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Birds will increase across Jacksonville Friday evening

Weather tools you can use to track the migration in the sky

Friday evening forecast show bird migration 3 hours after local sunset increasing up the east coast in advance of rain.
Friday evening forecast show bird migration 3 hours after local sunset increasing up the east coast in advance of rain. (Birdcast)

When, where and how far past Jacksonville will birds migrate?

Radar and weather models are forecasting a good night for bird watching the night after full supermoon Friday evening.

First some background

A billion or more birds, many small-weighing less than a couple quarters, travel across the Gulf of Mexico northward to America and Canada.

Many choose paths that double the distance and expose the birds to predators along the way but provide the greater Jacksonville and Georgia area with a colorful sight.

For those of us wanting to see the spring migration we are in luck. May is the peak month as some birds fly less direct routes along Texas or detour along the east coast of Florida directly over our heads.

April brings a spike in migration with a peak in May
April brings a spike in migration with a peak in May (.)

Some birds leave the tropics in nonstop flights of 60-100 hours that span oceans and continents!

Weekly mean spring nocturnal migration activity and direction of movement in the Gulf of Mexico region for the week of 4-10 May, 1995 to 2015. Circular buffers around radar stations represent migration activity scaled to radar reflectivity (a measure of biological activity), with weekly activity represented by size scaled to the activity at KCRP Corpus Christi and seasonal activity represented by colors scaled to the most intense movements of the spring period (L: light, M: moderate, H:heavy); arrows represent mean track direction (a measure of the direction birds are traveling) derived from radial velocity.
Weekly mean spring nocturnal migration activity and direction of movement in the Gulf of Mexico region for the week of 4-10 May, 1995 to 2015. Circular buffers around radar stations represent migration activity scaled to radar reflectivity (a measure of biological activity), with weekly activity represented by size scaled to the activity at KCRP Corpus Christi and seasonal activity represented by colors scaled to the most intense movements of the spring period (L: light, M: moderate, H:heavy); arrows represent mean track direction (a measure of the direction birds are traveling) derived from radial velocity. (University of Oklahoma)

Weather Doppler radars have been used by ornithologists since the 1970s to track bird migrations.

The Weather Authority Exact Track Radar often detects flocks of birds in the lower portions of the atmosphere that typically appear as a circular, halo, or donut-like pattern in reflectivity imagery called roost-rings.

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Birds can be compared to prevailing winds using Doppler velocity images to separate rain from avian targets. Whenever targets are moving across the wind or against the wind, or moving more than 10-15 knots faster than the wind, those targets are almost exclusively birds.

Blue is not rain. But birds which can be confused with other biological targets in the sky and temperature inversions.
Blue is not rain. But birds which can be confused with other biological targets in the sky and temperature inversions. (.)

Small insects, dust, pollen, and smoke often drifts with the wind or not much faster than windflow.

Know when and where to look for bird migrations

A website by the Cornell Lab of Ornithology will show you future bird migration activity based on weather forecast models. Realtime radar information is correlated with bird migration activity and machine learning algorithms to provide flight predictions.

It is forecasting an increase in activity Friday night May 8th after a cold front passes by and the winds turn southeasterly.

This is because birds prefer warm weather and favorable winds from the south. When the skies turn rainy and windy birds will hold off on flight.

Some birds fly all night when conditions are good and land just before dawn the next morning.

Birds generally take off 30-45 minutes after sunset flying around 9,000 feet for larger species and as low as 3,000 feet.

Current Migration hotspots based on weather radar detection for May 5, 2020.
Current Migration hotspots based on weather radar detection for May 5, 2020. (.)

For a better understanding of the long distance birds endure, you may love watching this documentary on the phenomenon.

So now is the time to look up and marvel at these long distance travelers.


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