Someone was asking about a Summer forecast so thought a brief overview of my
interpretation of what models indicate for June July August 2013 might be of
interest and by way of comparison a summary of some of the output in March
2012 for Summer 2012.

June July August 2013
Based on data available to 11 March 2013
UK suggests warmer than normal temperatures except for the E and SE of UK
where near normal. Near normal rainfall though with hint of well above
normal in the NW and well below in the SE.
NASA suggests warmer than normal most areas especially August but parts of E
of England near normal. Rainfall near normal.
FSU COAMPS slightly wetter and cooler than normal.
CFS2 picks out June for Scotland and July for England as the less wet
periods. Above normal rain over parts of S half of England in August Temps
near normal but above in NW parts of UK.

More recent CFS2 data to 15th March adds above normal rain for parts of
southern third of UK in June as well as August with a hint that Cornwall and
some W parts of Scotland may also see above normal rain.

USA National Multi Model Ensemble probs show enhanced probs for above
average PPN in S of UK in June, N of UK in July and N Ireland in August. No
signal for a departure from normal for temperature range.

In 2012 Seasonal Models available in March 2012 briefly suggested:
UK
TEMP: Mostly above normal (40-60%) except far N of Scotland.
PPN : Little signal - hint above above normal for parts of Wales and W of
England.
PMSL: Near normal, slightly above to the north and below to S of UK.

USA - NCEP CFS2 MONTHLY
Temp: No signal away from normal range
Monthly data - June July and August near normal.
PPN : Mostly near normal but far NW wetter and far SE drier than normal.
Monthly suggests June below normal in Scotland and Lincs above normal in
Wales and
NW England but normal elsewhere. July NW UK and parts of SW above normal
PPN, E of
England below normal, elsewhere near normal. August near normal but SE
England and parts
of Eire/N Ireland lower ppn totals than normal.

Temps for JJA 2012 were near or slightly below normal. Models did not give a
strong signal for the above normal rain (over all but the N of UK) but gave
some hints in that direction.