Severe Squall Line over Quebec August 18th 2008. Robert Michaud QSPC – Montreal October 29th 2008. Severe Squall Line – Aug 18th 2008. A strong thunderstorm line moved across western and southern regions of the province of Quebec;
Severe Squall Line over Quebec August 18th 2008
Robert MichaudQSPC – Montreal
October 29th 2008
A well defined low with frontal structure (Analysis of 12 and 18Z). Surface temperatures of 28ºC and dew point temperatures of 18 to 20ºC were reported in the warm sector.
Long wave trough at 500 hPa with significative short wave trough rotating toward the east with winds of 45-55 knots at the base of the LWT (Analysis of 500 hPa at 12 and 00Z).
We can clearly observed maximum winds at high and low levels (120 and 45 knots respectively) at the moment of the convective development at 18Z.
Potential instability and latent instability under 750 hPa
(CAPPI at 1.5 km)