There have been more updates from the Met Office today covering this weekend:
The detail regarding severe weather developments over the next few days are becoming gradually clearer now – the story for today is unchanged but the detail for Friday and Saturday has altered somewhat and is discussed in detail below.
Today will evolve similarly to yesterday with some welcome warm sunshine at times but with a scattering of heavy, locally thundery showers developing in response by early to mid-afternoon. A Yellow warning is in force for today’s showers covering Cumbria along with parts of N/E Lancashire, Greater Manchester and east Cheshire. The highest risk of surface water issues resulting from high-intensity rain over a short time period is greatest in the areas shaded Yellow (unsurprisingly) with disruption to transport links the most probable impact. That said, the risk of catching a heavy downpour extends to pretty much the whole of the region although any showers over Merseyside and west Cheshire should be more isolated. In the higher-risk areas the showers could linger well into this evening (the warning is valid til midnight) but should have largely faded away by midnight. Today’s Flood Guidance Statement (FGS), attached above, shows Cumbria, Lancashire and Greater Manchester on Yellow (low flood risk) for surface water.
There is now a consistent signal for a swathe of heavy rain to emerge from the continent and track WNW’wards across England and Wales. In yesterday’s briefing I expressed the hope that the band would move right through the region and on into Scotland. What is apparent now is that the area of heavy rain is set to take a much more southerly track with the southern half of the region receiving the main thrust of rain and potential disruption. There remains some uncertainty on the timing, extent and exact track of the rain but here’s my current best guess. The first rain looks set to reach S and E Cheshire late tonight (towards 0600) but allow a couple of hours either side of this. Then, through Friday morning the rain extends across all of Cheshire, Greater Manchester, Merseyside and much but perhaps not all of Lancashire. Some heavy interludes look inevitable, more particularly towards the Pennine areas. At present Cumbria looks like escaping much, if not just about all of this rain. Through the afternoon the heaviest of the rain should pull away to the west, leaving a legacy of lighter, more intermittent rain.
The FGS for Friday is now Amber for all areas except Cumbria and explains the flood risk arising from tomorrow’s rainfall in detail. In particular, like yesterday, I urge you to have a detailed look at the ‘Specific areas of concern’ map on page 2, noting the differences in flood risk between areas A, B and C, each of which contains some our region. The current Met Office Amber alert will be updated shortly with the Amber area-at-risk reflecting the subtle changes in the forecast over the past 24 hours.
The clear signal emerging is that as we move from Friday into Saturday, so attention will shift from the south of the region to the north and specifically Cumbria. A separate stream of rain will, during Friday night, begin feeding in off the North Sea into NE England and across the Pennines into Cumbria. This rain looks set to be persistent and at times heavy, although, like its Friday counterpart, there is still some uncertainty as to exactly where it will become anchored and how much of the heavier rain makes it across into Cumbria. In this kind of set-up I would expect the larger (and potentially disruptive) rainfall totals to occur mainly to the east of the M6, particularly across the eastern halves of both Eden and Carlisle council domains and the adjacent north Pennine areas. The Amber alert currently in force for Saturday will also be updated in the near future. The FGS remains Amber for all areas except Cumbria – this reflects the potential for impacts of Friday’s rainfall to continue to be felt into Saturday whilst across Cumbria the level of impacts arising from Friday night’s and Saturday’s rain curently warrant Yellow (low flood risk), rather than Amber (Medium) although this will be carefully monitored by the Environment Agency and Flood Forecasting Centre in case it needs revision.
Across north Cumbria in particular the rain could linger right throughout Saturday and perhaps well into Saturday night although the general intensity should tend to diminish into Saturday night.
Elsewhere Saturday looks a much quieter day in general although with the air still ‘unstable’ a few sharp showers can’t be ruled out if skies brighten up and temperatures nudge upwards.
See http://www.metoffice.gov.uk/public/weather/warnings/ (apologies the link is not live) for all current warnings.
Today – Yellow warning for rain valid til midnight.
Friday – Amber warning for rain valid the whole day (in process of being updated)
Saturday – Yellow alert for rain valid the whole day (in process of being updated)
Either the Met Office website or Hazard Manager for all current warnings and rainfall radar. Monitoring particularly recommended later this afternoon and early evening as locally torrential downpours develop.