Just because it's only 100 kW doesn't mean you have no chance (that is, if you're using something better than a portable DSP radio with a 4" ferrite bar designed for mediumwave and are not on the US west coast). What power do they run in the daytime? Any reason you couldn't try to snag them at that time of the morning (their time) right when they switch to their higher daytime power while most of the path is still dark? Or does "sunrise enhancement" only work for mediumwave?
My best catch of 774 JOUB from Akita, Japan, was made right after my local sunrise. Local pest 760 KFMB, 7.3 mi NW of me, runs 50 kW directional at night and 5 kW omnidirectional daytime, so it was easier to hear JOUB immediately after my local sunrise.
Here's a recording of that catch, as heard on my Tecsun PL-380 aided by the Select-A-Tenna.