October Log (Arnøya / Kågen / Laukøya and Tromsø)
Notes
- air temperatures below are measured on sea level
- if clear sky, assume inversion
2025-10-13—2025-10-20 (A)
- Air: a bit over zero o up to +5 degrees with no overnight refreeze
- Wind: SW-W-NW mostly moderate, strong breeze with some gale winds periods,
- Precipitation: a lot of precipitation in form of snow, wintry mix, hail, graupel and rain
- Observations: snow boundary all the way to the sea level, coming and going.
Some pocket with new snow in "eastern" aspects and just a bit sugar-ish in "western" aspects.
Wet snow and slush lower down, higher up perhaps metamorphosed into rounds and wet clustered snow where not cold enough.
2025-10-21—2025-10-30 (A) (T)
- Air: fridge temperatures 0-7 degrees
- Wind: SW-NE-SE fresh to strong breeze / up to gale SE wind during the weekend
- Precipitation: mostly overcast with some occasional rain showers
- Observations: consistent rests of melt freeze clustered snow lower down covered by a "nice" MF crust
Higher up in the mountains could be a dryer conditions, especially eastern aspects, crust up to 700 masl with some dry snow pockets higher up? What is the old snow turning into?
Summary
Overall pattern:
October opened winter with a warm, wet, wind‑dominated pattern. Snowline fluctuated between sea level and higher elevations, with repeated cycles of wet snow, refreezing, partial dry snow pockets, and strong wind transport. The month laid down the first transitional layers that shaped November’s early-season structure.
Temperatures:
Generally mild (+0 °C to +5 °C) with
poor or no overnight refreeze until late in the period. Repeated short cold pulses did not establish a stable winter regime. Any clear nights likely produced inversions but little lasting SH.
Wind:
Persistent and often strong winds from
SW–W–NW created:
- Strong scouring on windward slopes
- New-snow pockets on E aspects
- Early-season “sugar-ish” faceting on shaded W aspects
- Highly uneven distribution of the first snowfalls
Precipitation:
October brought
very mixed precipitation: snow, wintry mix, graupel, hail, and repeated rain. Snowline oscillated dramatically, often down to sea level but briefly disappearing again.
Snowpack evolution:
- Early/new snow accumulated mainly on E aspects and sheltered terrain.
- Western slopes developed weak, sugary early facets.
- Lower elevations repeatedly cycled through wet → slush → thin crusts → wet rounds.
- Upper elevations experienced early development of rounds and wet clustered grains, but wind exposure caused scouring.
Key layers entering November:
- Early MF/wet layers low down.
- Poorly bonded pockets of dry new snow on E aspects.
- Weak faceted snow on W aspects.
- A very patchy early-season base with strong spatial variability.
Overall:
October ended with a thin, inconsistent, and wind‑damaged early snowpack. The structure was fragile, spatially irregular, and primed for major changes once November brought more consistent precipitation.
