So, I’m at the Carleton Place Dragon Boat Festival today and the weather here is rather exciting. It’s been raining almost constantly since we arrived and there have been delays because of lightning. I’ve been watching the Franktown radar and it’s not encouraging.

The aviation forecast for Ottawa is equally bleak:
TAF CYOW 081141Z 0812/0912 14010KT P6SM SCT025 OVC100
TEMPO 0812/0817 4SM -SHRA BR OVC020 PROB40 0813/0815 VRB20G30KT 1SM TSRA BR BKN008 OVC020CB
FM081700 18012G22KT P6SM -SHRA OVC030
TEMPO 0817/0821 5SM -SHRA BR OVC015 PROB40 0817/0821 VRB30G50KT 1SM +TSRA BKN015 OVC030CB
FM082100 25012G22KT P6SM -SHRA OVC025
TEMPO 0821/0901 5SM -SHRA BR OVC020
FM090100 26015G25KT P6SM OVC020
FM090400 28010G20KT P6SM OVC025
FM090900 28010KT P6SM BKN030
RMK NXT FCST BY 081500Z

The 30 gusting to 50 knots winds with heavy thunderstorms forecast for this afternoon will be truly delightful.

So, I just took a look at the Franktown radar and saw this:

My immediate response was: eww!

The aviation forecast is equally impressive:

TAF CYOW 041738Z 0418/0518 18005KT P6SM -SHRA BKN025 OVC040 TEMPO 0418/0420 2SM TSRA BR BKN008 OVC020CB
FM042000 18005KT P6SM -SHRA SCT015 OVC030 TEMPO 0420/0501 3SM -SHRA BR BKN015 OVC030 PROB30 0420/0501 2SM TSRA BR BKN008
OVC020CB
FM050100 05005KT 6SM BR FEW005 OVC070 PROB30 0501/0508 2SM BR BKN005
FM050800 35005KT P6SM FEW020 SCT100 TEMPO 0508/0513 BKN020
FM051700 VRB03KT P6SM BKN040
RMK NXT FCST BY 042100Z=

My rule of thumb concerning TAFs is the longer they are, the more the weather is going to suck.

In this case, the suck factor is fairly high because there’s rain and mist with periods of thunderstorms between now and about 9pm this evening. I’ve circled the likely culprits for the thunderstorms and put a little arrow indicating the rough direction that line was moving as it came in the radar’s coverage area. The interesting thing you can see if you watch the loop is that the big green mass is moving northeast while the line of thunderstorms is moving southeastish. It looks like they’re converging on Ottawa, so things could be a bit exciting this evening.