Tornadoes and severe weather continue this afternoon after storm ripped through the Mississipi valley last evening. Severe weather will continue in portions of the Country the next couple of days. According to Joe D’Aleo at WeatherBell Analytics yesterday’s activity broke the 4^th longest period without significant tornadoes in spring.  This has been a very quiet April in terms of severe weather much of that due to the cool air from Canada overpowering the warm and humid air to the south.

This afternoon the radar is very active.  You can see on the image below all the reds and oranges.  These represent strong to severe thunderstorms. There are tornado watches and severe thunderstorm warnings occurring now and will likely continue all day.

Our weekend was marred thanks to a weather pattern known as the omega block.  This pattern occurs when the flow of the atmosphere which carries our storms becomes configures in a pattern representing the Greek letter Omega.  You can see on the image below how this pattern looks today.  The good news, at lease for the next 48 hours is that we will be under the nicer part of the block as the unsettled areas move east. 

As the block breaks down, a new storm will develop on the western part of the omega and bring a significant rain event to New England on Wednesday and Thursday.  Anytime we see an inch or more of rain, I would consider it significant.  The potential for street flooding and small streams flooding is there if we see rainfall amounts approach 2 or 3 inches which is possible.

The heaviest rain appears it will fall south of the Massachusetts Turnpike, but there is still over 48 hours before the bulk of the rain occurs and the exact track of the upcoming system will determine if southern Maine receives a little or a lot of rain.  The latter would create some issues, but we haven’t had extreme rainfall this spring, so major rivers will not reach flood stage based on the current forecast.

I believe most of the rain will occur from Wednesday evening through the morning Thursday.  This timing could shift 6 to 8 hours either way as the storm develops and we see how the jet stream starts to unfold.   It’s likely by the end of the day Thursday all areas will have seen the rain end bringing us a better forecast for Friday. The map below shows the postion of the rain later Wednesday.  Notice much of Maine is dry at that time.

The end of the week as well as the weekend looks dry and seasonable.  Temperatures will return to the upper 50s after being stuck in the very chilly 40s tomorrow and Wednesday.  During the upcoming rain you will most certainly need warmer clothes as the lack of sunshine and raw wind of the water make it feel very chilly.

Although we have only seen 5 days in the 60s in Portland this month, April 2014 is averaging just over a ½ a degree below long-term averages.  I suspect with the upcoming chilly air, the month will be a cooler one overall.  In terms of rain, we are under average and unless the upcoming rain amounts to well over an inch, the month is likely to go into the record books on the drier side of the curve. 

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