Technical Discussion
Risk of severe thunderstorms today for NB and perhaps parts of NS. An approaching upper level jet will help enhance vertical development. A passing thermal trough could mean destabilization this afternoon as upper levels could cool slightly. No clouds in the area right now so solar insolation will be maxed out this afternoon and temps in the high 20’s to low 30’s will be a significant contribution to Tstorm development. Add to that, a weak trough will move over northern NB this afternoon which will help as a lifting mechanism and also could create high helicity values at low levels. Low level moisture is quite high but not significantly deep as 850 mb dew points are quite low…so this could be a limiting factor on development. Precipitable water is only around 35 mm.
The weak through mentioned earlier will meander towards southern NB late this afternoon or evening, so to does the treat of severe tstorms.
Regional Impacts
NB – Supercell development is possible over northern NB this afternoon and southern NB late this afternoon or early evening. Large hail, winds gusting to above 90 km/h and heavy localised rain are all possible. A low probability of a tornado is not out of the question giving the possibility of supercell development.
NS – Heavy rain and hail possible, mainly along the valley and stretching towards New Glasgow. Northern NS could see the potential this evening as tstorms move in from NB.
PEI – Heavy rain, high winds and hail possible as tstorms move in from NB late this afternoon or evening.
Labrador – risk of non severe thunder showers.
Barrie MacKinnon