Posted: 25/04/2013 11:25 AM by Brisebois
Southern Yukon/northern BC continues in full on winter mode. A leading impulse already gave 10 to 15 cm along the YT/BC border. After a brief let-up in intensity another shortwave and accompanying surface low follows overnight into Friday. All the while the arctic frontal boundary will slowly be sagging southwards. Have maintained the current warnings (YDB, Roads, Cassiar, WWQ). YQH will be close…to the north of the front…as will WDL to the south of the front where a rain/snow mix will change over to snow this evening. Getpcpn shows something like 60 cm of snow for Muncho when all is said and done…not till Monday! Other area of concern is around YPR where the arctic and maritime streams converge and subtropical moisture has been ingested…24 hour totals will be in the 80 to 100 mm range.
Posted: 25/04/2013 1:25 PM by Wray
Long Range Discussion:
The Gem glb and the GFS have both been consistent in having a lo pressure centre in the Alaska panhandle with Srn rgns in the warm sector with slght chance precip. GFS has low slightly less deep, however, good positioning. By day 4 the GFS and Gem glb solutions diverge somewhat. Both have the centre of low pressure reformed in lee of Rockies with GFS low pressure slightly deeper than glb and a little further north. Early day 4 the GFS has the main cold front south of the S. Cst. Rgn, but the Gem Glb hangs back a bit with the cold front slightly north of Swrn BC, so slower progression. We’ll keep an eye on this to see if the models align, or diverge further. Day 5 sees all model solutions build a ridge back in over Swrn BC bringing a drying trend. That ridge will persist until late day 7 when another system from the N. begins to come Southward.
Posted: 25/04/2013 4:41 PM by Charbonneau
Some westerly gales expected to develop this evening through JDF, as the ridge offshore continues to weaken and sink southward. Meanwhile, a low off the Alaskan Panhandle will move southeastward, with an associated cold front reaching north of Haida Gwaii by morning. Ahead of this system, southerly gales are expected to develop tonight for the North Coast, and will spread to the central coast overnight. The strongest winds are expected to develop near Dixon East – with GEM indicating near storm force. Friday morning as the cold front begins to push southward, there is also a chance for some near storm force winds over Bowie, with a good pressure rise showing up behind the front. For now winds in these areas are 40-45 kt, but may need to be increased.