Weather deviations - terminal & en-route

I know this is a hard question to answer, but can a controller see when we deviate around wx without talking to you first?

A pet peeve I have is pilots who are afraid of clouds. They can circumnavigate the globe IFR, and never get close to a cloud. On multiple occasions, we've been assigned a heading, or told to go direct somewhere, and the Captain chooses to "tweak" the heading slightly to avoid a puff of cloud.

Now obviously we're not talking storm cells here, but the slight ones that the airplane radar doesn't even show- so I doubt they're on your scope. My most recent example was going into a fairly busy bravo, we're assigned a heading for downwind, and the Captain is turning up to 10-15 degrees left and right to steer clear. Now I'm all for passenger comfort, but I thought that it was a little ridiculous.

Now the usual excuse I get is

"we'll be back on the heading before the radar refreshes" in the terminal

or

"we're en-route, so we've got more spacing" if we're en-route

So the question is, can you guys detect when we do those minor deviations?

You bet your ASS we can see even a 5 degree turn or a 10 knot diffrence in ground speed. you guys are not pulling off anything on us its just most of the times the controller will not say anything, and in a terminal like Chicago you turning 15 degrees without asking can cause a loss of seperation, we run them pretty close here. the problem is if you dont say anything about the weather you take away our ability to pre plan for the next few aircraft or at least alert the supervisor the we may have WX that may affect the operation . you cant except good service if you keep the info to your self ATC is a two way street, you got to give somthing to get somthing back.

As far as enroute goes, I guess the best answer is, it depends...on the size of the sector you are in and the amount you deviate. The smaller the sector, and/or the larger the deviation, the more likely we are to notice it. If you are in a large sector and only deviating slightly, you might be able to get away with it for a short time. Also, if we are running you close to the 5-mile minimum spacing with another plane, we are more likely to notice it. Just because there is more space between you and the other plane than in a terminal environment doesn't mean we leave more than the minimum before making a move. We'll often wait until you are just barely beyond minimum separation to climb/descend you, and if you are 'riding the bubble' and deviate in the wrong direction, well, it's in our best interest to notice that quickly! As for the weather and radar refreshing, enroute weather only depicts moderate and greater precipitation, nothing else, so it sounds like what you are talking about would probably not show up on our radar. I believe terminal has different (better?) weather depictions. Also, our enroute radar refreshes at least every 12 seconds, sometimes significantly quicker, so it would have to be a pretty quick diversion to get it done before the radar refreshes.

In my facility we use a LOT of divergence:

5-5-7. PASSING OR DIVERGING

a. TERMINAL. In accordance with the following criteria, all other approved separation may be discontinued, and passing or diverging separation applied when:

1. Aircraft are on opposite/reciprocal courses and you have observed that they have passed each other; or aircraft are on same or crossing courses/assigned radar vectors and one aircraft has crossed the projected course of the other, and the angular difference between their courses/assigned radar vectors is at least 15 degrees.

NOTE-
Two aircraft, both assigned radar vectors with an angular difference of at least 15 degrees, is considered a correct application of this paragraph.

10-15 degrees? Yes, we notice. Almost immediately. Especially when 15 degrees is the number we're banking on...

Thanks for the responses guys. I appreciate it. Next time I'm flying with a Captain who does that I'll point it out.

I'll tweak it ever so slightly to avoid small Cumulous clouds, I don't know what you're flying but when I am in the Citations even the smaller clouds can cause a nasty few seconds for the people who pay rediculous amounts of money in the back not to be bounced around. If I CAN avoid it, I will try. Depends on the area though. I wouldnt make large deviations of more than 3 or 4 degrees without the A-OK from ATC.

I had a "Military aircraft" reduce from M.74 to M.62 with traffic 7NM in trail. Didn't say a word to me... PLEASE DONT DO ANYTHING WITHOUT COMMUNICATING!