Is the flute too low to play fortissimo here?

I know that you can't reach a forte dynamic on the flute in the first octave(at least in an orchestral context). But what I am wondering is how low a flutist can play fortissimo. You see, I am writing this piece for a piano flute duet to represent Spring and it has 3 main sections. Those sections are:

• A - Quiet, Molto adagio, A minor, very melodic, rocking fifths in the bass, melody rises out of the first octave - Warming up

• B - Fortissimo, Presto, still in A minor, more motivic towards the beginning and more melodic towards the end, octaves in the bass - Rainstorm with the sun peaking through the clouds towards the end of the storm

• C - Forte, Allegro, Picardy third to A major, joyful, melodic, Alberti bass in the bass, towards the end of the piece it becomes chords

There is a bridging A section between the B and C sections, this one being faster and hinting at the major tonality of the ending while still being in A minor. There is also a transition from the A section to the B section, where an accelerando and creschendo takes place.

You see, I am a bit worried that I might have written part of the Presto section too low for a flutist to play it fortissimo because the lowest note in the Presto is D in the second octave. If I have, I can just raise that part up an octave in the flute with no issues. Nope, not even the issue of going too high and having to switch to a piccolo. I can imagine that on a woodwind instrument, just how low or how high you can play at a certain dynamic has to do partly with the tempo(I know that on the piano, playing pianissimo at a Presto tempo is much more difficult than playing fortissimo at the same tempo).

But, is D in the second octave too low for a flutist to play fortissimo in a section that is at a Presto tempo? Or will everything be okay having D in the second octave being my lowest fortissimo note on the flute because it is a duet and not a whole orchestra? I'm just worried that the pianist might drown out the flute. The section I am most concerned about is Bars 46 and 47, where the flute plays a scalar motive to represent the wind of the storm and it is playing over an implied D minor harmony(I say implied, because the only notes in the left hand in that section are D's in octaves). The Presto starts about 2 minutes into the piece.

The area around middle c is where you have to be concerned with the flutes dynamic level. What you have is fine. 

3 minutes ago, jawoodruff said:

The area around middle c is where you have to be concerned with the flutes dynamic level. What you have is fine. 

 

So, I don't have to worry that the left hand octaves will drown out the flute here? That's a relief. I thought that maybe they would or that the lowest note that I have in the Presto would be impossible to play at a fortissimo dynamic.

You could always rewrite the passage if you're concerned. Better safe than sorry.

A good flautist can play fortissimo down to about the lowest G. After that, it starts becoming awkward.

Based on what I've seen, I'm more concerned about the complete lack of slurs or any phrasing. I hope this is just because you haven't finished it, because otherwise it implies that Every. Note. Should. Be. Clear. And. Detached.

You probably don't want that in this piece.

3 minutes ago, aMusicComposer said:

A good flautist can play fortissimo down to about the lowest G. After that, it starts becoming awkward.

Based on what I've seen, I'm more concerned about the complete lack of slurs or any phrasing. I hope this is just because you haven't finished it, because otherwise it implies that Every. Note. Should. Be. Clear. And. Detached.

You probably don't want that in this piece.

 

The lack of slurs is just because I haven't finished it. I tend to put the slurs in last, after I already have the tempo, dynamics, articulations like staccato and accent, melody, and harmony down.

The phrase in bar 14 wouldn't pose problems as the flute is solo. Nothing else would drown out the flute. As others have said it's weak in it's bottom 4th or 5th and needs very light harmony if an internal part or solo. It can sometimes hold it's own as the lowest note of quiet harmony, as in the last movement of Holst's Planets Suite. Remembering it's a duet it's as much up to the pianist to make adjustments if necessary. So it looks all right to me unless your pianist is a real thumper!

Yo have the option of the alto flute for this register.