How so? By adding a sharpie line? Since you brought up our kids, even a kid would see that line was added, not to "doctor" it, but to explain. It was added as an explanation for what he was saying: that if you extrapolate the trend in the direction that the official forecast was showing, it might reach Alabama. Any common sense, reasonable man would understand it that way. Those with TDS, however...
No, it demonstrates something more serious.
1. Trump made a mistake. Presumably.
2. That mistake had distracting consequences, thus requiring correction by the Weather/Hurricane Service officials in charge of communicating the forecasts.
3. Trump doesn't tolerate to be corrected.
4. Trump used a several days old forecast that was not decisive enough to prove him wrong (or right).
5. To doctor the outdated forecast he himself used a sharpie, assuming nobody would notice.
6. When asked about that alteration on the outdated forecast, he denied knowledge of it being doctored.
7. He then later produced a so-called "spaghetti" chart showing the "ensemble forecasts", which showed that most models proved him wrong.
8. He then demonstrated that he didn't know how to interpret such a chart (or he wouldn't have used it, since it proves the opposite of his claim).
9. He then ordered the NOAA officials to declare that he was right, threatening to fire those officials if they didn't.
10. Those officials then published an anonymous reaction, claiming that they had been wrong in correcting the president.
11. ...
Trump then got distracted/obsessed by another issue, the firing of Bolton, or did Bolton resign?