Recent radar cases

2024

Birds and insects 2024-05-17 - 19: birds towards north 1-3 km altitudes during the night, masses of insects to Gulf of Finland in the morning towards SW, sea-breeze front during the day against northerly flow.
Birds and insects 2024-05-14 - 16: temperatures rsising, and insects appear mostly below 1 km over the land, but westerly or northerly flows. Birds migrating mostly against the wind on the nights, but also towards ENE - Arctica over the Gulf of Finland.
Birds and insects 2024-05-08 - 10:
Birds and insects 2024-04-26 - 30: cold weather delayed spring migration of birds going on, warm air mass with insects from south on the 29th.
Precipitation 2024-04-22 - 24: freezing rain episode in southern Finland, then snowfall.
Snowfall 2024-04-19 - 21: Cold air mass long lasting snowfall event.
Birds 2024-04-14 - 16: against northerly flow, but heavy migration during the nights, rain as well.
Birds and insects 2024-04-12: rolls in northwesterly flow, probably turbulence related weak echoes, but also large insects and birds in the uplift lines.
Birds and insects 2024-04-08 - 10: heavy bird migration during nights and mornings. Large flocks on the 8th at Estonian coast, and heavy nocturnal bird migration to NW started on the 9nth, and morning birds to N over the sea.
Some insects during the day with the wind to east on the 8th, and on the 9th from E-SE from the cold sea.
Snow and rain 2024-04-05 - 07: quite a lot of snow in southern Finland at first, then warming up and some rain.
Thunderstorms 2024-04-01: a brief thick cloud episode with less than 1 mm rain in Hyytiälä, later on April 2-3 a lot of precipitation in southern Finland, snow in the end.
Birds and insects 2024-04-01: warm air mass temporarily, and rapid turn to northerly flow.
High level clouds and halo 2024-03-18:
Rain to snow 2024-03-15 - 17: warm air mass rapidly to cold air surge.
Precipitation 2024-03-13 - 14: maintenance visit at Hyytiälä site, low level radar returns but no precipitation observed at ground.
Rain and snow 2024-02-23 - 25: in the middle snow, but snow depth decreased over the period.
Snow and rain 2024-02-16 - 17: freezing and frozen rain in Hyytiälä.
Snow and rain 2024-02-07 - 09:
Snow and rain 2024-01-21 - 23:
Snow 2024-01-17: snowfall producing smooth layer of fresh snow.
Clouds 2024-01-09: afternoon, sunset, and night by city lights.
Snow 2024-01-03: lake-effect snowfall in cold easterly flow over the Gulf of Finland.
Stratospheric clouds 2024-01-03 - 07: continuing bright skies before sunrise and after sunset.

2023

Birds 2023-04-11: heavy morning and nocturnal migrations of birds.
Birds 2023-10-02:
Birds 2023-10-17 - 20: heavy and fast bird migrations early night to WSW-SW, after and north of large scale rain, in strong winds from NNE-ENE.
Birds 2023-10-23 - 26: easterly flow migration mainly along the coast to WSW, with precipitation.
Clear air 2023-04-16 - 20 heavy morning and nocturnal migrations of birds, sea-breeze and rolls, and chaff.
Clear air 2023-09-14
Clear air 2023-09-22: heavy insect migration on September 22-23 from south on the land areas and accross the Gulf of Finland.
Migrations 2023-08-07: migration from SE, temperature above 30 degrees in Hyytiälä on the 7th.
Migrations 2023-10-05: heavy insects migration southwards continuing over the sea with heavy nocturnal bird migration.
Low pressure 2023-10-07: high pressure tendencies.
Low pressure 2023-10-14:
Rapid wind change 2023-10-25 - 26:
Rain 2023-05-26: observed possible mesocyclone in Siltamäki (northern Helsinki) 14:00-14:30 EEST.
Rain 2023-07-28: heavy rain in Hyytiälä, about 70 mm/h intensity and longer period accumulation 50 mm.
Rain 2023-08-31: heavy rain band from south, thunderstorms with vortices in radar imagery.
Rain 2023-09-20: fast passing deep low pressure centre, especially in Hyytiälä.
:Stratospheric clouds 2023-12-17.
:Stratospheric clouds 2023-12-20.
:Stratospheric clouds 2023-12-31 as a bright skies before sunrise and after sunset.

2022

2022-04-11 - 14 morning and nocturnal migrations of birds, with precipitation in the end.
2022-04-17 - 19 heavy morning and nocturnal migrations of birds.
Birds 2022-05-02
Birds 2022-05-04
Migrations 2022-06-07
Rain 2022-09-15
Temperature 2022-01-15 includes Tonga volcanic eruption pressure wave.
Temperature 2022-09-06

Previous years and decades

Limited space in the "modern" web server may allow only about a month collection of the cases.
Previous cases for some decades may be available by e-mailing a request.

Bird and insect migrations and meteorological events.

Precipitation cases


2020-09-29 - 2010-10-04
2020-10-04 - 06
2020-10-07 - 09
2020-10-10
2020-10-16
2020-10-18
2020-10-21
2020-11-02 - 04
2020-11-11 - 12
2020-11-16 - 18 large scale rain events.
2020-11-18 - 20 large scale precipitation, melting layer at 2 km getting lower, and snowfall.
2020-11-21 large scale precipitation, from snow to rain.
2020-11-24 - 26 below freezing to warm air mass with precipitation.
2020-11-30 - 12-01 snow to rain.
2020-12-15 - 16 snow and warming.
2021-01-10 - 11 snowfall.
2021-01-12 - 13 heavy snowfall in southern Finland.
2021-01-16 lake-effect snowfall in cold air flow from NE-ENE.
2021-01-18 - 20 snowfall.
2021-01-21 - 23 heavy snowfall in southern Finland, and temperature above 0 degrees-C in the end.
2021-01-24 - 25 snowfall, and to rain in southern Finland slightly above freezing point at surface.
2021-01-26 - 28 long snowfall bringing about 20 cm more snow depth in Hyytiälä.
2021-01-29 - 30 snowfall continued and snow depth back to 60 cm level in Hyytiälä.
2021-01-31 - 02-02 snowfall continued but with less intensity and lower temperature.
2021-02-02 - 04 snowfall continued.
2021-02-05 - 08 light snowfall occurred intermittenly in well below freezing temperatures.
2021-02-09 - 12 light snowfall continued, with nocturnal surface inversion cases.
2021-02-14 - 15 light snowfall continued.
2021-02-18 - 21 snowfall to rain, a lot of freezing rain in the end.
2021-02-22 - 24 Saharan dust on the top ice layer of snow cover, melt water dirty spots later during warm period.
2021-04-24 - 26 .
2021-05-19 - 22 precipitation, mostly rain but some snow on the 21st in Hyytiälä.

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Migrations


2020-10-11
2020-10-13
2020-11-08 heavy nocturnal migration after sunset from NE towards SSW.

2021-04-16 - 21 morning and nocturnal migrations getting heavy and heavier.
2021-05-16 - 17 insects and birds.

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Meteorological phenomena


2020-11-07 - 10 surface inversions.
2020-11-24 - 25 atmospheric waves observed in Hyytiälä pressure, wind, etc.
2020-12-08 - 10 cooling episodes in below freezing air mass.

2021-01-15 surface inversions, below -30 degrees(C) in Hyytiälä.
2021-02-09 - 10 surface inversions with light snowfall episodes.
2021-02-16 - 17 surface inversion, below -30 degrees(C) in Hyytiälä.
2021-02-27 - 03-01 warm air mass episode.
2021-03-10 cold air mass surface inversion, below -30 degrees(C) in Hyytiälä.

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