Thanks SD Hi small_dog, that seems to be a SNOWTAM in METAR style.
A repeated previous report (99) (the following slash (/) is often used as visual divider from the rest of the report) saying that water or water patches (2) are covering 51% to 100% (9) of the runway with no measurable or significant depth (//) and breaking action good (95) In other words, the runway seems to be wet and BA is good.
The TREND is a forecast, and as such is valid for determining weather for the "one hour before and one hour after" requirement for the selection of alternates and the like.
10.13 TREND 10.13.1 For selected aerodromes, this is a forecast of significant changes in conditions during the two hours after the observation time: a.
The World Meteorological Organization's (WMO) publication No.
The following appears for Knock (5/apr/10) METAR METAR EIKN NIL= METAR EIKN NIL= METAR EIKN NIL= METAR EIKN NIL= I'm unable to find the exact meaning of 'nil' in ref to a metar in any abbreviation list. Typically there is a locally defined time window for the state authority to receive the METAR report.
'Wx nil' can mean No Sig= On a snowtam it means 'Clear and dry' in ref to rwy contamination. If this time window is missed the METAR is shown as a 'NIL' in the main bulletin and distributed later.
Change Indicator: BECMG (becoming) or TEMPO (temporary), which may be followed by a time group (hours and minutes UTC) preceded by one of the letter indicators FM (from), TL (until), AT (at); b. NOSIG replaces the trend group when no significant changes are forecast to occur during the trend forecast period.
Examples: BECMG FM1100 25035G50KT; TEMPO FM0630 TL0830 3000 SHRA. In Europe, when a statement of trend is attached to a METAR, that trend forecast is valid for two hours, not the three of a TTF.
That's my understanding without going to look it up, anyway. In my part of the world, a METAR is just that; a Report.