Day five of this dreaded block for parts of Northern, Central and Eastern Ontario.  Another cold and frosty morning today with some light snow cover in spots. Watch for more frost tonight. So far we have only reached 6c and clouds in Ottawa today after an ugly day yesterday only reaching 5c combined with on and off snow.  Just a reminder, to rub salt into the wound, our normal high temperature should be 18c…  All this while Southwestern Ontario basks in sunshine the last 2 days (although still below normal temperatures).

Take a look at this satellite image from yesterday noting the sharp cloud cut off just east of Toronto:goes_ecan_vvi_100

And basically the same thing today with the low pressure system just not moving away:May 9

However the block does some good for flood ravaged areas of Ontario and Quebec: this week looks mostly dry with low pressure systems being forced south of Ontario.  The next system eyeing the area is set for this weekend, but most models keep the bulk of the moisture just to our south.

Here is the latest GFS model for Saturday with a weak low pressure over Ontario and the stronger one to the south:Saturday

Come Sunday the two systems remain and the southern one becomes a stronger Nor’easter type system that hangs around New England and the Maritime’s for a couple days, again thanks to the block:Sunday

Eastern Ontario and Quebec will likely get stuck with showers and light rain from Saturday until late Monday.  However I think the total rainfall will be somewhere near 30 mm for the 3 days, a far cry from the 60 – 80 mm received over 2 days recently.  Here is the total rainfall in inches come Tuesday May 16th:rain

So the real question; when does this painful cold weather end and we start seeing some flowers and trees blooming?  Well we see immediate improvements starting tomorrow when temperatures finally manage to at least climb above 10c when the block lets go of the current system.  However it will continue to stay below normal (somewhere between 14 – 17c) right through to Thursday of next week.  Just in time for the May long weekend, I see temperatures climbing to 19c – 20c with some sun for Eastern Ontario.  However the GFS long range has been looking pretty wet from Monday (22nd) – Tuesday (23rd) through to the end of that week with temperatures staying near the 18c – 20c range.  The latest Euro weeklies look to have near normal temperatures through to the end of the month.  If this occurs I suspect May will finish off around 2 degrees below normal.

By the way, if you plan on being outdoors on the May long weekend, I suspect the bugs will be particularly bad this year with all the standing water around.  Although with the colder temperatures so far this month we may get lucky and they don’t hit until the following weekend.