TIL 1004171800EST
SIGNIFICANT ERUPTION WITH ASH EMISSION IN PROGRESS FM VOLCANO
EYJAFJALLAJOKULL 6338N01937W /ICELAND/.
MILANO FIR CONTAMINATED FM SFC TO FL350 INCLUDED.
ALL FLT OPS SUSPENDED EXC MIL, EMERG, HUMANITARIAN AND RESCUE FLT ACCORDING TO CIVIL AVIATION AUTHORITY PROVISION:
NOTAM LI/A2109/10
Hope this helps.