Do I need to file an alternate?
 

I have decided I'm going to pursue a career in the awesome industry! I've signed up to go to dispatch class next month to get my license. I'm trying to get a head start and learn some of this on my own. I have a question about an alternate situation.

Here is the TAF:

KDAL 142103Z 1421/1518 07007KT 6SM -RA SCT080 BKN010 OVC120
FM150200 04008KT 5SM -SHRA BR BKN070 OVC100
FM150500 09007KT 5SM -SHRA BR VCTS BKN040CB OVC070
TEMPO 1509/1513 2SM TSRA BR SCT020 BKN030CB OVC050
FM151300 09008KT 5SM -SHRA BR VCTS BKN020CB OVC040
TEMPO 1513/1517 3SM TSRA BR BKN015CB OVC025

Question #1
If my flight is scheduled to land at 0230 do I have to file an alternate? Even though the main body is forecasting ceilings below 2,000 feet can I just go based on the FM or are both the main body and FM controlling.

Question #2
If my flight is scheduled to land at 0930 would I need to file an alternate? From what I read you do have to file based on TEMPO forecasts.

Thanks for your help!!!!

Well first you have to figure out what rules you're operating under. The ADX is mainly based on domestic rules.

You have to take the worst case during the time period. Your first example splits two time periods. The first thirty minutes of the one hour before your ETA includes 1 thousand BKN so you need an alternate.

In your second example, the weather wizards think sometime between 9 and 13 the vis will be 2 miles. You can't say when that'll be so again you have to plan on the worst case and file and fuel for an alternate.