Below are plots of SYNOP/radiosonde BUFR coverage for 28 November to 2 December 2014 - reports as decoded at ECMWF, some reports not in standard BUFR are not decoded.
Please can data producers ensure that there is a reasonable overlap of TAC and BUFR data on the GTS (EUMETNET recommendation is six months), any attempt to rush the change will result in more errors, extra work for NWP centres and possibly worse forecasts. Note also that reformatted TEMP reports still as separate parts are not good BUFR and cause problems for NWP centres (some more than others).
Surface coverage
Almost 70% of stations now report in BUFR, reports from Japan are using an extended template - not processed at ECMWF yet. Iceland is now reporting BUFR from almost 100 stations, compared to about 20 in TAC.
Three countries (UK, Eire and Netherlands, shown green) ceased TAC SYNOP transmission on the GTS on 3rd or 4th November 2014 (see SYNOP ). ECMWF is now assimilating BUFR surface reports from these countries.
(Grey: TAC reports but no BUFR, Purple: BUFR reports but no TAC, Red *: position error. Light/dark blue indicates that there are less/more than 60% of the reports available in BUFR.)
Radiosonde coverage
Almost 70% of stations report in BUFR, only about 10% report proper BUFR with almost 60% reporting reformatted TEMP (see "structure" page and plots below). Reports may be incomplete (eg data above 100 hPa missing). The numbers have recovered from a dip (affecting several countries) seen at ECMWF in mid-November (due partly to slightly non-standard BUFR reports).
On 11 November 2014 ECMWF started assimilating a subset of the high resolution reports (about 16 stations from Europe plus some ASAP ships). After 21 November some of the ASAPs (those starting ASDE and ASEU) stopped reporting in TEMP SHIP format, they are now only available in BUFR format. We understand that some NWP centres are not yet in a position to assimilate BUFR radiosonde data, although they are working on this.
(Grey: TAC reports but no BUFR, Purple: BUFR reports but no TAC, Red *: position error. Light/dark blue indicates low/high vertical resolution BUFR data. Black ring - ship report, or identifier error!)
It can be difficult to distinguish proper BUFR from reformatted TEMP. The plot below (showing data received at the Met Office) shows stations reporting radiosonde drift in blue or green.
(Orange: reformatted TEMP. Green: stations reporting over 400 levels. Dark blue: <400 levels but drift reported. Light blue: occasional or zero drift values reported, data appears to be reformatted TEMP.)
The maximum number of levels reported (below) gives some information on the resolution of the reports.
(1-29 grey; 30-99 light blue; 100-299 dark blue; 300-999 green; 1000-2999 orange; over 3000 cyan.)
