Needs calibration, though. The TAFS in the print-out are all 9 hour tafs, the epic Heathrow one covers 30 hours
Cobalt beat me to it, but however, my way of doing it is this:
I copy paste the TAF and insert a line feed before each change group.
EGLL 030459Z
0306/0412 15009KT 9999 SCT030
PROB30 TEMPO 0306/0308 8000 -RA
TEMPO 0308/0312 6000 -RA BKN012
PROB30 TEMPO 0308/0312 4500 RADZ BKN008
PROB30 TEMPO 0312/0321 BKN014
PROB30 TEMPO 0321/0401 4000 +SHRA BKN014
BECMG 0401/0404 BKN007
TEMPO 0401/0409 6000
PROB30 TEMPO 0403/0408 4000 -DZ BKN004
BECMG 0407/0410 SCT015 BKN035
Now it becomes immediately more readable. Quite a few apps actually do that automatically.
Now if you wanna be progressive and agressive at the same time, you can kick out all the prob-tempos. Legally, you can drop prob-tempos for your planning, they are a meteorologists way of saying “I don’t really think so but can’t exclude it either” or “I got burned on this one last time so to be sure….”.
EGLL 030459Z
0306/0412 15009KT 9999 SCT030
TEMPO 0308/0312 6000 -RA BKN012
BECMG 0401/0404 BKN007
TEMPO 0401/0409 6000
BECMG 0407/0410 SCT015 BKN035
That is what you HAVE to use for planning purposes. As it shows, this would not have been an entirely good idea however.
Now this is how the day looked like (unfortunately in reverse order).
EGLL 041150Z AUTO 22013G24KT 9999 BKN028 11/04 Q0989 NOSIG
EGLL 041120Z AUTO 21011KT 180V250 9999 SCT024 SCT039 11/05 Q0989 NOSIG
EGLL 041050Z AUTO 23012KT 9999 NCD 10/04 Q0989 NOSIG
EGLL 041020Z AUTO 23010KT 190V260 9999 FEW020 10/05 Q0989 NOSIG
EGLL 040950Z AUTO 24010KT 9999 FEW014 10/07 Q0989 NOSIG
EGLL 040920Z AUTO 23009KT 190V260 9999 NCD 08/06 Q0989 NOSIG
EGLL 040850Z AUTO 23008KT 9999 NCD 08/06 Q0989 NOSIG
EGLL 040820Z AUTO 23008KT 9999 NCD 07/06 Q0989 NOSIG
EGLL 040750Z AUTO 22007KT 9999 NCD 07/06 Q0989 NOSIG
EGLL 040720Z AUTO 22006KT 9999 NCD 07/06 Q0989 NOSIG
EGLL 040650Z AUTO 21006KT 170V250 9999 NCD 07/06 Q0989 NOSIG
EGLL 040620Z AUTO 22006KT 190V250 9999 NCD 07/06 Q0989 NOSIG
EGLL 040550Z AUTO 21005KT 9999 NCD 07/07 Q0989 NOSIG
EGLL 040520Z AUTO 21006KT 9999 NCD 08/07 Q0989 NOSIG
EGLL 040450Z AUTO 20005KT 9999 NCD 08/07 Q0989 NOSIG
EGLL 040420Z AUTO 21007KT 9999 NCD 08/07 Q0989 NOSIG
EGLL 040350Z AUTO 21007KT 9999 NCD 08/07 Q0989 NOSIG
EGLL 040320Z AUTO 20007KT 9999 FEW038 BKN046 08/07 Q0989 NOSIG
EGLL 040250Z AUTO 17004KT 9999 FEW018 08/07 Q0989 NOSIG
EGLL 040220Z AUTO 18005KT 9999 BKN044 08/07 Q0989 NOSIG
EGLL 040150Z AUTO 18004KT 9000 OVC040 08/08 Q0989 NOSIG
EGLL 040120Z AUTO 19005KT 9999 BKN039 08/08 Q0989 NOSIG
EGLL 040050Z AUTO 15004KT 9999 FEW041 08/08 Q0989 NOSIG
EGLL 040020Z AUTO 13007KT 9999 BKN048 08/08 Q0990 NOSIG
EGLL 032350Z AUTO 09005KT 9999 -RA FEW013/// BKN035/// //////CB 08/08 Q0990 NOSIG
EGLL 032320Z AUTO 15004KT 7000 -RA FEW020/// BKN033/// //////TCU 09/08 Q0990 TEMPO SHRA
EGLL 032250Z AUTO VRB02KT 9000 -RA FEW025/// BKN041/// //////TCU 09/08 Q0990 TEMPO SHRA
EGLL 032220Z AUTO 23004KT 180V270 9999 -RA SCT023/// BKN039/// //////CB 09/08 Q0991 TEMPO SHRA
EGLL 032150Z AUTO 23011KT 7000 -RA VCTS SCT010/// BKN022/// //////CB 10/08 Q0991 RERA TEMPO 4500 SHRA BKN010
EGLL 032120Z AUTO 14003KT 9999 -RA FEW011/// BKN021/// //////CB 10/08 Q0990 RESHRA TEMPO 4000 SHRA
EGLL 032050Z AUTO 11006KT 9999 FEW046/// //////CB 10/08 Q0991 TEMPO SHRA
EGLL 032020Z AUTO 12005KT 9999 NCD 10/08 Q0991 NOSIG
EGLL 031950Z AUTO 13007KT 9999 NCD 10/08 Q0992 TEMPO SHRA
EGLL 031920Z AUTO 14006KT 9999 NCD 10/08 Q0992 NOSIG
EGLL 031850Z AUTO 16005KT 9999 NCD 10/08 Q0992 NOSIG
EGLL 031820Z AUTO 15008KT 9999 NCD 10/08 Q0992 NOSIG
EGLL 031750Z AUTO 15007KT 9999 NCD 10/08 Q0992 NOSIG
EGLL 031720Z AUTO 15008KT 9999 NCD 10/08 Q0993 NOSIG
EGLL 031650Z AUTO 16009KT 9999 FEW017 SCT033 10/08 Q0993 NOSIG
EGLL 031620Z AUTO 16010KT 9999 FEW016 11/08 Q0993
EGLL 031550Z 16010KT 9999 NSC 11/08 Q0993 NOSIG
EGLL 031520Z AUTO 17010KT 9999 FEW015 11/08 Q0994 NOSIG
EGLL 031450Z AUTO 17011KT 9999 FEW017 11/08 Q0994 NOSIG
EGLL 031420Z AUTO 16011KT 9999 FEW014 11/08 Q0995 NOSIG
EGLL 031350Z AUTO 16011KT 9999 SCT012 SCT041 11/09 Q0995 NOSIG
EGLL 031320Z 16012KT 9999 FEW010 BKN015 10/08 Q0996 TEMPO BKN014
EGLL 031250Z 15011KT 9999 FEW010 SCT012 BKN015 10/08 Q0996 TEMPO BKN013
EGLL 031220Z 16011KT 9999 FEW008 BKN012 09/08 Q0997 BECMG SCT014 BKN022
EGLL 031150Z 15009KT 9999 FEW007 BKN012 09/08 Q0997 BECMG FEW014 BKN025
EGLL 031120Z 14009KT 9999 FEW007 BKN011 08/07 Q0998 BECMG SCT013
EGLL 031050Z 14009KT 9000 -RA FEW006 BKN011 08/07 Q0998 TEMPO SCT011 BKN018
EGLL 031020Z 13009KT 9999 -RA FEW007 SCT009 BKN016 07/07 Q0999 TEMPO BKN012
EGLL 030950Z 14009KT 9000 -RA FEW007 BKN011 07/06 Q0999 TEMPO RA BKN009
EGLL 030920Z 14010KT 8000 -RA BKN012 07/06 Q1000 TEMPO RA BKN009
EGLL 030850Z AUTO 14009KT 9999 -RA OVC011 07/05 Q1000 TEMPO RA BKN009
EGLL 030820Z AUTO 13010KT 9999 -RA BKN013 BKN033 07/05 Q1001 TEMPO RA
EGLL 030750Z AUTO 12009KT 9999 -RA FEW015 BKN037 07/05 Q1001 TEMPO RA
EGLL 030720Z AUTO 12008KT 9999 -RA SCT023/// OVC038/// //////TCU 06/05 Q1002 TEMPO RA
EGLL 030650Z AUTO 14008KT 9000 -RA BKN025/// OVC040/// //////TCU 06/05 Q1003 TEMPO RA
EGLL 030620Z AUTO 15009KT 9999 -RA OVC041 07/05 Q1003 TEMPO RA
At 6z we already had -RA and OVC041. The light rain continued to somewhere around 11z. Low cloud BKN015 or less to 1320 (or rather until a human observer was still doing the METAR, then it went scattered.
So actually:
0306/0412 15009KT 9999 SCT030
PROB30 TEMPO 0306/0308 8000 -RA
TEMPO 0308/0312 6000 -RA BKN012
was accurate, while the Prob 30 actually happened.
PROB30 TEMPO 0308/0312 4500 RADZ BKN008
did not happen
PROB30 TEMPO 0312/0321 BKN014
did happen partly…
PROB30 TEMPO 0321/0401 4000 +SHRA BKN014
um, yea:
EGLL 032350Z AUTO 09005KT 9999 -RA FEW013/// BKN035/// //////CB 08/08 Q0990 NOSIG
EGLL 032320Z AUTO 15004KT 7000 -RA FEW020/// BKN033/// //////TCU 09/08 Q0990 TEMPO SHRA
EGLL 032250Z AUTO VRB02KT 9000 -RA FEW025/// BKN041/// //////TCU 09/08 Q0990 TEMPO SHRA
EGLL 032220Z AUTO 23004KT 180V270 9999 -RA SCT023/// BKN039/// //////CB 09/08 Q0991 TEMPO SHRA
EGLL 032150Z AUTO 23011KT 7000 -RA VCTS SCT010/// BKN022/// //////CB 10/08 Q0991 RERA TEMPO 4500 SHRA BKN010
EGLL 032120Z AUTO 14003KT 9999 -RA FEW011/// BKN021/// //////CB 10/08 Q0990 RESHRA TEMPO 4000 SHRA
While
TEMPO 0401/0409 6000
BECMG 0407/0410 SCT015 BKN035
Was not too far of either.
Now, what I note with no small surprise: The largest airport in the UK obviously does no longer employ a full time observer? Hmm. Autometar for quite some time and also quite some weather?
That explains to me why the meteorologist went quite into detail with the TAF indeed. Autometar, well, they work sorta, but they will never replace a human observer imho. So maybe the meteorologist wanted to compensate for that a bit.
If I had issued this TAF, I’d probably been a bit more positive and removed some of the PROB30’s but left the groups standing. But generally, I’d be quite ok with the outcome.
Currently, there is a little glitch in the time-space continuum at Zurich:
LSZH 112025Z 1121/1303 VRB03KT CAVOK TX15/1215Z TN00/1206Z
BECMG 1123/1203 4000 BR NSC PROB40
TEMPO 1203/1208 1500 BCFG
BECMG 1208/1210 CAVOK
TEMPO 1210/1217 04006KT
BECMG 1200/1203 2000 MIFG BKN004
It’s been updated in the mean time.
CCA LSZH 112025Z 1121/1303 VRB03KT CAVOK TX15/1215Z TN00/1206Z
BECMG 1123/1203 4000 BR NSC
PROB40 TEMPO 1203/1208 1500 BCFG
BECMG 1208/1210 CAVOK
TEMPO 1210/1217 04006KT
BECMG 1300/1303 2000 MIFG BKN004=
EGKK 170456Z 1706/1812 35005KT 9999 FEW030 PROB30 1706/1708 3000 BR MIFG PROB30 1802/1808 3000 BR PROB30 TEMPO 1808/1812 7000 -RADZ BECMG 1809/1812 25010KT
The only cloudbase forecast is FEW030 and how can you get -RADZ out of that?
The TAF for EGLL – not far away – makes more sense
EGLL 170454Z 1706/1812 33005KT 9999 FEW030 PROB30 1706/1709 3000 BR TEMPO 1722/1809 8000 PROB30 1800/1809 3000 BR BECMG 1809/1812 26010KT TEMPO 1809/1812 7000 -RADZ BKN012
Cloud above the MSA or 5000’ (whichever is higher) doesn’t have to be included in a TAF. So you can see CAVOK in a METAR/TAF and still not be able to see the sky.
Not saying that is the explanation here, but it is one thing to keep in mind.
A good point but I can’t remember the last time I saw cloud in the UK, with rain, and the cloud being above 5000ft 
Some examples from this morning:
METAR EGPK 170720Z 27014KT 9999 -RA FEW018 08/05 Q1025=
METAR EGPF 170220Z AUTO VRB02KT 9999 -RA FEW039 SCT048 03/02 Q1025=
The next one looks more like the usual UK situation
EGKK 171058Z 1712/1818 35005KT CAVOK BECMG 1721/1724 9000 NSC PROB30 1802/1808 3000 BR MIFG BECMG 1808/1811 26010KT 9999 BKN030 TEMPO 1811/1818 7000 -RADZ BKN012 PROB30 TEMPO 1816/1818 BKN008
Yes. Non-convective rain usually falls from higher cloud, and the lower layers of cloud arise from the humidity that it causes below. In a maritime climate like the UK, I agree it’s usual to have lower cloud associated with it, but under an approaching warm front, for example, that lower cloud does not always form where there’s rain. In the summer I did a trip over Germany with a thick layer above FL100 giving consistent moderate rain, but nothing much in the way of cloud below.
