The new warnings, which affect Scotland and Northern Ireland, read: “Rain or showers are expected through much of Sunday and Monday, and will merge into periods of heavy and persistent rain over high ground.
“Forty to 50mm of rain is likely to fall quite widely, and a few places may see 90 to 120 mm during this period.
“The largest totals are most likely across higher parts of Cumbria and Lancashire. The heavier rain should ease away from Scotland and Northern Ireland on Monday morning and from remaining areas on Monday afternoon.
“Strong winds will be an additional hazard across Northern Ireland, northwest England and southwest Scotland, with gusts of 50 mph in exposed places.”
The alert is in place from 6am on Sunday to 3pm on Monday, June 29.
The weather agency warned rain is likely to become heavy and persistent in places and may lead to some disruption – with interruption to power supplies likely in parts.