April turned out to be the wettest in 100 years, we’ve seen heavy thundery rain showers and at times persistent rainfall which has brought flooding to some areas, these theme has continued albeit on a less severe note as we’ve moved through the first week of May, but what can we expect for the remainder of the month?
It seems that we’ve become locked into a pattern we wanted in winter, High Pressure in the Atlantic extending up into the Arctic with Southerly tracking Low Pressure systems, had this pattern developed in Mid-Winter we would have been talking about widespread heavy and significant snowfalls, fortunately or unfortunately it’s May and the atmosphere has been warming for a couple of months now. Having said that, many models are indicating a High Pressure anomaly centered in the Atlantic which could last through May.
The NAO (North Atlantic Oscillation) is currently negative and is expected to remain so at least until the middle of the month, this suggests a continuation of the current pattern.
The MJO is forecasted to be in a weak Phase 7 and in May, this suggests a High Pressure ridge in the Mid-Atlantic, as can be seen on the composite below
So I think as we move through the course of the month, based on the factors above we’ll continue to see a generally cool, showery theme with High Pressure centered out in the Atlantic allowing Low Pressure to undercut bringing further rainfall across much of the United Kingdom, temperatures through this period are expected to be around average, with average-slightly above average rainfall.
Due to the very saturated grounds, any further heavy, prolonged rainfall may result in further flooding.