Dry conditions Quiet times on the western side. The team arrived on site at 2010 UTC to find dry soils and no rainfall till 2145 UTC when a few sparse raindrops fell. Since the weather wasn't providing much excitement, Aurélie and Jeremy installed an additional tipping bucket rain gauge in tandem with the Geonor weighing gauge. The group then put some time into redesigning the tarp setup in preparation for the coming deluge. Routine data downloads were conducted. Some light rain occurred sporadically while the group was on site, however precipitation did not persist past roughly 0230 UTC prompting the team to depart.
Field participants: Selina Mitchell, Jeremy Morris & Aurélie Desroches-Lapointe
Wet conditions Although the GEM2.5 model run didn't show any precipitation until 0100 UTC, the scattered cells we observed on the radar made Charlie and I leave BGI at 1900 UTC to arrive on site at 2005 UTC and take our first observation at 2010 UTC, after a data download at Fortress Junction. Charlie took the first shift. We arrived under cloudy but clear weather, but only a few minutes later, we started to observe strong winds, and some snow for about an hour. Charlie had the time to observe graupel first, and then aggregates getting smaller with time. The intensity of snow was the highest around 2030 UTC.
The weather then remained clear until 2240 UTC, when I saw a grey cloud coming from the north progressively covering the sky, and then a gusting wind coming from the north and medium-sized graupel falling for 30 minutes. Then it got clearer and clearer again. In the end the snow and gusts went on and off for the length of our shift, but the intensity was the highest between 2240 UTC and 2300 UTC, the snowfall intensity was then about 3.5/5. From time to time we were able to take some pictures of the snowflakes, but most of the time it melted too quickly for that. We didn't observe more than graupel and aggregates.
We left the site at 0600 UTC after a 10 hours shift, and let Juris and Hilary replace us for the nightshift.
Hilary and Juris arrived on site at 0600 UTC June 20. The drive to our site was very eventful with lots of wildlife spotted on the side of the highway, including what may have been a possible lynx or other large cat, as well as a bear squatting and eyeing us down on the right hand side of the Fortress road as we drove up! Charlie and Cécile caught us up on everything and left to head back to BGI to get some much deserved rest. When we arrived at the top there was very light snow and stopped around 0640 UTC. Visibility was clear and the wind was calm during that time. Snow started again at 0720 and became light-moderate with dendrites, small irregulars, and aggregates of dendrites. Winds were light from the south. Snow really began to accumulate at 0800 UTC and visibility became moderate, at times poor.
Juris started her shift changing the settings of the macrophotography camera. In the end, extra batteries were taken from the timelapse camera on the scaffold and used for the flash. Anyways it was too dark for the timelapse camera to capture anything. This solved the issue. Precipitation picked up around 1000 UTC with larger aggregates that lasted about 20 minutes. By 1030 UTC, precipitation had ended, agreed upon by songbirds as they were chirping away loudly. At 1130 UTC unrimed precipitation (needles, aggregates of dendrites and singular dendrites) amongst rimed precipitation were observed.
When I woke up for my next shift, it was a foggy winter wonderland! I began taking observations at 1200 UTC. Snow started again at 1230 UTC with light/moderate intensity and particles were mostly dendrites, aggregates of dendrites, and small irregulars. At 1310, graupel was spotted in addition to the snowflakes. Charlie and André came to replace myself and Juris at 1400 UTC, and we headed back to BGI. On the way down we conducted a carsonde, capturing a transition region.
André and I arrived on site at 1400 UTC, with the kestrel out of the car’s window and the cellphone filming the road. We observed an interesting transition on the way up in the precipitation type falling but also in the scenery. The first three hours of observations were pretty busy, with temperature around -1°C and snow intensity up to 4 (moderate to heavy). We took some nice pictures, but the crystal types were not very varied, it was mostly aggregates of dendrites (some large around 1.5 cm). An interesting thing that we notice during that time was that the wind was coming from S – SW all along the event, but the radar was showing cells coming from N. From 1700UTC, the intensity started to drop and the temperature increased. We had about 7.5 cm of accumulation on the board at that moment and at the end, it was entirely melted. So we left the site around 2000UTC, as green as it was the day before!
Field participants: Cécile Carton, Charlie Hébert-Pinard, André Bertoncini, Hilary Smith & Juris Almonte