When calculating your estimated payments the system uses annualized income. The IRS taxes you based on income for the year and not for each quarter and feels like you should pay it as you go.
HOWEVER
When calculating whether you owe a penalty with your tax return then the system allows you to enter your income by period in order to explain why you sent your estimates in the way that you did. So you can remove any penalty incurred when you file your tax return by entering your quarterly income at that point.
In order to be sure to avoid penalties altogether you should annualize your expected income and make the payments in advance. I understand your reluctance to do so because of the unpredictable November payment. But that is the safest way. (If the November payment is very small you can reduce or eliminate the 4th quarter payment in this instance).
The most economical way is to make the first three quarterly payments based on what you are 100% certain that you will receive during the year and then the 4th quarter payment based on what you receive in November. Then, when doing your tax return, you will need to enter your income into the penalty reduction part of TurboTax which directly fills out al of the information on the 2210. This will reduce your penalty - although it may not eliminate it (the IRS calculations are notably weird) - and explain why your 4th quarter payment is much larger.
@bosso3
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