May 2016 Forecast: Still under the blowtorch, but change could be coming

Hot and dry conditions remain in place as we go into May, April finished off 2-5C above normal and very dry with some parts of the province not receiving more than a millimetre or two of rainfall which is less than 10% of the normal April precip. Temperatures over much of the province managed to surpass the 25C mark and 30C in the NW part of the province. Grande Prairie set a new all time record for the month on the 18th at 29.4C(old 29.2C on Apr 25th 1977). April 2016 finished off one of the warmest in the last half century. Continuing a 4 month long string of well above normal months.

The effect of the continued warmth is a violent start to the fire season and trees are now in leaf 3 to 4 weeks early. Current long range forecasts show more near 30C heat, this time more widespread in store in May However there is an interesting similarity with other Major El Nino years, particularly ones that transition into a Moderate-Strong La Nina. The month of June during the 4 analogue years(1998,1988,1983,1973) had well above normal rainfall, in some cases nearly double the normal amount. And some of those years saw the change to that rainy period at the end of May. It is not known if this is a hallmark of an El Nino-La Nina transition or a coincidence.

May overall could be the 5th hot month in a row; with temperatures expected to be up to 5C warmer than normal in the northern Part of the province. Rainfall is likely to be below to well below normal with the exeption of parts of the south foothills and Rockies. However we are entering the convective season, so rainfall may vary dramatically from the forecast with a good thunderstorm.

May 1-10: Hot and dry. temperatures nearing 32C in eastern Alberta at times. Some potential for thunderstorms.

May 10-20:Warm with a few thunderstorms, Hot in south-eastern Alberta. Possibility of a few wetter days. Notable Chance of a thunderstorm outbreak in Central Alberta

May 20-31: Possible transition to a rainy pattern, otherwise another potential burst of heat. Severe thunderstorms begin

Below is a something I threw together showing the similarities regarding June following Major El Nino(station used, Edmonton INTL A)