Both GFS and ECM 12z ensembles look slightly more encouraging perhaps than they did yesterday.
The 12z GFS OP was at the top end, but there does seem to be a bit more of a marked warmup around the turn of the month. 20C may well be possible for favoured spots I imagine.
The ECM meteogram is introducing more uncertainty as soon as day 5 - still quite a lot to be resolved before we can have any confidence further into May.
For what it's worth, UKV has a raw 19C for Tuesday afternoon - of course key uncertainties still to be resolved.
Based on these three, a warmup looks to be coming around the turn of the month as I've highlighted previously, but there's nothing I'm seeing that suggests anything notable.
Again, easy to forget how fast things are changing at this time of year. By early May date records are around 27-28C, so for a warm spell to be at all notable it would have to hit mid 20s. At the moment we're nowhere near that on any of the model output.
Summary
Probably increasing chances compared to yesterday of at least a 2-3 day warmup around the turn of the month. Favoured spots have a chance of hitting 20C, possibly feeling warm at times and a welcome improvement if you're looking for warmth, certainly. But still a long way from anything particularly notable at this stage. And I say this as someone who would welcome something significantly warmer - if the output supports it I'll be the first to say so.
Further ahead the cooldown beyond the first few days of May now looks a bit more uncertain than it did, but given the uncertainties as soon as day 5 probably not worth losing too much sleep over that at this stage in any case.