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Provisional UKMO data for Summer(JJA) suggested warmest/driest since 2006
UKMO forecast issued in March and April hinted at this but May issue went colder/wetter hence contingency forecast was also poor.
Verification of Experimental Seasonal Summary Forecast for UK area, June July August 2013 - compiled 7Sept2013

Met Office Summer mean temp
Met Office Summer mean rain

Met Office Anomaly Graphs
Met Office Monthly Anomaly Charts

Season temperature mostly above normal especially in the N half of UK (more so for the older 1961-90 averaging period)

Seasons rainfall generally below normal except parts of Midlands and N England where locally above normal and normal for N Ireland and NE Scotland.
Note CPC rain data less clear cut for dry conditions over Scotland.

See orignal forecast summary for detail of forecast.

DATA available in May 2013 for June July August 2013
Overall some models hinted at normal and hence warmer summer the recent ones but no help withdrier than normal
Summary - some idea of S being cooler relative to average with implied better than normal summer
1. Russia: forecast to cold but got the N/S idea and suggested below normal rain for S.
2. USA - FSU : suggested N/S graduation and above or near normal temps OK but rain not so good.
3. USA - CFS2 : some idea of drier areas but no indication of above normal altough normal implies warmer than recent years.
4. UK : rain forecast poor temp split ok but again model too cold.
5. USA - NASA : not helpful
6. USA - IRI : Fair stab at the north being warmer but rain not helfull.
7. KMA - a little cool but got the warmer N and hint cooler south not so good with rain
8. JMA - got the drier trend and more ridging but not so good with temperature
9. NMME so idea of warmer temps but rain not helfull.

DATA available in April 2013 forJune July August 2013
Little different to later data with hints a normal and in the N or NW above normal temps. Rain forecast poor.

Below are the summaries in the summer 2013 forecast which was based on earlier runs for the summer going back to Feb 2013 - main theme for the warmer summer was correct but rainfall signal fairly poor.
Issue 5 last update 29 May 2013.
UKMO 280513 contingency points to colder than normal June (consistent with CFS2) over UK and below average values for the summer overall with above normal rainfall in June and slightly above for the summer. (CFS 2 suggest NW drier and SE possibly wetter in June).
Note: model seems forecast too cold so nearer normal temps might be a better guide.
Comment - Hints from models of a normal UK summer (hence better than recent summers overall) but with near normal temps and near normal rain being the main theme. Some hints at drier areas in output but no consensus suggestion of early summer being drier may mean convective PPN may dominate.

USA - NCEP CFS2 26 May13 - signal for Spain and parts of Med coasts to be cooler than normal. Unsettled summer for med?
TEMP: Season: normal
JUN SE may be cooler otherwise normal JUL normal AUG normal
PPN: Season: SW Eire, SW England, N and NE England and E/SE England part of N Ireland, W and S Scotland, drier than normal - elsewhere normal.
JUN much of UK and Eire below normal strong signal, but central S England normal. JUL Mostly below normal. Parts of S coasts England, N Eire and N Ireland also N Scotland normal AUG Normal but wetter for much of central England and Wales, Eire and central Scotland.

Issue 4 Data available in May 2013.

Comment - Hints from models of a normal summer (hence better than recent summers overall) but with near normal temps and near normal rain being the main theme. Some hints at drier areas in output but no consensus.

Russian data (1/5/13): suggests near normal temp (hence warmer than last 2 summers) but also with N Sea and Sea S of Eire colder than normal so some risk to these coasts of lower temps.
Normal PPN but across much of England and Wales drier than normal (note model unlikely to capture summer thunder showers).
USA CFS2 10 day average of ENS runs to 3/5/2013: Temp for season not far from normal but hint of N Sea coasts cooler.
PPN normal except - Jun SE drier than normal far NW of Uk wetter (several of the newer daily outputs have this reversed with NW and SW drier but E/SE wetter). Jul much of the SE,S and SW of England as well as parts of Wales drier than normal. W Scotland wetter.
Aug N of England and W Scotland drier than normal but inland central southern England wetter.
NASA GSFC 100513 some coastal areas at risk from cooler temps but mostly near normal and near normal rain but hints of wetter in NW of UK - points to normal summer hence slightly warmer and drier than recent years for the south and east at least.
FSU GSM - 100513 near or slightly warm than normal except cooler in far SW and SE. Midland and N Scotland normal or slightly drier otherwise normal or slightly wetter.
UKMO 140513 - TEMP: Eire, N Ireland and Scotland most likely to be near normal with the southern third cooler and the SE of England at risk of well below normal temps. PPN: Mostly near normal but with low probs SW England and N Isles/far N Scotland being drier than normal. Risk of well above normal rain close to far SE of England som risk for this area.
KMA - 140513 - suggests better than recent summers.
PMSL :Season: slightly above normal pressure (mean flow NW'ly). JUN and JUL slightly above normal pressure, especially NW of UK AUG: near normal
850TMP: Season: slightly above overall. JUN and JUL slightly above normal. AUG normal.
500Z: Season: slightly above overall. JUN and JUL slightly above normal. AUG normal.
IRI - 200513 - PPN no signal away from normal. Probs for above normal temps range from 40 or 45% in the south to 60% in the north but with chance of well above nomal temps N Scotland.

Japan JMA 11MAY2013 overall more ridging and slighlty drier than normal
Temp: Season N Ireland and nornern third of Eire, Scotland and northern two thirds of England and Wales cooler. Normal or above in S.
JUN Slightly above normal but parts of N and E England and S Scotland cooler. JUL slightly cooler except in S of UK. AUG slightly above
PPN : Season slightly drier JUN slightly above parts of S and SE slightly below. JUL slightly below normal except S of UK. AUG slightly below
PMSL: Season slightly above normal. JUN slightly above. JUL slightly below normal. AUG slightly above

Comment 28Apr2013 - some of the newer output from CFS2 gave stronger hint towards warmer and perhaps drier summer running into Sept with even some hints tht May may not be a cool as previously forecast. See seasonal page for more info.

Issue 3 data to 16th April 2013 - seasonal forecast page may have additional updates.
Summary - Possibly a cooler start to summer than normal, especially in the S of UK and also near N Sea coasts
Indication of a normal temperature regime otherwise across the UK with some indication of above normal temps (eg UK suggests warming in NW and W)
Overall signal for a warmer summer than recent years though nearer the longer term warmer average of recent decades.
Rainfall patterns more uncertain with some models indicating some drier than normal spells for July. Hint also of a S or SE type with thundery spells, especially in August.
BUT cannot rule out some localy above normal rainfall.

For individual models summary see the seasonal forecast.

Issue 2 on 11 March 2013
Summary - Main signal is for a near normal summer (a better summer compared to the cool and wet of recent years) and possibly for a warmer than normal School Holiday
period though with risk of rain possibly thundery in August in southern half UK.
UKMO suggests warmer than normal temperatures except for the E and SE of UK where near normal combined with near normal rainfall though with hint of well above normal in the NW and well below in the SE.
NASA suggest 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 Jun for Scotland and July for England as the less wet periods. Possibly thundery in August warm rain! Temps near normal but above in NW parts.
NMME near normal.

Issue 1 on 3 Feb
Summary - Mostly near normal rainfall but southern, more likely SE England possibly wetter than normal - high risk for June an July rather than August.
Temperatures near normal but with above normal sea temps near the SW prospect of some inland warm temperature.
This points to an unsettled or changeable start to the summer, especially in the south, but with warmer and possibly drier period in August

NASA GFSC 080213 data offer some support for above normal temps in July and August but only slightly above in the S of England. Little rain signal.

NMME 020213 slightly above normal temp for season.

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