The recent pattern featuring cascading cool air into central and eastern regions will abate over the course of the medium range as upper troughiness shifts NE to higher latitudes and a milder continental flow becomes established into early July. BC & portions of AB look to be the exceptions next week as a trough digs in from the NW but this is seemingly on the transient side moving into the extended range.
06z GFS ensembles 500mb height anomalies @ hour 120 / day 5:
Broad-scale upper ridging could take hold over the USA farther out, bulging northward and bringing more typical summer warmth to many regions with it.
500mb height anomalies @ hour 240 / day 10:
Question marks remain as to whether this mean ridge becomes anchored farther to the SW and heights lower again in parts of east down the road, possibly leading to more of a back-and-forth temp profile and renewed activity while heat shifts westward again to some degree.
We’ll continue to keep a measured eye on these developments and will update regularly to keep on top of any changes to the forecast.
500mb height anomalies @ hour 360 / day 15:
Regardless this pattern change should confine most of the below-normal values near Greenland with muted effects on a limited section of Atlantic Canada.
00z NAEFS temp probabilities, days 8-14:
In the meantime storms and associated moisture will track through eastern parts of NL as well as the GL into QC & the Maritimes through the course of the short-range.
06z RGEM @ hour 12 / 24 / 36 / 48:
Total precip @ hour 48:
EDIT: EC has issued a summary for yesterday’s storms in NB, indicating that a possible tornado may have occurred.
Weather summary for New Brunswick issued by Environment Canada at 8:27 a.m. ADT Wednesday 28 June 2017. Discussion. An unstable airmass moved over New Brunswick Tuesday afternoon and into the evening producing numerous severe thunderstorms bringing torrential rain, large hail and strong winds. One severe thunderstorm formed near Doaktown last evening and may of spawned a tornado that moved into the Blissville and Blackville areas during the evening hours. The following is a summary of weather event information received by Environment Canada. Severe weather watcher confirmed large hail and damaging winds in the Plaster Rock area. Loonie to golf ball size hail along with wind gusts close to 100 km/h were reported with that particular thunderstorm. A tornado warning was issued for a very strong thunderstorm near Doaktown based on Doppler radar. Rotation was observed throughout the cell. No confirmed reports have been received by EMO or the weather office. We will update this bulletin if and when new information becomes available. Please note that this summary may contain preliminary or unofficial information and does not constitute a complete or final report. End/ASPC