BWO emergence

[PhilC]

Some good points and things to learn in this post.

To the original topic though I think it's fairly simple...water temp.
The early season olives predictably hatch at the sunniest and warmest part of the day. They are light sensitive though so later in the year when the temps are up, they pick and choose when they wanna harch so they prefer low light times.

My first day on Savage river MD...we planned on doing brookies during the day and then coming back when the sulphurs pick up in the evening. Bad idea, the savage runs cold so the sulphurs harch mid day when it is the warmest and sunniest. Without much sun they didn't hatch at all... I think this is important when it's their "time" of year, their biological clock tells them it's time and they're full grown nymphs, then they hatch when it's most comfortable just like early olives

 

[pcray1231]

One nice thing about fishing is that the best fishing tends to happen at the most comfortable times for humans to be fishing!

Think about it. In winter, a warmish day, at midday is best. In summer, the early mornings and late evenings are best on the larger streams. During the day, your best bet is smaller, colder, fully canopied streams.

 

[outsider]

I've almost always found that early season BWO's like the sun, but the later hatches (May, June) prefer overcast, slightly wet days, even constant rain in some experiences.

These observations ranged from the Letort Spring Run to Young Woman's Creek, and in between. But hey, I've only experienced this over a 50 year period, so what do I know.

Fished a decent BWO hatch today, bright sunny skies.

 

[Chaz]

My experience matches that of Old Lefty. Keep in mind that on low pressure days everything that flies has difficulty getting airborne, from jets to mayflies. It's not just baetis and or BWO's. Cloudy days just make it more difficult, perhaps you've noticed that raptors seem to sit in trees on obvious perch during a low pressure period. Even on cool mornings they simply just sit, until the sun warms the air enough to create updrafts.
Think of cool water creating cool air above it, you know the fog hanging low over the water. Sometimes you won't see the fog but the sir is less dense when the air sits over cool water and it's sinking. It's part of the reason that trout seem more active and more flies are in the air where the sun first hits the water during the early morning.

 

[CLSports]

Interesting thread and a lot of very good points.

One other question I have. Do the Baetis hatch more consistently on limestone streams as opposed to freestoners? If so, then water temps and water temp fluctuations through the night and into the next day may play a key role in hatch timing and duration along with the other factors mentioned.

 

[Chaz]

Some of the Baetis Species swim to the bottom after the spinner drops to the surface to lay eggs. It is always good to try a soft hackle when fishing the spinner fall.
As for low pressure, while out fishing on Sunday, with a front approaching after a good start to the day, the feeding activity dropped of the table in mid-afternoon, I can only figure that it was a drop in barometric pressure. The wind changed to more easterly and the air cooled.

 

[Acristickid]

Saw a good amount of spinners on Sunday morning on Spring Creek. Wonder it they were bwo's. It's was about 9 or so. Sunny warm day.

 

[Kipper12]

Slightly off mark fish mainil fish main stem del river. Sulfur hatch mid May come and go with certain water temp. On west br much colder water sulf hatch all summer why not on main

 

[Kipper12]

Please excuse typos